Dec-Jan.2013 issue by EnergyBlitz

12-13 March 2013,New Delhi, India

IN BETWEEN ANERT's Solar Rooftop Programme: Ensuring consistent and clean ENERGY By Anmol Singh Jaggi & Ali Imran Naqvi

Current Scenario of India's Renewable Energy Industry By Staff Writer

India makes a solar hybrid comeback By Heba Hashem

The Competitive Challenge Facing Concentrated Solar Thermal Power By Harry Valentine

Concentrating Solar Power (CSP) emerging as a proven technology By M.R.Menon

A look at the history of hybrid technology systems worldwide

By Staff Writer

World's largest concentrated solar power plant By Jonathon Porritt, Environmentalist and Writer

VIEW POINT: Niche 25 MW to 50 MW multipurpose solar pv (low tariff) power project developments at every taluka of good solar irradiation states of India for energy security and food security By Praveen Kumar Kulkarni

How a grid connected solar power system works?

Concentrated Solar Power and Combined Solar Power to claim their respective share in the ensuing energy revolution By Staff Writer

INDUSTRY NEWS: Completion of Concentrating Solar Power Plants in India Delayed At least half of the U.S. $1.4 billion projects won't be built on time

NEW TECHNOLOGY: Nanoparticles Make Steam without Bringing Water to a Boil

Malaysia: 8 MW of solar PV FiT quota up for grabs Staff Writer

ENERGY

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DECEMBER-JANUARY 2013

Advisory Board Dr. A. Jagadeesh | India Dr. Bhamy Shenoy | USA Er. Darshan Goswami | USA Elizabeth H. Thompson | Barbados Pincas Jawetz | USA Ediorial Board Salman Zafar | India Editor & Publisher M. R. Menon Business & Media P. Roshini Book Design Shamal Nath Circulation Manager Andrew Paul Printed and Published by M.R.Menon at Midas Offset Printers, Kuthuparamba, Kerala Editorial Office 'Pallavi' Kulapully Shoranur 679122, Kerala (E-Mail: editor.energyblitz@gmail.com) Disclaimer: The views expressed in the magazine are those of the authors and the Editorial team | energy blitzdoes not take responsibility for the contents and opinions.energy blitz will not be responsible for errors, omissions or comments made by writers, interviewers or Advertisers.Any part of this publication may be reproduced with acknowledgment to the author and magazine. Registered and Editorial Office 'Pallavi, Kulapully, Shoranur 679122, Kerala, India Tel: +91-466-2220852/9995081018 E-mail: editor.energyblitz@gmail.com Web: energyblitz.webs.com

Energy is the driving engine of our modern society. Every day when we look at issues such as climate change, an increasing volatility and dependence on oil and other fossil fuels, and rising energy costs is necessary to rethink our attitude to energy production and consumption. Therefore, renewable energy sources represent the most logical waytowards a sustainable energy target and greener future. The years between 2008 and 2011 have been challenging for photovoltaic energy industry and the financial crisis that has affected the global economy has spared no industry sector. Some of the oldest U.S. and European photovoltaic module manufacturers bankrupted. Prices of photovoltaic modules dropped significantly with more than 50% in less than 2 years. This drop on the other hand presented opportunity to many investors for building of more solar installations than planned. However, increased efforts are still necessary to achieve this target. Well balanced mix of renewable energy generation facilities should be priority target for each country. Concentrated solar power (CSP) is an ideal and utility-scale solar solution that can provide hundreds of megawatts of electricity to the grid. Also, CSP is an important solar technology for homeowners to be aware of because it has the potential to provide significant amounts of clean, renewable energy that could be provided to us by our utility. Of all the current solar technologies, concentrated solar power has the most promise of providing a large-scale, sustainable alternative to fossil-fuel power plants. The first thing to understand about concentrated solar power is that the primary form of energy it generates is solar thermal energy, also known as heat. This is very important because heat is able to be efficiently stored at significantly less cost than electricity. For solar technologies, energy storage is critical since the Sun isn't always available for energy production. Most often, oil or molten salt is used to store the heat generated by the concentrated solar energy. This is very cost-effective compared to using batteries for storing solar electricity. It is heartening to note that CSP costs have already begun to decline as production increases. According to a 2008 Sandia National Laboratory presentation, costs are projected to drop to 8 to 10 cents per kilowatt hour when capacity exceeds 3,000 MW. The world will probably have double that capacity by 2013. The price drop will likely occur even if the current high prices for raw materials like steel and concrete continue (prices that also affect the competition, like wind, coal and nuclear power). CSP plants can also operate with a very small annual water requirement because they can be air-cooled. And CSP has some unique climate-friendly features. It can be used effectively for desalinating brackish water or seawater. That is useful for many developing countries like India today, and it's a must-have for tens if not hundreds of millions of people if we don't act in time to stop global warming and dry out much of the planet. Such desertification would, ironically, mean even more land ideal for CSP. Finally, we will need more electric transmission everywhere. The good news is that because it matches the load most of the day and has cheap storage, CSP can share power lines with wind farms. When all countries get serious about global warming, we will need to get serious about a building a transmission system for a low-carbon economy, too.

Ramanathan Menon

ANERT's Solar Rooftop Programme: Ensuring consistent and clean ENERGY By Anmol Singh Jaggi & Ali Imran Naqvi Acute power shortages are crippling the growth of many states in India, one of the world's fastest growing economies. Energy deficit figures published by Central Electricity Authority for the year 2011-12 presents a strong case for the existence of a market for the diesel gen-sets as critical back-up power system. An inevitable increase in the prices of grid electricity and diesel coupled with Lower Lifetime Operation Cost of Solar PV Generation opens a clear opportunity for solar rooftop projects to replace the diesel gensets based electricity.

beefy penalty of Rs.15 per unit for domestic consumers in case their monthly usage exceeds the 300-unit mark. Prior to the order, domestic consumers were paying a flat rate of Rs.7.50 per unit in case their consumption lied in the range of 300 to 500 units. The new tariff has come into force from December 15, 2012 and will be valid until May 31, 2013, during which period the situation would be reviewed on a monthly basis. Around 96,000 households with monthly consumption more than 300 units are likely to be impacted by this order. Amidst this dilemma, Kerala Government's scheme of installing 10,000 solar rooftop systems of 1kW each, seems to have come as a relief to such consumers afflicted by frequent power cuts and ever increasing cost of electricity. Agency for Non-conventional Energy & Rural Technology (ANERT) published public notice on 26th September, 2012 inviting applications from households who wish to be a part of this scheme. This article provides insight into the concept & need of solar rooftops viz-a-viz ANERT's scheme. What is a rooftop solar photo voltaic power (SPV) plant? • Sunrays are absorbed by the solar panels and converted into DC current • DC Current is fed to the Inverter which converts it into AC Current • Electricity from Inverter and grid/generator are fed to the Load through distribution panel • Only the electricity requirement not already met by the solar power is imported from the grid/generator In case of power requirement during night or excessive power cuts, batteries can be used.

It is common knowledge that electricity prices have been moving north for various reasons. In particular, the emotional travails of consumers in Kerala do not seem to be reaching an end. In a move that would aggravate their pains, Kerala Electricity Regulatory Commission (KERC) in its latest order dated 12th December, 2012, has imposed a

• Batteries are charged using solar panels and when solar is not available, then by grid • Batteries supply power during power cuts and can also be used at night • The system is programmed to operate on following logic

Typically, a solar rooftop system works in the following manner:

A matrix of operating scenarios has been presented in the table above: Around the world The SPV residential market in US witnessed a quarterly record high of 118 MW of solar panels being installed, growing 12% sequentially. The

data, from the Australian government's Clean Energy Regulator and the International Energy Agency, shows that Australia installed a total of 785 MW of solar power last year, mostly small-scale panel systems on residential and business complexes. What you get in ANERT's 1kW scheme?

The heart of every PV system is the array of photovoltaic modules. Today, the overwhelming majority of PV modules are crystalline silicon, made from the second

most abundant element on earth. But despite the fact that most PV modules utilize similar technology, there can be considerable variations in performance. Some of the following critical factors are used while selecting the modules:

1. Efficiency 2. Bill of Materials (BoM) (Components used for manufacturing of panels) 3. Warranty terms 4. Certifications from IEC/MNRE 5. Temperature co-efficient The other important component of the rooftop system would be a solar Power Conditioning Unit (PCU), which is an integrated system consisting of a solar charge controller, inverter and a grid charger. It charges the battery bank either through solar output or grid. The PCU continuously monitors the state of battery voltage, solar power output and the loads. The most conspicuous differentiating factor about the systems that need to be provided under the ANERT scheme is the battery, which can be based on two technologies: VRLA and Tubular Gel technology. A comparison has been presented below:

Stratification is caused by the fact that the electrolyte in the battery is a mixture of water and acid and, like all mixtures, one component, the acid, is heavier than water. Therefore, acid will begin to settle and concentrate at the bottom of the battery. This higher concentration of acid at the bottom of the battery causes additional build-up of lead sulfate (sulfation), which reduces battery storage capacity and battery life. Notably, however, charge input from solar arrays some times is insufficient to keep the batteries fully charged. During cloudy or rainy days, batteries are discharged but not charged. These conditions result in battery operating in PSOC, cycling and deep-cycling conditions. Also, solar systems are installed in open atmosphere exposing the batteries to extreme temperatures. Other lead acid batteries fail in such conditions due to sulphation, stratification, corrosion and plate shedding. In such rigors of operations, the combination of tubular plate and gelled electrolyte (TGel) is better equipped for solar applications. When a battery has been subjected to deep discharge (commonly referred to as over-discharge), the amount of electricity which has been discharged is actually 1.5 to 2.0 times as great as the rated capacity of the battery. Consequently, a battery which has been over-discharged requires a longer charging period than normal. Many a

times, an over-discharged battery cannot be recharged, it is not reusable.

Civil Structure for Module Mounting Protecting your existing structure is paramount. Typically, galvanized iron with a thickness of 80 microns should be used for erecting structure for mounting panels on them. The structure should be able to withstand wind velocity of 150 kmph and should be designed as per the load bearing capacity of the roof.

Maintenance In order to realize the optimized generation potential of the system, a comprehensive maintenance program is necessary. This includes regular (weekly) cleaning of the panels, digital monitoring and analysis of performance, emergency response and regular inspection of array connections/safety considerations. A proper care of system, as prescribed by the manufacturers, will ensure a long life and in turn help realize the true worth of the investment. The following preventive maintenance practices are recommended:

Depends on the wind zone of the site

Loads a 1kW system can handle: A 1-kW solar rooftop system can power most of our home appliances.

Typically, the following loads can work with this system:

Economics of the system: The tariff at which domestic consumers are billed has been increasing steadily and expected to do so in the future. As per the new tariff regime in Kerala, per unit usage above 300 units will be billed at Rs 15. Considering the fact that ANERT's 1 kW system with 5400 Wh T-Gel batteries

would be sold at an average price of Rs 2 lakhs and the subsidies are available from the MNRE and ANERT, consumers installing the system are expected to recover their investments in less than 5 years. The following economics work out for the project:

Motor loads like these might entail a surge, which could be handled by the PCU, subject to appropriate protection

Comparative analysis of the solar rooftop system, diesel generator sets and inverter-battery system Merits and de-merits of each of these systems have been tabulated below:

To sum it all up, solar is the best alternative and ANERT solar rooftop programme has the required recipe to help the people of Kerala do away with their power-related References: Http://www.kseb.in/index.php?option=com_jdownloads &itemid=&task=view.download&catid=4&cid=5960 http://www.thehindu.com/news/states/kerala/domestic-

troubles and enjoy the benefits of consistent and clean e n e r g y, n o t t o m e n t i o n , a f f o r d a b l y !

power-tariff-to-go-up-in kerala/article4192323.ece http://www.nasdaq.com/article/us-rooftop-solar-boom-willhelp-sunpower-cm199182#.unrdz2_qkvu http://www.solardaily.com/reports/australia_leads_in_roofto p_solar_999.html

Anmol Singh Jaggi Anmol Singh Jaggi & Ali Imran Naqvi: Both are key management personnel at Gensol. Gensol has worked on solar power projects worth 350 MW capacity and is currently working on a large number of rooftop projects across India. Both of them have a keen focus to make ANERT's solar rooftop programme a huge success. Ali Imran Naqvi

Current Scenario of India's Renewable Energy Industry By Staff Writer â&#x20AC;&#x153;Energy-starved India is becoming a vibrant market for renewable energy. This bodes well for a country that has often seen its industrial and economic growth inhibited by a truncated supply of conventional powerâ&#x20AC;? Grid-connected renewable power today accounts for as much as 20.2 GW or 11% of India's 182.3 GW of installed power capacity. The majority share - 55%, or 99.8 GW is still accounted for by coal-based thermal power. Gas-fired thermal power, totalling 17.7 GW, contributes an additional 10%, while the 38.7 GW of hydropower accounts for 21%, and nuclear 2.6% with 4780 MW.

Incentive-fuelled Incentive-laden policies have fuelled growth in India's renewable energy sector. Wind power is the fastest growing with a record 3,163 MW of wind energy capacity added in the financial year 2011/12, bringing the country's total wind capacity to 17.4 GW. This marks a steady rise, from 2,350 MW the previous year, 1,565 MW in 2009/10 and 1,485 MW in 2008/09. India thereby retains third place, behind China and the U.S., in terms of new installations. The addition of 3,500 MW of wind capacity now appears within reach in 2012/13, foreseen or unforeseen drawbacks not withstanding.

Solar, wind and biomass are finding increased favour, with burdensome coal and gas supplies denting capacity targets. Only 52 GW of the 78.6 GW originally envisaged under the 11th Five Year Plan that ended March 2012, has been added, at a cost of US$145 billion. The 10th Plan (200207) also saw a meagre 21.2 GW capacity added, against a

Grid-connected solar capacity also surged from 18 MW in 2010 to 277 MW in 2011, again making 500 MW of capacity seem attainable this year. Solar photovoltaic (PV) power plants totalling over 180 MW were set up in the country and off-grid installations of over 50 MW were completed as well.

target of 41.1 GW. The 12th Plan (2012-17) now aims for a capacity addition of 103.3 GW at a combined investment of US$223.7bn, which includes commensurate transmission and distribution capacities.

Renewable power has been particularly beneficial for an enormous, (3.28 million km2) over-populated (1.2bn) country like India. Hundreds of thousands of solar lights, solar water heating systems and biogas plants have been installed in the country, illuminating over 9,000 remote and inaccessible villages so far.

The continuing trend of missed targets has widened peak demand deficit in the country to 12%. This has clearly undermined the Government's avowed mission of Power to All by 2012.

Soaring investment Clean energy investments in India reached a record US$10.3bn

in 2011, up 52% from the US$6.8bn invested in 2010, according to Bloomberg New Energy Finance (BNEF): “This was the highest growth figure of any significant economy in the world, the country accounting for 4% of global investments in clean energy,” says Ashish Sethia, Head of Bloomberg's India research. “The large growth was driven by a 7-fold increase in funding for gridconnected solar projects: From US$0.6bn in 2010 to US$4.2bn in 2011, almost the same level of investments as wind, which totalled US$4.6bn.” Sethia mentions that while there was concern at the beginning of last year that increasing lending rates might hit investment, policy measures like the Jawaharlal Nehru National Solar Mission (JNNSM) and renewable energy's increasing cost competitiveness eventually made 2011 a record year. While an addition of 15 GW of wind capacity has been proposed for the 12th Plan, the National Solar Mission of the Ministry for New and Renewable Energy (MNRE) aims at adding 20 GW of solar power capacity by 2022. The Ministry estimates the potential for solar energy

for most parts of the country to be around 20 MW/km2 of open, shadow-free area covered with 657 GW of installed capacity. Asset financing for utility-scale projects remains the main type of clean energy investment in India, with US$9.5bn in 2011. Venture capital and private equity investments also revived, with US$425 million invested in 2011, over four times the 2010 figure. A stock market slump, however, dampened equity-raising via the public markets last year, with only US$201m raised compared with a record US$735m in 2010.

BNEF chief executive Michael Liebreich deems India's record performance in 2011, and the momentum it is carrying into 2012, as one of the bright spots in the clean energy firmament: “With support mechanisms falling

away in the U.S., the ongoing financial crisis in Europe, and China already going flat out, it is gratifying to see some of the world's other major potential markets coming alive,” he remarks. “India is firmly in the lead group and we are seeing interest around the world in being part of what is unfolding there.”

Powering ahead Renewable energy is central to India's climate change mitigation efforts. The country's vast market potential and industrial, financing and business infrastructure have made it a favourable destination for Clean Development Mechanism (CDM) projects, with renewable energy projects having the major share. There have been 727 registered CDM projects in India, accounting for a fifth of such projects worldwide. Of these, 520 are renewable energy projects, of which wind accounts for 225, followed by 6 for solar energy and 82 for hydropower. India has hitherto established 3,056 MW of power capacity based on biomass/bagasse cogeneration, with a further 2,600 MW targeted for the 12th Plan period. Incentives such as concessional customs duty on machinery and component imports, excise duty exemption, accelerated depreciation on major components, and relief from taxes and capital subsidy are being provided for the set up of biomass power projects. A preferential tariff is also provided for the sale of power from biomass power plants. The National Solar Mission aims at promoting grid-connected solar power to a level that will bring the cost of solar power generation to grid parity. December's competitive bidding for projects totalling 350 MW witnessed some of the lowest quoted tariffs in the world. They averaged Rs. 8.77/kWh (US$0.18/kWh), the lowest having been Rs. 7.49/kWh (US$0.15/kWh). Tariffs exceeded Rs. 18/kWh (US$0.36/kWh) at the start of the Mission two years ago. All indications are for further decreases in solar PV, though costs have not come down this fast for concentrated solar power (CSP), where they are still in the range of Rs. 12-13/kWh (US$0.24-0.26/kWh). Wind too is competitive as an electricity resource. There is no competitive bidding in wind so far, the tariffs ranging Rs. 3.54.5/kWh (US$0.07-0.09/kWh): “Barring China, India has the lowest cost-per-MW for wind energy in the world up to 60% cheaper than Europe,” notes Tulsi Tanti, founder, chairman and managing director of the Pune-headquartered Suzlon Energy Ltd. “It has absolutely no fuel costs, providing a stable pricing visibility for over 20 years a huge competitive advantage to corporate India, particularly to SMEs.” The billionaire entrepreneur estimates wind energy to have saved India 67m tonnes of coals imports, translating to savings of US$6bn

India makes a solar hybrid comeback By Heba Hashem turbines or biomass. Lessons could be learnt from China's Hanas New Energy Group, which is building Asia's first ISCC station in Yanchi with a goal of 92.5MW for completion by October 2013, or from Italy's Enel, which is constructing the 1.5MW Trebois CSPbiomass bi-generation plant to continuously produce electricity for the city of Rome.

Solar islands at the integrated solar combined cycle power plant of Kuraymat, Egypt. Image courtesy Paul Langrockt, Solar Millennium. “Amid India's ongoing struggle with domestic coal shortage that has led some power producers to curtail operations and others to start importing coal, the country's MNRE (Ministry of New and Renewable Energy) has rolled out a pilot program that will take concentrated solar power (CSP) hybridization to another level. Will this help ramp up the much needed power supply?” In the fiscal year ending March 2012, Tata Power, India's largest private power producer, had imported 5.5 million tons of coal from Australia and Indonesia and is now eyeing more overseas mines as it tries to secure fuel supplies. Similarly, Coal India Limited (CIL) recently declared it could only supply 60% of its requirement and would not be able to meet its mandatory 80% commitment; a dilemma that prompted the state-controlled mining company to consider imports. As a result, power deficits in the southern part of India rose to as high as 4,350MW in May 2012, while the north had a deficit of 3,000MW. In addition, nearly 400 million people, about one-third of India's population, have no electricity at all.

An integrated solution The situation, however, indicates huge potential for CSP hybridization, as upgrading existing fuel-fired plants to ISCC (Integrated Solar Combined Cycle) systems could boost steam production and consequently electrical output at a relatively low extra cost. Not only can CSP be easily integrated into conventional fossil-fired thermal power plants, but it could also be combined with gas-fired wind

India's Ministry of New and Renewable Energy (MNRE) is already setting up an authority to promote and execute biomass-based power projects on the lines of Solar Energy Corporation of India (SECI). "We are focusing to promote biomass-based power generation in the country. For this, the Ministry is planning to set up a company for biomass energy, same as we set up SECI last year”, said Tarun Kapoor, joint secretary of the MNRE. According to MNRE data, biomass availability in India is estimated at about 500 million tons per year, while surplus biomass is estimated at about 120150 million tons per year, corresponding to a potential of about 18,000MW of power generation.

Made for India? Considering that peak electricity demand in India has been far greater during recent summers than peak winter demand, and that CSP delivers its maximum output during these peak periods, ISCC stations would be ideal for the country's changing power demand characteristics. The possibility of adding thermal storage capacity also extends CSP's operational range. Moreover, by taking advantage of the e x i s t i n g infrastructure associated with the development of a conventional thermal power plant

such as site access, power transmission links and a steam turbine power island the economics of the CSP component become significantly enhanced. As with any solar installation, DNI should be as high as possible and cooling methods should be taken into consideration. Many locations in India are known to have high levels of direct normal insolation, while dry cooling could be opted for, as carried out with Algeria's Hassi R'Mel ISCC plant. Rajasthan in particular where a 100MW ISCC project with a solar yield of 35MW was proposed more than two decades ago but remains at the bidding stage has the highest solar irradiation in the country of around 5.56.5kWh/m² per day and an average DNI of 2200kWh/m² per year. The state also has stretches of government-owned wasteland that are barren and sparsely populated. “There is tremendous potential for CSP hybridization in India. One could install a small capacity CSP plant near the conventional coal-based thermal power plants as capacity addition mainly for peak load requirements, or one could add conventional fuel-based capacity to a CSP thermal plant as backup for 24 x 7 operations and also during cloudy weather”, Hiro Chandwani, CEO and founder of Hiro Energy-Tech, tells CSP Today. He adds that great potential also lies in designing a hybrid plant with another renewable source like wind, tidal or wave energy for 24 x 7 supply of power, which is not possible from individual sources alone. This makes ISCC ideal for industrial applications that need uninterrupted power. “The only challenge would be the possibility of future scarcity and higher costs of coal”, Chandwani notes.

Hybrid program takes off The reality of falling PV prices in the international market cannot be ignored; having reversed the interest of some developers for investing in CSP, while the costcompetitive bidding route followed by the Indian government for awarding solar projects has also limited the capacity allocation for CSP systems in Phase Two of the National Solar Mission (NSM). However, the MNRE recently announced a separate CSP hybrid program through which it will support the development of four hybrid pilot projects: the first, planned for Rajasthan, will be a CSP plant integrating hybrid cooling, with the objective of reducing water consumption; the second involves a CSP plant with steam

temperature above 500 Cº; the third will be a CSP plant with 10 or more hours of solar thermal salt storage to achieve round the clock operation; and the fourth will comprise a CSP plant with 30% natural gas support, which is likely to be in the form of an ISCC. “The capacity of each project will be decided based on land availability and the commitment by the respective state government. Plant capacity may change from 20MW to 50MW depending upon the land size made available by each state”, explained a senior adviser on the Indian solar power industry, who preferred to remain anonymous. Commenting on the current coal deficits, he stressed that India has huge coal reserves which need to be explored. “The ongoing reforms and infrastructure development in the coal sector will address the present crises”. Demonstration projects in the upcoming CSP hybrid program will be site-specific and located one each in the different states, including Rajasthan, Gujarat, Tamil Nadu, and Andhra Pradesh. Most importantly, the government will be facilitating the allotment of land, water resources, grid interface and connectivity, geotechnical reports, environment and forest clearances, and Power Purchase Agreements (PPA) with distribution licensees. Projects are expected to be evaluated and selected through a transparent and competitive bidding process under the guidelines of the MNRE and the Renewal Fuel Standard Program (RFSP). At present, four ISCC plants are operational worldwide: the 150MW Hassi R'Mel in Algeria of which 25MW comes from CSP; the 470MW Ain Beni Matar in Morocco where 20MW is provided by CSP; the 140MW Kuraymat in Egypt from which 40MW is generated through CSP; and the US's first hybrid solar thermal facility the Martin Next Generation Solar Energy Centre in Florida that has a 75MW CSP capacity. China, Mexico and Iran are also constructing ISCC plants, while Turkey is constructing the world's first Integrated Renewables Combined-Cycle plant in Karaman. The 530MW Dervish project will feature a General Electric combined-cycle gas turbine fed with 50MW of solar-generated steam and 22MW of wind turbines, scheduled for completion by 2015. Until recently, ISCC technology was not formally recognised under the NSM, and thus related projects could not technically be taken up under the framework. But with the introduction of the new solar-thermal hybrid program that comes under the MNRE's energy strategy for 2011-2017 and will involve interaction with the Ministry of Petroleum and Natural Gas, the picture is about to change.

Heba Hashem is a freelance journalist based in Dubai, reporting regularly on the solar and nuclear energy industries to CSP Today, PV Insider Today, and Nuclear Energy Insider. Her articles have also appeared in the in-flight magazines of Qatar Airways and Emirates Airlines, covering regional business and environmental issues. Holding a B.A. in Communications and Media Studies from Middlesex University, London, and a B.A. in English-Arabic translation from Cairo University, she is a member of the Chartered Institute of Journalists since 2009. Her contact email: enquiry@hebahashem.com website: www.hebahashem.com

The Competitive Challenge Facing Concentrated Solar Thermal Power By Harry Valentine

Image of the solar furnace at Odeillo in the French Pyrenees “Several energy sector commentators, writers and journalists have recently questioned the viability of concentrated solar thermal power conversion, even going so far to proclaim its impending demise. Solar thermal power conversion in the USA occurs to the north of 30°N, the latitude of New Orleans and also Cairo, Egypt and Delhi, India. Except that most of the planned solar thermal power conversion in the Middle East and India will occur to the south of 30°N while in Australia it will occur to the north of 30°S. Concentrated solar thermal power conversion outside of the band between 30°N and 30°S is seasonal and less cost competitive than power generated inside that band of latitude” Recent advances in photovoltaic and concentrated photovoltaic technologies have raised efficiency and lowered the price of a very versatile technology. Lowmaintenance PV technology can easily be installed on the roofs, sides and incorporated into the window glass of buildings in mainly small-scale installations in dry and arid locations. While decentralized PV conversion incurs higher cost than buying power from the grid, the PV technology along with flow-battery technology serves a very useful purpose by providing a measure of energy security at locations where power outages occur frequently. The competition facing concentrated solar thermal power conversion places greater emphasis on evaluating the possible future of the technology while using past development in the field as being part of a learning curve. There is merit to using a parabolic reflector to concentrate solar thermal energy on the metal water pipe to heat water for some application. The ongoing need for hot water

assures a continued market for parabolic reflectors. There are locations around the world where water, including seawater will still be available and where sunshine is plentiful. Low-Grade Solar Heat: There are many forms of low-grade solar thermal power conversion that allow for the use of organic rankine cycle engines. The list of naturally occurring low-grade heat sources includes ocean thermal energy conversion (OTEC) and solar thermal salt ponds at coastal locations. Energy researchers in India are still testing the potential to generate electric power using the difference in temperature between the warm ocean surface (35°C) at tropical locations and cooler water (15°C) found at much greater depths at the same location.Salt ponds capture rather the infrared spectrum of light while potable and low-salinity water would reflect the infrared spectrum. The temperature at the bottom of salt ponds can reach temperatures of 65°C to 95°C. Cold ocean currents (25°C) flow along several coastal locations around the world where salt ponds may be developed and include: West Coast of Australia; West Coast of South Africa and Namibia; West coast of Morocco; West coast of Northern Chile and Southern Peru and Northwestern coast of the USA. Compared to OTEC operation, an organic Rankine cycle engine will operate at higher efficiency over the difference in temperature between a coastal salt pond and a nearby cold ocean current. A spiral coil of pipe made of corrosion-resistant material would be installed on the bed of the pond to collect heat. The salt pond would preheat water flowing through the spiral pipe at 80-psia after which it would be heated by parabolic reflector technology to 148°C (300°F). The organic Rankine-cycle engines would then operate at their maximum allowable temperature and at the efficiency of most commercially available PV technology. The solar thermal technology would incur lower initial and log-term costs. Steam-based Solar Thermal Conversion: It was a natural

progression to develop parabolic reflectors from heating water to generating steam and involves unraveling water tube boilers to achieve such a purpose. The sheer size and extent of a water tube boiler that is heated by concentrated solar thermal energy presents numerous challenges that include leakage and heat loss across the installation. There may be an advantage to taking the extensive water tube system out of the parabolic reflectors and replacing them with the combination of heliostats and compact boilers. In some concentrated solar thermal power installations, it would be possible to convert a coil mono-tube boiler into a tightly wound, pancake shaped, flat spiral mono-tube boiler. In other installations, it may be possible to enlarge the coil boiler to include multiple parallel tubes wound on a large diameter and perhaps including a series of inner (preheat) coils and outer (super-heat) coils. There are tropical locations where it would be possible to use the combination of reflector and heliostat technology to focus concentrated solar thermal energy on to both sides either design of boiler. The boiler may be housed between panes of transparent sapphire-aluminum-oxide to minimize heat loss. While the heliostat technology collect an equal area of sunlight as parabolic reflectors, the more compact boilers could operate at higher pressure and higher temperature while incurring less heat loss and lower potential for leakage than an extensive water tube system. The installation could generate hotter steam at higher pressure to operate steam engines at higher thermal efficiency. The most recent developments in steam power conversion involve generating ultra-critical steam at pressure levels in excess of 3000-psia at temperatures exceeding 540째C (1000째F). Water-tube boilers made from special martensite steel can operate at the elevated temperatures and pressures. The range of expanders includes specially built steam turbines and even specially built uniflow piston engines developed by Cyclone Power in the USA that can achieve the thermal efficiency of a diesel engine. Prototype concentrated solar thermal installations heated by heliostat technology have recently appeared. Alternative Concentrated Solar Thermal Power: There alternative non-phase change forms of concentrated solar thermal power conversion include several types of airbased and gas-based engines that include Stirling-cycle engines and thermo-acoustic conversion technology. The latter concept involves using heat to generate lowfrequency sound waves that drive linear alternators to generate some 50kW of electric power at equivalent efficiency levels of over 40%. Solar-heated Stirling-cycle engines can generate up to equivalent output at marginally lower efficiency and involve a high capital cost.

The thermal power research of several groups located in Spain, Australia, the USA, Canada, Greece, Singapore and South Africa revolve around solar-heated chimney technology. One version of the technology proposed to use chimneys built to a height of 1000m to 1500m while a similar floating tower would be made of fabric and be held aloft by balloon technology. A competing concept

proposed to use a tower of lower height in which to use available heat to produce a vortex that could pull an air stream through ground-level turbines. The higher towers would produce powerful updrafts that would pull air through ground level air turbines and propose to generate some 200MW to 300Mw of power. While it would be possible to combine solar salt pond technology with thermal tower or thermal chimney technology at some locations, most researchers propose to use arrays of solar reflectors to concentrate heat on to the towers. A proof of concept of solar heated tower technology has been demonstrated at Manzanares in Spain and produces up to 50kW of output. The low-cost option would combine the solar salt pond with a vortex engine, however such a combination may be possible only at a few locations around the world despite the small size of the tornado the vortex engine would produce. Solar Heated Brayton-cycle Engines: The introduction of engine components made from silicon carbide has raised the efficiency and performance capability of small turbine engines. Silicon carbide can maintain constant mechanical properties up to 1400째C with extraordinarily high thermal conductivity. Ongoing developments related to silicon carbide technology suggest the potential to develop high-temperature heaters for externally heated air turbine engines. The air heater system downstream of the engine compressor would include a recuperative heat exchanger to recover a large percentage of exhaust heat, a spiral-coil primary air heater made from high-temperature stainless steel and an air superheater made from reinforced silicon carbide. While a trio of a recuperative heat exchanger, primary heater and super-heater may sustain the operation a micro-turbine engine, groups of such trio's could sustain the operation of a much large engine of much higher output. The same heliostat heated solar thermal technology can be adapted to turbines that operate on compressed air stored in subterranean caverns instead of on compressed air from enginedriven compressors. In the former case, the solar heated turbines would deliver 50% to 60% greater output due to the absence of the power required by the turbine-driven air compressor. There is potential to combine seasonal compressed air energy storage (CAES) with high-temperature concentrated solar thermal power and the concept may be cost competitive against PV technology in large-scale applications. Hybrid Solar Thermal Technology: There are a variety of methods by which to combine concentrated solar thermal power technology with other technologies. The possibilities include: ? Super-heat saturated direct/indirect steam from geothermal wells; Super-heat steam from a light water nuclear power installation ? Convert water to saturated steam that will be super-heated by combustion ? Preheat air that will be superheated by combustion in a turbine engine ? Use natural gas combustion after sunset and before sunrise Hybrid technology has the potential to provide a niche for concentrated solar thermal technology in a variety of engine

applications that use steam, air of a gas as the working fluid. Solid-State Thermoelectric Technology: Present examples of solid-state thermoelectric conversion technology operate at a conversion efficiency of 5%. There is much research underway in the USA and in Western Europe to raise the conversion efficiency to within range of PV power and steam-based technology. Solid-state thermoelectric technology has several applications outside of concentrated solar thermal technology, including being placed on top of a fireplace where it can generate power to recharge batteries or provide interior lighting to a residence or building. Thermal Energy Storage: The solar heated salt pond is both a solar collector and thermal energy storage system that stores heat using the latent heat of fusion. Building a transparent cover over a salt pond will minimize heat loss during the over night hours while allowing daytime transmission of the infrared spectrum. There is potential to convert small salt caverns to low-grade heat storage systems (150째C) where heat is pumped in during the day and extracted at night to operate either organic Rankincycle engines or air-based thermal chimney engines. The solar thermal power industry has pioneered the development of heat-of-fusion thermal energy storage systems capable of generating steam and that are based on mixtures of naturally occurring sodium and/or potassium salts. Such materials involve low costs and provide greatly extended useful life expectancies. Research is underway to develop eutectic mixtures of lithium-aluminates capable of generating high-grade superheated steam. Whereas the very large-scale air-based chimney engines can operate on low-grade heat, small-scale air-based engines operate on very high-grade heat at some 1000째C. Containers made of silicon carbide can certainly store heatof-fusion materials that melt at that temperature. The list would include eutectic mixtures of the hydrated and nonhydrated hydroxides and oxides as well as the oxides and fluorides of the same metals. A mixture of the oxide and hydroxide of thorium would combine high density with a high level of thermal storage in a relatively compact package. Conclusions: Solar PV technology has already established several unique niches in the world of small-scale and decentralized power generation. Many forms of solar PV technology already operate free from state subsidy and that trend would likely continue into the future and expand. The dropping cost of PV technology relative to its output make it an attractive option for small-scale applications, with potential for large-scale applications.

Concentrated solar thermal power using parabolic reflector technology also has its own unique market niche such as heating water at numerous locations around the world. Most large buildings around the world have need for heated water, as do many thermal-desalination plants. The same technology can be adapted to low-grade thermal power conversion involving organic Rankin-cycle engines. The cost of heliostat technology as compared to PV technology will determine as to which technology gains favor in large-scale power generation. There is potential to combine heliostats with a different design to boiler to raise thermal efficiency and possibly reduce capital cost. In some nations, it may be possible to desalinate seawater using the exhaust steam from steambased solar thermal power installations. The ability to combine concentrated solar thermal power conversion with a related technology in a hybrid system offers to create a unique niche for such technology. Combining seasonal compressed air energy storage technology (CAES) with concentrated solar thermal power technology can allow the hybrid technology to generate greater output from the same number of reflectors during the summer months, when demand for power soars in many nations. The CAES hybrid concept can include a combined-cycle thermal technology that involves both Brayton and Rankinecycle engines to raise power output and overall thermal efficiency while operating on concentrated solar thermal power. Exhaust heat from the Rankine-cycle engine may be used to operate a thermal desalination plant. The option to apply hybrid technology and combined-cycle technology to concentrated solar thermal power conversion offers to create a viable niche for an expanded version technology. Such technology may best operate in locations that have the following characteristics: ? ? ? ? ? ?

Excess power generation during winter Excessive demand for power during summer Potential to introduce (seasonal) CAES technology Location is near an oceanic coast (thermal desalination) Optimal latitude between 35째N and 35째S Application is of large-scale

Despite the increasingly competitive nature of PV technology, there may be scope to enhance the versatility and competitiveness of concentrated solar thermal technology. While the 2-solar technologies have their respective unique niches, the evolving competition between them will create unique market applications for each technology. Both technologies are likely to evolve and develop further over the years ahead as their respective market niches evolve and develop.

Harry Valentine holds a degree in engineering and has a background in free-market economics. He has undertaken extensive research into the field of transportation energy over a period of 20-years and has published numerous technical articles on the subject. His economics commentaries have included several articles on issues that pertain to electric power generation. He lives in Canada.

Concentrating Solar Power (CSP) emerging as a proven technology By Ramanathan Menon “The basic concept of concentrating solar power (CSP) is relatively simple. CSP devices concentrate energy from the sun's rays to heat a receiver to high temperatures. This heat is transformed first into mechanical energy (by turbines or other engines) and then into electricity. CSP also holds potential for producing other energy carriers (solar fuels)” CSP uses renewable solar resource to generate electricity while producing very low levels of greenhouse-gas emissions. Thus, it has strong potential to be a key technology for mitigating climate change. In addition, the flexibility of CSP plants enhances energy security. Unlike solar photovoltaic (SPV) technologies, CSP has an inherent capacity to store heat energy for short periods of time for later conversion to electricity. When combined with thermal storage capacity, CSP plants can continue to produce electricity even when clouds block the sun or after sundown. CSP plants can also be equipped with backup power from combustible fuels.

These factors give CSP the ability to provide reliable electricity that can be despatched to the grid when needed, including after sunset to match late evening peak demand or even around the clock to meet base-load demand. Collectively, these characteristics make CSP a promising technology for all regions with a need for clean, flexible, reliable power. Further, due to these characteristics, CSP can also be seen as an enabling technology to help integrate on grids larger amounts of variable renewable resources such as solar PV or wind power. While the bulk of CSP electricity will come from large, ongrid power plants, these technologies also show significant

potential for supplying specialized demands such as process heat for industry, co-generation of heating, cooling and power, and water desalination. CSP also holds potential for applications such as household cooking and small-scale manufacturing that are important for the developing world. The possibility of using CSP technologies to produce concentrating solar fuels (CSF), such as, hydrogen and other energy carriers, is an important area for further research and development. Solar-generated hydrogen can help de-carbonize the transport and other end-use sectors by mixing hydrogen with natural gas in pipelines and distribution grids, and by producing cleaner liquid fuels. “The first commercial plants began operating in California in the period 1984 to 1991, spurred by federal and state tax incentives and mandatory long-term power purchase contracts. A drop in fossil fuel prices then led the federal and state governments to dismantle the policy framework that had supported the advancement of CSP. In 2006, the market reemerged in Spain and the United States, again in response to government measures such as feed-in tariffs (Spain) and policies obliging utilities to obtain some share of power from renewables and from large solar in particular” As of early 2010, the global stock of CSP plants neared 1 GW capacity. Projects now in development or under construction in more than a dozen countries (including India, China, Morocco, Spain and the United States) are expected to total 15 GW. Parabolic troughs account for the largest share of the current CSP market, but competing technologies are emerging. Some plants now incorporate thermal storage. By contrast, photovoltaics (PV) and concentrating photovoltaics (CPV)

produce electricity from the sun's rays using direct conversion with semi-conductor materials. The sunlight hits the Earth's surface both directly and indirectly, through numerous reflections and deviations in the atmosphere. On clear days, direct irradiance represents 80% to 90% of the solar energy reaching the Earth's surface. On a cloudy or foggy day, the direct component is essentially zero. The direct component of solar irradiance is of the greatest interest to designers of high temperature solar energy systems because it can be concentrated on small areas using mirrors or lenses, whereas the diffuse component cannot. Concentrating the sun's rays thus requires reliably clear skies, which are usually found in semi-arid, hot regions. The solar energy that CSP plants use is measured as direct normal irradiance (DNI), which is the energy received on a surface tracked perpendicular to the sun's rays. It can be measured with a pyrheliometer. DNI measures provide only a first approximation of a CSP plant's electrical output potential that take advantage of both direct and diffuse irradiance, such as photovoltaics (PV), are assumed to have a competitive advantage. The main differences in the direct sunlight available from place to place arise from the composition of the atmosphere and the weather. Good DNI is usually found in arid and semi-arid areas with reliably clear skies, which typically lay at latitudes from 15° to 40° North or South. Closer to the equator the atmosphere is usually too cloudy and wet in summer, and at higher latitudes the weather is usually too cloudy. DNI is also significantly better at higher altitudes, where absorption and scattering of sunlight are much lower. Thus, the most favourable areas for CSP resource are in North Africa, southern Africa, the Middle East, northwestern India, the southwestern United States, Mexico, Peru, Chile, the western part of China and Australia. Other areas that may be suitable include the extreme south of Europe and Turkey, other southern US locations, central Asian countries, places in Brazil and Argentina, and other parts of China. While existing solar resource maps agree on the most favourable DNI values, their level of agreement vanishes when it comes to less favourable ones. Important differences exist, notably with respect to the suitability of northeastern China, where the most important consumption centres are found. However, precise measurements can only be achieved through ground-based monitoring; satellite results must thus be scaled with ground measurements for sufficient accuracy. Several studies have assessed in detail the potential of key regions (notably the United States and North Africa), giving special consideration to land availability: without storage, CSP plants require around 2 hectares per MWe, depending on the DNI and the technology. Even though the Earth's “sunbelts” are relatively narrow, the technical potential for CSP is huge. If fully developed for CSP applications, the potential in the southwestern US states would meet the electricity requirements of the entire United States several times over. Potential in the Middle

East and North Africa would cover about 100 times the current consumption of the Middle East, North Africa and the European Union combined. In short, CSP would be largely capable of producing enough no-carbon or low-carbon electricity and fuels to satisfy global demand. A key challenge, however, is that electricity demand is not always situated close to the best CSP resources. As demonstrated over decades by hydropower dams in remote regions, electricity can be transported over long distances to demand centres. When distance is greater than a few hundred kilometres, economics favour high voltage direct-current (HVDC) technology over alternative-current technology. HVDC lines of gigawatt capacity can exceed 1000 km and can be installed across the seabed; they also have a smaller environmental footprint. Electricity losses are 3% per 1000 km, plus 0.6% for each conversion station (as HVDC lines usually link two alternative-current areas).This creates opportunities for CSP plant operators to supply a larger range of consumers. However, the cost of constructing major transmission and distribution lines must be taken into account. At present, there are four main CSP technology families, which can be categorised by the way they focus the sun's rays and the technology used to receive the sun's energy. Parabolic troughs (line focus, mobile receiver): Parabolic trough systems consist of parallel rows of mirrors (reflectors) curved in one dimension to focus the sun's rays. The mirror arrays can be more than 100 m long with the curved surface 5 m to 6 m across. Stainless steel pipes (absorber tubes) with a selective coating serve as the heat collectors. The coating is designed to allow pipes to absorb high levels of solar radiation while emitting very little infra-red radiation. The pipes are insulated in an evacuated glass envelope. The reflectors and the absorber tubes move in tandem with the sun as it crosses the sky. All parabolic trough plants currently in commercial operation rely on synthetic oil as the fluid that transfers heat (the heat transfer fluid) from collector pipes to heat exchangers, where water is preheated, evaporated and then superheated. The superheated steam runs a turbine, which drives a generator to produce electricity. After being cooled and condensed, the water returns to the heat exchangers. Parabolic troughs are the most mature of the CSP technologies and form the bulk of current commercial plants. Most existing plants, however, have little or no thermal storage and rely on combustible fuel as a backup to firm capacity. For example, all CSP plants in Spain derive 12% to 15% of their annual electricity generation from burning natural gas. Some newer plants have significant thermal storage capacities. Linear Fresnel reflectors (line focus, fixed receiver): Linear Fresnel reflectors (LFRs) approximate the parabolic shape of trough systems but by using long rows of flat or slightly curved mirrors to reflect the sun's rays onto a downward-facing linear, fixed receiver. A more recent design, known as compact linear Fresnel reflectors (CLFRs), uses two parallel receivers for each row of mirrors and thus needs less land than parabolic troughs to produce a given output. The main advantage of LFR systems is that their simple design of flexibly bent mirrors and fixed receivers requires lower investment costs and facilitates direct steam generation (DSG), thereby eliminating the need for and

cost of heat transfer fluids and heat exchangers. LFR plants are, however, less efficient than troughs in converting solar energy to electricity and it is more difficult to incorporate storage capacity into their design. Solar towers (point focus, fixed receiver): Solar towers, also known as central receiver systems (CRS), use hundreds or thousands of small reflectors (called heliostats) to concentrate the sun's rays on a central receiver placed atop a fixed tower. Some commercial tower plants now in operation use DSG in the receiver; others use molten salts as both the heat transfer fluid and storage medium. The concentrating power of the tower concept achieves very high temperatures, thereby increasing the efficiency at which heat is converted into electricity and reducing the cost of thermal storage. In addition, the concept is highly flexible; designers can choose from a wide variety of heliostats, receivers, transfer fluids and power blocks. Some plants have several towers that feed one power block. Parabolic dishes (point focus, mobile receiver): Parabolic dishes concentrate the sun's rays at a focal point propped above the centre of the dish. The entire apparatus tracks the sun, with the dish and receiver moving in tandem. Most dishes have an independent engine/generator (such as a Stirling machine or a micro-turbine) at the focal point. This design eliminates the need for a heat transfer fluid and for cooling water. Dishes offer the highest solar-to-electric conversion performance of any CSP system. Several features the compact size, absence of cooling water, and low compatibility with thermal storage and hybridisation put parabolic dishes in competition with PV modules, especially concentrating photovoltaics (CPV), as much as with other CSP technologies. Very large dishes, which have been proven compatible to thermal storage and fuel backup, are the exception. Promoters claim that mass production will allow dishes to compete with larger solar thermal systems. Parabolic dishes are limited in size (typically tens of kW or smaller) and each produces electricity independently, which means that hundreds or thousands of them would need to be colocated to create a large-scale plant. By contrast, other CSP designs can have capacities covering a very wide range, starting as low as 1 MW. The optimal size of troughs, LFR and towers, typically from 100 MW to 250 MW, depends on the efficiency of the power block. Some smaller CSP devices combine fixed receivers with parabolic troughs or, more often, dishes (called “Scheffler dishes”). They are notably used in India for steam cooking devices in facilities that serve thousands meals per day. Dishes have also been used for process heat by gathering the heat collected by each dish; feeding a single power Central receiver Solar Tower Heliostats RCSP status today block to produce electricity this way is possible, but this option does not seem to be pursued at present.

Solar thermal electricity without concentration is also possible. Highly efficient non-concentrating solar collectors could evaporate enough steam to run specific power blocks (e.g. based on organic Rankine cycles). The efficiency would be relatively low in comparison to CSP

technologies discussed above, but non-concentrating solar power could capture both direct and diffuse sunlight (like PV modules) and thus expand the geographic areas suitable for solar thermal electricity. Low-cost thermal storage and fuel backup could give this technology interesting features when and if it becomes commercial. Enhancing the value of CSP capacities In arid and semi-arid areas suitable for CSP production, sunlight usually exhibits a good match with electricity demand and its peaks, driven by air-conditioning loads. However, the available sunlight varies somewhat even in the sunniest places. Furthermore, human activity and thermal inertia of buildings often maintain high demand for electricity several hours after sunset. To provide a larger share of clean electricity and maximise CO2 emission reductions, CSP plants will need to provide base load power. Thermal storage and backup or hybridisation with fuels help address these issues. Thermal storage All CSP plants have some ability to store heat energy for short periods of time and thus have a “buffering” capacity that allows them to smooth electricity production considerably and eliminate the short-term variations other solar technologies exhibit during cloudy days. Recently, operators have begun to build thermal storage systems into CSP plants. The concept of thermal storage is simple: throughout the day, excess heat is diverted to a storage material (e.g. molten salts). When production is required after sunset, the stored heat is released into the steam cycle and the plant continues to produce electricity. Studies show that, in locations with good sunlight (high DNI), extending electricity production to match this demand requires a storage capacity of two to four hours. In slightly less sunny areas, storage could be larger, as it also helps compensate for the somewhat less predictable resource. The solar field is somewhat larger relative to the rated electrical capacity (i.e. the plant has a greater solar multiple 3), to ensure sufficient electricity production. As a result, at maximum sunlight power, solar fields produce more heat than their turbines can absorb. In the absence of storage, on the sunniest hours, plant operators would need to “defocus” some unneeded solar collectors. Storage avoids losing this energy while also allowing for extending production after sunset. For example, some trough plants in Spain store enough heat in molten salts to produce power at the rated capacity of the turbine (50 MWe) for more than 7 additional hours CSP plants with large storage capacities may be able to produce base-load solar electricity day and night, making it possible for low-carbon CSP plants to compete with coal-fired power plants that emit high levels of CO2. For example, one 17 MW solar tower plant under construction in Spain will use molten salts as both heat transfer fluid and storage medium and store enough heat energy to run the plant at full load for 16 hours. Storage has a cost, however, and cannot be expanded indefinitely to prevent rare events of solar energy shortages. A current industry focus is to significantly increase the temperature to improve overall efficiency of CSP plants and reduce storage costs. Enhanced thermal storage would help to guarantee capacity and expand production. Storage potentially makes base-load solar-only power plants possible, although fuel-powered backup and hybridisation have their own advantages and are likely to remain, as described below.

Backup and hybridization: Virtually all CSP plants, with or without storage, are equipped with fuel-powered backup systems that help to regulate production and guarantee capacity especially in peak and mid-peak periods. The fuel burners (which can use fossil fuel, biogas or, eventually, solar fuels) can provide energy to the heat transfer fluid or the storage medium, or directly to the power block. In areas where DNI is less than ideal, fuelpowered backup makes it possible to almost completely guarantee the plant's production capacity at a lower cost than if the plant depended only on the solar field and thermal storage. Providing 100% firm capacity with only thermal storage would require significantly more investment in reserve solar field and storage capacity, which would produce little energy over the year. Fuel burners also boost the conversion efficiency of solar heat to electricity by raising the working temperature level; in some plants, they may be used continuously in hybrid mode. CSP can also be used in hybrid by adding a small solar field to fossil fuel plants such as coal plants or combined-cycle natural gas plants in so-called integrated solar combined-cycle plants (ISCC). As the solar share is limited, such hybridisation really serves to conserve fuel. A positive aspect of solar fuel savers is their relatively low cost: with the steam cycle and turbine already in place, only components specific to CSP require additional investment. Such fuel savings, with capacities ranging from a few megawatts to 75 MW, are being built adjacent to existing or new fossil fuel power plants in Algeria, Australia, Egypt, Iran, Italy and the United States (in the state of Florida). Grid integration of CSP plants: The storage and backup capabilities of CSP plants offer significant benefits for electricity grids. Losses in thermal storage cycles are much smaller than in other existing electricity storage technologies (including pumped hydro and batteries), making the thermal storage available in CSP plants more effective and less costly CSP plants can enhance the capacity of electricity grids to accommodate a larger share of variable energy sources, thereby increasing overall grid flexibility. As demonstrated in Spain, connecting CSP plants to some grid sub-stations facilitate a greater share of wind energy. CSP plant backup may also eliminate the need to build fossil-fired “peaking” plants purely to meet the highest loads during a few hours of the day. Although the optimal size of CSP plant is probably 200 MW or more, many existing grids use small power lines at the ends of the grid in less-populated areas, which cannot support the addition of large amounts of electricity from solar plants. Thus, in some cases, the size of a CSP plant could be limited by the available power lines or require additional investment in larger transport lines. Furthermore, it is often easier to obtain sites, permits, grid connections and financing for smaller, scalable CSP plant designs, which can also enter production more quickly. Plant cooling and water requirements as in other thermal power generation plants, CSP requires water for cooling

and condensing processes. CSP water requirements are relatively high: about 3000 L/MWh for parabolic trough and LFR plants (similar to a nuclear reactor) compared to about 2000 L/MWh for a coal plant and only 800 L/MWh for combined-cycle natural gas plants. Tower CSP plants need less water per MWh than trough plants, depending on the efficiency of the technology. Dishes are cooled by the surrounding air, and need no cooling water. Accessing large quantities of water is an important challenge to the use of CSP in arid regions, as available water resources are highly valued by many stakeholders. Dry cooling (with air) is one effective alternative used on the ISCC plants under construction in North Africa. However, it is more costly and reduces efficiencies. Dry cooling installed on trough plants in hot deserts reduces annual electricity production by 7% and increases the cost of the produced electricity by about 10%. The “performance penalty” of dry cooling is lower for solar towers than for parabolic troughs. Installation of hybrid wet/dry cooling systems is a more attractive option as such systems reduce water consumption while minimising the performance penalty. As water cooling is more effective but more costly, operators of hybrid systems tend to use only dry cooling in the winter when cooling needs are lower, then switch to combined wet and dry cooling during the summer. For a parabolic trough CSP plant, this approach could reduce water consumption by 50% with only a 1% drop in annual electrical energy production. CSP for niche markets: CSP technologies can be highly effective in various niche markets. Mid-sized CSP plant can fuel remote facilities such as mines and cement factories. Even small CSP devices (typically using organic Rankine cycles or micro-turbines) can be useful on buildings to provide electricity, heat and cooling. CSP plants can produce significant quantities of industrial process heat. For example, a solar tower will soon produce steam for enhanced oil recovery in the United States. At a smaller scale, concentrating sunlight can be used for cooking and artisanal production such as pottery. The advantages could be considerable in developing countries, ranging from independence from fossil resources, protection of ecosystems from deforestation and land degradation, more reliable pottery firing and, in the case of cooking, reduction of indoor air pollution and its resulting health impacts. Large CSP plants may also prove effective for cogeneration to support water desalination. CSP plants are often located in arid or semi-arid areas where water is becoming scarcer while water demand is increasing rapidly as populations and economies grow. CSP plants could be designed so that low-pressure steam is extracted from the turbine to run multi-effect distillation (MED) stages. Such plants would produce fresh water along with electricity, but at some expense of efficiency loss in power production. Economic studies suggest that it might be preferable, however, to separate the two processes, using CSP for electricity production and reverse osmosis for desalination, when the working temperature is relatively low, as with trough plants. Cogeneration of electricity and fresh water would probably work best with higher temperature levels, such as with towers. With respect to concentrating solar fuels, current R&D efforts

have shown promise in a number of necessary steps, including water splitting, fossil fuel decarbonisation and conversion of biomass and organic wastes into gaseous fuels. Success in these areas affirms the need for larger-

scale experiments to support the further development of CSF as part of the global energy mix. (Courtesy: International Energy Agency)

He has more than two decades of experience as a journalist and a writer on Energy and Environment subjects, interacting with energy sectorsboth conventional as well as non-conventionalin India and the Kingdom of Bahrain. In the Eighties, he was the Bahrain Correspondent for 'Middle East Electricity' magazine published by Reeds, U.K. He also worked as the Media Manager (India) for Washington, DCbased publication 'Business Times' which promotes India's commercial interests in North America. He was also the editor and publisher of 'Sun Power', a quarterly renewable energy magazine during 1995-2002. His contact email address: moothedathramanathan@gmail.com

A look at the history of hybrid technology systems worldwide By Staff Writer â&#x20AC;&#x153;Hybrid technology systems combine two or more technologies with the aim to achieve efficient systems. Possible combinations are: wind-solar photovoltaic (PV) hybrid systems, wind-diesel hybrid systems, fuel cell-gas turbine hybrid systems, wind-fuel cell hybrid systems, etc. (see the short descriptions below). Hybrid systems combine numerous electricity production and storage units to meet the energy demands of a given facility or community. They are ideal for remote and isolated applications such as communications stations, military installations, islands and rural villagesâ&#x20AC;?

Wind-PV hybrid system In this combination, the wind/engine generator acts a backup supply for the AC (alternating current) loads which can be supplied directly to the load without the use of inverter units; the electricity generated from PV is DC (direct current) by nature. A wind-PV hybrid system is composed of the core part constituting of PV modules and a wind turbine, a DC-AC inverter, batteries, a charge controller regulator, and a backup power resource for battery storage systems. PV modules convert sunlight into direct current electricity and they operate using the semiconductor principles that govern diodes and

transistors. The PV modules can be wired together to form a PV array, which increases the available voltage and increases the available current. However, the power produced is the same in both combinations. A typical PV module measures about 0.5 m2 and produces about 75 Watts of DC electricity in full sunlight. Overcharging of a battery by the PV array and wind turbine is prevented through a charge controller regulator. Most modern controllers maintain system voltage regulation electronically by varying the width of DC pulses sent to the batteries through a

phenomenon called pulse width modulation (PWM). Backup power resource can be maintained either from a generator or from the utility grid when too much energy is consumed or when there is not enough electricity generated from the windPV hybrid system. Wind-Diesel Hybrid Systems This combination enables the use of a renewable energy source in remote and isolated areas, where the grid structure is weak, insufficient or even not existing, and the cost of energy often constitutes a considerable part of the local economy. By connecting a wind turbine to a diesel generator back-up system,

an uninterrupted power supply can be acquired, thus securing 100% supply. The diesel generator will take over production when the power generation from the wind turbines is temporarily insufficient to cover the grid demand. The wind turbines are virtually always connectable to the existing diesel generator sets. The new Wind-Diesel concept allows the size of the wind turbine generators to exceed the size of the diesel generators. The maximum fuel saving is achieved by declutching and stopping the diesel engine when the supply from the wind turbine generator exceeds the grid demand. The Wind-Diesel hybrid technology has the advantage of using standard control systems, implemented with modern diesel generators that control the voltage and frequency, even when the diesel engine is not in operation. If the energy production from the wind turbines is higher than the grid demand, the frequency is controlled by the use of a dump-load, which can utilise the excessive wind energy for a numerous other purposes. Fuel Cell-Turbine (FCT) Hybrid Systems A fuel cell uses hydrogen (or hydrogen-rich fuel) and oxygen from air to create electricity by an electrochemical process without combustion. The absence of a combustion process eliminates the formation of pollutants such as NOx, SOx, hydrocarbons and particulates and significantly improves electrical power generation efficiency. Further efficiency gains can be realised by integration of a turbine with the fuel cell. In this direct operating mode, the fuel cell serves as the combustor for the gas turbine. Residual fuel in the high temperature fuel cell exhaust mixes with the residual oxygen in an exothermic oxidation reaction to further raise the temperature. Both the fuel cell and the gas turbine generate electricity, and the gas turbine provides some balance-of plant functions for the fuel cell, such as supplying air under pressure and preheating the fuel and air in a heat exchanger called a recuperator. In an indirect mode, the recuperator transfers fuel cell exhaust energy to the compressed air supply, which in turn drives the turbine. The expanded air is supplied to the fuel cell. The indirect mode uncouples the turbine compressor pressure and the fuel cell operating pressure, which increases flexibility in turbine selection. Critical issues are the integration of pressure ratios and mass flows and the dynamic control through start-up, shutdown, emergency, and load-following operating scenarios. Several successful examples of the implementation of different types of hybrid technologies can be observed throughout the world:

One of the oldest PV hybrid systems and at the same time the first 'large scale' PV system in Europe was installed in 1983 at island of Terschelling in the Netherlands (Lysen, 2000). At the Higher Maritime School 'Willem Barentsz' a 43 kWp PV system was coupled to a 75 kW wind turbine

and a large battery bank. A second example is found on Curaรงao, the Netherlands' Antilles. Since March 1984 the local radio station 'Radio Hoyer' uses a PV powered transmitter, with a battery and a diesel backup. The system is installed on the top of the mountain Tafelberg, and is remotely monitored from the capital Willemstad. The Tortoise Head Guest House on French Island, Victoria, Australia, generates its power from a remote power wind and PV hybrid system that has been operating since 1995 with support from UNEP (UNEP, 2003). The Guest House is located 150 m from the seashore, which makes it an ideal site for a wind turbine. The system includes: 10 kW wind turbine; 840 W PV array; 2 diesel generators of 15 kW and 25 kW; battery storage (wired to produce a system voltage of 120 Volts DC); and a 10 kW inverter to convert the DC into the Australian standard of 240 Volts AC and 50 cycles per second. The energy uses of the Guest House include: electricity for lighting, water pumping, cold room, freezer, dish washer, domestic appliances, communication equipment and some heating, LPG for water heating and cooking, wood from fallen trees for space heating; solar water heaters to pre-heat water; and diesel for back up electric generator. The Guest House consists of six large bedrooms (for 2-6 people each), 5 doublebed cabins and meeting/conference facilities. About 68% of the energy comes from wind, 11% from PV and 21% from diesel. The Guest House continues to reduce diesel and LPG consumption through the use of additional solar water heaters and energy efficiency measures. A wind-PV hybrid system is being used at the Samunsan Forest and Wildlife Sanctuary, 60 KM North of Kuching, in Sarawak, Malaysia. The population of the community fluctuates between 20-70 people, including children who return to the community on weekends, tourists, and scientists. The facilities of the Sanctuary include a dormitory, bungalow, guestrooms, office, amenities block, store rooms, boat shed and power shed. The objectives of installing the system were to: provide reliable 'grid quality' power supply 24 hours a day; power refrigerators and freezers for tourist services, health, and preserving scientific specimens; reduce environmental impacts; reduce costs; reduce dependence on fossil fuels; minimise potential supply disruptions; enable the community, tourists, and researchers to work and study in the evenings; and reduce the risk of fire associated with the use of candles or kerosene lamps. The system includes: 2.5 kW wind turbines mounted on a 26 m tower; a 900 W PV array; 2 lead acid batteries storing 2 kWhs; 5 kW inverter; 30 kW diesel generator; and remote monitoring equipment. The community has been trained to perform all maintenance activities, which has also increased the community's appreciation of the system. The wind turbine generates the largest proportion of electricity over the year while in the summer the PV output is at its maximum. The diesel generator is mostly used in the summer, due to periods of low wind speed and an increase in electricity demand arising from tourism, research and community activities. The system was installed in 1997 at the cost of US$ 60,000. In 1998, a wind/PV hybrid system was installed in Point Hick

lighthouse which was converted to a tourist resort in Southeast Victoria, Australia. The resort consists of several accommodation cottages and a low-cost bunkhouse for low budget tourists. The resort is situated in the Cann River national park. The objectives of this hybrid system were: to meet all the electricity demands of the managers and tourist cottages; to reduce the use of diesel operation; to reduce the costs of diesel fuel; and to reduce the environmental impacts from using fossil fuels. The systems consisted of a 10-kW wind turbine on an 18 m tower with 550 W PV array and a 20-kW diesel generator. The inverter used had a capacity of 10 kW. The storage system consisted of a 120-kWh lead acid battery storage. The wind turbine provided an average of 42 kWh/day at a wind speed of 5-6 m/s while the PV array generated a daily average of 2.8 kWh under 5 hours of direct sun. The total system cost amounted to US$ 65,000. Holwell Farm within the Dartmoor National Park, in Devon, UK, is using a 20-kW Remote Area Power Supply (RAPS) system incorporating a wind turbine system, 20kWh battery storage and a backup 25-kW diesel generator (UNEP, 2003). The system provides electricity for agricultural activities, bed and breakfast tourist accommodation and other domestic uses. The farm is located 2.5 km from the nearest electricity grid. The threeblade wind turbine has a rotor diameter of 8.8 m, a hub height of 24.4 m and is mounted on a lattice tower. An automated control system ensures that AC power is always available and switches to the diesel generator when batteries are 80% discharged or when electrical demands are high. Costa de Cocos is a small scuba diving and fishing resort in Southern Quintana Roo, Mexico, with 12 houses, a restaurant/bar, dive shop, and a workshop. The resort was previously powered by a succession of small (5-20 kW) diesel generators operating just four hours each evening. However, in 1996, a RAPS system consisting of a 7.5-kW wind turbine, battery storage, and two 5.5-kW inverters were installed to provide the resort with electricity throughout the day. The wind turbine is placed on a 24-m tower with protection against salt corrosion. The batteries are located in a specially designed integrated rack assembly. The system cost is approximately US$ 35,000 and has a payback period of 8-10 years. Another successful example of the hybrid project installation is the Mexican Hybrid Solar Thermal Power Project. A solar thermal/natural gas-fired hybrid power plant in Baja California Norte with a total net installed capacity of about 300 MW, including about 30 MW for the solar component has been constructed through this project. The plant is a part of the Comisi贸n Federal de Electicidad system expansion plan. The largest European PV wind hybrid system is located on the Pellworm Island in Germany. The PV array has the capacity of 600 kW and will be enlarged with an additional 300 kW array. The first 300 kW array was build in 1983 and the second part was connected in 1992. This hybrid system is grid-connected. The eventual 900-kW capacity will enable the production of nearly 800 MWh/year.

Another successful example of hybrid technology is a PVwind-diesel hybrid system in Kythnos Island of Greece. It has been in operation since 1983. This plant utilises a 100-kW PV array, a 100-kW wind turbine, and a 600-kWh battery. The entire system is connected to the existing distribution grid, which is fed by a 200-kVA diesel generator. Three 50-kVA inverters operate simultaneously to deliver power to the grid. The plant is monitored in order to optimise the amount of renewable energy available to the grid. The Wilpena Pound power station of South Australia combines a 100-kWp PV system, a battery storage of 400 kWh, an inverter and a 440-kWp diesel generator. At night, a computerised smart controller automatically switches between the battery storage and the most-efficient diesel generator combination to match the load. A modem-link provides remote monitoring and control facilities. In Thailand, PV hybrid systems have been installed as pilot projects since 1990. Most of them were adapted for national parks and wildlife preservation areas or rural villages that do not have access to electricity. Nine off-grid PV hybrid systems ranging from 5 to 82.5 kW, with a total installed capacity of about 285 kW, are in operation and constitute about 10% of the total PV power installed in Thailand. The first hybrid power system in a wildlife sanctuary, Huai Kha Khaeng, was set up by King Mongkut's University of Technology Thonburi in 1998 with the aim to assess technological, economic and operating aspects and to study the penetration of PV in remote and preserved areas. During 19982003, the system supplied 44,504 kWh (PV supplying about 88.5% of the total demand) or an average of 24 kWh/day. The PV/diesel hybrid system installed at Huai Kha Khaeng wildlife sanctuary in 1998 was optimised in order to meet an increasing demand for a clean and reliable power source. The system can supply electricity to load because the diesel generator works to compensate any inconvenience caused by photovoltaic. PV-wind-diesel hybrid systems were installed in 1999 at Phu Kradung, a high-elevation national park in Loei Province, and at Tarutao, an island in a marine national park in Satun Province, Thailand. There could be several barriers to the implementation of hybrid technologies and these need to be overcome for a successful establishment of projects. Hybrid systems generally have a relatively high investment cost, which makes smaller projects unattractive to the investors, lenders, project developers, and manufacturers. Similarly, these technologies have several technical barriers which include: requirement of redundant generation systems, a time limitation for the generation of electricity, need for sophisticated control systems, need for storage systems, and transmission line losses. Other aspects in the implementation chain of these hybrid technology systems in developing countries could be the limited credit worthiness for potential investors; absence of a power purchase agreement with energy users (e.g. through the grid operator); absence of energy or power systems in the villages; lack of information on market, employment, rural development and other economic information; lack of vocational education, communication availability or other social development activities; lack of human capital to properly operate the power plants; and lack of financing partners.

There are several research programmes on hybrid technologies all over the world, mainly in developed countries. For instance, Princeton Energy Resources International (PERI) has undertaken various research programmes on wind power and other wind-based hybrid technologies. PERI has developed several databases and analysis tools to track and analyse wind system and subsystem cost, performance, and other characteristics (Princeton Energy Resources International, no date). Recent use of these has involved projections of expected technology development paths over time and evaluation of financing/ownership on both a corporate balance sheet basis by investor-owned utilities and tax-free public utilities, and a project finance basis through independent power producers. To help facilitate adoption of wind/diesel hybrid systems, PERI has analysed the potential market for replacing existing diesel plants with wind turbines in rural Alaska (USA) for the National Renewable Energy Laboratory (Princeton Energy Resources International, no date). The objective of this assessment was to characterise the size of the wind-diesel hybrid market so that the State of Alaska and Alaskan rural electricity authorities can determine the level of effort required to develop wind projects. An initial list of about 90 Alaskan villages was identified as having outstanding wind resource potential. The result of this analysis was a ranking that identifies the villages where wind/diesel hybrids will have the most favourable economic characteristics. During 2001, the Photovoltaic fuel cell hybrid systems (PVFC-SYS) project was carried out as a European Commission research project on the hybrid technology. The main aim of the project was to study and develop a low-power energy generation system, which would utilise the synergies between a photovoltaic generator and a Proton Exchange Membrane fuel cell. Such a system in the range of 5 to 10 kW is intended to be a future competitor to hybrid PV-Diesel systems, especially from an environmental point of view as emissions of both exhaust gases and noise will be drastically reduced. The overall target of the project was the development of a hybrid system based on an innovative package using hydrogen as a fuel. This can be considered a zero emission system. The use of the so-called innovative components will open new possibilities of future cost decrease, both in the investment, operational and replacement point of view. Since there are no moving parts, less maintenance is required and the lifetime of the components is expected to be higher.

In 1998, China launched an ambitious 'Brightness Programme' that targeted household and village-scale applications of solar PV and wind energy in off-grid regions, particularly in western China. In 2002, the Chinese Government started a major new rural electrification initiative called the Song Dian Dao Xiang programme (National Township Electrification Programme). This programme is directed at electrifying approximately 1000 townships in seven provinces in western China with about 17 MW of village-scale hybrid systems (mainly PV, with some wind, combined with

batteries and diesel back-up systems). The required funding amounts to RMB 2 billion (USD 240 million), which covers 50% of the capital costs of village power systems (in Tibet: 100%). In 2001, 70 village-scale hybrid power systems (wind and/or PV combined with battery storage and many using backup diesel generators, ranging in size from 5-200 kW) were installed in China (Martinot and Wallace, 2003). A 100-kW wind-diesel hybrid village power plant was under construction in 2002 in Zhejiang (Bei Long Dao). A second hybrid system consisting of 80 kW of wind and 20 kW of PV power became operational in Xinjiang in December of 2002. Market studies indicate that by 2010 at least 1000 MWp of stand-alone PV hybrid systems will be installed worldwide, both for remote buildings and on islands. In order to realise this potential and reduce the costs of these hybrid systems, still a lot of work remains to be done, for example, through standardisations and modularity and by developing proper monitoring systems to reduce maintenance costs. Technology transfers from industrialised countries could help improve these implementation chains and demonstrate the working of the hybrid systems. The aforementioned EU research group study in this respect recommends to improve the reliability of systems, reduce their costs, and reduce maintenance need or make maintenance easier. In order to meet these targets, the research has focused on different aspects such as improvement of the methods and techniques to reduce cost for the wind assessment and optimisation of rotor controls along with optimisation of the overall system layouts and controls. In addition, co-operative R&D projects, co-ordinated to use the best technology from each member of the EU are required to improve the technology for all. Directing current testing facilities to develop norms and standards in their demonstration projects will help in the continued development of this market for Europe. For the future development of the international market of the hybrid technologies in developed countries, various stakeholders must be brought together and appropriate financing modalities used to facilitate sustainable, decentralised markets for those technologies that have the attributes of fuel flexibility and hybridisation, particularly with renewable technologies. The primary challenges for organising and delivering hybrid project financing will stem from the large number of small projects, which characterise most of these rural, peri-urban and urban markets. In developing countries like India, there is a necessity of creating and utilising near-term capital and targeted subsidies, reflecting the fact that hybrid systems are currently precommercial and not yet financially viable. The countries should develop concessional co-financing which uses commercial methods tied to commercial capacity building and conducting strategic programmes of hybrid systems. Renewable energy sources such as wind and solar used in windsolar hybrid systems are sustainable energy sources as they are easily and abundantly available in nature. Similarly, hydrogen, which is used in fuel cells, could be by far the most abundant fuel resource since it is part of the water molecule. Hydrogen used in fuel cells is converted to electricity, but it can also be

combusted as with the space shuttle rocket boosters using liquid hydrogen. The hybrid systems with combustion turbines and fuel cells can create systems with exceptionally high efficiency with low emissions. The hybrid systems, in general, combine generation and storage technologies so that excess of electricity can be generated during optimal times while electricity is used from the storage at other times. This will help in achieving sustainability in energy for future. In contrast to conventional power generation systems (diesel generators, coal power, natural gas combustion), renewable energy technologies can generate heat and electricity without producing GHG emissions. Utilisation of renewable energy could play an important role in reducing GHG emissions. Considering the total life cycle of the energy generation process, it has been demonstrated that wind turbines are the cleanest and green energy systems and that hydrogen based fuel cells are environmentally friendly. However, in remote communities wind or fuel cells as stand-alone systems lack reliability, but when combined they could become more reliable. PV and fuel cells represent two very promising industries in term of employment, in particular with respect to the identificaiton and development of new applications. A general assessment of the cost of fuel cell hybrid technology carried out by Rastler and Lemar (2002) shows that costs of any type of hybrid technology are expected to fall to US$ 600 - 1100 per kW for the period beyond 2010. The US Department of Energy has made a target of reducing the cost of fuel cell turbine hybrids to US$ 400/ kW by 2010. The life-cycle cost for a wind energy hybrid system requires the estimation of the following quantities: system life, component and total capital costs per unit of outputs (e.g., wind turbine, engine generator, controls, inverter, AC/DC converter), as well as the battery storage cost per kWh, total hardware cost plus installation and indirect costs occurring (capital cost), annual operation and maintenance and fuel costs, and equipment replacement costs occurring during the system lifetime. If the system is a wind PV hybrid system, then the total cost will include the investment and installation cost of solar panels. Wind energy systems are one of the most cost-effective home-based renewable energy systems. A small turbine can cost anywhere between US$ 3,000 and 35,000, depending on size, application, and service agreements with the manufacturer. According to the American Wind Energy Association, typical home wind system costs approximately US$ 32,000 (10 kW). As a general rule of thumb, the cost of a residential turbine is estimated at US$ 1,000 to US$ 3,000/kW. Hence, the cost of hybrid systems with wind energy systems could decrease in the near future. In Thailand, most PV hybrid systems were installed through the co-operation of King Mongkut's University Technology Thonburi, the Provincial Electricity Authority and the Electricity Generation Authority of Thailand. The systems were funded by the Energy Policy and Planning Office, though the communities have been responsible for

operation and maintenance of the systems. The costs of the systems depend on size, location, customer type and technical specification. The cost of grid-connected systems amounts to about US$ 2/Watt whereas for standalone systems the costs amount to about US$ 34/Watt. The Inner Mongolia Autonomous Region (IMAR) has been working in the past decade to provide stand-alone renewable power systems to rural area households: more than 120,000 households have started generating electricity with 100-300 watt wind generators (American Wind Energy Association, 2001). In the first phase of this project, the University of Delaware, the US National Renewable Energy Laboratory, and the Inner Mongolia team completed a levelised cost analysis of rural electrification options for several counties. It was found that for the output range of 200-640 kWh/yr, levelised cost of energy produced is US$ 0.50-0.63/kWh. In the case of a PV system only, for the output range of 120-240 kWh/yr, the levelised cost of electricity produced would be US$ 0.770.83/kWh. For small hybrid systems in the range of 400-750 kWh/yr, the cost amounts to US$ 0.57-0.72/kWh, and for the large hybrid systems, with an output range of 560-870 kWh/yr, the costs are US$ 0.43-0.57/kWh. For the types of systems currently being deployed for stand-alone electrical generation in rural areas of IMAR, wind generators are the least-cost option for household electricity (American Wind Energy Association, 2001). National Energy Technology Laboratory (NETL) and Fuel Cell Energy (FCE) are working collaboratively to do large-scale expedient testing of an atmospheric Direct FuelCell/Turbine (DFC/T) hybrid system. The R&D efforts have thus far resulted in significant progress in validating the DFC/T cycle concept. FCE has completed successful proof-of-concept testing of a DFC/T power plant based on a 250-kW DFC integrated initially with a Capstone 30 kW and then a 60 kW modified mictroturbine. The results of the system tests have accumulated over 6,800 hours of successful operation with an efficiency of 52%. In 1995, in China, the State Development and Planning Commission (SDPC), the State Economic and Trade Commission (SETC) and the Ministry of Science and Technology (MOST) formulated a “Programme on New and Renewable Energy from 1996-2010” and launched the “Sunlight Programme”, which will run until 2010 and which covers PV systems. It is designed to upgrade the country's manufacturing capability of solar technologies, to establish large-scale PV and PV-hybrid village demonstration schemes, home PV projects for remote areas and to initiate gridconnected PV projects. The “Brightness Project”, which was first launched in 1996 is aimed at providing electricity from solar and wind energy in a number of remote regions (WEC, no date). The Canadian CANMET Energy Diversification Research Laboratory (CEDRL) addresses the challenges associated to the technical needs via its PV hybrid Programme. This five-year initiative, which started in 2001, consists of R&D and technology transfer activities aimed at improving the performance and cost effectiveness of these systems, and at increasing the capacity of the solar industry to supply efficient systems.

World's largest concentrated solar power plant By Jonathon Porritt, Environmentalist and Writer engineering to get from sunshine to electricity, and I was astonished by just how big and complex that makes a plant of this kind.

Pic: Jonathon Porrit I am seriously delighted at this photo. That's me and Dr. Nawal Al-Hosany standing by one of the 258,048 mirrors that make up the Shams1 Concentrated Solar Power (CSP) plant in Abu Dhabi. It will be the biggest CSP plant in the world, stretching out over 2.5 square kilometres, and generating 100 MW of electricity when it goes on line at the end of the year. Dr. Nawal is Director of the Zayed Future Energy Prize, and Masdar is the driving force behind the many different initiatives going on in Abu Dhabi to promote sustainable energy. Which makes it all just a little bit weird. Abu Dhabi is one of the biggest oil producing countries in the world. As I was standing there, I kept thinking that in all likelihood there was a vast puddle of oil below my feet, just waiting to be extracted, refined, shipped and burned in some of the world's ever-growing number of cars. I'll return to that in a minute. But first let's just celebrate this beautiful, forceful power plant springing up out of the Abu Dhabi desert. At one level, it's all quite simple. The 258,048 mirrors are assembled in parabolic troughs that track the passage of the sun from dawn to dusk. They 'concentrate' the sunlight onto tubes running down the middle of the troughs. These tubes are full of oil which is heated by the sun to nearly 400° C. Heat exchangers then convert that heat into steam, which drives the turbine, which drives the generator which produces the electricity.

We were there at around midday, so it was seriously hot you couldn't stand next to the mirrors for very long! But it was also dusty it is, after all, in the middle of a desert. And that poses a huge challenge in terms of keeping the mirrors dust-free so that their performance is not affected. That means they've had to develop special vehicles that are constantly tracking up and down the 120 km length of parabolic troughs to keep them sparkling. In short, it's not easy. And it's expensive. But as one of our fellow visitors said, “what do you expect with a nuclear reactor?” I've often described the sun as “the only fusion reactor we're ever going to need to power the world”, and that doing it this way is a whole lot simpler than trying to build our own puny little fusion reactors. It's still an engineering triumph. And all done courtesy of Abu Dhabi's massive oil revenues which have inevitably prompted people to level charges of hypocrisy against the whole Masdar initiative. What is the value of 100 MW of solar set against the emissions of millions of tonnes of CO2 and other greenhouse gases from all that oil? Fair point. But what conclusions should we draw from it? That Abu Dhabi should stop producing oil? Let's not be too naïve here. That Abu Dhabi shouldn't do anything to promote renewables either from an R&D point of view or through schemes like Shams? Or through the Zayed Future Energy Prize, which celebrates the achievements of the best initiatives and organisations involved in renewable and sustainable energy all around the world? That would seem to be a bit selfdefeating. For me, near-zero carbon electrons from Abu Dhabi is just one of those sustainability paradoxes that you have to live with. Which is why I am looking forward to Shams 1 being the first of a whole generation of CSP plants around the world.

It's not quite as simple as that! There's a lot of fancy Jonathon Porritt, Co-Founder of Forum for the Future, is an eminent writer, broadcaster and commentator on sustainable development. Established in 1996, Forum for the Future is now the UK's leading sustainable development charity, with 70 staff and over 100 partner organisations including some of the world's leading companies.

VIEW POINT:

Niche 25 MW to 50 MW multipurpose solar pv (low tariff) power project developments at every taluka of good solar irradiation states of India for energy security and food security By Praveen Kumar Kulkarni “Sustainable Solar PV project development is a challenge and can be easily solved the following way if implemented in true spirit of Democracy with transparency” We propose : -A 25 to 50 MW of solar PV power project + Dry grain storage godown to store the dry food grains as per FCI guidelines + 1 MW Biomass power plant (in the 2nd phase depending upon biomass availability) at every taluka. + 5000 MT Cold Storage unit (in the 2nd Phase). The second phase items are intentionally kept out of scope of this article at present. However, there shall be land provision for the same to attract the people with such expertise for further sustainability with intrinsic value chain. -Select the villages / Taluka where there is no electrification or no power in the existing grid for more than 4 hours/day from the grid line. -Chain of substations for evacuation with new grid lines to be established along these 8 to 10 talukas by the State Government with ADB funding. Proposed Business Model with an in principle policy support to attract Many Entrepreneurs in rural area with reduced overheads for a reduced tariff: Assumptions for a 25 MW Solar PV power project as per CERC guide line on ROE, but, the rate of Interest for term loan (interest subsidy proposed) is assumed as 4% on rupee term and the loan term as 15 years. The results are tabulated to know the Cost of Generation (COG) and the IRR of 12% (mini) with a low tariff of Rs.5/kwh with a tariff escalation of 3% per year. Let the interested developers who can offer such business number can come forward so that the Nation gets benefitted. No further REC benefits etc shall be provided. This shall be a total cost to the government to buy the power as the interest subsidy is being proposed by us. Instead of Viable Gap Funding or Capital Subsidy (due to failure of such capital subsidy for Biomass plants and to use the national wealth in a more effective way), we strongly propose an Interest subsidy to get the project interest at ONLY 4% (Fixed rupee term Interest rate). Let the Government form / raise the Clean tech fund and pay the Debt fund at this rate of Interest or let the promoters arrange the loan (from the Government designated or

nominated Banks or Institutions of INDIA or Abroad) and get the differential interest subsidy payable (from State of Centre Government with Escrow amount) per year against performance of the plant of having delivered the number of units as assumed! This will make the project developer to PERFORM else PERISH. If lesser energy generation, then, the interest payable shall be reduced. Thus, we do not subsidize the CAPEX and invite good quality players in Solar PV Power Generation. Let the developers hire competent EPC with good products within the Project Cost of Rs.8 Crore/MW. This can vary every year and CERC can furnish such guidelines on CAPEX from time to time and open the market and one need not waste time in reverse bidding, running around the ministers or Centre or State Government officers or such DISCOMs etc. Let the Village Panchayat or Zilla Parishad (District), who want to have power generation in their district or village, come forward with land bank and attract the investors, thus, land acquisition problems can be reduced. DISCOMS must buy at Rs.5/kwh with a PPA with 3% annual increment with a tripartite agreement and Assured Letter of Credit from the respective state government. This kind of PPA can be fixed for a year and let any developer come forward with a capacity capping per developer per year, otherwise, deep pocket people will only get richer. Government can promote local entrepreneurs through “Entrepreneur Funding” policy which is in the making for the further sustainability and for the local job creation at RURAL LEVEL. This will also ensure the common people to access low cost Solar PV power as early as possible. With the further drop of PV equipment price, the situation will improve further with good players and with more jobs, wealth creation and distribution for many Entrepreneurs, which is more democratic with transparency. Energy Access for ALL in true spirit. Since the development of evacuation facility is with State Government, it must comply on time. Failure to do so, shall attract dismissal of the local officers or their team, thus, we make the local administration responsible. As the Village Panchayat and ZP are involved, the cable running in many farms will not be a problem and grid shall be ensured with redundancies to ensure power in the grid with a provision for Hybrid mix and future growth. Local government involvement will make the people aware (expose) to elect their local representative in a better democratic environment. Land acquisition shall be through VP or ZP local administration as the developer need not run from pillar to post.

The expenses related to Taxes, duties, transmission costs etc shall not be loaded to the Developer and one can further

reduce the tariff. If the Income tax can be waived for Developers of Solar PV power project, the accelerated depreciation benefit

game (which played havoc in Wind mill without sustainability) can be eliminated and the village level entrepreneurs with funding through national policy on entrepreneur funding can make way for many entrepreneurs for the local area sustainability with responsibility, thus, the project promoters will take pride in local area development. Thus, with detailed calculations shared, we can create good business case to develop local entrepreneurs with necessary support from large EPC companies to create good quality national assets. Thus, there will be a very good eco system by eliminating the project award to known coterie and then selling the equity to make money without executing the project or such corrupt practices during the award or sanctioning the project etcâ&#x20AC;Ś. Thus, money is made available with necessary security, low cost debt fund (from donor or Kfw, IREDA etc) to reduce the tariff of Solar PV power. Government can give a thought on this kind of business plan preparation with clarity on numbers for sustainability (for all RE resources) to attract SMALL entrepreneurs with mentoring, monitoring to create good quality national assets with real PPP model. The numbers illustrated can be debated, discussed, improved and then made as a policy for a Financial year for quick development while the project allotment agencies must

facilitate for quick redressal of the project development, irrespective of which party in the ruling. Let the system work and not the politics, once, the policy with principles are decided with no payouts as the project allotment is open for the Project developers who can show the required credentials with good EPC company, Equity money in the bank with land arrangement with VP or ZP and then approach the State or Central government with good quality money with necessary RBI clearances. Thus, there won't be mad rush of applications, waiting for clearances from allotment department etc. There shall not be delay in sanctioning the debt fund as it shall be through FIs or Cleantech Fund with credit line secured well in advance as the CAPEX is fixed. Whatever savings on CAPEX, it is for the benefit of the Project Developer for their efficient project development and hence reduced interest burden. The company which comes up with lesser CAPEX or lesser loan amount, it shall be given first preference as there is no CAPEX subsidy. There will only be Interest subsidy and that too payable at the end of year after showing the generation performance and MUST be reimbursed to the developer within 15 days of such valid document submission or a LC can be ensured or an Escrow amount be kept.

IMPORTANT NOTE: THE PROJECT DEVELOPERS WITH LESS EXPECTATIONS ON RETURN ON EQUITY WILL STAND BETTER CHANCE !

Important Note : International Donor Organisation, Cleantech Promotion Organisations, Csr Believer Good Corporate Companies Can Manage With Irr Of 12% With A Good Business Case. The Dry Grain Storage, Biomass And Cold Storage Units With Their Separate P & L, Will

Improve Project Irr And Help In Inclusive Growth With Good Job Creation At Rural Area. (Tariff Cost Escalation Of 3% Per Year Is Illustrated For Irr Of 12%)

The author is a Gold Medalist from SLN College of Engineering, Gulbarga University. Industrial work experience over 23 years with PSU, MNCs. He had worked for: Tungabharda Steel Products Ltd, Hospet from 1988 to 1995. Executed engineering of 21 Hydro Mechanical Equipment projects. Deputed to Japan for 5 months as part of UNIDO program to become JICA participant-1994. He introduced CAD in TSPL with software programs for design of Gates, Hoists and Cranes. He was deputed to TSPL Hyderabad branch to assist business development of Steel Plant Equipments. With SMS Demag India Ltd, German MNC), he engineered Steel Melt Shop equipments of Jindal Vijay Nagar Steel Plant. Apart from being the Head of Secondary refining equipments viz. VD, VOD, RH, RHOB, SMS equipments, he supported the pre-bid and business development activities thru ICB of SMS Demag Secondary refining equipments. Visited SMS Demag, Duisburg on company assignments ALSTOM Portugal / India (French MNC) hired him as a Consultant and Part of Management team to launch Hydro Mechanical Equipment in India in their Baroda factory. Prepared Business plans, Export support (1ME,Owenfalls ,Uganda), tendering support to realize and launch Omkareshwar Project. Visited ALSTOM Lisbon, France, Grenoble on assignments and important missions. He was a Project Manager of Omkareshwar HME (24 ME) and as Implementation Manager to rebuild (15ME) Alstom Baroda factory to manufacture Hydro turbines, Generators and HME to cater to their Indian and Export Markets. He visited USA, Russia for special equipment evaluations, purchase and installations. He was the Project Director of Nam Ngum, Laos HME project (10ME). Established KK NESAR PROJECT PRIVATE LIMITED to execute renewable energy projects on EPC basis with a collaborative business approach with Indian specific needs. His contact email: praveenkulkarni@kknesar.com

How a grid connected solar power system works?

While the technology behind solar power may seem complex, when broken down, grid connect is easy to understand as it only requires a few components installed in your home or business.

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rate for the power used. As all of the components in a grid connect system have no moving parts, you can expect a long and hassle free life from your solar power system! Generous government renewable energy rebates mean you can also save thousands on a grid connect system for a limited time!

The sun shines on the solar panels generating DC electricity The DC electricity is fed into a solar inverter that converts it to AC electricity. The AC electricity is used to power appliances in your home. Surplus electricity is fed back into the main grid.

Whenever the sun shines, the solar cells generate electricity. The grid connect inverter converts the DC electricity produced by the solar panels into AC electricity, which can then be used by the property/household. If a grid connect system is producing more power than is being consumed, the surplus is fed into the mains power grid. Some electricity companies will meter the electricity fed into the grid by your system and provide a credit on your bill. Other companies will install a bi-directional meter which will run backwards as your system feeds electricity into the grid. When the solar cells are not producing power, for example at night, your power is supplied by the mains power grid as usual. The energy retailer charges the usual

Most customers choose a roof mounted solar system. For most of India, the modules should be south facing in order to take full advantage of the sun.

Concentrated Solar Power and Combined Solar Power to claim their respective share in the ensuing energy revolution By Staff Writer collected during daytime can be stored in concrete, molten salt, ceramics or phasechange media. At night, it can be extracted from the storage to run the power block. Combined generation of heat and power by CSP is particularly interesting, as the high value solar input energy is used with the best possible efficiency, exceeding 85 %. Process heat from combined generation can be used for industrial applications, district cooling or sea water desalination. CSP is one of the best suited technologies to help, in an affordable way, mitigate climate change as well as to reduce the consumption of fossil fuels. Therefore, CSP has a large potential to contribute to the sustainable generation of power. Parabolic Trough Power Plants as well as Solar Power Towers and Parabolic Dish Engines are the current CSP technologies. Concentrated Solar Power Plant Concentrated Solar Power (CSP) is based on concentrating sunlight onto a small surface which is then heated. The heat is converted to energy through either a sterling engine or a fluid that is heated and used for power generation. Precise movement is essential for this installation to work effectively. CSP can be obtained through different solar power systems such as a solar tower with heliostats, a parabolic through and a Fresnel collector. Concentrated Photovoltaic (CPV) power generation uses the same photovoltaic material as PV. On CPV panels the solar radiation is however concentrated onto the material using lenses. This creates a much higher electricity output pr. m2 photovoltaic material. For the installation to work it is essential that the CPV panels follow the sun during the day. Photovoltaic (PV) power generation is done by employing panels composed of a number of cells containing photovoltaic material (often silicon). This photovoltaic material then converts solar radiation into electric current. While solar tracking is essential for both CPV and CSP to deliver power it is not the case for PV. The reason for choosing tracking on a PV installation instead of just having a fixed installation is an increased energy output during the day. Whether it is feasible to install a tracker is thus dependable on whether the increased energy output (kWh) weights up the additional cost of the tracking system. Return on investment of the tracking part in a solar tracking system is approximately 4-5 years.

In a simple way, the solar radiation can be collected by different Concentrating Solar Power (CSP) technologies to provide high temperature heat. The solar heat is then used to operate a conventional power cycle, such as a steam or gas turbine, or a Stirling engine. Solar heat

In many regions of the world, every square kilometre of land can produce as much as 200 to 300 GWh/year of solar electricity using CSP technology. This is equivalent to the annual production of a conventional coal or gas fired 50 MW power plant or over the total life cycle of a CSP system to the energy contained in 16 million barrels of oil. The exploitation of less than 1 % of the total CSP potential would suffice to meet the recommendations of the Intergovernmental Panel on Climate Change (IPCC) for a long-term stabilization of the climate. At the same time, concentrating solar power will become economically competitive with fossil fuels. This large solar power potential will only be used to a small extent, if it is restricted by the regional demand and by the local technological and financial resources. But if solar electricity is exported to regions with a higher demand and less solar energy resources, a much greater part of the potential of the sunbelt countries could be harvested for the protection of the global climate. Combined Solar Power Combined Solar Power (CSP) or Hybrid renewable energy source is becoming popular because it is composed of two or more energy sources. This combination of two energy sources is an efficient way of generating energy. CSP or Hybrid energy systems are used in remote areas for power generation. The use of hybrid power generations came forward due to the high prices of oil. The use of hybrid energy systems can optimize the power supply especially in rural areas. However, it is still considered expensive and difficult to combine two or three energy sources together, but it is a one time expense. This one time expense can be of many uses to people living in remote areas There are many sources of combining renewable energy sources to produce power but two of them are biomass wind fuel cell and photovoltaic wind. The first hybrid energy sources biomass wind fuel cell is a combination of 60% biomass and 20% wind

power along with the derivation of energy from fuel cells. The hybrid energy sources can help farmers to run their tube wells to provide water to their irrigation land. Combining two or three energy sources to form one source is capable of generating efficient energy to power a house or a small industrial unit. The photovoltaic wind power is the combination of solar cells and wind turbines to generate electricity. The energy by wind turbines and solar panels is combined in a battery bank. It is then transformed to the inverter and then it helps in generating alternate current. The hybrid energy sources are much more cost effective and environment friendly. Hybrid energy sources can be used to generate electricity which can power many applications like TV, water pumps, grinders, irons and other machinery. It can help the users to run electrical appliances as well as outdoor and indoor lights. These power systems can supply direct current and alternate current accordingly. The hybrid energy is useful only if we do not overlook the important considerations before deploying this energy. The input and output parameters should be compatible to each other. Also analyze the variations in the two very different energy sources like wind energy and solar power. The reduced range of power supply and the variation in the energy capabilities of both power plants should be monitored using charge controller. It is imperative to use power inverters to transform electric current into usable form like alternate current. There are few basic hybrid systems without which the working of the hybrid systems is not possible. For example if we want to generate electricity by combining photovoltaic and wind power we must possess an array of solar panels, wind generators, a backup storage and battery system and a power converter. The photovoltaic panels or PV generators is a combination of series of solar panels. These solar panels are in turn made up of solar cells. An array of solar panels alone is considered an important and powerful energy sources. The wind generator converts the energy of the wind (kinetic energy) into mechanical energy. The energy generated from both sources is combined into one battery inverter or storage unit. This storage unit conserves the energy generated form the solar panels and wind turbines. This energy is then converted to usable energy by using inverter. Just like solar and wind power plants the hybrid power plants can also be off grid and on grid therefore increasing the diversity of this energy technology. The word 'hybrid' is used to refer to something made by combining different elements. Modern science has seen dramatic advances in hybrid technology, giving birth to hybrid cars such as the Toyota Prius and incorporating information and communications technology (ICT) systems that automate smart-houses and eco homes. Similarly, hybrid energy systems have been designed to generate electricity from different sources, such solar panels and wind turbines.

Hybrid energy systems often consist of a combination between fossil fuels and renewable energy sources, and are used in conjunction with energy storage equipment (batteries). This is often done either to reduce the cost of generating electricity from fossil fuels or to provide back up for a renewable energy system, ensuring continuity of power supply when the renewable energy source fluctuates. One of the biggest downfalls of renewable energy is that energy supply is not constant; sources like solar and wind power fluctuate in intensity due to the weather and seasonal changes. Therefore, a reliable backup system is necessary for renewable energy generating stations that are not connected to a national power grid. These systems consist of a variety of power control methods and storage equipment which include battery banks and diesel generators among others. The power systems that are connected to the national grid don't have this problem because, in most cases, there are many different sources of power contributing to the national electricity supply. There are several types of hybrid energy systems such as windsolar hybrid, solar-diesel, wind-hydro and wind-diesel. The design of a system or the choice of energy sources depends on several considerations. The factors affecting the choice of hybrid power technology can also tell us why people use hybrids and some of the advantages. The main factors are cost and resources available. The cost hybrid power technology greatly affects the choices people make, particularly in developing countries. This also depends on the aim of the project. People who are planning to set up a hybrid energy project for their own use often focus on lowering the total investment and operational costs while those planning to generate electricity for sale focus on the long-term project revenue. As such, systems that incorporate hydrogen storage and fuel cells are not very common with small scale projects. The viability of one hybrid energy system over another is usually pegged on the cost of generating each kilowatt. The availability of the natural resources plays an enormous part when selecting the components of a hybrid energy system the right power generation location and method must be chosen. Often, a hybrid system is opted for because the existing power resource is not enough to generate the amount of power needed which is often the case when using micro-hydro plants. In some developing countries, such as parts of Ethiopia, a wind-solar hybrid power system, consisting of wind turbines and solar photovoltaics was found to be most viable. This was because the wind resource alone was not sufficient to meet the electric load. Solar P.V. cells were very expensive, so it wasn't feasible for the project developers to use solar power alone. Hybrid systems are most suitable for small grids and isolated or stand-alone systems as hybrid power generation is, by definition, a solution for getting around problems where one energy source isn't sufficient. The popularity of hybrid energy systems has grown so much that it is now a niche-industry in itself with custom systems being engineered for specific functions. For CSPs to claim their share in the ensuing energy revolution, concerted action is required over the next ten years by scientists, industry, governments, financing institutions and the public.

INDUSTRY NEWS:

Completion of Concentrating Solar Power Plants in India Delayed At least half of the U.S. $1.4 billion projects won't be built on time India, planning $1.4 billion of solar-thermal power stations, expects half of the projects to be delayed and some to be scrapped as U.S. supplies stall and dust-clouds diffuse the radiation required to drive generation. Of the 500 megawatts of projects due to be completed in February and May, only a third of that capacity may be ready on time, said Tarun Kapoor, joint secretary at the Ministry of New and Renewable Energy. Three of the 10 ventures are unlikely to be built, he said in an interview in New Delhi. The delays are a blow to General Electric Co., Siemens AG and Areva SA, which have acquired stakes in solar-thermal equipment makers since 2009 on the expectation the technology could compete with coal- and gas-fired power. Solar-thermal plants, which focus sunlight on liquids to produce steam and drive turbines, can store energy, allowing electricity to be delivered around the clock. Developers have delayed five plants, or 320 megawatts of capacity, because they've been unable to get heat-transfer fluid from the only two U.S. suppliers, according to Kapoor, who said those suppliers are backed up with orders. Companies such as Lanco Infratech Ltd. have also reported high dust levels in the desert areas where many plants are built. The dust particles scatter the sun's rays, reducing the direct solar radiation that can reach a plant's receptors. “Solar-thermal projects are heavy engineering projects, carried out in hostile conditions, and even the most experienced firms have built only a few, and not always with perfect success,” said Jenny Chase, head of solar research at Bloomberg New Energy Finance. “It's not surprising delays are common.” Areva has already scrapped a 250-megawatt solar-thermal complex in Australia this month after failing to get government funding. In India, the solar-thermal program had generated orders for about $150 million of turbines from suppliers including GE and Siemens, which could now be affected. Torsten Wolf, a spokesman for Munich-based Siemens, said he couldn't immediately comment. GE's India office also declined to comment.

The government hasn't decided whether it'll penalize projects that miss completion deadlines, according to

Kapoor. “We don't want them to fail,” he said. “We want to see them built.” India has promoted solar energy to boost generation capacity and cut chronic electricity shortages. Insufficient coal and gas for conventional thermal-power plants has prompted the central government to hold clean-energy capacity auctions as it pursues a solar output target of 20,000 megawatts by 2022, a 20-fold increase. Solar-thermal technology is valued for its ability to store energy, while solar photovoltaic plants convert sunlight directly into electricity and need batteries for storage. Both technologies have benefited from government incentives. Areva predicted in 2010 that global use of solar-thermal power would grow about 30-fold this decade. Even with state support, some developers have favored the alternative photovoltaic technology after the cost of the silicon panels it uses plunged 56 percent in two years amid a supply glut. “The declining cost of photovoltaic technology puts pressure on governments and developers planning solar-thermal electricity generation,” said BNEF's Chase, who calculates solar-thermal power costs at a minimum $140 a megawatt-hour, compared with $100 for photovoltaic. “It's not always easy to justify the extra cost.”

Reliance, Godawari A Reliance Power Ltd. project using an Areva reflector system that doesn't require heat-transfer liquid is proceeding on time, Kapoor said. Godawari Power & Ispat Ltd. also expects to meet the May deadline after obtaining supplies of the fluid, he said. Aurum Renewable Energy Pvt., which also planned to use a reflector system, hasn't made any progress, he said. Aurum Renewable, which was considering turbines from GE, Siemens and Sumitomo Heavy Industries Lid's Shin Nippon Machinery Co. for its 20-megawatt project, didn't respond to emails and phone calls seeking comment. Lanco didn't respond to requests for confirmation of a delay to its 100-megawatt plant. The company is also the contractor for KVK Energy & Infrastructure Pvt.'s 100-megawatt project. Siemens decided to offer its unprofitable solar-energy division for sale in October. The business grew out of the acquisitions of solar-thermal companies, including Solel Solar Systems for $418 million in 2009.

India emerging as one of the leading solar PV markets in the world

India is emerging as one of the leading solar PV markets in the world as the country is blessed with immense potential for solar energy as most of the states have more than 300 sunny days and the specific average annual solar energy yield in India is estimated between 1700 1900 kWh per kWp. Indian Solar power has the potential to generate 50,000 MW which would be enough to meet over 5% of power requirement by 2022. Solar power has emerged as one of the key renewable sources and presents an exciting opportunity for India. In past few years, the solar PV industry has experienced substantial growth primarily driven by favourable policies of central and state governments to support its development. The Gujarat State Solar Policy and the Centre's Jawaharlal Nehru National Solar Mission (JNNSM) are at the forefront of solar power development in India. As a result, power generation capacities from solar have increased from 20 MW in FY'2011 to nearly 940 MW in FY'2012 and by June 2012 it crossed 1 GW. Most of the installed capacity over 600 MW comes from Gujarat.

States like Tamil Nadu, Andhra Pradesh, Punjab, Jharkhand, Karnataka and Maharashtra are emerging as more prominent future PV installation destination for developers and installers. These states have taken positive steps and introduced their own solar programmes as well as FITs, or are expected to announce their solar ambitions in the course of this year to exploit their solar potential. Along with grid connected solar PV installation, Indian PV market represent huge potential for off-grid application too. The JNNSM programme targets off-grid electrification about 200 MW expected by 2013, 1 GW by 2017 and a cumulative installation over 2 GW until 2022. This exhibits huge potential market for off-grid, stand along and hybrid systems. This market segment that is quite specific to emerging markets could kick-off PV installations faster than expected. (Source: www.kuickresearch.com)

MNRE Sanctions Funds to 41 Cities Under “Development Of Solar Cities” Programme The Ministry of New and Renewable Energy (MNRE) is implementing a Scheme on 'Development of Solar Cities' which provides support for 60 cities to develop as Solar Cities in the country. The Ministry has given sanctions for 41 cities for developing as Solar Cities. Gandhinagar, Nagpur, Chandigarh and Mysore are being developed as Model Solar Cities. The Ministry has approved the Master Plants for the 28 Cities and the project installations have already started in few cities. In pursuance of the programme, a one day 'National Meet on Solar Cities' was inaugurated by Shri. Gireesh B. Pradhan, Secretary, Ministry of New and Renewable Energy on 22nd November 2012, at India International Centre, New Delhi. The Secretary asked the Municipal Corporations to enhance the use of renewable energy in their area and save the fossil fuel based energy. They can amend the building bye-laws suitably to promote the solar water heaters, solar SPV rooftop systems, kitchen waste based plants in the various establishments of the city. Smt.

Nisha Singh Joint Secretary, Ministry of Urban Development, emphasized the need for the concerned Ministries to work in coordination with each other. About 150 persons actively participated in the one day event including the representatives of Municipal Corporations, Developers, Financial I n s t i t u t i o n s , International Agencies, Manufactures, Investors, Technology Providers and State Nodal Agencies, banks etc. The aim of this meet was to discuss the “Ways Forward” after Master Plan for execution of renewable energy/energy efficiency related projects in respective solar cities. The Municipal Commissioners of Thane, My sore and Shimla actively participated in the event.

Renewables take their place in the Sun…

According to World Energy Outlook 2012, a steady increase in hydropower and the rapid expansion of wind and solar power has cemented the position of renewables as an indispensable part of the global energy mix; by 2035, renewables account for almost one-third of total electricity output. Solar grows more rapidly than any other renewable technology.

2030, the UN Year of Sustainable Energy for All has generated welcome new commitments towards this goal. But much more is required. In the absence of further action, nearly one billion people will be without electricity and 2.6 billion people will still be without clean cooking facilities in 2030. Nearly $1 trillion in cumulative investment is needed to achieve universal energy access by 2030.

Renewables become the world's second-largest source of power generation by 2015 (roughly half that of coal) and, by 2035, they approach coal as the primary source of global electricity. Consumption of biomass (for power generation) and biofuels grows four-fold, with increasing volumes being traded internationally. Global bioenergy resources are more than sufficient to meet our projected biofuels and biomass supply without competing with food production, although the land use implications have to be managed carefully. The rapid increase in renewable energy is underpinned by falling technology costs, rising fossilfuel prices and carbon pricing, but mainly by continued subsidies: from $88 billion globally in 2011, they rise to nearly $240 billion in 2035. Subsidy measures to support new renewable energy projects need to be adjusted over time as capacity increases and as the costs of renewable technologies fall, to avoid excessive burdens on governments and consumers.

Water needs for energy production are set to grow at twice the rate of energy demand. Water is essential to energy production: in power generation; in the extraction, transport and processing of oil, gas and coal; and, increasingly, in irrigation for crops used to produce biofuels. We estimate that water withdrawals for energy production in 2010 were 583 billion cubic metres (bcm). Of that, water consumption the volume withdrawn but not returned to its source was 66 bcm. The projected rise in water consumption of 85% over the period to 2035 reflects a move towards more water-intensive power generation and expanding output of biofuels.

Despite progress in the past year, nearly 1.3 billion people remain without access to electricity and 2.6 billion do not have access to clean cooking facilities. Ten countries four in developing Asia and six in sub-Saharan Africa account for two-thirds of those people without electricity and just three countries India, China and Bangladesh account for more than half of those without clean cooking facilities. While the Rio+20 Summit did not result in a binding commitment towards universal modern energy access by

Water is growing in importance as a criterion for assessing the viability of energy projects, as population and economic growth intensify competition for water resources. In some regions, water constraints are already affecting the reliability of existing operations and they will increasingly impose additional costs. In some cases, they could threaten the viability of projects. The vulnerability of the energy sector to water constraints is widely spread geographically, affecting, among others, shale gas development and power generation in parts of China and the United States, the operation of India's highly water-intensive fleet of power plants, Canadian oil sands production and the maintenance of oil-field pressures in Iraq. Managing the energy sector's water vulnerabilities will require deployment of better technology and greater integration of energy and water policies.

Concentrating Solar Power: World's largest linear fresnel solar thermal power station commences operation in Spain

Novatec Solar_30 MW Solar Thermal Power Station_PE 2_Spain The 30 MW solar thermal power station built by Novatec Solar GmbH (Karlsruhe, Germany) using its proprietary solar field technology, has been completed and is in operation. PE2's solar boiler includes a mirror surface of 302,000qm making it the world's largest operational solar thermal power station based on linear Fresnel collector technology, Novatec Solar emphasizes. The PE2 solar boiler consists of 28 rows of linear Fresnel reflectors, each approximately 950 meters long. The mirrors, which are installed approximately one meter above ground, reflect the sunlight onto a receiver located eight meters above the ground. Sunlight heats up the water in the receiver and turns it to steam, which powers two 15 MW turbine generator units. The plant is connected to the Spanish electricity grid. Air-cooled condensers are used to re-circulate water back to the solar boiler in order to conserve valuable water in this arid region. Mirror cleaning is performed by automated cleaning robots that use very little water.

Clean energy for 12,000 Spanish households PE2's 30 MW electrical output is generated exclusively by solar power and will produce approximately 50 million kW hours of electricity per year. Annually, this equates to a reduction of carbon dioxide emissions of over 16,000 metric tonnes and enough clean energy to power 12,000

Spanish households. Novatec Solar was the EPC contractor for the project and was responsible for the construction and commissioning of PE2. The Spanish UTE Errado PE2, a TSK and OHL joint venture, built the balance of plant. The project company Tubo Sol PE2, S.L. is owned by the Swiss utilities Elektra Baselland (51%), Industrielle Werke Basel (12%), Elektrizitätswerke der Stadt Zürich (10%), Elektrizitätswerke des Kantons Zürich (6%), Energie Wasser Bern (6%) and Novatec Solar (15%).

PE2 will operate under the Spanish feed-in tariff system A consortium of Bayerische Landesbank, Commerzbank and Rabobank arranged PE2's limited recourse project finance debt funding in May 2011 which included export credit insurance provided by Euler Hermes. The plant is registered under the “Special Regime” established by the Spanish Royal Decree RD 661/2007 and will operate under the Spanish feed-in tariff system. “The successful commissioning of PE2 is a major milestone for Novatec Solar,” says Guido Belgiorno-Nettis AM, Chairman of the Shareholders Committee of Novatec Solar. “It confirms the reliability, competitiveness and scalability of our Fresnel technology. In partnership with ABB, we look forward to continuing to introduce our solar boiler technology into our target markets.”

NEW TECHNOLOGY: Nanoparticles Make Steam without Bringing Water to a Boil “A new trick could reduce the energy needed for many industrial processes and make solar thermal energy much cheaper. Why and How It Matters?”

“It's a new way to make steam without boiling water,” says Naomi Halas, director of the Laboratory for Nanophotonics at Rice University. Halas says that the work “opens up a lot of interesting doors in terms of what you can use steam for.” The new technique could, for instance, lead to inexpensive steamgeneration devices for small-scale water purification, sterilization of medical instruments, and sewage treatment in developing countries with limited resources and infrastructure. The use of nanoparticles to increase heat transfer in water and other fluids has been well studied, but few researchers have looked at using the particles to absorb light and generate steam.

Rice University's Neumann (left) and Halas pose next to a test rig that directs sunlight onto an aqueous nanoparticle suspension (in glass portion of apparatus) and rapidly generates steam without boiling the water. Credit: Jeff Fitlow/Rice University Steam is a vital part of many different industrial processes, including solar thermal power generation. Steam is a key ingredient in a wide range of industrial and commercial processesincluding electricity generation, water purification, alcohol distillation, and medical equipment sterilization. Generating that steam, however, typically requires vast amounts of energy to heat and eventually boil water or another fluid. Now researchers at Rice University have found a shortcut. Using light-absorbing nanoparticles suspended in water, the group was able to turn the water molecules surrounding the nanoparticles into steam while scarcely raising the temperature of the remaining water. The trick could dramatically reduce the cost of many steam-reliant processes.

The Rice team used a Fresnel lens to focus sunlight on a small tube of water containing high concentrations of nanoparticles suspended in the fluid. The water, which had been cooled to near freezing, began generating steam within five to 20 seconds, depending on the type of nanoparticles used. Changes in temperature, pressure, and mass revealed that 82% of the sunlight absorbed by the nanoparticles went directly to generating steam while only 18 % went to heating water.

In the current study, Halas and colleagues used nanoparticles optimized to absorb the widest possible spectrum of sunlight. When light hits the particles, their temperature quickly rises to well above 100 °C, the boiling point of water, causing surrounding water molecules to vaporize. Precisely how the particles and water molecules interact remains somewhat of a mystery. Conventional heat-transfer models suggest that the absorbed sunlight should dissipate into the surrounding fluid before causing any water to boil. “There seems to be some nanoscale thermal barrier, because it's clearly making steam like crazy,” Halas says. The system devised by Halas and colleagues exhibited an efficiency of 24% in converting sunlight to steam. Todd Otanicar, a mechanical engineer at the University of Tulsa who was not involved in the current study, says the findings could have significant implications for large-scale solar thermal energy generation. Solar thermal power stations typically use concentrated sunlight to heat a fluid such as oil, which is then used to heat water to generate steam. Otanicar estimates that by generating steam directly with nanoparticles in water, such a system could see an increased efficiency of 3 to 5% and a cost savings of 10% because a less complex design could be used. Otanicar cautions that durabilitythe ability of nanoparticles to repeatedly absorb sunlight and generate steamstill has to be proved, but adds that the 24% efficiency achieved in the current study is encouraging. “It's just the beginning for optimizing this approach,” he says.

Improving thermal energy storage tanks with a concrete layer Panneer Selvam, center, Micah Hale, left, and Matt Strasser display the thermocline energy storage test system outside the Engineering Research Center in south Fayetteville.

or are hazardous to storage tanks. For an example, the most efficient and least expensive method of packed rock use as media leads to thermal ratcheting an event where stress during the thermal cycling where expansion and contraction causes the tank walls to break. Selvam and doctoral student Matt Strasser came up with a solution by designing a structured thermocline system that uses parallel concrete plates instead of packed rock inside a single storage tank. Thermocline systems are units with distinct boundaries separating layers that have d i f f e r e n t temperatures.

Panneer Selvam, center, Micah Hale, left, and Matt Strasser display the thermocline energy storage test system outside the Engineering Research Center in south Fayetteville. Engineering researchers at the University of Arkansas came up with a thermal energy storage system that performs as a viable alternative to other currently available methods used to store energy collected from solar panels. Use of the newly developed design could increase annual energy production while significantly decreasing production costs of concentrated solar power plants, while ensuring longer operation without disastrous breakdowns. “The most efficient, conventional method of storing energy from solar collectors satisfies the U.S. Department of Energy's goal for system efficiency”, said Panneer Selvam, professor of civil engineering. “But there are problems associated with this method. Filler material used in the conventional method stresses and degrades the walls of storage tanks. This creates inefficiencies that aren't calculated and, more importantly, could lead to catastrophic rupture of a tank.” Current energy storage methods rely on molten salts, oils or beds of packed rock as media to conduct and maintain heat inside thermal energy storage tanks. Although these methods are found to be efficient, they are either expensive

The plates were made from a special mixture of concrete developed by Micah Hale, University of Arkansas associate professor of civil engineering. The mixture has survived temperatures of up to 600°C (1,112°F). The storage process takes heat, collected in solar panels, and then transfers the heat through steel pipes into the concrete, which absorbs the heat and stores it until it can be transferred to a generator. Modeling results showed the concrete plates conducted heat with an efficiency of 93.9%, which is higher than the Department of Energy's goal and only slightly less than the efficiency of the packed-bed method. Tests also confirmed that the concrete layers conducted heat without causing damage to materials used for storage. In addition, energy storage using the concrete method cost only $0.78 per kilowatt-hour, far below the Department of Energy's goal of achieving thermal energy storage at a cost of $15 per kilowatt-hour. “Our work demonstrates that concrete is comparable to the packed-bed thermocline system in terms of energy efficiency”, said Selvam, who also directs the university's Computational Mechanics Laboratory. “But the real benefit of the concrete layers is that they do not cost a lot to produce compared to other media, and they have the unique ability to conduct and store heat without damaging tanks. This factor alone will increase production and decrease operating expenses for concentrated solar power plants.”

Storing solar energy indefinitely now possible thanks to carbon nanotubes The idea of reversibly storing solar energy in chemical bonds is gaining a lot of attention these days. A group of researchers from MIT have developed a novel application of carbon nanotubes which shows potential as an effective approach to store solar energy for use whenever it's needed.

constrain their physical structure, the resulting molecules gain new properties that aren't available in the separate materials. Thermo-chemical storage of solar energy uses a molecule whose structure changes when exposed to sunlight, and can remain stable in that form indefinitely. Activated by a stimulus (such as a small temperature change or a flash of light), it can quickly release its stored energy in a burst of heat. The key of controlling solar thermal storage is an energy barrier separating the two stable states the molecule can adopt. If the barrier was too low, the molecule would easily return to its â&#x20AC;&#x153;unchargedâ&#x20AC;? state, failing to store energy for long periods. On the other hand, if the barrier was too high, the molecule would not be able to easily release its energy when needed.

The method simplifies the process by combining energy harvesting and storage into a single step.

While their findings show the energy-storage capability of a specific type of molecule, the researchers claim the way the material was designed involves a general concept that can be applied to many new materials. Many of these have already been synthesized by other researchers for different applications, and would simply need to have their properties fine-tuned for solar thermal storage.

Previously, the chemicals used to achieve this type of

One of the great advantages of this approach in harnessing solar

conversion and storage either degraded within a few cycles, or included the element ruthenium, which is rare and expensive. Jeffrey Grossman, the Carl Richard Soderberg Associate Professor of Power Engineering at MIT, and postdoc Alexie Kolpak have created a new material which is a combination of carbon nanotubes and a compound called azobenzene.

energy is the fact that the material is capable to both converts and stores energy. It's robust, it doesn't degrade, and it is cheaper than the ruthenium-containing compound, but it also is more 10,000 efficient at storing energy in a given amount of space. Solar Tunnel' To Power 4,000 Trains Annually.

Produced by using nanoscale templates to shape and

Europe's first “solar tunnel” is providing power to high-speed trains running between Paris and Amsterdam…

The 3.6-kilometer (2.2-mile) tunnel, built to protect trains from falling trees as they pass through an ancient forest near Antwerp, is covered with solar cells and could generate 3.3 MWh of electricity annually. Enfinity, the company behind the project, says that's equivalent to the average annual consumption of nearly 1,000 homes. It also claims that the tunnel will decrease CO2 emissions by 2,400 tons per year. “For train operators, it is the perfect way to cut their carbon footprints because you can use spaces that have no other economic value and the projects can be delivered within a year because they don't attract the protests that wind power does,” Bart Van Renterghem, the UK head of Enfinity, told the Guardian. The $22.9 million project uses 16,000 solar panels covering 50,000 square meters (roughly 538,000 square feet), which is about the size of eight football pitches. They will provide enough electricity to power 4,000 trains a year. The first of those trains left Antwerp on Monday, filled with commuters and students.

The trains tap into the solar energy as they pass through the tunnel at 186 mph. The electricity also provides power for lighting, signals and other infrastructure. “By using electricity generated on-site, we eliminate energy losses and transport costs,” says Enfinity chief executive Steven De Tollenaere. Enfinity has said there had been plans afoot to introduce similar solar infrastructure in the UK but recent cuts to financial incentives would make the projects “unviable.” “Apparently the UK Government is more concerned about the Treasury than the mid and long-term carbon reduction objectives that we have,” van Renerghem said. “Personally, I think it is short-sighted.” Energy minister Greg Barker MP said in response: “We want to create a long-term platform for growth. Now that does mean that, in the short term, large-scale schemes aren't going to get the sort of funding that we see in Belgium currently. There are a lot of exciting things in solar but we have got to think it through so that we get good value for the bill-payers as well as a great deal for the solar pioneers.”

Dr. Manmohan Singh, Prime Minister of India National Action Plan on Climate Change "Our vision is to make India's economic development energy-efficient. Over a period of time, we must pioneer a graduated shift from economic activity based on fossil fuels to one based on nonfossil fuels and from reliance on no-renewable and depleting sources of energy to renewable source of energy. In this strategy, the sun occupies centre-stage, as it should, being literally the original source of all energy. We will pool our scientific, technical and managerial talents, with sufficient financial resources, to develop solar energy as a source of abundant energy to power our economy and to transform the lives of our people. Our Success in this endeavor will change the face of India. It would also enable India to help change the destinies of people around the world."

Malaysia: 8 MW of solar PV FiT quota up for grabs Staff Writer The Sustainable Energy Development Authority Malaysia (Seda Malaysia) has opened up since September 24, 2012, 8 MW of solar photovoltaic (PV) feed-in tariff (FiT) quota for residential homeowners under its new 2,000 Solar Home Rooftop Programme. Applications for the FiT have started at 8am on September 24th 2012 Of the 8 MW, 2 MW will be for the fourth quarter of 2012 (estimated to cover 500 homes) and 6 MW is for 2013 (to cover 1,500 homes). To encourage participation, applicants under the programme need not show proof of financial ability.

including funding, to support the 100,000 homes is being looked at. Get a service provider Applicants are advised to engage a solar PV service provider for technical and financial details required for their submissions, says Badriyah. The directory of service providers was made available on Seda Malaysia's website from September 18th. “It must be individual home applications for private residential properties,” Fong says, adding that management committees of condominiums and apartments will not be eligible for this homeowners' programme, and would need to wait for allocation under different categories. Seda Malaysia have also conducted briefings in Putrajaya (September 18th), Malacca (September 20th), and Penang (September 27th) to facilitate better understanding on the procedures and requirements for e-FiT applications. “This is part of our public engagement to brief them on the procedures and requirements,” Fong says. New degression rates for solar

Seda Malaysia chairman Tan Sri Fong Chan Onn announced the details of the programme at the authority's Eid Al-Fitri open house on September 13th. In late July 2012, Fong announced that the government wants 2,000 homes to be equipped with solar PV by 2012, and another 10,000 by 2013, but he revised it downwards seven weeks later to 2,000 for the next 15 months until end-2013. To ensure parity, applicants can only make an application a day, and each application is allowed a maximum of 12 kW. To put this in context, a double-storey house rooftop can usually accommodate a 4 kW system (Note: 1 kW of PV installation requires about 10 sq m of space).

Seda chief executive officer Badriyah Abdul Malek says the 2,000 homes programme is part of a more ambitious programme for 100,000 homes but the authority will kick off with the 2,000 homes programme while the infrastructure,

The new FiT quotas (for biogas, biomass, mini hydro and solar PV for bigger and commercial installations) for the third quarter of 2012 and degression rates for solar have been announced at the International Sustainable Energy Summit 2012 (ISES 2012) on November 7th and 8th. Changes in subisidiary legislations affecting new applicants were also be announced then. Funding is biggest obstacle to getting more to set up solar PV on their roofs. The cost of installing a rooftop system is between RM10,000 and RM12,000 (around Indian Rupees 2,16,000 or US $3922) per kW. Badriyah says most homeowners who are already enjoying the solar FiT selffunded their installations. She says Seda Malaysia is still in talks with banks to encourage them to give out loans for PV installations, and some like CIMB, Maybank, HSBC, Bank of China, Ambank and Bank Pembangunan Malaysia have shown interest. (Courtesy: Green Prospects Asia.Com)