April-May 2012 issue by EnergyBlitz

Solar Power Tree - a new concept of harnessing solar power in a smaller space By Dr. S.N. Maity

Green Business Ideas: Cheap Solar Power is possible By Sandeep Goswami

Elements for an Energy Efficient House By Dr. L. Ashok Kumar

Why desalination plants successful around the world? And, why can't India take a serious look at this technology? By Ramanathan Menon

Concentrated Solar Power (CSP) Technology: Sahara Forest Projects new source of fresh water, food and energy By Staff Writer

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An Analysis of India's Biodiesel Program 34 By Salman Zafar Extraction process of biofuel from Algae and its importance By Er. R.V.Ramana Rao B.E.,B.L. FIE

Prospects for Renewable Energy in Commercial Marine Propulsion By Harry Valentine WATER: Essence of human and industrial survival By A.K.Shyam

There is a lot of water on Earth, but more than 97% of it is salty and over half of the remainder is frozen at the poles or in glaciers. Meanwhile, around a fifth of the world's population suffers from a shortage of drinking water and that fraction is expected to grow. One answer is desalinationbut it is an expensive answer because it requires a lot of energy. Existing desalination plants work in one of two ways. Some distil seawater by heating it up to evaporate part of it. They then condense the vapoura process that requires electricity. The other plants use reverse osmosis. This employs high-pressure pumps to force the water from brine through a membrane that is impermeable to salt. That, too, needs electricity. Even the best reverse-osmosis plants require 3.7 kilowatt hours (kWh) of energy to produce 1,000 litres of drinking water. Recent researches indicate that we can produce that much fresh water with less than 1 kWh of electricity, and no other paid-for source of power is needed. This process is fuelled by concentration gradients of salinity between different vessels of brine. These different salinities are brought about by evaporation. The process begins by spraying seawater into a shallow, black-bottomed pond, where it absorbs heat from the atmosphere. The resulting evaporation increases the concentration of salt in the water from its natural level of 3.5% to as much as 20%. Low-pressure pumps are then used to pipe this concentrated seawater, along with three other streams of untreated seawater, into the desalting unit. Salt is made of two ions: positively charged sodium and negatively charged chloride. These flow in opposite directions around the circuit. Each of the four streams of water is connected to two neighbours by what are known as ion bridges. These are pathways made of polystyrene that has been treated so it will allow the passage of only one sort of ioneither sodium or chloride. Sodium and chloride ions pass out of the concentrated solution to the neighbouring weak ones by diffusion though these bridges (any chemical will diffuse from a high to a low concentration in this way). The trick is that as they do so, they make the low-concentration streams of water electrically charged. The one that is positive, because it has too much sodium, thus draws chloride ions from the stream that is to be purified. Meanwhile, the negative, chloride-rich stream draws in sodium ions. The result is that the fourth stream is stripped of its ions and emerges pure and fresh. It is a simple idea that could be built equally well on a grand scale or as rooftop units the size of refrigerators. Of course, a lot of clever engineering is involved to make it work, but the low pressure of the pumps needed (in contradiction to those employed in reverse osmosis) means the brine can be transported through plastic pipes rather than steel ones. Since brine is corrosive to steel, that is another advantage. Moreover, the only electricity needed is the small amount required to pump the streams of water through the apparatus. All the rest of the energy will come free, via the Air and from the Sun!!

Solar Power Tree - a new concept of harnessing solar power in a smaller space By Dr. S.N. Maity

Today there is a very big demand of an alternative power, a feasible source of non-conventional energies which would be purely green like solar energy, wind energy, tidal power, hydro power etc. Power from sun, as it is believed, is the only major alternative in comparison to other sources of renewable energies presently being tried to replace the conventional source of energies like coal, gas, oil, etc

following a pattern of spiralling phyllotaxy as found in a natural tree. It would take only 1% of land area in comparison to general PV-housing layout as being practiced at present. As example, it requires 0.4 Sq.M basements for 2.2 Kwh PV power, whereas by present general method of housing the PV arrays a land of 40 Sq.M is necessary for layout. It has so many other advantages to be discussed in this paper.

Then how to tap the power of sun for our purpose on earth? There are many ways being devised from time to time for absorbing the sun rays coming towards the surface of earth. But most simplest and efficient is the solid silicon crystalline photo voltaic (PV) module till date. The other methods of sun absorption like reflection, concentration, water heating etc. are the costly and complicated and efficiency is also less compared to crystalline photovoltaic (PV) modules laid direct to the sun. One need to erect the PV panels under the sun so that the surface of panel gets the maximum sun of the day being laid at an angle. Today the general method is that hut like inclined structures are made over the land surface to hold the solar panels. Now for an example, the generation of 2MW power from PV module system requires the land of 10 Acres approx. for housing the panels only. But land is going to be the greatest crisis of the earth rather it is already a burning crisis in most of the countries. The cultivable land which is going to be the costliest commodity in the near future, if used for other than agriculture, it will be uncountable loss. Our many national projects are facing the severe problem of acquisition of land. Therefore if land area is used for capturing the solar power it would never be cost effective and viable for the human society.

Introduction: There is a big hue and cry over energy crisis from all over the world mainly for two reasons, firstly the natural resources are going to be exhausted very soon and the other is whether we should continue with the available natural resources of carbonaceous compound which is posing threat of greenhouse gas effect to human being every day. People are trying over different sources to find out non conventional energies, mainly some sort of renewable source of energy or the green energy like solar energy, wind energy, tidal power, hydro power etc. Power from sun, as it is thought today, is the only major alternative in comparison to other sources of renewable energies presently being tried to replace the conventional source of energies like coal, gas, oil etc.

Therefore there is a need for devising a method and fabricating a suitable device so that the solar power can be absorbed without occupying much surface area, rather utilizing the minimum amount of land and the electricity must be economically viable... Here comes the idea of a Solar Power Tree a new invention of installing PV modules on a tall pole like structure with leaf like branches surrounding it

Then how to tap the power of sun to be absorbed for our purpose? There are many ways being devised time to time for absorbing the sun rays coming towards the surface of earth, but most efficient and easily available is the solid silicon crystalline photo voltaic (PV) module form till date. There are other forms like amorphous or thin film etc. But efficient most is t h e s o l i d crystalline PV cells for direct absorption of sun light. The other methods of sun absorption like reflection, concentration, water heating etc. are the costly and

complicated and efficiency is also less compared to PV modules.

Fig. 2 Conventional solar plant Fig. 3 Conceptual model of solar power tree

General methodology: In our country the solar power generation system are generally being designed by this type of solid crystalline (PV) in different places. One needs to erect the PV panels under the sun so that the surface of panel gets the maximum sun of the day being laid at an angle. The very common application of solar panel is that a poll of small height having one or two panels clamped on its top with a single or couple of lights (stand alone) fixed below to enlighten the roads etc. (Fig. 1). For more power in kilowatts it is required to have suitable structure over the landed area in an open space to hold the solar panels. Therefore hut like permanent fixed structure are made (Fig. 2) to lay the PV panel over them. Now for an example for the generation of 1MW power from PV module system i.e. conventional inclined hut like structures (Fig. 2 & 7) requires the land surface of 8 to 10 Acres approximately for housing the panels only. But land is going to be the greatest crisis of the earth rather it is already a burning crisis in most of the countries. One can find there are news of fights frequently between the farmers and the administration for acquisition of land for any industrial purposes. Again most of the agricultural areas are generally away from the conventional power plants and are in need of electricity. But again if you cover the agricultural land for laying solar panels then how cultivation would be possible? The cultivable land if used for other than agriculture it w o u l d b e uncountable loss. And thus many national projects are facing the severe problem of acquisition of land. Therefore if vast land is used for capturing the solar power it would never be cost effective and viable for the human society.

Need for new invention: Therefore there is a need for devising a method and fabricating a suitable device so that the solar power can be absorbed without occupying much surface area or land which is going to be the costliest commodity in the near future. Rather, the device and method should be such that it would be utilizing the minimum land for maximum solar power absorption by creating maximum solar surface and it was only possible by devising a holding system of PV modules with a vertical pole standing on the ground and holding the PV panels at a height. Here comes the idea of a device of installing a tall metallic pole of 50 to 70 feet height founded on a basement of (2 X 2) Sq. feet area, which will hold all the required panels on its body like a tree (Fig3,4&5). The surface land therefore is used only a maximum of 4 to 5 Square feet. Of course, it needs some base foundation for holding the taller pole but most of the foundation work will be below the ground surface. Fig. 4 Solar power tree for 2 KWh (Area 3 Sq. Ft) Uniqueness and Advantages: The uniqueness of this single pole/solar power tree system is that the solar PV modules will be fixed throughout the tall pole following a pattern of spiralling phyllotaxy with due adjustment of load distribution over the pillar for its balancing. At the same the pattern is so maintained that the top panels wouldn't obstruct the bottom ones and each panel of the tree would get the maximum sun in a day time. The other uniqueness is that all the Solar Panels will be hanging through their connecting stemsystem attached with the main trunk (Pole) and may be made flexible in all direction so that they can best avoid the wind pressure due to heavy

of paddy land are used for solar power tree plantation, the shadow being created by the panels would not touch the land in most of the cases (as the Solar Power Trees would be very tall) and even if it touches, it won't cover the surrounding field by its penumbra so that growth of plants would be restricted.

storm affecting over the main pole / trunk. The leaves (panels) would preferably be spring loaded and the Joints of stems would be flexible. The panels will be naturally facing towards the sun at an angle as required so that they can fix up maximum solar energy in a day time. The advantages of this system is that it takes about 1% of land area in comparison to general PV housing layout, as example it requires 0.5 Sq M basement for 2.2 KWH PV power (Fig. 8) whereas for the same solar power by present general method of housing the PV arrays, a land of 50 Sq M is necessary for layout (Fig. 7). The other advantage is that this system does not require the acquired big landed property at a single place, rather for this type of solar power generation the Road sides, the islands in between wide roads / highways, the boundary walls of paddy lands, the crossings of boundary walls etc. can be used. Another advantage is that even if the divider walls

The unique advantage is that because of pattern of laying of panels following phylotaxy of natural trees and using the small size panels, the shadows coming from the panels of upper level do not interfere with the lower panels in most of the daytime. If sometimes they obstruct the lower ones that cover only very small percentage of panel area and for a little while only. The dust deposition on the panels is a big problem for such type of solar power generation. Generally, as the panels of SPT are placed at higher height they are less subject to dust deposition. Again as the SPT structure is like a pagoda tree and an arrangement of water spraying from the top of the tree could make the panels clean if it works for a few minutes in the morning every day. There is a big advantage in laying of panels inherited in this device of SPT that all the panels can be laid in East West direction, unlike the general fixed hut like structure where they are laid in South North direction in general. An easy method can be devised with this SPT so that all the panels can be tilted around an angle of 450 as to get the maximum sun for whole the day. Instead of sophisticated electro-automated device, a simple mechanical device of pulling a rope can tilt all the panels from East West to West East direction to get the maximum sun path in a day quite economically. Fig. 9 Solar power tree is a tall single trunk with m u l t i - l e a v e s

Example: Fabrication, Installation and Commissioning of Solar Power Tree

This is a collection of 26 Nos. Solar PV Panels, which is mounted on a single tall pole with the help of suitable supporting arrangement. Total power generation is 2KWh at peak hour on a clear sunny

After erection the whole assembly is to be painted to prevent from corrosion. The whole assembly is to be anchored and

Civil Works

Foundation of Battery Bank

Foundation of Pole

day.   

grouted firmly at the site of erection. The arrangement maintains a Phyllotaxy pattern. The electricity so produced being stored in a battery bank of suitable capacity The battery bank being protected from overcharging by Auto Cut-off Mechanical System

The following drawing shows the General arrangement of the PV Panels, Panel Supports and the Pole. Altogether 26 Nos. of panels are arranged in a Phyllotaxy pattern. The Dimensions are tentative and may be deviated if required according to height of the pole.

Data Collection : The table given below shows the day wise variation and comparison of controller current between standard 40W panels fixed with an inclined hut like structure and similar type panels attached with the solar power tree under the invention. The data was collected for three days.

Conclusion: The solar power trees can be planted without any acquisition of vast land exclusively for this purpose in a particular place. They can be installed on the road sides as they consume around 4 Sq. Feet of area for a single tree. The village roads and the big boundary walls of paddy lands can provide sufficient space for planting solar power trees that can supply enough power for electrification of villages and irrigation activities. The state and national highways are big sources for Solar Power Tree (SPT) plantations. Two sides of single road high ways and the three sides of double road highways including Island in between can be utilised for solar power trees (Fig. 9). A simple calculation

shows that if the National Highway is used for plantation of solar power trees from Kolkata to Asansol which is around 300 kms in length it would be possible to produce 110 MW by installing solar power trees of 2KW capacity through the road sides at a certain interval (say 15 meter between two trees). This would actually require 660 Acres of land for the same power generation at a single place by the existing method of laying out solar panels in a conventional way i.e. over the roofs of low height fixed structures. Hopefully if this new method of SPT plantation is adopted widely it would be possible to produce sufficient energy and to satisfy the demand of power for the world keeping the best ecological balance and preserving the nature as it is.

Dr. S. N. Maity is a Chief Scientist with CSIR-CMERI, Durgapur & Ex-Controller General of Patents Designs and Trademarks (CGPDTM). He has a Ph.D. (ENGG.) (Design & Development of Mechanical Supports). Completed 55 R&D Projects as project leader/coordinator mainly on underground structure, mechanicalsupport design & solar projects; 62 Patents, 3 US & 5 European patents; Published 57 Technical papers; Tech. Transfer: 14 Patents Commercialised with earnings more than Rs.70 lakhs; CGPDTM: As Controller General of Patents Designs and Trademarks Could make Indian Patent system fastest in the world within a period of 13 months of deputation; Awards : i) CSIR Golden Jubilee CMRI Whitaker Award -1993-94; ii) NRDC Invention Award - Republic Day, 1995; iii) CSIR Technology Award 26th Sept., 1995; iv) National Design Award 2000, and V) Arya Bhatt Award 2006

Green Business Ideas: Cheap Solar Power is possible By Sandeep Goswami Most Small Companies who are installing roof top Solar Panels are doing so to get the Tax rebate in India. They are also doing it to "earn" Carbon Credits. For the lay business person "earning" carbon credits means "profit". While it cannot be true because the system of Carbon Credit fund is just to improve your IRR, and can't be found under BUA; I do not like to discourage this trend. W h y ? Simple - to earn Carbon Credits one has to do a C D M project. And I love that. Then if it c a n b e proven to be a valid project worthy of Carbon Credit funds, great! By that time they understand that, they do a good job and can see the benefits all around to bother much for the "profit" through CER's. If they get it its nice but the life-cycle benefits of a Green Building is consolation enough. But Carbon Credit can become profitable, at least with due diligence and revised thought by the CDM authority. And be given as an incentive to those who would be able to do rural electrification or as in the case of India, provide electricity in tier III towns for a decent time with the help of the wires and cables the Government of the day may have installed during the election years, but forget to insure supply of power on a regular basis once chosen to govern. Not because they chose not too, but during the heat of elections most forget that there is a term technical and/ or economic feasibility. But when did full truth ever help win an election in the World? Let us discuss an idea, about how we can make Solar Power at a cheaper cost. The life of a Solar panel is 25 years, but it is assumed that the efficiency drops to 80% in the 10th year. And by the first five years the RoI is achieved. Now as newer and more efficient panels are being produced, there could be a cause for worry that it would be more and more difficult to sell them, as the traditional first

enterprises to take up the challenge and having installed Solar Parks would still be holding on to the "old" SPV for its 25 year life span. So how does one make the Solar PV industries grow? How would the cost be covered and more efficient panels generating more power and consuming less space and lighter in weight too come into the market? One idea could be by selling old solar panels ! It is a great eco-idea and to encourage this, we need participation from all stake holders. Second sale is popular in automobile, mobile phone and many products, the market system is mature. All it needs is to tweak it to conform to the SPV industry. Imagine villages in India, Africa, Brazil and other developing nations who have a huge socio-economic gap among its Peoples and yet are emerging economies of the future; could create a Program of Activities where in a Public -Private partnership can be mooted and a viable business plan developed. From Village roofing; thus eliminating traditional thatch roof which is becoming more dearer as communities shift away from agrarian life-style and there is land use change; to community shelters for the destitute sleeping in the cold & rain; to roofing alternatives for very small-scale or cottage industries; to providing power to their electric stoves, thus eliminating the GHG from Gobar Gas plants the ideas can be many and each more practical and wonderful than the earlier. Now add to this the Green Climate Fund and let the project proponents recoup some of their investment (which is lower to start with in second sale product) through Carbon Credit. Hope someone would develop on this idea and present it at the Rio+20 to be held in Rio de Janeiro, Brazil, on June 20-22, 2012.

Elements for an Energy Efficient House By Dr. L. Ashok Kumar

â&#x20AC;&#x153;Energy efficiency is the fastest, cheapest, and cleanest energy resource we have. Efficiency is not conservation or deprivation; it is getting what you want for less. Efficiency saves consumers and businesses money on their energy bills, reduces global warming pollution. It is Government policy to reduce energy use and carbon dioxide emissions from the burning of fossil fuels. Energy performance standards will continue to rise so that, by 2016, it is intended that new houses will be mainly passive, that is to say, designed to consume little or no energy in use. However, upgrading the thermal efficiency of the existing building stock presents a challenge, particularly where the building was built using traditional materials and construction methods and is of architectural or h i s t o r i c a l i n t e r e s t â&#x20AC;?

People enjoy old buildings for the sense of history they evoke, the craftsmanship they represent and for the solidity of their construction. However, there is sometimes a perception that old buildings are cold. It is true that they can sometimes be

draughty, and the degree of tolerance shown by their users is testimony to the value people place on architectural character and a sense of place, which compensate to quite a large extent for any shortcomings in comfort. Historically, heating solutions included a roaring fire or an ever-burning stove emitting pleasurable warmth. Of course, our forebears were somewhat hardier than ourselves, having different expectations in terms of heat and comfort. Extra clothing and bedclothes, hot water bottles and even different dietary habits played their part in keeping people warm in their day-to-day lives during the colder months. From the mid twentieth century onwards, the availability of cheap fossil fuels enabled an increasing number of households to avail of central heating, supplying heat to all rooms; a concept almost unheard of in earlier times. Today, however, there is an increasing awareness of the importance of energy and fuel conservation. In tandem with higher expectations in relation to the general warmth of the indoor environment, this

awareness has led to new standards and types of building construction intended to ensure that the energy consumed by a building during its useful life is minimised. These new standards in modern buildings have influenced the expectations of users of older buildings. When dealing with a historic building, there are other matters which the users and building professionals who care for old buildings should address, matters that are to do with the architectural character of a building, repair and maintenance issues, older forms of construction and the particular characteristics of traditional building materials. This article sets out to provide introductory guidance for owners and to act as an aide-memoire for building professionals and contractors. You have much to consider when designing and building a new energy-efficient house, and it can be a challenge. However, recent technological improvements in building elements and construction techniques also allow most modern energy-saving ideas to be seamlessly integrated into house designs while improving comfort, health, or aesthetics. And even though some energy-efficient features are expensive, there are others that many home buyers can afford. While design costs, options, and styles vary, most energyefficient homes have some basic elements in common: a well- constructed and tightly sealed thermal envelope; controlled ventilation; properly sized, high-efficiency heating and cooling systems; and energy-efficient doors, windows, and appliances. Thermal Envelope A thermal envelope is everything about the house that serves to shield the living space from the outdoors. It includes the wall and roof assemblies, insulation, air/vapor retarders, windows, and weather stripping and caulking. Wall and Roof Assemblies Most builders use traditional wood frame construction. Wood framing is a â&#x20AC;&#x153;tried and trueâ&#x20AC;? construction technique that uses a potentially renewable resourcewoodto provide a structurally sound, long-lasting house. With proper construction and attention to details, the conventional wood-framed home can be very energy- efficient. It is now even possible to purchase a sustainably harvested wood. Some of the available and popular energy- efficient

construction methods include the following: Optimum Value Engineering (OVE) This method uses wood only where it is most effective, thus reducing costly wood use and saving space for insulation. The amount of lumber has been determined to be structurally sound through both laboratory and field tests. However, the builder must be familiar with this type of construction to ensure a structurally sound house. Structural Insulated Panels (SIPs) These sheets are generally made of plywood or oriented-strand board (OSB) that is laminated to foam board. The foam may be 4 to 8 inches thick. Because the SIP acts as both the framing and the insulation, construction is much faster than OVE or stick framing. The quality of construction is often superior because there are fewer places for workers to make mistakes. Insulating Concrete Forms (ICF) Houses constructed in this manner consist of two layers of extruded foam board (one inside the house and one outside the house) that act as the form for a steel-reinforced concrete center. It's the fastest technique and least likely to have construction mistakes. Such buildings are also very strong and easily exceed code requirements for areas prone to tornadoes or hurricanes. Insulation An energy-efficient house has much higher insulation R-values than required by most local building codes. An R-value is the ability of a material to resist heat transfer, and the lower the value, the faster the heat loss. For example, a typical house in New York might have insulation of R-11 in the exterior walls and R-19 in the ceiling, while the floors and foundation walls may not be insulated. A similar, but well- designed and constructed house will have insulation levels that range from R-20 to R-30 in the walls and from R50 to R-70 in the ceilings. Carefully applied fiberglass batt or rolls, wet-spray cellulose, or foam insulation will fill wall cavities completely. Foundation walls and slabs should be as well insulated as the living space walls. Poorly insulated foundations have a negative impact on home energy use and comfort, especially if the family uses the lower parts of the house as a living space. Also, appliancessuch as domestic hot water

heaters, washers, dryers, and freezers that supply heat as a byproduct are often located in the basement. By carefully insulating the foundation walls and floor of the basement, these appliances can assist in heating the house. While most new houses have good insulation levels, it is often poorly installed. In general, gaps and compaction of insulation reduce its effectiveness. Air/Vapor Retarders Water vapor condensation is a major threat to the structure of a house, no matter what the climate. In cold climates, pressure differences can drive warm, moist indoor air into exterior walls and attics. The air condenses as it cools. The same can be said for southern climates, just in reverse. As the humid outdoor air enters the walls and encounters cooler wall cavities, it condenses into liquid water. This is the main reason why some buildings in the South have problems with mold and rotten wood after they're retro- fitted with air conditioners. A vapor retarder is a material or structural element that can be used to inhibit the movement of water vapor, while an air retarder can inhibit airflow, into and out of a house's envelope. How to design and install vapor retarders depends a great deal on the climate and on the chosen construction method. However, any water vapor that does manage to get into the walls or attics must be allowed to escape. Regardless of climate, water vapor migration should be minimized by using a carefully designed thermal envelope and sound construction practices. Systems that control air and water vapor movement in homes rely on the nearly airtight installation of sheet materials on the interior as the main barrier. The Airtight Drywall Approach (ADA) uses the drywall already being installed along with gaskets and caulking to create a continuous air retarder. In addition, seams where foundation, sill plate, floor joist header, and subfloor meet are also carefully sealed with appropriate caulk or gasket material. Consult your local building codes official on the best vapor retarder method to use in your area.

Windows The typical home loses more than 25 percent of its heat through windows. Even modern windows insulate less than a wall. Therefore, an energyefficient house in a heating-dominated climate should, in general, have few windows on its

northern, eastern, and western sides. Total window area should also not exceed 8 to 9 percent of the floor area for those rooms, unless the designer is experienced in passive solar techniques. If this is the case, then increasing window area on the southern side of the house to about 12 percent of the floor area is recommended. This is often called solar tempering.A properly designed roof overhang for south-facing windows will help prevent overheating in the summer. North, east, and west windows should have low Solar Heat Gain Coefficients (SHGC). South windows with properly sized overhangs should have a high SHGC to allow winter sun (and heat) to enter the house. The overhang blocks the high summer sun (and heat). If properly sized overhangs are not possible, a low SHGC glass should be selected for the south windows. At the very least, you should use windows (and doors) with an Energy Star label, which are twice as energy efficient as those produced 10 years ago, according to regional, climatic guidelines (note: houses with any kind of solar tempering have other guidelines). The best windows are awning and casement styles because these often close tighter than sliding types. In all climates, window glass facing south without overhangs can cause a problem on the cooling side that far exceeds the benefit from the winter solar gains. Weather stripping and Caulking You should seal air leaks everywhere in a home's thermal envelope to reduce energy loss. Good air sealing alone may reduce utility costs by as much as 50 percent. When compared to other houses of the same type and age. You can accomplish most air sealing by using two materials: caulking and weather stripping. Caulking can be used to seal areas of potential air leakage into or out of a house. And weather stripping can be used to seal gaps around windows and exterior doors. Controlled Ventilation Since an energy-efficient house is tightly sealed, it needs to be ventilated in a controlled manner. Controlled, mechanical ventilation prevents health risks from indoor air pollution, promotes a more comfortable atmosphere, and reduces air moisture infiltration, thus reducing the likelihood of structural damage. Furnaces, water heaters, clothes dryers, and bathroom and kitchen exhaust fans expel air from the house, making it easier to

depressurize an airtight house if all else is ignored. But natural-draft appliances may be back-drafted by exhaust fans, which can lead to a lethal buildup of toxic gases in the house. For this reason, sealedcombustion heating appliances, which use only outside air for combustion and vent combustion gases directly to the outdoors, are very important for ventilation energy efficiency and safety. Heat recovery ventilators (HRV) or energy recovery ventilators (ERV) are growing in use for controlled ventilation in airtight homes. These ventilators can salvage about 70 percent of the energy from the stale exhaust air and transfer that energy to the fresh air entering by way of a heat exchanger inside the device. They can be attached to the central forced air system or may have their own duct system. Other ventilation devices, such as through-thewall or “trickle” vents, may be used in conjunction with an exhaust fan. They are, however, more expensive to operate and possibly more uncomfortable to use because they have no energy recovery features to precondition the incoming air. Uncomfortable incoming air can be a serious problem in northern climates and can create moisture problems in humid climates. Therefore, this ventilation strategy is only for arid climates. Other systems pull outside air in with a small outside duct on the return side of the furnace Air leakage can occur in many places throughout a home Heat recovery ventilation Heating and Cooling Systems

Specifying the correct sizes for heating and cooling systems in airtight, energy-efficient homes can be tricky. Rule-of-thumb sizing is often inaccurate, resulting in wasteful operation. Conscientious builders and heating, ventilation, and airconditioning contractors size heating and cooling equipment based on careful consideration of the thermal envelope characteristics. Generally, energy-efficient homes require relatively small heating systems, typically less than 50,000 Btu/hour even for very cold climates. Some require nothing more than sunshine as the primary source of heat along with auxiliary heat from radiant infloor heating, a standard gas-fired water heater, a small boiler, a furnace, or electric heat pump. Any common appliance that gives off “waste” heat can also contribute significantly to the heating requirements for such houses. If an air conditioner is required, it's often a small unit and sufficient for all but the warmest climates. Sometimes only a large fan and the cooler evening air are needed to make the house comfortable. The house is closed up in the morning and stays cool until the next evening. Smaller-capacity heating and cooling systems are usually less expensive to buy and operate. This helps recover the costs of purchasing more insulation, and other energyefficient products, such as windows and appliances. Always look for the Energy Guide label on heating and cooling equipment. The label will rate how efficient it is as compared to others available on the market. In climates where summer cooling requirements dominate, light-colored materials and coatings (paint) on the exterior siding and roof can help reduce cooling requirements by up to 15 percent. Carefully selected and placed vegetation in any climate also contributes to reduced cooling and heating loads. Energy-Efficient Appliances Appliances with relatively high operating efficiencies are usually more expensive to purchase. However, higher efficiency appliances provide a measure of insurance against increases in energy prices, emit less air pollution, and are attractive selling points when the home is resold. Home buyers should invest in high-efficiency appliancessuch as water heaters, clothes washers and dryers, dishwashers, and refrigeratorsespecially if these appliances will be

used a great deal. Because all major appliances must have an Energy Guide label, read the label carefully to make sure you buy the most efficient appliance. To help you choose wisely, major appliances with an Energy Star label exceed the federal government's minimum efficiency standards by a large percentage. Energy-efficient lighting helps keep energy bills down by producing less heat and reducing cooling requirements. Fluorescent lighting, both conventional tube and compact, is generally the most energy- efficient for most home applications. Advantages and Disadvantages Houses that incorporate all of the above elements of energy efficiency have many advantages. They feel more comfortable because the additional insulation keeps the interior wall at a more comfortable and stable temperature. The indoor humidity is also better controlled, and drafts are reduced. A tightly sealed air/vapor retarder reduces the likelihood of moisture and air seeping through the walls. They are also very quiet because the extra insulation and tight construction helps to keep exterior noise out better. But these houses also have some potential disadvantages. They may cost more and take longer to build than a conventional home if there's a lack of builder familiarity with new construction techniques and products available on the market. Even though the house's structure may differ only slightly from conventional homes, the builder and contractors may be unwilling to deviate from what they've always done before. They may need more training if they have no experience with these systems.

evaluated to determine the optimum design and orientation for the house. There are energy-related computer software programs that can help with these evaluations. The design should accommodate appropriate insulation levels, moisture dynamics, and aesthetics. Decisions regarding appropriate windows, doors, and heating, cooling and ventilating appliances are central to an efficient design. Also the cost, ease of construction, the builder 's limitations, and local building code compliance should be competently evaluated. Some plans are relatively simple and inexpensive to construct, while others can be extremely complex and, thus, expensive. An increasing number of builders are participating in the federal government's Building America and Energy Star Homes programs, as well as local home energy rating programs, all of which promote the construction of energy-efficient houses. Many of these builders construct energy-efficient homes to differentiate themselves from their competitors. Construction costs can vary significantly depending on the materials, construction techniques, contractor profit margin, experience, and the type of heating, cooling, and ventilation system chosen. Because energyefficient homes require less money to operate, many lenders now offer energy-efficient mortgages (EEMs). EEMs typically have lower points and allow for the stretching of debt-toincome ratios. State and local government energy offices can be contacted for information on regionspecific financing. In the end, your energyefficient house will provide you with superior comfort and lower operating costs, not to mention a higher real estate market value.

Building and Buying Before you start a home-building project, the building site and its climate should be carefully

Dr. L. Ashok Kumar has completed his B.E., (EEE) from University of Madras and ME (Electrical Machines) from PSG College of Technology, Coimbatore, Tamil Nadu, and MBA (HRM) from IGNOU, New Delhi and PhD (Wearable Electronics) from Anna University, Chennai. He has both teaching and industrial experience of 14 years. At present he is working as Associate Professor in the Department of Electrical & Electronics Engg. He has got 11 research projects from various Government funding agencies. He has published 32 Technical papers in reputed National and International Journal and presented 65 research articles in International and National Conferences. He has received YOUNG ENGINEER AWARD from Institution of Engineers, India. He is a member of various National & International Technical bodies like ISTE, IETE, TSI, BMSI, ISSS, SESI, SSI & TAI. His areas of specializations are Wearable Electronics and Renewable Energy Systems. His contact: lak@eee.psgtech.ac.in - Mob # 098432 81115

Why desalination plants successful around the world? And, why can't India take a serious look at this technology? By Ramanathan Menon Minjur desalination plant is the largest desalination plant in India being built on a 60-acre site in Kattupalli village near Chennai

submarines. Most of the modern interest in desalination is focused on developing costeffective ways of providing fresh water for human use in regions where the availability of fresh water is, or is becoming, limited. Large-scale desalination typically uses extremely large amounts of energy as well as specialized, expensive infrastructure, making it very costly compared to the use of fresh water from rivers or groundwater. However, along with recycled water this is one of the few non-rainfall dependent water sources particularly relevant to countries like Australia which traditionally have relied on rainfall in dams to provide their drinking water supplies. The traditional process used in these operations is vacuum distillationessentially the boiling of water

â&#x20AC;?Water demand and supply have become an international issue due to several factors: global warming (droughts are more often in arid areas), low annual rainfall, a rise in population rates during last decades, high living standards, and the expansion of industrial and agricultural activities. Fresh water from rivers and groundwater sources are becoming limited and vast reserves of fresh water are located in deep places where economical and geological issues are the main obstacles. Therefore, it has turned into a competition to get this vital liquid and to find more feasible and economical sources that can ameliorate the great demand that the world is living nowadays and avoid water restrictions and service interruptions to domestic water supply. And, desalination is an excellent alternative for getting fresh waterâ&#x20AC;? Introduction Basics of desalination plants Desalination, desalinization, or desalinisation refers to any of several processes that remove some amount of salt and other minerals from water. More generally, desalination may also refer to the removal of salts and minerals, as in soil desalination. Water is desalinated in order to convert salt water to fresh water so it is suitable for human consumption or irrigation. Sometimes the process produces table salt as a by-product. Desalination is used on many seagoing ships and

at less than atmospheric pressure and thus a much lower temperature than normal. This is because the boiling of a liquid occurs when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature. Thus, because of the reduced temperature, energy is saved. A leading distillation method is multi-stage flash distillation accounting for 85% of production worldwide in 2004. Fresh drinking water from the ocean The principal competing processes use membranes to desalinate, principally applying reverse osmosis technology. Membrane processes use semipermeable membranes and pressure to separate salts from water. Reverse osmosis plant membrane systems typically use less energy than thermal

distillation, which has led to a reduction in overall desalination costs over the past decade. Desalination remains energy intensive, however, and future costs will continue to depend on the price of both energy and desalination technology. Cogeneration Cogeneration is the process of using excess heat from power production to accomplish another task. For desalination, cogeneration is the production of potable water from seawater or brackish groundwater in an integrated, or "dual-purpose", facility in which a power plant is used as the source of energy for the desalination process. The facility's energy production may be dedicated entirely to the production of potable water (a standalone facility), or excess energy may be produced and incorporated into the energy grid (a true cogeneration facility). There are various forms of cogeneration, and theoretically any form of energy production could be used. However, the majority of current and planned cogeneration desalination plants use either fossil fuels or nuclear power as their source of energy. Most plants are located in the Middle East or North Africa, due to their petroleum resources and subsidies. The advantage of dual-purpose facilities is that they can be more efficient in energy consumption, thus making desalination a more viable option for drinking water in areas of scarce water resources. In a December 26, 2007, opinion column in the The Atlanta Journal-Constitution, Nolan Hertel, a professor of nuclear and radiological engineering at Georgia Tech, wrote, "... nuclear reactors can be used ... to produce large amounts of potable water. The process is already in use in a number of places around the world, from India to Japan and Russia. Eight nuclear reactors coupled to desalination plants are operating in Japan alone ... nuclear desalination plants could be a source of large amounts of potable water transported by pipelines hundreds of miles inland.

Desalting is expensive and energy-intensive, according to Peter Gleick, president of the Pacific Institute, an environmental research group based in Oakland, Calif. The institute released a study on desalting in June 2006 that detailed its potential but also the hurdles to widespread use of the technology.

â&#x20AC;&#x153;Conservation and efficiency are cheaper at the moment,â&#x20AC;? Gleick said. To build a desalination plant and use the water locally costs about $1,000 per acre-foot, he said, or $3.06 for 1,000 gallons. Take, for example, the desalting plant recently built in Perth, Australia. It cost $357 million. It will desalt more than 26 million gallons of water a day, enough, on average, to serve about 58,300 homes. It also will use 23 megawatts of electricity produced from wind, as much as used by 17,250 average single-family homes. But the Perth plant like Yuma's and the many others like it across the United States and around the rest of the world also proves that desalination is a feasible option, proponents say. New Technologies High efficiency solar distillation unit In 2003, Zonnewater BV (The Netherlands) developed a prototype desalination unit based on solar energy (95% thermal solar energy and 5% photovoltaic or wind energy), suited for coastal areas with an average temperature of 30 deg Celsius. The prototype, installed on the Caribbean island of Bonaire, is a small 1 m3 greenhouse-type construction that produces 40 litres of water per day (lpd). The company says that 50 lpd per m3 is possible if use is made of internal condensation. The only competitor, Zonnewater claims, is a Japanese model that produces 10 lpd per m3. The unit consists of a glass greenhouse connected to a similar unit made of concrete and painted white. The high efficiency rate is a result of specialised electronic equipment used to enhance air circulation between the two sections. Periodic washing with salt water reduces the negative effect of solar reflection by the salt produced by the unit. In the next development phase, Zonnewater plans to optimise the design, develop a marketing strategy and reduce costs by using other materials. Solar desalination: vacuum system developed for small-scale applications The University of Florida's Solar Energy and Energy Conversion Laboratory (SEECL) has developed a low-cost gravity-induced vacuum solar desalination system suitable for remote areas. The vacuum is created by filling a 10 metre high U-

shaped pipe with water and placing it upside down, with one end of the pipe suspended in a tank of salt water and one in fresh water. The vacuum significantly lowers the boiling or evaporating temperature of the water that gets heated by a solar collector. The water is converted into steam in an evaporator that surrounds the U-shaped pipe, enters a condenser and is then collected in a tank. Tests on a small prototype revealed an energy efficiency of 90%, compared to 50% for conventional "flat basin" solar stills, according to SEECL director, Prof. Yogi Goswami. New desalination technology taps waste heat from power plants Desalination is often touted as one solution to the world's water woes, but current desalination plants tend to hog energy. In 2003, University of Florida researchers had developed a technology that can tap waste heat from electrical power plants as its main source of energy, an advance that could significantly reduce the cost of desalination in some parts of the world. “In the future, we have to go to desalination, because the freshwater supply at the moment can just barely meet the demands of our growing population,” said James Klausner, a UF professor of mechanical and aerospace engineering, whose research was funded by the U.S. Department of Energy. “We think this technology could run off excess heat from utility plants and produce millions of gallons each day,” said Klausner, lead author of an article on the system that appears in the current issue of the Journal of Energy Resources Technology. He co-invented the technology with fellow UF mechanical engineering professor Renwei Mei. More than 7,500 desalination plants operate worldwide, with two-thirds of them in the Middle East, where there often is no other alternative for fresh water, Klausner said. The technology is less common in North America, with plants located mostly in Florida and the Caribbean producing only about 12% of the world's total volume of desalinated water, he said. U.S. residents get less than 1% of their water from desalination plants, he said. The need for desalination is likely to grow, however, as the population increases and residents

consume more fresh water. In Florida, for example, desalination has been touted as one solution for metropolitan areas where freshwater resources are becoming ever scarcer. With more than 97% of the Earth's water supply composed of salt water, desalination is even more urgent in developing nations, such as China, Japan and India, Klausner said. “China has a large and growing demand, Japan has a large demand, the Middle East, Sub-Saharan Africa I look at it as a worldwide problem,” he said. Most commercial desalination plants now use either distillation or reverse osmosis, Klausner said. Distillation involves boiling and evaporating salt water and then condensing the vapor to produce fresh water. In reverse osmosis, high pressure pumps force salt water through fine filters that trap and remove waterborne salts and minerals. Boiling the vast amounts of water needed for the distillation process requires large amounts of energy. Reverse osmosis uses less energy but has other problems, including mineral buildup clogging the filters. That's the main technical issue plaguing the largest desalination plant in the United States, Tampa Bay Water's $108 million plant in Apollo Beach. Although it was supposed to produce 25 million gallons of freshwater each day, the plant, beset by technical and financial problems since opening in 1999, currently is shut down. Employing a major modification to distillation, Klausner's technology relies on a physical process known as mass diffusion, rather than heat, to evaporate salt water. In a nutshell, pumps move salt water through a heater and spray it into the top of a diffusion tower a column packed with a polyethylene matrix that creates a large surface area for the water to flow across as it falls. Other pumps at the bottom of the tower blow warm, dry air up the column in the opposite direction of the flowing water. As the trickling salt water meets the warm dry air, evaporation occurs. Blowers push the now-saturated air into a condenser, the first stage in a process that forces the moisture to condense as fresh water. Klausner said the key feature of his system is that it can tap warmed water plants have used to cool their machines to heat the salt water intended for desalination, turning a waste product into a useful

one. He has successfully tested a small experimental prototype in his lab, producing about 500 gallons of fresh water daily. His calculations show that a larger version, tapping the waste coolant water from a typically sized 100-megawatt power plant, has the potential to produce 1.5 million gallons daily. The cost is projected at $2.50 per 1,000 gallons, compared with $10 per thousand gallons for conventional distillation and $3 per thousand gallons for reverse osmosis. Because the equipment would have to extract as much heat as possible from the coolant water, it would need to be installed when a plant is built, he said. Another potential caveat is that a full-scale version of the mechanism would require a football field-sized plot on land, likely to be expensive in coastal areas where power plants are located, Klausner said. Presumably a utility would sell the fresh water it produces, recouping and then profiting from its investment, he said. Klausner said a miniature version of the full-scale system could be run using solar or other forms of heat, which might be useful for small towns or villages. UF has applied for a patent on the technology. Klausner's research was funded by a $200,000 grant from the Department of Energy. Desalination plants around the world “Desalination facilities exist in about 120 countries around the world. The capital and operating cost for desalination have tended to decrease over the years. Even though energy prices have increased the desalting cost have been decreasing. The cost of obtaining and treating water from conventional sources has tended to increase because of the increased levels of treatment being required in various countries to meet more stringent water quality standards. This rise in cost for conventionally treated water also is the result of an increased demand for water, leading to the need to develop more expensive conventional supplies since the readily obtainable water sources have already been used”

Many factors enter into the capital and operating costs for desalination: capacity and type of plants, plant location, feed water quality, labour cost, energy cost, financing cost, ease of concentrate disposal, level of instrumentation / automation and

plant reliability. However, as a guideline the reader can take the production cost of a brackish water desalination plant to be Rs. 10 to 15 per m3. The production cost for a sea water desalination plant varies between Rs. 40 to 50 per m3. Whereas, the production cost of desalted water from effluent varies from Rs. 15 to 50 per m3 depending upon the TDS load in the effluent stream. The world's largest desalination plant is the Jebel Ali Desalination Plant (Phase 2) in the United Arab Emirates. It is a dual-purpose facility that uses multi-stage flash distillation and is capable of producing 300 million cubic metres of water per year. By comparison the largest desalination plant in the United States is located in Tampa Bay, Florida, and operated by Tampa Bay Water, which began desalinating 34.7 million cubic meters of water per year in December 2007. The Tampa Bay plant runs at around 12% the output of the Jebel Ali Desalination Plants. The largest desalination plant in South Asia is the Minjur Desalination Plant near Chennai in India producing 100,000 cubic meters of water per day, or 36.5 million cubic meters of water per year. This Rs. 600-crore plant at Minjur was commissioned on in July 2010. This facility will draw water from the Bay of Bengal, process it using the reverse osmosis technology and supply purified water to the city. According to International Desalination Association's 2009 Report, there are 14,451 desalination plants in operation worldwide, producing 59.9 million cubic meters per day (15.8 billion gallons a day), a year on year increase of 12.3%. The world's first ever low temperature thermal desalination plant in Lakshadweep Islands was built at a cost of about Rs. 5 crore to produce one lakh litre of potable water from sea water. The plant uses “Low Temperature Thermal Desalination” technology. In this method relatively warm water is flashed inside a vacuum flash chamber and the resultant vapour is condensed using cold water. The temperature difference which exists between the warm surface sea water (28 to 30 degrees Celsius) and deep sea cold water (7 to15 degrees Celsius) would be effectively utilized to produce potable water apart from power generation, air conditioning and aquaculture. This technology has been utilized in the first ever

low temperature thermal desalination plant which has been commissioned at Kavaratti. The plant is housed in a structure on the shore. The bathymetry at the island is such that 13 degrees Celsius water is available at a depth of 350m at a distance around 400m from the shore. The cold water is brought to the surface through a 600m long pipe. The technology was first demonstrated in a pilot project of 5000 liter/day at Chennai and is now being used for the first 100,000 liter/day plant at Kavaratti. The cost of desalination would be around 25 paise per litre and will progressively cost less as the capacity is increased. Though the concept was known for a long time, due to practical difficulties it was never attempted. This approach of providing water is extremely useful for islands like Kavaratti where there is no other source of fresh water and the environment is

Coastlines of India The whole of India is facing a never ending water crisis. India, which had enough drinking water for its people in 1951 at 5,177 cubic meters per person per year, is becoming a water-deficient country. In India, around 20 major cities are on the coast line and the water requirement for all these cities in 2008 stood at 6,267 million liters per day (MLD). The coastal cities experiencing tremendous growth are Mumbai, Chennai, Surat, Kolkata, and Vizag. Around 93% of the total water requirement from coastal cities is from these five cities. The rest is with cities such as Cochin, Bhavnagar, Kozhikode, Mangalore, Kakinada, Tuticorin, and others. The projected water requirement for all coastal cities in 2026 is estimated to be 23,607 MLD, a four-fold increase from 2008. By 2026, Mumbai will be the largest consumer of water among coastal cities in the country. The city alone would account for 55% of the total water demand at that point, according to a report of Frost & Sullivan, an international consultant, released in 2010.

extremely fragile. ? As of June 30, 2008 there were 13,869 "contracted desalination plants" worldwide, according to Global Water Intelligence and the International Desalination Association. ? Top 10 desalination countries as of June 30, 2008, according to Global Water Intelligence and the International Desalination Association. â&#x20AC;&#x153;Indian coastline stretches about 5,700 kms on the mainland and about 7,500 kms including the two island territories and exhibits most of the known geomorphological features of coastal zones. The long coast line of India is dotted with several major ports such as Kandla, Mumbai, Navasheva, Mangalore, Cochin, Chennai, Tuticorin, Vishakapatnam, and Paradipâ&#x20AC;?

Scary, but given the unbridled construction activity in the already congested city and growing population, the monsoons may not be enough to meet its water needs. In anticipation of such a scenario, the Mumbai Metropolitan Region Development Authority (MMRDA), the planning body for the Mumbai metropolitan region (MMR), has decided to set up three desalination plants to retrieve normal water from sea. Drinking water scarcity is higher in coastal regions in comparison with the interior parts of India; in coastal areas, the groundwater is saline and not suitable for drinking. Therefore, desalination of sea water becomes an ideal solution to bridge the widening gap between growing water needs of urban population and scarcity in supply in major coastal cities in India. Extending supply from dams or transporting through tankers has been proven costlier than water supplied by desalination. Continuous efforts to amend the desalination technology have brought down the cost of desalination technique, thereby reducing the per liter cost of water. Conclusion

Desalination projects not only provide solutions for drinking water needs, but also for industrial needs as well. A few desalination projects have been announced for the industrial applications such as the Rs. 6 billion worth project in the coastal Kutch district under Build, Operate, Own and Transfer (BOOT) basis, NTPC Tamil Nadu Energy

Company's desalination project worth Rs. 1.26 billion to be executed by Ion Exchange India, Rajasthan State Mines and Minerals Ltd (RSMML) project worth Rs. 3 billion in Nagaur to be executed by Doshion Limited are a few among them.

Joint ventures and private participation would be the key to a fast development of desalination projects in India. The Chennai-based Minjur desalination project is a JV between Hyderabadbased IVRCL and Befesa, Spain. JVs are ideal in this market as the domestic water firms can meet civil and structural requirements, while the foreign firms can bring in the much-needed reverse osmosis membrane technology along with operation and maintenance (O&M) expertise.

The chart given below depicts the water requirement in major coastal cities in India. Ramanathan Menon has more than three 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 abroad. 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, DC-based 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. He also worked as the SubEditor-Media Manager for a quarterly energy/environment magazine titled 'energyn manager' published by The Society of Energy Engineers and Managers from Kerala. Currently he is the editor and publisher of a bimonthly energy and environment magazine 'Energy Blitz'. His contact email address: moothedathramanathan@gmail.com / editor.energyblitz@gmail.com

Concentrated Solar Power (CSP) Technology:

Sahara Forest Projects new source of fresh water, food and energy By Staff Writer

Conceptual illustration of the Sahara Forest Project â&#x20AC;&#x153;The world's surface may be conveniently divided into thirds. Two thirds are covered by the oceans, and if the planet was ground flat by a giant scraper, it would be covered by seawater, a mile deep. Thus while we are short of fresh water, we have an abundance of seawater. Of the land's surface, roughly one third is occupied by mankind in various states of development, one third is forest (and shrinking) and the remaining third is desert (and growing)â&#x20AC;? The world is running short of fresh water. With agriculture accounting for some 70% of all water used, the shortage is closely linked to food production. The provision of clean water is a precondition to life, health and economic development and the lack of water in many parts of the world is the root cause of much suffering and poverty. Present methods of supply in arid regions include: over-abstraction from ground reserves, diverting water from other regions and energy-intensive desalination. None of these methods are sustainable in the long term and inequitable

distribution leads to c o n f l i c t . To m a k e m a t t e r s worse, global warming is tending to make dry areas drier and wet areas wetter. Since the 1980's, rainfall has increased in several large regions of the world, including eastern North and South America and northern Europe, while drying has been observed in the Sahel, the Mediterranean, southern Africa, Australia and parts of Asia. In parts of India, the water table is now 150m below the surface and falling by 6m a year. The International Water Management Institute recently estimated that in India, about 250 cubic kilometres of water are abstracted for irrigation each year. That is at least 100 cubic kilometres more than the rains put back. It feeds India. But as every year passes, the aquifers get emptier. Fortunately, the world is not short of water, it is just in the wrong place. Converting seawater to fresh water in the right quantities and in the right places offers the potential to solve all the problems described above. Many, if not all of the world's deserts formerly supported vegetation, and were it not for the lack of fresh water, they could do so now. We have demonstrated, albeit on a tiny scale, that it is relatively straightforward to convert seawater into fresh water, and thus enable crops and trees to grow in some of the hottest and most arid places on earth. The following notes illustrate how this process could be scaled up in a commercially viable way and seeks to identify where it could be of greatest advantage. The growth in demand for water and increasing

shortages of supply are two of the most certain and predictable scenarios of the 21st century. Agriculture, with a high demand for water, is a major pressure point. A shortage of water will also affect the carbon cycle as shrinking forests will reduce the rate of carbon capture, and the regulating influence that trees and biomass have on our climate will be disrupted, exacerbating the situation further. The Sahara Forest Project is a scheme that aims to provide fresh water, food and renewable energy in hot, arid regions as well as re-vegetating areas of uninhabited desert. This proposal combines the seawater greenhouse concept with concentrating solar power (CSP). CSP is a form of renewable energy that produces electricity from sunlight using thermal energy to drive conventional steam turbines. It is claimed that these technologies together will create a sustainable and profitable source of energy, food, vegetation and water. The founding team behind the Sahara Forest Project was composed of experts from Seawater Greenhouse Ltd, Exploration Architecture, Max Fordham Consulting Engineers and the Bellona Foundation. The scale of the proposed scheme is such that very large quantities of seawater would be evaporated. By using locations below sea level, pumping costs would be eliminated. Among planned activities are one pilot project in Jordan and one in Qatar. The Sahara Forest Project aims to provide a new source of fresh water, food and renewable energy in hot, arid regions, as well as providing conditions that enable re-vegetating areas of desert. The Sahara is used here as a metaphor for any desert that formerly supported vegetation and could do so again, given sufficient water.

The growth in demand for water and increasing shortages are two of the most predictable scenarios of the 21st century. Agriculture is a major pressure point. A shortage of water will also affect the carbon cycle as shrinking forests reduce the rate of carbon capture, and the regulating influence that trees and vegetation have on our climate will be disrupted, exacerbating the situation further. Fortunately, the world is not short of water, it is just in the wrong place and too salty. Converting seawater to fresh water in the right places offers the potential to solve all these problems. This ambitious proposal combines two established

technologies the Seawater Greenhouse and Concentrated Solar Power to achieve highly efficient synergies. Both processes work optimally in sunny, arid conditions. Seawater Greenhouses have been built in some of the hottest regions on earth, Abu Dhabi and Oman for example, where they create freshwater from seawater, while providing cooler and more humid growing conditions, enabling the cultivation of crops all year round. Concentrated solar power is increasingly seen as one of the most promising forms of renewable energy, producing electricity from sunlight at a fraction of the cost of photovoltaics. The process uses mirrors to concentrate sunlight to create heat which is used to drive conventional steam turbines to generate electricity. Less than 1% of the world's deserts, if covered with concentrating solar power plants, could produce as much electricity as the world now uses. By combining these technologies there is huge commercial potential to restore forests and create a sustainable source of fresh water, food and energy. The scheme is proposed at a significant scale such that very large quantities of seawater are evaporated. Given that what goes up must come down, every drop of water evaporated will contribute to rainfall - somewhere. A 10,000 hectare area of Seawater Greenhouses will evaporate a million tonnes of seawater a day. If the scheme were located upwind of higher terrain then the air carrying this 'lost' humidity would be forced to rise and cool, contributing additional water to the mist or cloud. By using a location that lies below sea level, seawater pumping costs may be eliminated. There are a number of large inland depressions in Egypt, Libya, Tunisia and Eritrea for example. In each case, the prevailing wind direction is from the sea to the mountain areas inland. Currently there are some 200,000 hectares of conventional greenhouses in Mediterranean region and this area has been growing at around 10% a year. Most of these, if not all, face water quality and availability issues and indeed many contribute to the depletion of ground water. By using greenhouses to create fresh water from seawater, the problem is reversed. D

Energy efficiency of coal handling systems for thermal power plants By M. Siddhartha Bhatt & N. Rajkumar â&#x20AC;&#x153;Coal popularly known as black diamond is a national resource which needs to be used efficiently for energy security. In the present day scenario of a coal fired thermal power station, when the station coal stock is less than 10 days of plant running capacity, the energy efficiency of the coal quantity and heating value from mine to final combustion should be high (94-95 %). The operating energy efficiency for many stations covering India geographically is in the range of 60 % to 90 % with an average value of around 72 %. The energy efficiency of the coal system impacts the unit and station heat rates and energy efficiency significantly. A number of measures for ensuring efficient utilization of coal such as automation of weight, tracking of railway rakes, online coal energy management through software, automated sampling, accurate gross calorific value (GCV) measurement, etc., are required to ensure that the energy efficiency of coal handling system (mine dispatch to boiler bunker) is maintained at around 94-95 %. clear cut responsibilities are to be assigned to various sections to control and track the lossesâ&#x20AC;?

process of transfer from the mine to the boilers. Coals and most other solid fuels being of variable heating value are priced based on the product of the quantity (tonnes) and the quality (gross heating

value in kcal/kg). Coal follows a long route from the time it is mined till it is ultimately combusted

Introduction Coal (popularly known as black diamond) is the primary energy source of the thermal power stations (TPS) which is the back bone of the Indian power sector. The Indian power sector with a capacity of 185 GW (December 2011) is next only to USA (1200 GW), China (800 GW), Japan (300 GW) and Russia (250 GW). The major chunk of India's capacity is by coal fired generation (100 GW). Indian coals are of high ash (25-50 %) with gross calorific values (GCV) in the range of 23004500 kcal/kg. With the import of coal to sustain power generation on the rise, energy efficient utilization of coal resources is essential. Efficient use of coal calls for effective transfer, storage, monitoring and management to ensure that there are minimal losses in quantity or quality in the

in the utility boilers. As the coal moves from the mine to the coal plant and finally into the furnace (boiler) there is a drop in its audited/declared quantity and quality in the course of its movement, handling and storage. The energy efficiency of coal handling is given by, Typical allowable loss in coal quantity (due to moisture loss, pilferage, handling loss, etc.) can be 1.5-2 % from the mine to coal yard and 1-1.5 % in

the coal yard or 3 % in all. Likewise the drop in heating value in the coal yard due to storage and handling related problems could be around 100 kcal/kg for storage of around 10 days station supply. This gives a mass efficiency of 97 % and heat efficiency of 97.5 %. The overall efficiency could be around 94.6 % or in the range of 94 to 95 %. For measuring the coal system efficiency, the coal quality (heating value, GCV in kcal/kg) and quantity (tonnes) need to be measured and tracked at three points in the fuel transition: ď&#x192;ź Mine or sending end ď&#x192;ź Coal yard (receiving point of the TPS) ď&#x192;ź Bunker of the boiler just before its milling and injection into the furnace. Normally in any typical station, there will be different varieties of coals such as imported high GCV coal, washed coals, raw unprocessed coals, etc. The rejects are also stored in the coal yard for periodic disposal. Quantity Measurement Coal measurement is first at the sending end (mine) and then at the receiving end (TPS entrance). The difference is recorded and reconciled as transit loss. The coal consumption is estimated through inventory checks once in every 10 days which are reconciled based on the station performance. Measurement of individual unit consumption is generally not present/practiced in most stations and consumption of individual units are apportioned based on their individual energy generation, heat rate, etc. These do not give very accurate individual unit performance Sending end measurement: Receipt coal is weighed (gross and tare) at the mine or sending end through weigh bridges and the weight is known through the railway receipt (RR). The coal is again weighed (gross and tare) at the receiving end at the power station through weigh bridges at the wagon tippler hopper/track hopper/truck hopper, etc.. In case of washed / imported coal the weighment is at receiving end only and transit loss is not calculated.

30 The

wagon at the receiving end is weighed

(through static pit type weigh bridges with load cells with analog output/printout or through inmotion weigh bridges). At the end of each shift, the printout of the weigh bridge (or the manual readings) are re-entered in a data base in a different section. Since the wagons are spread out into various tipplers (in the case of pit type weighment), reconciliation time constant to determine the weight and transit loss is as high as 5-6 days. Even in the case of in-motion weigh bridges, the time constant is as high as 4-5 days. An outage of the weigh bridge measurement system for one day will lead to an uncertainty of 3 rakes (174 wagons) of coal. The measuring systems for computing transit loss (in the case of pit type wagon to wagon weighment) are obsolete (analog outdated instrumentation, manual recording at several places and double recording) resulting in wastage of manpower for recording purposes when it can easily be automated [1]. Manual intervention increases chances of errors which are difficult to debug. Technology up gradation in this critical area of their operation is called for. Global positioning system technology for precisely mapping and tracking the movement of the trains for effective tracing the origin and location of the transit loss is an appropriate solution. Rail signature system at the sending end and receiving end are also essential to avoid tampering. Since the weigh bridges are analog in design with open loop communication, human intervention is required and hence fully automated pitless in motion weigh bridges with digital interface and provision for data communication to a central server or receiver control room is required. The presently existing pitless in motion weigh bridges need to be converted into intelligent electronic devices (IEDs) and seamlessly communicate with the overall plant automation. High speed in-motion weighbridge solutions are also available. The Railway receipt (RR) need to be sent digitially to the TPS through a communication media, well before the consignment actually reaches the coal yard to minimize time delay. Boiler consumption measurement: Presently coal consumption measurement in individual units is not available in most stations. It

is estimated by apportioning on the basis of units generated and specific coal consumption which do not reflect on the realistic coal consumption of any particular unit in question. The coal entry into the boilers of each unit needs to be measured. Typical technologies for coal measurement are belt weighers, gravimetric feeders, online dynamic coal flow measuring and balancing systems besides a host of others. Use of fully automated IEDs for on-line coal inflow and consumption may be used. Microprocessor based gravimetric feeders or belt weighers to bunkers (with electronic interfaces and drivers) or online coal flow measuring and balancing systems may be installed in all units for measurement of coal consumption. Heating Value Measurement Three heating values are of significance: i. UHV: Useful heating value -a commercial heating value for payment purposes and to reconcile sending end and receiving end heating value. The receiving end UHV must not be lower than 150 kcal/kg of the sending end UHV and there must not be grade slip. ii. GCV: Gross heating value (which is equivalent of Higher heating value, Gross heating value and Higher calorific value) of the received coal sampled at the point of unloading. GCV (as fired basis) of the receipt coal at the coal yard and sampled at the receiving point. This is connected to the UHV by the formula given by Coal ministry. iii. GCV: Gross heating value of the coal fed into the boiler and sampled either at the conveyor belt to the bunker or at the coal feeder. This is sampled at the conveyor belts just prior to the bunker or at the coal feeder. This value should be within Âą100 kcal/kg of the receipt coal GCV. UHV and GCV though connected are different. UHV is determined by measuring the ash and moisture contents. GCV is determined by proximate analysis as well as by bomb calorimeter. GCV is higher than UHV as per the data given by the Coal Ministry. For coal procurement the formula for UHV which is used is given by,

UHV = 8900 138 [Ash(%)] 138 [Moisture (%)] Based on the UHV the coals are graded into 7 grades [A (if UHV exceeds 6200 kcal/kg) and G (if lower band UHV exceeds 1300 kcal/kg)]. The GCV (kcal/kg) at 5 % moisture and the UHV (kcal/kg) are related by the following formula based on the following relationship: GCV = 2437.5 + [0.6679 (UHV)] The band width of the in-grade variation 9.7 % for A grade and goes up to 28.6 %. The allowable difference in sending and receiving end UHV is 150 kcal/kg without grade slip. In many of the TPS, an average drop of declared monthly average GCV of 500-1200 kcal/kg is seen in the coal yard itself, on a steady basis. In a well managed process, small positive and negative deviations of the same magnitude are seen in the monthly average GCV drops. The monthly average GCV of coal must not exhibit a serious drop between the received and fired values especially when the storage must be within 10 days stock. The drop in monthly GCV between the receiving end and bunker is within Âą100 kcal/kg. Manual sampling has a tendency to restrict the coal only to the surface of the heap. Automatic rake sampling through auger is essential. Mechanical scooping (swing arm/chain bucket) is essential for supply belt scraper. Primary & secondary sample crushers and sample pulverizers for the sample preparation process must be in order. The quartering and coning processes need to be streamlined and refined. The GCV of bunkered or fired coal needs to be determined only by an automatic combustor (bomb calorimeter). The process of transfer of data from the bomb calorimeter (presently manual) needs to be automated and authenticated by back up data either from a print out of the memory of the bomb calorimeter or print out of each value. The sample to sample variation in a rake (for receiving end coal) for each rake and in-sample variation will be very useful. Fully automatic TGA analysis of coal with provision for transmission of the results (TGA traces) to a central server or control room from

where the different groups can view it, is required. This analysis must be done before the coal goes to the bunker so that the operator is well aware of the

combustion characteristic during the shift. This is a good aid for combustion control and boiler excess air and carbon monoxide control. Ultimate analysis (CHN elemental analysis) mapping of coal from different mines and sources is essential at least once a month instead of biannually. This is useful for process optimization of boiler efficiency and is an essential requirement for optimization of heat rate since it is used for computing the flue gas flow quantities and excess air flow through the boiler. Energy Efficiency of Coal Systems of Stations Figure 1 gives energy efficiencies of coal systems of some of the stations recorded during studies. It can be seen the energy efficiency for various stations is in the range of 60% to 88 %. The average value is around 72 %. Ideal values are 94-95 % which make an allowance of 2-3 % overall loss of mass for the complete system (transit + internal losses) and a loss of 100-150 kcal/kg for internal handling, storage and measuring errors.

On storage for long periods there is a tendency for loss of heating value due to weathering, rainfall, etc., but since the storage time is within 10 days of supply this must not be a critical issue.

Best Practices A software is to be in place for online coal energy management in the plant. The software inputs data from the various field instruments (IEDs) for coal receipt from various sources, coal consumption at various bunkers and inventory levels. This must also computes the coal consumption, heat consumption, heat rate, etc., at various points, on line. The sharing of responsibility of coal consumption in the plant can be as follows: ? Coal weight and coal GCV/UHV between the coal mine and the entrance of the CHP of the TPS: Fuel Management/Co-ordination Cell which functions outside the TPS. ? Coal weight and coal GCV drop between Coal Handling Plant and the bunker: Coal handling Plant. It will be the responsibility of the coal handling plant to account for coal weight and coal GCV drop between receipt point and the bunkers.  Coal weight and coal GCV beyond the bunker: Operations In-charge Some of the technical measures for coal management are as follows: Sourcing and storage plan of coals Stacking is done in as many as five places may be reduced to one/two stack yard to avoid multiple handling.  Coal compartments of different collieries, raw and washed must be isolated as the type of coal compatibility is required to be established.  Maintaining minimum 3 days' supply of reasonably dry coal in a rain protection dome.  Avoiding coals with high levels of fines or use of fines transfer technologies like closed conveyor belts similar to those in cement plants.  Handling of imported, washed and indigenous raw coals separately and blending them technically.  Preferring coals with sandy background to coals with clayey background during the monsoon months.

M a n a g e m e n t o f c o a l y a r d  Storage pile design improvement through compacting. Pyramidal shapes with drains on either side lead to low water absorption. Further the piles must not have surface depressions or pits.  Tarpaulins to cover wagons  Providing slopes for drainage of water  Concreting of storage yards and providing retaining walls  Rain water channeling, dredging and cleaning of flow passages  Rain guards for conveyors  Compacting by special compactors instead of bull dozers. Provision for ground level tippling (non-pit type) of wagons

iii. Both receipt and consumption need to be separately monitored and reconciled through automated and computerized system. There must not be human intervention in the primary measurement and recording systems. iv. The responsibility and accountability for coal quantity and GCV must be divided between Fuel management cell (sending end to receiving end), Coal handling Plant (receiving end to bunkers), and Operations (consumption at bunkers). Acknowledgement: The knowledge reported herein is partly of the work for the Maharashtra Electricity Regulatory Commission (MERC), Mumbai which is gratefully acknowledged.

Conclusions The main conclusions of the study are as follows: i. The energy efficiency of coal systems is around 70-75 % in many TPS. This implies that nearly 25-30 % of the energy in coal does not find its place into the boilers or combustors. Ideal efficiency is around 94-95 %. ii. A robust measuring and recording system backed up by software for a complete energy management package is required to be put into place for tracking the losses more accurately.

Reference: [1] Best practices guide for MPSGCL power plants, submitted to MERC, Energy Efficiency & Renewable Energy Division, Central Power Research Institute, Bangalore-560080 [2] Siddhartha Bhatt M. & B. H. Narayana (2005), Towards bench marking of gross heat rate in coal fired thermal power stations- a rational approach, Journal of CPRI, 2 (1):9-18 [3] M.Siddhartha Bhatt, Rajashekar P. Mandi and N. Rajkumar (2010), A Need for Innovation-Coal handling and Conveying in Thermal Power Plants, Bulk Solids Handling (Germany), Special Issue on Coal and Coke, Oct.2010, 30(7):1-4.

M. Siddhartha Bhatt is Additional Director and Divisional Head of the Energy Efficiency & Renewable Energy Division of CPRI. An energy expert he has a professional experience of 30 years at CPRI and has extensively contributed in the areas of energy analysis, energy efficiency & renewable energy. He has published over 40 international journal papers in the area of energy efficiency and one book. He has developed several energy products and holds 5 patents. In the area of industrial consultancy he has undertaken a large number of power audits, energy efficiency studies and studies on renovation, modernization & life extension of thermal and hydro power plants. He has been awarded the Young Scientists Award (1984), Mysore University Golden Jubilee Award for Science and Technology (1988), CBIP Best paper Award (1998). His contact email address::msb@cpri.in N. Rajkumar has a professional experience of 15 years at Central Power Research Institute (CPRI) at its Centres in Bangalore and Thiruvananthapuram in the field of energy audit and energy conservation. He is presently working in Energy Efficiency&Renewable Energy Division of CPRI as Engineering Officer. He received M.Sc in Energy Science from Madurai Kamaraj University and M.Tech in Energy Management from Devi AhilyaViswavidyalaya, Indore.He has carried out energy audit in thermal power stations, buildings and various process industries. He has designed and developed solar thermal systems. He has published more than 30 technical papers in international and national journals, conferences and seminars in energy conservation and renewable energy. He is a life member of Solar Energy Society of India (SESI) and Life Member of Society of Energy Engineers and Managers (SEEM). He is an accredited Energy auditor by Bureau of Energy Efficiency, New Delhi. He is a trained ISO 9000:2000 series lead auditor. His contact: rajkumar@cpri.in

An Analysis of India's Biodiesel Program By Salman Zafar Introduction India, being the world's fifth largest energy consumer, is in the midst of robust economic development, growing industrialization and rising human. Every sector of Indian economy

Based on extensive research carried out in agricultural research centers across the country, it was decided to use Jatropha curcas oilseed as the major feedstock for India's biodiesel programme. National Biodiesel Policy The Government of India approved the National Policy on Biofuels in December 2009. The biofuel policy encouraged the use of renewable energy resources as alternate fuels to supplement transport fuels (petrol and diesel for vehicles) and proposed a target of 20 percent biofuel blending (both biodiesel and bio-ethanol) by 2017. The government launched the National Biodiesel Mission (NBM) identifying Jatropha curcas as the most suitable tree-borne oilseed for bio-diesel production. The Planning Commission of India had set an ambitious target covering 11.2 to 13.4 million hectares of land under Jatropha cultivation by the end of the 11th Five-Year Plan.

agriculture, industry, transport, commercial, and domestic needs inputs of energy. The growing consumption of energy has led to increasing dependence on fossil fuels, such as coal, oil and gas. Currently, India uses petroleum products to meet 95 percent of its transportation energy needs and is increasingly reliant on imports to meet this demand. Promotion of energy conservation and increased use of renewable energy resources are twin planks of any sustainable development mechanism. The Government of India is vigorously exploring ways to ensure energy security and is looking for alternate fuels to meet the increasing energy demand. The biofuel policy, adopted in 2009, envisages 20 percent blending of both biodiesel and bioethanol by year 2017. It also hopes to increase energy security by launching one of the biggest non-edible oilseed-based biodiesel programs in the world.

Biodiesel is typically made from vegetable oil though animal fat can also be used. Rapeseed oil has 82 percent of the share of the world's biodiesel feedstock, followed by sunflower oil, soybean and palm oil. The choice of feed is country specific and depends on availability. In India, non-edible oil is most suitable as biodiesel feedstock since the demand for edible oil exceeds the domestic supply.

The National Biodiesel Mission was to be implemented in two stages: A demonstration project carried out over the 1) period 2003-2007 aimed at cultivating 400,000 hectares of Jatropha to yield about 3.75 tons oilseed per hectare annually. A commercialization period during 20072) 2012 with continuing Jatropha cultivation and installation of more trans-esterification plants to position India to meet 20 percent of its diesel needs through biodiesel. The first phase was taken up during 2003-2007 and included several programs on promotion of largescale Jatropha plantations in forests and wastelands, procurement of seed and oil extraction, transesterification, blending and trade and technological R&D. The second phase of expansion targets to make the program self-sustainable by producing enough biodiesel to meet the 20 percent blending target. To ensure a fair price to the Jatropha farmers, various state governments have offered a minimum purchase price (MPP) for Jatropha seeds. The MPP is in place for biodiesel also, the present rate being Rs 26.50 per litre for biodiesel. In addition, some subsidy programs and tax concessions are also part of the government's efforts to boost the production of feedstocks for biodiesel.

Several public institutions like National Oilseeds and Vegetable Oils Development Board, state biofuel boards, state agricultural universities and non-state actors like non-governmental organizations, self-help groups, cooperative societies, etc. are also actively supporting the biofuel program in various capacities. Major Feedstock for Biodiesel There are three major steps in biodiesel production: (i) plantationproduction of oil seeds, (ii) oil extractionproduction of straight vegetable oil (SVO), and (iii) trans-esterification production of biodiesel. Biodiesel in India is mostly produced from the oils extracted from the seeds of Jatropha, mainly because of the fact that edible oil is scarce and the country already depends on huge quantity of imported oils for edible purposes. Apart from Jatropha, Pongamia pinnata, Mahua, Neem and Castor are a l s o considere d as good source of n o n edible oilb a s e d biodiesel in India. Jatropha is a genus of nearly 175 species of shrubs, low-growing plants, and trees. However, discussions of Jatropha as a biodiesel are actually means a particular species of the plant, Jatropha curcas. The plant is indigenous to parts of Central America, however it has spread to other tropical and subtropical regions in Africa and Asia. Jatropha curcas is a perennial shrub that, on average, grows approximately three to five meters in height. It has smooth grey bark with large and pale green leaves. The plant produces flowers and fruits are produced in winter or throughout the year depending on temperature and soil moisture. The curcas fruit contains 37.5 percent shell and 62.5 percent seed. Jatropha curcas can be grown from either seed or cutting. By virtue of being a member of the Euphorbiaceae family, Jatropha has a high adaptability for thriving under a wide range of physiographic and climatic conditions. It is found to grow in all most all parts of the country up to an elevation 3000 feet. Jatropha is suitable for all soils including degraded and barren lands, and is a perennial occupying

limited space and highly suitable for intercropping. Extensive research has shown that Jatropha requires low water and fertilizer for cultivation, is not grazed by cattle or sheep, is pest resistant, is easily propagated, has a low gestation period, and has a high seed yield and oil content, and produces high protein manure. Pongamia pinnata or Karanj is a n o t h e r promising non-edible oil seed plant that can be utilized f o r o i l extraction for biofuels. The plant is a native of India and grows in dry places far in the interior and up to an elevation of 1000 meters. Pongamia plantation is not much known as like Jatropha, but the cost effectiveness of this plant makes it more preferred than other feedstock. Pongamia requires about four to five times lesser inputs and giver two to three times more yield than Jatropha which makes it quite suitable for small farmers in India. However, Pongamia seeds have about 5-10 percent less oil content than Jatropha and the plant requires longer period to grow as the gestation period is about 6-8 years for Pongamia against 3-5 years in Jatropha. Biodiesel Production in India The biodiesel industry in India is still in infancy despite the fact that demand for diesel is five times higher than that for petrol. The government's ambitious plan of producing sufficient biodiesel by 2011-2012 to meet its mandate of 20 percent diesel blending is unrealized due to a lack of sufficient Jatropha seeds to produce biodiesel. Currently, Jatropha occupies only around 0.5 million hectares of low-quality wastelands across the country, of which 65-70 percent are new plantations of less than three years. Several corporations, petroleum companies and private companies have entered into a memorandum of understanding with state governments to establish and promote Jatropha plantations on government-owned wastelands or contract farming with small and medium farmers. However, only a few states have been able to actively promote Jatropha plantations despite government incentives.

blending is unrealized due to a lack of sufficient Jatropha seeds to produce biodiesel. Currently, Jatropha occupies only around 0.5 million hectares of low-quality wastelands across the country, of which 65-70 percent are new plantations of less than three years. Several corporations, petroleum companies and private companies have entered into a memorandum of understanding with state governments to establish and promote Jatropha plantations on government-owned wastelands or contract farming with small and medium farmers. However, only a few states have been able to actively promote Jatropha plantations despite government incentives. Large-scale blending of biodiesel with conventional diesel has not yet started in India. Commercial production of biodiesel from Jatropha and non-edible oilseeds is small, with estimates varying from 140 to 300 million liters per year from 20-odd biodiesel plants scaterred across the country. The biodiesel produced is sold to the unorganized sector (irrigation pumps, agricultural usage, diesel generators etc) and to experimental projects carried out by automobiles and transport companies. There has been no commercial sale across the biodiesel purchase centers which may be attributed to low biodiesel purchase price of Rs 26.5 per liter which is much below the estimated biodiesel finished production cost (Rs 30 - 40 per liter. Inefficient marketing channels and lack of feedstock supply are among some of the major factors that have contributed to higher production costs. Some of the big companies active in Indian biodiesel sector are British Petroleum, D1 Oils, General Motors, Southern Online Biotechnologies, Emami Biotech, Naturol Bioenergy, Nova Biofuels etc. According to a recent policy brief paper published by the National Centre for Agricultural Economics and Policy Research (NCAP), around 3.21 million tons of biodiesel would be required from an estimated area of 3.42 million hectares to meet a

target of 5 percent blending by 2011-12 while Asian Development Bank estimates that 32 million hectares of wastelands should be allocated to biodiesel crops, together with some yield improvements, to meet the 20% blending target stipulated in Indian biofuel policy. Major Roadblocks A major obstacle in implementing the biodiesel programme has been the difficulty in initiating large-scale cultivation of Jatropha. The Jatropha production program was started without any planned varietal improvement program, and use of low-yielding cultivars made things difficult for smallholders. The higher gestation period of biodiesel crops (35 years for Jatropha and 68 years for Pongamia) results in a longer payback period and creates additional problems for farmers where state support is not readily available. The Jatropha seed distribution channels are currently underdeveloped as sufficient numbers of processing industries are not operating. There are no specific markets for Jatropha seed supply and hence the middlemen play a major role in taking the seeds to the processing centres and this inflates the marketing margin. Biodiesel distribution channels are virtually nonexistent as most of the biofuel produced is used either by the producing companies for self-use or by certain transport companies on a trial basis. Further, the cost of biodiesel depends substantially on the cost of seeds and the economy of scale at which the processing plant is operating. The lack of assured supplies of feedstock supply has hampered efforts by the private sector to set up biodiesel plants in India. As of now, only two firms, Naturol Bioenergy Limited and Southern Online Biotechnologies, have embarked on commercial-scale biodiesel projects, both in the southern state of Andhra Pradesh. In the absence of seed collection and oil extraction infrastructure, it becomes difficult to persuade entrepreneurs to install transesterification plants.

Salman Zafar is a Cleantech Entrepreneur, Advisor, Consultant and Writer. He is involved in creating mass awareness on renewable energy technologies and waste management systems. He has successfully accomplished a wide range of cleantech projects, mainly in the areas of biogas technology, biomass utilization, waste-to-energy and solid waste management. Salman has participated in numerous national and international conferences as a keynote speaker, session chair, invited speaker, panelist, roundtable moderator etc. Salman is a prolific writer and has authored more than 55 articles in reputed journals, magazines, newsletters and blogs on renewable energy and environmental issues. He can be reached at salman@bioenergyconsult.com

Extraction process of biofuel from Algae and its importance By Er. R.V.Ramana Rao B.E.,B.L. FIE India has an installed capacity of 1,76,500 MWs of power as on 31.10.2011, and still facing a peak load power shortage of 15% and a regular power shortage of 9%. Even to day 40% of Indian population is far reaching to receive the

conventional energy to light their homes and 30% of world population lives in India without electricity. The per capita consumption is contemplated to be enhanced from present level of 450 units to 1000 Units as per the Indian National Electricity Policy envisaged in IE Act 2003 by the year 2012. The Unreliable power supply is the reason for wastages of Diesel oils due large scale usage of DG Set and inverters during power interruptions, apart from the above, regular Power interruptions causing huge loss of manpower and production , effecting 400 millions at any moment of time causing severe production loss industrial, and Agricultural front. With existing resources of fossil fuels like coal, gas and oil, it would be very difficult to meet this demand in future. The Indian coal is very poor quality and with 40% ash content, resulting high carbon emission and producing a high amount of fly ash which would be very difficult to handle the fly ash which is a by product of coal burning besides highest carbon emission from burning of coal. With the present rate of consumption the existing oil and gas resources are going to be exhausted within 40 to 50 years which is going to be a major threat for the entire globe. It is also to note that about 65% of our natural resources of fossil fuels had already been spent by the present

generation leaving a meager quantity of 35% of the total estimated quantity for the next generations. It is pertinent to say that unless the fossil fuels are carefully used and saved or it is difficult for survival for the next generations. It is also equally important that scientists are to find out ways and means to develop under R&D programmes some more alternative fuels either for full replacement or partial replacement of existing fuels. In the above context, the entire world is looking forward for the generation of Electricity through Non-Conventional primary Energies like wind, solar, geothermal and to run the world vehicular population by using, biomass, bio fuels etc., for running all types of transport vehicle either by the solar energy or through batteries stored by the solar energy towards their commitment to mitigate carbon emissions as per protocol agreement by UNFCC. The western world has already succeeded in establishing such non conventional energies, and India is now advancing its involvement in generating power through nonconventional energies and presently wants to install a solar energy to 20,000MWs by the year 2020 which will generate 25-30 TWHs annually helping to reduce the gap between demand and supply. The Government has to take more efforts to pursue the Scientists for inventions to go alternative energies in petroleum and other products. The present contribution of Electrical energy through non-conventional sources is only 10.1% against 64% from Thermal energy sources. The carbon emissions from these generating stations are causing alarming effect on the environment, resulting enhanced global warming. Presently in most of the DG Set the HSD in all farms are used for Electricity generation as a substitute of Electricity especially during frequent power failures. Unmindful usage of HSD and ignorant usage without minding the performance levels of DG Set a lot of diesel oil is wasted resulting highest generation cost of Electrical Energy from DG Sets.

Now it has become very important, to use the bio fuels either using directly or to mix with conventional oils,and gains utmost important to save fossil fuels thus to save investment on the cost of generation. Algae fuel might be an alternative to fossil fuel and uses algae as its source of natural deposits. Most of the private entrepreneurs and also government agencies are funding to reduce capital and operating costs and make algae fuel production commercially viable to reach the common investor. The ALGAE consumes the carbon dioxide available in the atmosphere for its natural growth like other plants but more quantity. We can make use the excess carbon dioxide released from the generating stations by adopting carbon capturing technology. This process saves the earth from environmental effects besides more energy generation from thermal power stations. High oil prices, the world oil crisis, have increased the interest in farming the algae (algae culture ) with all natural resources for extracting bio diesel, bio ethanol, bio gasoline, bio methanol, bio butanol and other bio fuels, using land that is not suitable for agriculture. For all commercial levels production of oil from Algae, normally do not require any fresh water for its growth. And hence fresh resources need not be disturbed or investment on the freshwater can easily be avoided. The Algae can also be produced using ocean and waste water, recycled water. The production of Algae is costlier per unit mass as the high input capital costs and also maintenance cost of the plant at least in the initial stages. But its effectiveness can be noticed as the http://en.wikipedia.org/wiki/Algae_oil cite_note-5efficient energy out put is around 5070 times that of energy per unit from that of second- generation bio fuels crops and algae fuel can reach price parity with oil in 2020 if granted production tax credits and other tax holidays that Government announcing from time

The ALGAE fuel contains Bio diesel, Bio butanol, Bio gasoline, methane, ethanol, The oil content in the Algae is the percentage of oil in relation to the dry biomass needed to get it, i.e. if the algae lipid content is 40%, one would need 2.5 kg of dry algae to get 1 kg of oil.

Biodiesel Most advance research results indicates that efficient algal-oil production is being done in the private sector, but predictions from small scale production experiments says using algae to produce biodiesel is the only viable method by

PetroDiesel

BioDiesel

which to produce enough automotive fuel to replace current world diesel usage. If algae-derived biodiesel were to replace the annual global production of 1.1bn tons of conventional diesel, a land of 57.3 million hectares would be required and hence highly favorable production of oil than the production of other bio fuels. The Micro algae grows much faster and its yield per unit area is estimated between 5000 to 20,000 US gallons/acre/year or 4,500 to 18,000 Cu.mt/ Sq KM. Microalgae have much faster growth rates than terrestrial crops. The per unit area yield of oil from algae is estimated to be from between 5,000 to 20,000 US gallons per acre per year (4,700 to 18,000 m3/km2路a). Microalgae are capable of producing large amounts of biomass and usable oil in either high rate algal ponds or photo-bio-reactors. This oil can then be turned into biodiesel which could be sold for use in automobiles. Regional production of microalgae and processing into bio fuels will provide economic benefits to rural communities. Bio butanol Butanol can be made from algae. This fuel has an energy density 10% less than gasoline, and greater than that of either ethanol or methanol. In most gasoline engines, butanol can be used in place of

gasoline without any modifications. In several tests, butanol consumption is similar to that of gasoline, and when blended with gasoline, provides better performance and corrosion resistance than that of ethanol. Biogasoline Bio-gasoline is gasoline produced from biomass such as algae. Like traditionally produced gasoline, it contains between 6 (hexane) and 12 (dodecane) carbon atoms per molecule and can be used in internal-combustion engines. Methane Methane a form of natural gas can be produced from algae in various methods, namely Gasification, Pyrolysis and Anaerobic Digestion. In Gasification and Pyrolysis methods methane is extracted under high temperature and pressure. Anaerobic Digestionhttp://en.wikipedia.org/wiki/Algae_oil cite_note-21 is a straight forward method involved in decomposition of algae into simple components then transforming it into fatty acids using microbes like acidific bacteria followed by removing any solid particles and finally adding methanogenic bacteria to release a gas mixture containing methane. Jet fuel /Aviation bio fuels In Indian Petroleum Sector all Public Sector Petroleum companies are enhancing the prices of petroleum products which are linked with international prices and causing major financial hardship for the vehicle owners. The major expenditure to the individual earnings are going toward Petrol or HSD to keep running their vehicles.

deployment of algal fuels members to be using 10% alternative fuels by 2017.And many trials have been conducted to use aviation bio fuel in many air lines for its suitability and sustainability. Development in this sector:- In February 2010, the Defense Advanced Research Projects Agency announced that the U.S. military was about to begin large-scale production oil from algal ponds into jet fuel. A larger-scale refining operation, producing 50 million gallons a year, is expected to go into production in 2013, with the possibility of lower per gallon costs so that algae-based fuel would be competitive with fossil fuels. The projects, run by the companies SAIC and General Atomics, are expected to produce 1,000 gallons of oil per acre per year from algal ponds. Other major oils produced from Algae is Ethanol, Vegetable oils, Hydro cracking transport fuels, Algae cultivation Algae can produce up to 300 times more oil per acre than conventional crops, such as rapeseed, palms, soybeans, or jatropha. As algae have a harvesting cycle of 110 days, it permits several harvests in a very short time frame, a differing strategy to yearly crops .Algae can be cultivated faster than the other food crops substantially. Algae can also be grown on land that is not suitable for other established crops even with moderately hot temperatures or semiarid tropics, for instance, arid land, land with excessively saline soil, and drought-stricken land. This minimizes the issue of taking away pieces of land from the cultivation of food crops . Algae can also grow on marginal lands, such as in desert areas where the groundwater is saline, rather than utilize fresh water. Because algae strains with lower lipid content may grow as much as 30 times faster than those with high lipid content, the difficulties in efficient biodiesel production from algae lie in finding an algal strain, with a combination of high lipid content and fast growth rate, that isn't too difficult to harvest; and a cost-effective cultivation system (i.e., type of photo bioreactor) that is best suited to that strain. There is also a need to provide concentrated CO2 to increase the rate of production.

Rising jet fuel prices are putting severe pressure on airline companies and further passing the burden to the airline travelers. This increased fuel prices, forcing the Governments to more concentrate on the Bio fuel research, to see the aviation fuel to be kept at lower possible prices. This has become an incentive for the Algae oil production and more concentration on bio fuel production though not a complete substitution of hydrocarbons.

Algae types

In this direction the International Air Transport Association supports research, development and

Research into algae for the mass-production of oil is mainly focused on microalgae such as seaweed.

The preference towards microalgae is due to its less complex structure, fast growth rate, and high oil content (for some species). However, some research is being done into using seaweeds for biofuels, probably due to the high availability of this resource. The following species listed are currently being studied for their suitability as a mass-oil producing crop, across various locations worldwide: ? Botryococcus braunii ? Chlorella ? Dunaliella tertiolecta ? Gracilaria ? Pleurochrysis carterae (also called CCMP647). ? Sargassum, with 10 times the output volume of Gracilaria. Carbon Dioxide Each tonne of microalgae absorbs two tons of CO2. In the future, they will use the algae residues to produce renewable energy through anaerobic digestion. The large quantities of carbon dioxide can be made available through Carbon Capturing Technology, adopted and make use of emissions of Carbon Dioxide thermal power projects. In India 64% of power is from thermal power stations, l there are more proposals for installation of thermal power plants to bridge the supply demand Energy gap. With this more carbon emissions are expected which is detrimental to Environmental balances.

The utilization of wastewater and ocean water instead of freshwater is strongly advocated due to the continuing depletion of freshwater resources in the main lands. However, heavy metals, trace metals, and other contaminants in wastewater shall decrease the ability of cells to produce lipids biosynthetically and also impact various other workings in the machinery of cells Investment and Pay back periods There is always uncertainty about the success of new products and investors have to consider carefully the proper energy sources in which to invest. A drop in fossil fuel oil prices might make consumers and therefore investors lose interest in renewable energy. As this technology is newly introducing in India, though it is familiar in other western countries the pay back periods can be calculated when once it gets familiarity. The people should understand the usability of bio fuels from Algae along with the other petroleum products and an awareness is to be brought among the people for its sustainability in its development.

A possible nutrient source for Algae to grow up is waste water from the treatment of sewage, agricultural, or flood plain run-off, all currently

The National Algae Association (NAA) is a nonprofit organization of algae researchers, algae production companies and the investment community who share the goal of commercializing algae oil as an alternative feedstock for the biofuels markets. The NAA gives its members a forum to efficiently evaluate various algae technologies for potential early stage company opportunities.

major pollutants and health risks. The waste water cannot feed algae directly and must first be processed by bacteria, through anaerobic

The European Algae Biomass Association (EABA) is the European association representing both research and industry in the field of algae technologies, currently with 79 members. The association is headquartered in Florence, Italy. The

Wastewater

digestion. If waste water is not processed before it reaches the algae, it will contaminate the algae and kill much of the desired algae strain.

general objective of the European Algae Biomass Association (EABA) is to promote mutual interchange and cooperation in the field of biomass production and use, including biofuels uses and all other utilisations.

The Form of Algae BioFuel produced from Algae. Often called Algae Oil, Algae Fuel or Oilgae is a 3rd generation bio-fule produced from Algae. Vegetable oil, biogasoline, biomethanol, biodiesel, bioethanol, biobutanol and other biofuels can be made from Algae. Algae Oil Production system The drawbacks of algae fuel are ?

Fuel from algae is quite expensive

Harvesting of algae is difficult

Since algae biofuel production is a relatively

new technology, more research is required to develop standardized protocols for cultivation and biofuel production. Summary The process of producing a fuel from plant and animal

oils is a relatively simple process that has been proven over many years. The growing of Algae Oils is a well known process and the production of more or less oil is a function of the selection and feeding of the specific strain of algae. Algae Oil is primarily used in the process of producing biodiesel fuel. Transesterification, the chemical process of making biodiesel, is also a relatively simple and well understood process. The process is stable and not nearly as hazardous as the production of petro diesel. The production process also produces little or no noxious gasses to pollute the air around the refinery. The Finished product, Biodiesel, is an environmentally friendly, renewable fuel with little or no noxious gas release during the process of combustion. The production of biodiesel requires one eighth of the energy required to produce ethanol and is usable in its undiluted state. The demand for biodiesel for use in all sectors now serviced by petro diesel is projected to grow at an exponential rate.

Algae Oil is a potential answer to the success of renewable energy. The production of Algae Oil is almost nonexistent in the US at this point in time, making this an extremely sound venture.

The author is a BE (Electl), BL.,FIE. Graduated from Andhra University in 1973in Engineering and 1987 in Law. He is a Certified Energy Auditor approved by Bureau of Energy Efficiency and a Lead Auditor and Certified Energy Manager- cum -Auditor. He has 33 years of experience as Electrical Engineer in power sector APEPDCL (Formerly APSEB) and retired as Executive Engineer. Worked as Energy Manager / Consultant in JBS Consultancy Service and as Consultant Electrical Engineer & Energy Auditor in Indian Register of Shipping. Had worked as Principal in Aviation Academy, an Institute of Engineering & Technology for 6 months.

Prospects for Renewable Energy in Commercial Marine Propulsion By Harry Valentine

Uniflow Steam Engine While commercial marine transport companies replaced steam-powered ships with dieselpowered variants, many of the world's navies still operate small fleets of steam-powered vessels.

electric power in Argentina, Spain, Holland, the UK, the USA and Finland. Siemens and several competitors offer a range of commercially proven water-tube boilers, wood-chip-gasifiers plus steam turbine engines and related electrical generation

Over the long-term future, prevailing world oil prices could encourage alternative fuel development in commercial ship propulsion. One option would convert cost-competitive renewable energy into steam and use it as the basis for transAtlantic marine propulsion. The electrically driven propellers that are used on azipod-equipped vessels provide opportunity to retrofit a steamelectric power generation system into a modern vessel.

equipment that can be fitted into a steam-electric ship.

The power output of many of the world's woodfired power stations matches the power requirements of many ships. There are numerous wood-chip fired, steam-based power stations of 2MW (2,000kW or 2865-Hp) to over 100MW (100,000kW or 134,225-Hp) output that generate

Marine Fuel Tender: The available volume aboard commercial vessels may carry sufficient wood fuel for shorter voyages. Large ocean-going vessels that undertake transoceanic voyages would need to carry an additional supply of wood chip fuel. The equivalent of a towed marine fuel tender may carry the additional fuel. It may be an oceanic barge designed with small-water area multiple hull technology to reduce water drag. The towing cable may carry a power cable from the main ship to the fuel tender, as well as support a hollow telescopic tube. Power from the main ship would operate a propeller, thrusters, rudders and auger mechanisms

aboard the fuel tender. The telescopic tube would function as a conduit carrying wood chips from the tender unit to the fuel bunker aboard the main ship. The tender unit would be disconnected from the main ship upon approach to a port, where a tug would tow the tender to a servicing and refueling facility. Upon departure, the fully serviced tender would be reconnected to the main ship. Direct-Drive Propellers: The power train of many modern container ships comprises an air-started, bi-directional rotation diesel engine that rotates at 75-RPM to 80-RPM directly driving a propeller. Prior developments in the steam power industry indicate possible scope to convert an existing 2-stroke marine reciprocation engine to operate on steam. The prior developments occurred in rural, outback Australia to generate electric power using available local biomass resources. Diesel to Steam Conversion: Entrepreneurs with technical expertise converted 2-stroke diesel engines built by General Motors (Detroit Diesel) and by Lister to operate as singleacting, uniflow steam engines. Steam entered the engine via valves built into the cylinder head and exhausted via the ports. The engines achieved a remarkable peak thermal efficiency of some 25%. A German company called Enginion later built a 3cylinder version of the same engine that used powdered carbon graphite suspended in water as engine lubricant. The engine was tested in a car built by Skoda. In an effort to reduce exhaust emissions during the early 1970's, South California Rapid Transit District tested several steam-powered buses, including one powered by a piston engine converted to operating on steam. During a period of high fuel prices during the early 1980's, several US Railway companies entertained discussions about coal-fired modern steam railway propulsion. One of the proposals involved converting a 16cylinder 2-stroke diesel engine from GM's Edison Electro-motive division to compound steam operation, with 5-cylinders operating on highpressure steam and 11-cylinders operating on lowpressure steam. The combustion of hydrocarbon fuels (diesel, gasoline, natural gas, propane) produces a combination of carbon dioxide and steam (water vapor) inside the cylinders of piston engines. Given that a portion of the gas inside the cylinders

of piston engine is water vapor, is an indication that it may be possible to remove the carbon dioxide from the gas and operate the cylinder on 100% water vapor. Converting a Marine Engine: The precedent of converting existing 2-stroke diesel engines from diesel power to single-acting steam power provides a basis by which for a possible conversion of a 2-stroke marine diesel engine to steam power. The research and design to convert a locomotive engine (10” bore x 12” stroke) from diesel to steam can serve as a template upon which to convert a much larger displacement marine engine (38” bore x 98” stroke). A water-tube boiler of 900-psia was to supply steam to a converted locomotive engine that was to be rated at 3300-Hp. In a diesel engine, maximum cylinder pressure occurs near top-dead-center (TDC) and cylinder pressure drops as piston moves toward bottomdead-center (BDC). Variable inlet valve timing is essential in reciprocating steam engines. It is the means by which to regulate engine output. With variable valve timing, it is possible for maximum cylinder pressure to remain constant for up to 80% of the cylinder volume, before the inlet valve closes. The inlet valve can also close after admitting steam at maximum pressure for 10% of maximum cylinder volume (10% cut-off ratio). The research into converting a 16-cylinder locomotive engine of 3600-Hp diesel output suggested that the steam-powered version could deliver some 3300-Hp, perhaps higher power with a higher-pressure boiler. A large marine diesel engine converted to steam power may be expected to produce over 90% of its rated diesel output. Such an engine may require more than one water-tube boiler that would be controlled by a computer. Some steam-powered vessels of an earlier era were powered by 3-stage expansion reciprocating steam engines. Such operation is possible in a modern 2stroke engine converted from diesel to steam power. A large-displacement 7-cylinder of 18,200litres/cylinder may operate 1-cylinder on highpressure steam, 2-cylinders on intermediate pressure steam and the remaining 4-cylinders on low-pressure steam. The 14-cylinder version of the engine may operate 2-cylinders at high pressure, 4cylinders at intermediate pressure and 8-cylinders on low-pressure steam.

engine may operate 2-cylinders at high pressure, 4cylinders at intermediate pressure and 8-cylinders on low-pressure steam. There may be need to reheat exhaust steam leaving the high-pressure cylinders and prior to entering the intermediate and low-pressure cylinders. The reheat phase may boost both engine output and thermal efficiency. While there may be scope to lubricate the engine bearings with oil, there may be benefit to lubricating the piston rings using powdered graphite suspended in water. There are several methods by which to pump a mixture of graphite and water up the piston rod into the piston rings, and then recover the graphite from the condensing system and piston ring â&#x20AC;&#x153;blow-byâ&#x20AC;?. A 2-stroke marine diesel engine converted to steam operation will require a vacuum pump to create a low-pressure zone at the exhaust ports, to help evacuate exhaust steam from the lower-pressure cylinders. A combination vacuum pump and steam re-compressor could pull exhaust steam from the higher-pressure cylinders, and then push the steam through the reheat pipes and into the intermediate pressure and low-pressure cylinders. The residual ultra-low-pressure steam that remains in the cylinders will be compression heated as each piston approaches TDC, preheating the cylinder walls and cylinder head prior to the admission of a fresh charge of steam. Combustion System: A gasifier system will extract the combustible gases from the wood chips. The gases will then be ignited in close proximity to the water tubes that convert water into steam, as well as the reheat tubes that carry steam from the high and intermediate pressure cylinders. The combustion system would also require the operation of one or more fans to draft the combustion system and sustain its operation. Gasifier technology is well proven in wood-chip power stations and in modernized steam locomotives.

Steam Ship Routes: There would be potential to operate wood-chipfueled modern steam-powered ships on several routes where wood fuel is available. There are tropical rainforests across Indonesia, Malaysia and Thailand as well as across parts of Central and South America. There are mixed forests in parts of China, parts of North America as well as parts of Western Europe plus coniferous forests across much of Western North American. Modern wood-fueled, steam powered ships may be suited for operation on routes where wood fuel may be easily available. Major ports along such routes would be in close proximity to forests where lumbering is practiced. Such routes may include: -

Chennai (Madras) Singapore Chennai (Madras) Kuala Lumpur Singapore - Jakarta Singapore Hong Kong Seoul Hong Kong Jakarta Hong Kong Manila Hong Kong Manila Singapore Hong Kong - Vancouver

Conclusions: The power industry operates much proven thermal equipment that may be adapted for operation in a modern steam-powered ship. Precedents already exist in the steam power sector that pave the way for the conversion of a diesel-powered ship to steam propulsion, including the conversion of a reciprocating marine diesel engine to steam operation. During a period of high oil prices, a new generation of wood-fired, steam-powered marine propulsion systems may incur lower energy costs and possibly lower overall operating costs on select routes, when compared to oil-powered ships.

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 and can be reached by e-mail at harryc@ontarioeast.net

WATER: Essence of human and industrial survival By A.K.Shyam “Water is the liquid of life for human survival as the body can not perform in its absence. Water is indeed an integral part of the human body and nearly two litres of water is lost throughout the day. Water accounts for 66% of Human body and requires at least one and half litres of water a day. Despite several options, thirst can be satisfactorily quenched by water and water alone. Unimaginably, just 2% dehydration reduces performance by 20%” The rapid increase in global population and simultaneous decrease of fresh water resource combined with mismanagement, wastage and pollution have threatened the very survival of human race on earth. United Nation estimates that 75% of the world population won't have reliable clean water by 2025. It is therefore just not a mere scientific pursuit but deserves a nobler perspective at this juncture.

Water Composition on Earth: Earth is often referred to as “blue planet” as this is caused by reflection from oceans, covering 71% of earth's area. Salt water of

the oceans and freshwater make up the water composition on earth and their distribution is as follows:

“We have been using water without any type of control since the beginnings of the industrial era. Since then, very few measures have been taken that guarantee an efficient use of water. It is urgent to change this way of acting. Water is scarce, is wrong distributed and badly used. But it is present in all aspects of our life” Water usage: Nearly 20% - 1.1 billion people in the world still do not have access to safe water. Teeth cleaning requires just a quarter litre of water. While, average bath requires 80 litres, average shower uses just 35 litres. Agriculture accounts for highest usage of 70% followed by industry (22%) and domestic (8%) respectively. The most popular 'Financial Audit' principle seems to have caught up with almost everything in the modern context energy audit, professional audit, etc. It is therefore appropriate that we look at 'Water Audit' as well in view of the crisis that we are likely to end up with sooner or later IF, our lifestyles continue the way it has been until today, particularly in the urban centers.

Global fresh water availability percentage though small, holds not only the humans but the industrial sector by its cuff when short of desired demand. Nature had its own way of cleansing and providing water in the cleanest form unthinkable in the modern advanced technological propositions. For example, water flowing through variety of plant species in the thick forests used to pick precious nutrients to render it most ideal for drinking directly without treatment. Human interference has today forced us to explore ways to treat even the dirtiest water to reduce the growing burden on water. Compulsions both at the domestic and industrial level have led us to introspect into the consumptive patterns for optimizing them and conserving. India's annual per capita of 1850 m3 is just about one fourth of the world average of 7690 m3. . Water use in sanitation, maintenance, mechanical systems, building processes and irrigation are understandably different. Preliminary inventory of these facilities would throw light on the potential of reducing the water quantity without affecting the process drastically. Large industries/agricultural and municipalities/metros consuming 15 MLD fall into large water consumer category while, Industrial clusters, CETPs, Medium Industries/Townships consuming between 3 & 15 MLD are categorized under Medium Water Users and Large hotels, IT parks, Theme Parks, Industrial and Private Township consuming 500 cum/day to 3000 cum/day are categorized as Small Water Users with commercial complexes/Government Offices/building, builders, colonies using less than 500 cum/day are considered as Tiny Water Users. Municipality / Corporations supplying water to the urban households charge them based on their monthly consumption recorded through the meters. Flow rate is time taken to fill a bucket of known quantity expressed as litres / minute. This would vary in different outlets and average flow rate can be calculated measuring the flow rate for each outlet and then averaging them. A typical urban household consumes water for kitchen, shower, utensil wash, laundry, toilet plus leakages. The consumption for a family of five could be summarized as under: Shower 10 litres of water per minute; 8 minutes a day 400 litres / day Kitchen 2.83 litres per minute; 15 minutes running 212 litres / day Laundry 140 litres of water per load; 5 times a week 140 litres / load Toilet Single flush uses 9 litres of water; 15 times per day 135 litres / day Leakage One pipe leak of 0.0225 litre/minute flow 32 litres per day Converting the above figures into weekly consumption would lead us to a total of 6157 litres of water or about 920 litres per day. Shower 400 litres / day - Shower duration reduction, low flow showers or sensors would save 50% Kitchen 212 litres / day - Careful washing with appropriate flow, smart fixtures save 50% Laundry 140 litres / load - Water efficient, front loaders machines use less than 120 litres per load Toilet 135 litres / day - Modern dual flush, smaller tanks would require 3 to 6 litres per flush Leakage 32 litres per day - Timely Fixing of leakages would save this wastage The above options combined with the following practices could bring in better awareness of water consumption in the household. Green building principles followed by periodic water audit would reduce the household consumption of precious water. Such savings for either a residential locality or even group housing societies would indeed be quite substantial. Savings of this magnitude indirectly reduces the electricity which otherwise would have been required to pump it to the overhead tanks.

One pump of 375 watt run for half an hour consumes 188 watts of power Or 1.66 watt is required to pump one litre of water (lifting 15000 litres per day) or 0.311 watt (lifting 75000 litres per day). 1000 watt hr is equal to one kWh. It is further interesting that one of the major cities in India required about 6000 mld but received just 3850 mld out of which

about 700 mld is lost through theft and leakages. About 80% (2520 mld) of the remaining 3150 mld that is distributed is converted to sewage water. The actual water for drinking and cooking is not more than 50 mld. Water harvesting: Municipalities / corporations may have no other option but to reduce the water supply in future considering the rate at which urban growth has been increasing. It is therefore necessary that citizens realize this situation and prepare for the worst to follow over the next couple of years through options available at this juncture. The benefits of rainwater harvesting is being realized as it would meet non-drinking water needs and facilitates recharge of the ground water for better capacity of the bore-wells. Outline of rainwater harvesting: Facilitating natural rainwater filtration in to underground by some artificial method has been recognized as an efficient measure of water conservation. Such storages meet the domestic requirement. Rainwater in the form of surface runoff or roof top would be ideal for storage. Rooftop harvesting allows storage in a tank or could be diverted to recharge. This method is less expensive and effective. Rooftop being the catchment, transportation, first flush and filter would follow in sequence. The rooftop rainwater is carried through preferably UV resistant water pipes with a mesh at the mouth of each drain to restrict floating material. Since the first shower is likely to carry undesirable contaminants, it is ideal to flush this water avoiding contamination of subsequent rain water ideal for storage. Having ensured that water is now ready for storage, it is important to filter this water to remove turbidity, color and microorganisms through filter, the basic function of which is to purify water. Filters could be varying type: 1.

Sand Gravel Filter: A brick masonry filled with pebbles, gravel and sand with each layer separated by wire mesh

Charcoal Filter: Could be similar to number 1 or in a drum with an additional layer of thin charcoal to absorb odor.

PVC Pipe filter: About 1 to 1.2 m and a dia of six inches for 1500 sq.ft roof and 8 inches dia for roofs more than 1500 sq.ft. Wire mesh divides the pipe into three compartments with each compartment filled with gravel and sand alternately. Charcoal could be inserted in between. This could be positioned either horizontally or vertically. 4. Sponge Filter: As the name indicates, this is just a PVC drum with a layer of sponge in the middle.

Rainwater so directed to the storage tank deserves designing according to the catchment and with an overflow system. Water from such tanks could be used for washing and gardening etc.. There are indeed many ways of recharging ground water Recharging bore wells/dug wells/pits/trenches/shafts/percolation tanks. Although the efforts on groundwater recharge in some parts of India have been appreciated, the available technical evaluation seems to reach any conclusion on its impact. Systematic and scientific evaluation on these efforts of recharge would throw a better understanding for others to emulate for greater benefits of the community. Current industrial use of water: It is amply clear to even common man that the culprit imposing serious threat to the natural

resources land, air and water is the unstoppable population. Increasing water use may touch 90% of freshwater by 2025. Although agriculture sector accounts heavily 70% of all water withdrawals, industrial usage deserves a serious consideration towards conservation. Climate change seems to further complicate the issue through risks and global uncertainties. Growing population and shrinking freshwater send crying need of monitoring and reevaluation leading into an insight of adoption and adoptive water management in the industrial sector. Conservative options for industries: Wastewater, like any other by product (ash) of power generation need be treated as resource rather than a waste. Waste water is sometimes recycled and reused onsite - A common type of recycled water is water that has been reclaimed from municipal wastewater, or sewage. Although there are a few regulations on water reuse, it is the implementation and monitoring which have hampered the progress to reap the best. More importantly, dissemination of good practices of one utility to others would benefit larger base. Industries could evaluate some of the following options in addition to meeting the regulatory obligations: Aquifer Storage and Recovery (ASR) Artificial aquifer recharge (AR) is the enhancement of natural ground water supplies through infiltration basins or injection wells. Aquifer storage and recovery (ASR) is a specific type meeting both augmenting ground water resources and recovering the water in the future for various uses. Treated drinking water, surface water, storm water or treated wastewater effluent could be diverted to a storage tank and allowed to recharge ground water after proper filtration medium.. Storm water Management: This may need retention ponds as direct piped system is not advisable. The water of the retention ponds needs to be filtered through appropriate meshes to prevent undesired elements to contaminate ground water. Desalination: While average sea water contains 34.7 ppt salts, brackish water upto 30 ppt and in a worst situation, saline water with a range of 30-50 ppt could be considered for desalination. However, the large amounts of waste residuals generated through desalination need careful and proper disposal. In addition, Efforts to provide water resource managers and decision makers to meet future demands of climate change and demographic and economic development deserves a separate attention. Biological treatment varies greatly: i.

Ability to control and minimize impact of toxic constituents in wastewater on indicative organisms when treated water is released falls under Bio-assay / toxicity control;

ii.

Ability to remove biodegradable organic compounds - BOD removal efficiency

iii.

Similarly, removal of chemically oxidizable substances that may or may not be degradable COD removal

iv.

Residue of the biological solids Sludge. Collect, dewater and dispose

Converting ammonia contaminated in wastewater to nitrates- Nitrification efficiency Natural water cycle is driven by solar energy sun heats up sea / surface water; water rises in the form of water vapor; water vapor of higher layers is cooled down which falls as rain, hail or snow. Letting the water flow through turbines, kinetic energy of water is converted to electricity.

Volume and head of water determine the potential energy of a waterfall. The energy production (P) is measured in kWh and is calculated with the help of the formula P=(V Hn)/Kp Where, V=total average inflow to the turbine(s) during a year (m3) Hn=average net head of water[m] Kp=3600/(n 9,81 p) [m2 s2/h kg]n=average efficiency for turbine, generator and transformer during a year.

p= water density We see that the decisive factors are volume and head of water. The other factors are the efficiency of the turbine and generator and the water density. However, the principle could be adopted at the domestic level for electricity generation either connecting the taps or allow the water of the overhead tank to micro turbine. Inadvertently, humans tend to leave the taps open for longer time than desired There has been an effort to understand the science of water consumption in terms of their percentage in a product / crop / material produced. This assessment has been accordingly categorized into the following: ( Source: Hoekstra, A.Y., Chapagain, A.K., Aldaya, M.M. and Mekonnen, M.M. (2011) The water footprint assessment manual: Setting the global standard, Earthscan, London, UK.: :. Green water footprint Volume of rainwater consumed during the production process. This is particularly relevant for agricultural and forestry products (products based on crops or wood Blue water footprint Volume of surface and groundwater consumed as a result of the production of a good or service. Consumption refers to the volume of freshwater used and then evaporated or incorporated into a product. Grey water footprint The grey water footprint of a product is an indicator of freshwater pollution that can be associated with the production of a product over its full supply chain. It is defined as the volume of freshwater that is required to assimilate the load of pollutants based on natural background concentrations and existing ambient water quality standards. It is calculated as the volume of water that is required to dilute pollutants to such an extent that the quality of the water remains above agreed water quality standards. Water therefore, is one of the most vitally important resources on this planet for survival. Since water sustains all life on this planet, we must ensure that our water remains pure and plentiful for future generations.

A.K. Shyam is an Environmental Specialist and had authored few publications on energy efficiency. He had headed the department of environment, health and safety with Reliance Energy Ltd. His major achievement was getting the Environmental Clearance for the 7,480 MW Gas Based Combined Cycle Project. He is a B.Sc.(Hons.) Botany Major, Zoology & Chemistry Minor, M.Sc. Botany (Plant morphology specialization) and Ph.D. in Plant Taxonomy. His contact email address: asoorshyam_delhi@yahoo.com)