energy facts
Solar energy 2010 Guidelines and technical instructions – professional edition
Solar energy 2010
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�Climate change, and how we address it, will define us, our era and ultimately the global legacy we leave for future generations.� Ban Ki-moon. UN Secretary-General.
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Solar energy – Basic energy of the future Energy shortage – what energy shortage? In just ten minutes, the Earth receives as much radiant energy from the sun as its entire population uses in a year. Yet at the same time we are struggling with a chronic energy crisis, with constantly increasing use of fossil fuels and increasing emissions of greenhouse gases. We are not far off Peak Oil – i.e. the point of maximum production of crude oil, after which production will start to fall off, causing energy prices to increase dramatically unless something is done. The energy that we do use must be used more efficiently, and we must make greater use of new sources of energy. This is where solar energy comes into the picture. Today, it meets only 0,2 % of the world’s energy requirements for heating and cooling: a proportion that must be increased if we are to overcome the global energy crisis. Scientists point out that there is a potential for solar energy to be supplying half the world’s energy requirements in 50 years’ time. However, it’s important that we should start now, making increasing direct use of the sun as an energy source. If we can raise today’s percentage of 0,2 % of our energy supplied by solar energy to 5 %, we shall save 1 500 000 000 tonnes of CO2 emissions every year. In Sweden, the solar energy sector has suggested a planning target of 8 TWh of solar energy by 2020 to the Government. 4 TWh of solar electricity is sufficient to supply 800 000 detached houses with their domestic electricity requirements. A further 4 TWh can be provided in the form of solar heating, equivalent to the heat demand of a town the size of Göteborg. There are two solar energy areas that are particularly interesting. The first is that of solar cells for electricity production. Althoug the technology is already available on the market today, it is hardly commercially viable as a source of large scale electricity production. However, extensive research is in progress, and we can expect higher efficiencies and lower production costs in the years to come. The second area, which is already commercially viable, is that of thermal solar energy, i.e. for the production of heating and cooling by means of solar collectors. Thermal solar
4
energy systems deliver far more energy than do electricity producing solar cells. The future energy cost of thermal solar energy is forecast as about 30–70 öre/kWh, which means that is already a viable investment. In addition, solar energy produces the least CO2 emissions of any form of energy technology during its life cycle. Thermal solar energy systems are robust, proven and work perfectly well even in Nordic conditions. Provided that those dealing with them know what they are doing, design, calculations and installation are essentially simple. If a solar energy system is to operate properly, it is vital that it has been correctly designed, that it has an appropriate capacity and that it is installed as intended. Unfortunately, there are at present too many consultants and installation contractors who are unaware of all the aspects, leading to the installation of poor quality systems and dissatisfied customers. This is one of the reasons why thermal solar energy has not properly taken off as a real and efficient form of energy for heating and cooling. However, there are also countless examples of professionally designed and installed systems that perform excellently and which have delivered ‘free energy’ for over 30 years without problems. These are systems that have been designed and installed correctly from the start, and it is from them that we have collected knowledge, experience and advice that are published in this guide to thermal solar energy, with support from the country’s leading solar energy experts. Its target group of readers are professional users such as town planners, property owners, architects, technical facilities managers, consultants and installation contractors. We see this guide as contributing to practical knowledge to provide real support for the use of thermal solar energy as the basic energy supply of the future. Stockholm, February 2010 Klas Ståhl, Managing Director, S Solar Robert Sundqvist, Research and Development Manager, S Solar
Solar energy 2010
content
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WHAT IS ENERGY?
10 ENERGY SOURCES 12 USE OF ENERGY 18 HOW LONG WILL THE ENERGY LAST? 20 THE CLIMATE THREAT ON TOP OF THE AGENDA 22
the swedish energy agency on the energy situation
24 SOLAR ENERGY IS PART OF THE SOLUTION 26 INSOLATION
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Martin Hedberg on the threat to the climate
36
MARKET DEVELOPMENT
5
Everything in the universe is made of energy.
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Solar energy 2010
“Energy cannot be destroyed or created, but only converted to other forms of energy.” First Law of Thermodynamics
What is energy? Energy can be simple and complicated at the same time. We should therefore spend a few minutes on explaining everything from the start. Energy is the basis of all life: it provides us with light, warmth and food. Everything in the entire universe has been made from energy. Energy can be neither created nor destroyed: It can only be converted, from one form to another. The law of conservation of energy is one of the cornerstones of the universe. Regardless of what process that is considered, the total of the energy in the system will be unchanged at the end. All the energy in today’s universe must therefore have originated from an unimaginably small volume at the time of the Big Bang, about 13 000 million years ago. The sun is the ultimate basis for a gigantic energy system which supplies the Earth with about 15 000 times as much power as we use today. Put another way, the sun supplies enough energy in 15 minutes to meet human energy demands for one year. The sun is the engine for all photosynthesis processes, all growth, coal, oil, gas, hydro power, wind power and solar energy.
Power and energy are not the same Energy comes from the Greek ‘ι’ and ‘ergon’, with the approximate meaning of ‘inherent force’. Energy is movement, or the potential for movement. Its fundamental unit of measurement and expression is the internationally standardised joule (J). However, the joule is a very small quantity of energy, so that we need, for example, a good 4 joules to heat one gram of water through one degree. For practical applications, we therefore use the larger unit of the kilowatt hour (kWh), which is the same as 3 600 000 J. Power, which we measure in watt (W), can be described as the capacity of a machine to do work, or the capacity of a lamp to provide light. If 1 joule (J) of energy is converted in a time of 1 second (s), then the rate of doing so (the power) is 1 watt (W). This means that, for example, a 40 W light bulb uses about 1 kWh in a day, which is the same as 1000 Wh. Strictly, the energy in the lamp has not been used, but merely converted into light and heat.
Power and energy When comparing different forms of energy it is vital to use the same concepts. Unfortunately, confusion often creeps into the debate, with one of the reasons being a misunderstanding of the basic concepts of power and energy.
Solar energy 2010
40W
x 24h = 1 kWh
A 40 W lamp, left on for one day, uses almost 1 kWh (1000 Wh).
7
What is energy?
Does this relationship between power and energy seem difficult to you? If so, you’re not alone. A survey among the country’s HVAC consultants found that about 25 % of them could not correctly describe the difference. We can simplify the concepts of power and energy by comparing them with water from a tap. The rate of water running out of the tap represents the power: the amount of water supplied represents the energy. With the tap only partly turned on, it might take a minute to fill a one litre bowl. By turning the tap on fully, it can fill the same bowl in a few seconds: the volume, in other words, is given by the rate of flow multiplied by time. This illustrates the link between power and energy: energy is equivalent to the water volume, while power is equivalent to the flow. Water volume, Water flow, measured measured in litres in litres per second Energy, measured in joules Power measured in watts (or kWh) (or joules per second)
Get a feel for energy
1 kWh is the energy used by a cooker hotplate in an hour 1 MWh is the energy used by a refrigerator and freezer in a year 1 GWh can heat 40 electrically heated detached houses for a year 1 TWh is approximately the total amount of energy used by the whole of Sweden in one day, i.e. all forms of energy, and energy for transport.
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Units
PREFIX
kilo
SYMBOL
k M
G T
FACTOR
10³
109
mega
106
giga
tera
1012
“It is impossible to convert heat completely into work in a cyclic process.” (That is, it is impossible to extract energy in the form of heat from a high-temperature energy source and then convert all of that energy into work.) Second Law of Thermodynamics
Energy has different qualities (exergy) Energy can have different qualities, depending on what type of energy is concerned. Everything depends on how convertible the energy is. The measure of quality of energy is referred to as exergy , and varies for different types of energy. Electrical and mechanical work, for example, can be completely converted, while heat is considerably less easily converted. Electrical energy has a high exergy, and can be relatively easily converted to (for example) thermal energy. However, attempting to convert thermal energy into electricity is more difficult, as thermal energy has a low exergy. This means that
Solar energy 2010
1 kWh of electricity is of a higher quality than 1 kWh of heat, and can be used to perform more work. To raise an exergy value from a lower level to a higher level requires the input of higher level energy, e.g. as in a heat pump.
Exergy values of different energy forms % Exergy
Energy by virtue of position
100
Energy by virtue of movement
100
Electrical energy
95
Nuclear energy
93
Sunlight
95
Oil/gas
95
Biofuels
90
Hot steam
60
District heating
30
Waste heating
5
http://exergy.se
What is the practical use of exergy? As opposed to energy, which cannot be destroyed, exergy is something that we have to make the best use of, and utilise in the most efficient manner. It is, for example, wasteful to use electricity for providing heat, when there are other forms of energy that would be more suitable.
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Solar energy 2010
Energy sources We usually divide our energy sources into two main categories: renewable and non renewable. Mixing the concepts of energy source and energy carrier is a common mistake. District heating, for example, is an energy carrier, which can have received its energy from anything from solar collectors to a boiler fired by coal. Electricity is another example of an energy carrier, that can have been created from such widely different energy sources as wind power or nuclear power. It is therefore directly wrong to claim that district heating automatically has a high environmental profile if you do not also know how the energy delivered to the district heating system has been produced.
Renewable energy sources Renewable energy sources include solar energy, wind and wave power, hydro power, bioenergy in the form of biogas, pellets, wood chips, logs etc., and geothermal energy.
renewable energy sources also all have a natural end point, as their quantities are finite and at some point in the future are going to run out. On the other hand, renewable energy sources are not entirely without their drawbacks. Hydro power and wind energy require large areas of land. Bioenergy presents the risk of degrading biological diversity, competing with the production of foodstuffs and with the production of raw materials for construction and the pulp and paper industry. Bioenergy also results in atmospheric emissions, as it normally involves a process of combustion. Using large quantities of bioenergy shortens the CO2 cycle time, which means that we are bypassing a possible CO2 sink that would have been available if trees had been left to grow for a longer period of time. Methane, which is formed in landfills and digestion processes, is a very strong greenhouse gas. From the point of view of reducing climatic impact, it should be burnt and given preference over other energy sources, including bioenergy or solar energy.
Non renewable energy sources These include fossil forms of energy such as natural gas, crude oil and coal, which have been created over a very long period of time and which consist of finite quantities. Uranium, which is the raw material for nuclear power, is also a non renewable energy source. Peat is regarded as somewhere in between a form of renewable energy and a fossil fuel as a result of its relatively short time of about 100 years for renewal.
Calorific values of some common fuels Quantity Fuel
1 ton
Coal
7 560
27,2
1 m3
Crude oil
10 070
36,3
1 m3 Rapeseed oil
9 340
33,6
1 m3
9 100
32,8
1 m Ethanol
5 900
21,2
1 000 m3
Natural gas
11 048
39,8
1 ton
Pellets, 11 % moisture
4 670
16,8
1 ton
Wood fuels, 30 % moisture 3 530
12,7
1 ton
Peat, 35 % moisture
12,8
1 ton
Domestic waste
2 800
10
I kg
Natural uranium
140 000
504
Petrol
3
Differences of different types of energy. The different types of energy have their own advantages and drawbacks. From an environmental point of view, it is generally the view that renewable forms of energy are to be preferred. They do not have the same environmental impact as the fossil fuels (oil, coal and natural gas) and nor do they contribute to greenhouses gases to the same extent. Non
Solar energy 2010
KWh/ GJ/ unit unit
3 550
The Swedish Steel Producers’ Association Energy Handbook
11
Fossil fuels dominate world energy sources, making up over 80 % of supply in total.
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Solar energy 2010
Use of energy Man is using more and more energy – both in total and per person. Higher living standards and greater expectations in terms of comfort and convenience are the main factors increasing the use of energy. Global use of energy has doubled since 1965, with an annual rate of increase of about 1–2 % at present. The following pages present a selection of figures and data on energy use, both world wide and in Sweden.
and nuclear power delivers about 6 %. There are major differences in energy use between regions, both in per capita use and in terms of the type of energy source. These differences depend on factors such as availability of energy in different countries, economic development, infrastructure and climate. Any imbalance between supply and demand for some particular type of energy in one region spreads rapidly to affect the whole world.
The world Fossil fuels dominate world energy sources, making up over 80 % of supply in total. At 33 %, oil is the largest energy source, followed by coal at 26 % and natural gas at 21 %. Renewable energy sources deliver 13 % of energy supply, World energy supply, basic energy, 1990–2006
World use of oil, 1990–2007
TWh
TWh
150 000
50 000 Hydro poWer
oTHer
120 000
nuclear poWer
90 000
naTural gaS
cHina
40 000
aSien eXcluding cHina africa
30 000
eu oTHer
20 000
60 000 oil
ruSSia
10 000
30 000 coal and coKe
norTH america
19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06
19 95
19 94
19 93
19 92
19 91
06
05
20
04
20
03
20
02
20
01
20
00
20
99
20
98
19
97
19
96
19
95
19
94
19
93
19
92
19
91
19
90
19
19
19 90
0
0
Source: IEA Energy balances of Non OECD countries, 2008
Solar energy 2010
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Use of energy FIGUR 51
Sweden
CHINA ASIEN EXCLUDING CHINA AFRICA
700
30 000 HeaT pumpS in diSTri cT
EU
HeaTing planTS
600
OTHER
naTural gaS, ToWn gaS
nuclear poWer, groSS
20 000
500
RUSSIA
10 000
Hydro poWer
300
06
05
20
04
06
20
04
20
20
00
20
98
19
96
19
94
19
92
19
90
19
88
19
86
19
84
19
82
80
19
78
19
19
76
74
19
19
70
72
19
19
The use of crude oil and oil products has fallen by about 43 % since 1970. FIGUR 10
Sweden’s total energy use of renewable energy 700 HEAT PUMPS IN DISTRICT HEATING PLANTS
600
NATURAL GAS, TOWN GAS
proporTion of reneWaBle energy uSe
CONVERSION AND DISTRIBUTION LOSSES LOSSES IN NUCLEAR POWER STATIONS
500 400
DOMESTIC TRANSPORT
300
40
500
35
400
30
NUCLEAR POWER, GROSS
HYDRO POWER
300
BIOFUELS COAL
06 20
04
02
00
20
98
20
19
96
OIL PRODUCTS
94
19
92
19
90
19
88
19
86
19
84
19
82
19
80
19
78
19
76
19
74
19
72
19
70
Hydro power makes the 100 greatest contribution to the increase in the proportion of renewable energy use. 0 This is followed by increased use of renewable energy in industry and the residential sector. In the transport sector, renewable energy accounts for only a small proportion.
19
20
02 20
00 20
98 19
96 19
94 19
92
200
19
06
20
04
20
20
00
20
98
19
96
19
94
19
92
19
90
88
19
86
19
84
19
82
19
80
19
78
19
76
19
74
19
19
72
70
19
02
INDUSTRY
0
19
RESIDENTIAL, SERVICE ETC.
100
19
200
90
25
Sources: Energy use in 2008: Swedish Energy Agency
14
FIGUR 11 45 PROPORTION OF RENEWABLE ENERGY USE
Solar energy 2010
06
45
04
700
20
PERCENTAGE FOREIGN TRANSPORT AND USE FOR NON-ENERGY PURPOSES
20
800
19
02
oil producTS
FIGUR 8 TWh
600
20
02
100 0
Total energy use in Sweden, 1970–2007
20
01
20
00
20
99
20
98
19
97
19
96
19
95
19
94
19
93
19
92
19
91
90
200
03
NORTH AMERICA BiofuelS coal
0
20
400
19
06
05
Total energy supply in Sweden, excluding net electricity exports
40 000
TWh
20
04
20
03
20
02
20
01
20
00
20
99
20
98
19
97
19
96
19
95
19
94
19
93
19
92
19
91
19
90
19
19
50 000
19
Effective use of energy in Sweden in 2007 amounted to 404 TWh, or 624 TWh in total if weHYDRO also POWER include distribution losOTHER 120 000 ses, supplies of bunker oil for maritime traffic and losses in NUCLEAR POWER nuclear power production. Industry is using essentially the 90 000 same amount of energy today as in 1970, while the residenNATURAL GAS tial and service section has slightly reduced its use of energy. 60 000 Energy use in the transport sector, on the other hand, has OILbe increased by about 87 % since 1970, and continues to 30 000 dominated by oil products. The most important energy carCOAL AND COKE riers for the residential and service sector are electricity and 0 district heating, while energy use in industry is dominated by electricity and biofuels. 150 000
19
FIGUR 49
30
20 06
20 04
20 02
20 00
19 98
19 96
19 94
19 92
19 90
25
FIGUR 12
LAND USE APPLICATIONS 7 %
OTHER SERVICE ACTIVITIES 4 % RESIDENTIAL AND COMMERCIAL PREMISES 87 %
HOLIDAY HOMES 2 %
INDUSTRI
Energy use in the residential and service sector The residential and service sector – which consists of homes, FIGUR 12 Breakdown of energy use holiday homes, commercial premises excluding industrial premises, agriculture, the construction sector, street lighting, LAND USE APPLICATIONS 7 % OTHER SERVICE ACTIVITIES 4 % RESIDENTIAL AND HOLIDAY HOMES 2 % effluent treatment plants and electricity and waterworks – COMMERCIAL uses about 35 % of Sweden’s total final energy use, or about PREMISES 87 % 143 TWh. The number of residential buildings in the country is increasing: in 2006, there were almost 4.5 million dwelling units, which is an increase of about 40 % since the 1970s. However, total energy use has remained relatively constant, despite the increase in the number of dwelling units. 58 % of the energy use in the sector is met by renewable energy. The increasing proportion is due to the expansion Breakdown of energy use in the residential and service sector, 2006. of district heating, powered by a high proportion of renewable energy. It is primarily apartment buildings that are being converted to district heating, while in the detached house sector it is the use of heat pumps or biofuels that is Sweden’s total proportions of renewable energy use increasing. FIGUR 8 TWh
80
Increasing use of electricity, 80 particularly in commercial premises
70
70
Electricity use in the residential and service sector has in60 creased since 1970, with electricity for domestic purposes accounting for the greatest increase in commercial premises, 50 having risen from 8.4 TWh in 1970 to over 30 TWh in 2006. 40 The reason for this increase is to be found in new require30 ments such as better lighting and comfort cooling. On average at 62 kWh/m² (excluding heating) electri20 city use is lowest in schools, as compared with 78 kWh/m² in 10 health care premises and 102 kWh/m² in offices.
elecTric HeaTing
ELECTRIC HEATING
60 50
domeSTic elecTriciTy
40
DOMESTIC ELECTRICITY
30 20 10
Solar energy 2010
06
04
02
98
20
06
20
04
20
02
20
20
20
20
00
98 19
20
96
96 19
19
90
19
19
19
19
84 19
82
19
80
78
19
19
19
19
ELECTRICITY FOR DOMESTIC PURPOSES
19
94
19
94
19
92
90
19
92
19
88
86
19
88
84
19
86
82
19
80
19
19
78
76
19
19
74
72
19
76
70
19
74
19
72
19
19
70
0
00
elecTriciTy for domeSTic purpoSeS
0
15
Use of energy Heating, including domestic hot water production 81 TWh of energy in 2006 were used for space heating and domestic hot water production, equivalent to 60 % of total energy use. Of this, 42 % (34 TWh) were used in detached houses, 32 % (26 TWh) in apartment buildings, and 26 % (21 TWh) in office buildings, commercial premises and public premises. A third of detached houses are heated by electricity. Of them, over half are heated by direct electric heating, with the remainder being heated by waterborne electric heating. Mixed heating systems (i.e. in combination with electric heating) are common in detached houses, with about 40 % of
Final energy use TWh 200 oTHer fuelS
BiofuelS, peaT eTc.
them having such systems in 2006. The commonest combination was that of biofuels and electricity, used in over 23 % of detached houses. The use of heat pumps has increased substantially in recent years, so that one in three detached houses had heat pumps in 2006. On the other hand, only 10 % of detached houses are heated by district heating. District heating is the commonest form of heating in apartment buildings. In 2006, about 76 % of apartment building floor area was heated by district heating alone. 10 % of the area was heated by combinations with heat pumps. In total, apartment buildings use 22 TWh of district heating, 1.5 TWh of electricity heating, 1.5 TWh of oil, 0.3 TWh of gas and 0.2 TWh of biofuels. District heating is also the commonest form of heating in office buildings, commercial premises and public premises, having a coverage of 59 %.
150 diSTricT HeaTing
100 elecTriciTy
50
oil producTS drifTel
19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06
0
Final energy use in the residential and service sector, 1970-2007.
16
High oil prices leading to conversion The high prices of oil have driven the trend towards reduced use of energy and a change to electricity, district heating and biofuels. (At the same time, the change to electricity and district heating results in an increase in conversion and transmission losses in the country’s entire energy system.) In addition to these changes, actual energy conservation measures such as additional insulation of buildings or replacement of windows have resulted in reduced use of energy.
Solar energy 2010
81 TWh of energy in 2006 were used for space heating and domestic hot water production, equivalent to 60 % of total energy use.
Solar energy 2010
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A comparison of finite and renewable energy sources A comparison of finite and renewable energy sources, TWyear. Figures for the finite energy resources show total energy reserves: those for the renewable energy sources indicate annual potential. Source: SCS Solar Update, April 2009.
0
–7
25 S GA ar ye W TURAL5 T NA 21
ea /y ENERGY ar AVE ye W TW 3 2–
0.
r/
IND ar ye
W
a ye TW
r
3–
THE SUN 23 000 TWyear/year
11 r
a ye URANIUM TW 00 –3
90
e gy er n
SS r ea /y BIOMA ar ye TW
us
6
A 16 nn T W ua ye l g ar lo /y ba ea r le
OIL r a ye TW
1
0
24
EC r OT yea r/
a ye TW
2– ER W ar PO r/ye a ye HYDRO TW 4 3–
6–
ea ERMAL /y TH ear y GEO W T 2
0.
3
0.
r
r
TIDALyea r/
a ye TW
S
ar
SERVEye RE TW 0 TAL 90 TO
1 OCEAN THERMAL ENERGY CONVERSION. Electricity production technology based on the temperature difference between deep water and surface water.
18
Solar energy 2010
How long will the energy last? There is not really any energy shortage on Earth. At any given instant, the power being used on the planet amounts to about 15 TW, of which 2 TW consists of electricity. The energy being used or received in nature amounts to about 120 000 TW, in the form of solar energy, wind power, wave energy and bioenergy. In other words, we have access to about 7000 times more power than we need. Unfortunately, the problem is that we have not yet created the necessary systems to be
able to benefit from these enormous energy sources with which we are surrounded. As we base anything up to 80 % of our energy production on non renewable energy sources, it is a fact that they will eventually run out. According to the EU, the commonest forms of non renewable energy, if used at the present rate of increase, can be expected to run out as shown in the table below.
Energy reserves
OIL [barrels]
COAL [tonnes]
Total world reserves, 1st January 2009:
1 206 780 968 626
Total world reserves, 1st January 2009:
841 086 192 000
World rate of use, per second
986 barrels
World rate of use, per second
203 tonnes
Expectation of running out:
22nd October 2047
Expectation of running out:
19th May 2140
Total world reserves, 1st January 2009:
174 436 171 550 404
Total world reserves, 1st January 2009:
18 096
World rate of use, per second
92 653 m続
World rate of use, per second
0,0000042222017 ton
Expectation of running out:
12th September 2068
Expectation of running out:
28th November 2144
NATURAL GAS [m続]
URANIUM [tonnes U235]
The above dates are estimates, and represent one way of describing world requirements of sustainable and renewable energy sources.
Solar energy 2010
19
The climate threat at the top of the agenda We know that the availability of non renewable energy sources is limited, but it is hardly that which is the biggest problem today. The environmental and climate threat overshadows everything else, and must take precedence in any discussion of resources. CO2 concentrations in the atmosphere are 30 % higher today than before the start of industrialisation, over 150 years ago. The UN IPCC climate panel states that this increase
has already changed the world’s climate. The Earth’s average temperature, for example, has increased by 0.5 °C in the last 100 years. Glaciers have started to melt, and sea levels have risen by 3 cm. The relationship between human influence, caused by increased carbon dioxide concentrations in the atmosphere from combustion of coal and oil, is regarded as almost entirely certain.
Carbon dioxide emissions from combustion, per inhabitant and by GNP 2005, in the EU and OECD countries kg CO2 per GNP (2000, USD) 2,50
2,00
czecH repuBlic poland
japan drifTel denmarK & uniTed Kingdom
uSa
luXemBourg
25 ,0
norWay
auSTralia
canada
20 ,0
eu
7, 5
25 0,
0
0
5, 0
france SWiTzerland SWeden iceland
Belgium ireland
5
Spain iTaly
porTugal
12 ,5
meXico
0,50
15 ,0
Hungary
TurKey
22 ,5
neW zealand auSTria germany Korea finland neTHerlandS
greece 1,00
17 ,
SlovaKia
10 ,0
1,50
Carbon dioxide emissions from combustion, per inhabitant and by GNP 2005 in the EU and OECD countries. Source: OECD in figures, 2007
20
Solar energy 2010
Co2 emission 2002 Source: World Bank Group
MORE THAN 20 000 10 000–20 000 5 000–10 000
16
2 000–5 000
Even with a temperature rise of only 2 °C, millions of persons will risk a shortage of clean water, and up to 30 % of economic systems risk being destroyed. A temperature rise of 3 °C represents a boundary at which scientists expect that the sea and biosphere would become a carbon dioxide source, rather than a carbon dioxide sink as today. This would mean that a temperature rise of over 4 °C would be unavoidable. Glaciers would melt, ice would disappear and sea levels would rise. A temperature rise of 5 °C represents the threshold at which almost all life on Earth would be wiped out.
A scenario worth thinking about The quantities of carbon dioxide that are the result of anthropogenic combustion are nothing in comparison with what could happen in a worst-case scenario. Enormous quantities of frozen methane exist in deep ocean depths
Solar energy 2010
MALI
UGANDA
BANGLADESH
TOGO
NIGERIA
PAKISTAN
YEMEN
GUATEMALA
INDIA
URUGUAY
CHINA
TURKEY
GABON
INDONESIA
ETHIOPIA
0
PHILIPPINES
1
BRAZIL
2
EGYPT
3
THAILAND
MEXICO
SWEDEN
MALAYSIA
WORLD 4 AVERAGE
ARGENTINA
5
IRAN
6
FRANCE
7
SOUTH AFRICA
8
UKRAINE
9
GERMANY
10
JAPAN
11
RUSSIA
12
UNITED KINGDOM
13
CZECH REPUBLIC
14
LESS THAN 2 000
NORWAY
15
CANADA
17
MOZAMBIQUE
18
GDP per capita $
AUSTRALIA
19
USA
20
SAUDI ARABIA
Tonnes per capita
and in the Arctic permafrost, held in these locations by a combination of low temperatures and high pressure. With the Earth’s average temperature - and thus the ocean temperatures - rising, there is a risk of these methane hydrates being released. Methane is a greenhouse gas that is 21 times as potent as carbon dioxide. If these enormous quantities of methane were to be released into the atmosphere, they would create a runaway catastrophe situation, with steadily rising temperatures and even more methane. However, an uncontrollable global temperature rise is not a likely scenario, although scientists are becoming more and more convinced that it has happened in the Earth’s past. About 250 million years ago, volcanoes in Siberia emitted enormous quantities of carbon dioxide into the atmosphere, causing a temperature rise of 5 °C and wiping out 95 % of all life on the planet’s surface. One of the IPCC scenarios postulates a 6 °C temperature rise during this century: a scenario that should be given serious thought.
21
Tomas Kåberger, Director-General of the Swedish Energy Agency.
THE SWEDISH ENERGY AGENCY ON THE ENERGY SITUATION Tomas Kåberger is the Director-General of the Swedish Energy Agency. He has worked in the energy field for many years, with experience of several public commissions, research, and representative appointments, and is well known in connection with energy technology and energy matters in general. In the academic world, he has been an adjunct professor. What are the energy challenges facing the world? On the global level, we need to establish an energy system that can support global welfare over a long period of time. This is a challenge that can be met by efficient use of renewable energy, supported by sustainable systems for the use and re-use of materials. Total energy use is increasing world-wide. Is this a trend that can be broken? Energy use is not increasing in all the rich nations. Improving the efficiency of energy use can – and should – cancel out increased use in the rich countries. Where is the greatest potential for improving our efficiency of use of domestic energy? It’s difficult to say where the potential is greatest. Some ef-
22
ficiency improvements are very profitable, while others may reduce the amount of energy used very considerably, but are less profitable in cost terms. One promising technology is that of light-emitting diodes for lighting, which can reduce the amount of electricity required to about a tenth or even a twentieth. At the same time, the technology gives opportunities for completely new ways of providing lighting: in the form of wall coverings, ceiling panels, furniture or glass sheets. What is the Swedish Energy Agency doing to assist the transition to an energy system with less of a climate impact? The Agency supports research and development, and assists commercialisation of new ideas and technologies, as well as providing advice to energy users and information for the political decision-making processes. What part do you see solar energy playing as a future energy source? Solar energy will be society’s main energy source. The debate on future energy sources is very concerned with wind power, and also to some extent with electricity
Solar energy 2010
from solar cells, but thermal solar energy is not getting the same amount of attention. What are your views on this? Solar heat is simple, and not as exciting an area for research. It’s already sufficiently competitive not to need any eye-catching political support, and it doesn’t have as great a visual impact as does wind power. Yet despite this, the amount of solar thermal energy delivered world-wide is about the same as that of wind power, and greater than that of solar cell capacity. Sales of solar collectors and solar energy systems have increased substantially in Sweden in recent years; admittedly from a very low level. Yet at the same time we’re far behind countries such as Germany or Austria, where solar energy has become an industry. Why are we so far behind, and what’s needed in order to kick-start demand and industrial-scale production in Sweden? ... and we’re also behind China on a per-capita basis! There’s an excellent market potential in Sweden, but what we’re lacking is a supplier who has got everything down to a straightforward sales process, and delivering a simple, reliable installation. But no doubt someone will soon crack it and get rich by doing so. There are lots of solar electricity products, such as parking meters and automatic lighting systems, that need to be upgraded with larger solar cells and more electricity storage capacity if they’re to work properly at our latitudes. So that’s another niche market opportunity. In which application areas do you see solar energy having the best development potential? In Sweden, we need several square metres of collectors per inhabitant for space heating and domestic hot water; in other
Solar energy 2010
parts of the world, solar heating can be used for powering absorption heat pumps for cooling. The first architects who learn to use solar energy technology in façades and roofs will be contributing to very profitable solar energy supply. It doesn’t matter which is the greater: we should do everything that’s viable as soon as possible. Do you see any prejudice against, or wrong views on, solar energy? Yes, lots, but we need to ignore them. Solar heating is simple, often profitable and can be used as a complement to all other forms of heating. That’s what’s important! What will the ideal energy system of the future look like? I don’t know. The future will see constant change and development - hopefully, development that doesn’t destroy the prospects for continued development. What advice would you give to a local authority or a housing company wanting to go in for solar energy? A lot of what used to be impossible or unprofitable has become both possible and profitable today. My advice would be to bring in experts on solar energy to look for profitable opportunities, both for solar electricity and for solar heating, and the opportunities will be found. And what are your personal driving forces in respect of energy and climate? I’m sufficiently young to want to save the world, but sufficiently experienced to know that it has to be done in an nondisruptive way if it’s to be successful, and sufficiently canny to start with something that’s also profitable.
23
Solar energy is part of the solution The energy radiating to the Earth from the sun is free, and will never run out during human lives. Its use is essential if we are to reduce the combustion of fossil fuels. However, it will not be enough simply to increase the supply of energy: it is also vital that we should learn to use energy more efficiently. Concepts such as energy economics, energy accounting and energy management will become increasingly important in the future. Various initiatives intended to improve the efficiency of energy use are being expressed in the form of new EU directives. The phasing out of incandescent lamps, for example, is expected to reduce the quantity of electricity used in Europe by an amount equal to the entire electricity use of Hungary. Energy supply is also bound up with independence and security. Present-day energy systems, with their dependence on oil and raw materials, are extremely vulnerable to economic and political disturbances. Prices represent a considerable risk element, and energy can quickly become bound up in market wars and political struggles. Solar energy, as a form of energy source, has an inherent stability and reliability. Its production technology is fully costable, so that its price over the next 20 30 years can be calculated. In addition, a solar energy plant means that an energy purchaser is in a better negotiating position than he would be if he were able only to choose a specific energy source from a specific supplier.
24
Solar energy will not be our only source of energy, even though the insolation on the roof of a typical Swedish detached house supplies five times more energy per year than the house uses in total. Additional energy will be needed on cold winter days, which means that thermal solar energy in particular will have to be complemented by other forms of energy, such as biofuel based district heating. We therefore need an acceptance of the limitations and conditions of the technology, together with an understanding of how other forms of energy systems work and how they can all work together in a single system. Efficiency 80
SOLAR HEATING [50–75 %]
70 60 50 40 30 SOLAR ELECTRICITY [12–21%]
20 10 0
BIOFUEL [0,002 %]
Actual efficiencies for different forms of solar energy utilisation.
Solar energy 2010
COP of 50 200 for solar energy of the efficiency of heat pumps. Heat pumps have a COP of about 3–4, which means that one unit of energy input (electricity) delivers 3–4 units of useful energy (heat). If we apply the COP concept to a solar energy plant, delivering electricity or heat, we obtain COPs in the range 50–200.
The Coefficient of Performance (COP) is a concept used to indicate the efficiency of (for example) heat pumps or other means of delivering energy. It is given by the result of dividing the quantity of useful energy delivered by the amount of energy put into the process. COP is an important indicator
Average power output of solar cells and solar collectors (W/m²) ANCHORAGE
87
EDINBURGH
94
OSLO
95
DUBLIN
99
502 548
SOLAR HEAT OUT
571
STOCKHOLM
104
HAMBURG
105
LONDON
109
600 606 629
MUNIC
124
PARIS
125
715 721
131
BERN
PV OUT
542
756
TOULOUSE
143
NEW YORK
147
848
SEATTLE
147
848
BOSTON
149
CHICAGO
155
825
860 894
KANSAS CITY
171
ROME
176
MADRID
177
ATLANTA
182
LISBON
185
1067
ALGIERS
186
1073
SALT LAKE CITY
189
1090
ATHENS
190
1096
TUNIS
196
1131
HOUSTON
197
1137
MALAGA
199
1148
FREETOWN
200
1154
SAN FRANCISCO
204
ALBUQUERQUE
207
LIBERIA
210
LIMASOL
215
ACCRA
217
MIAMI
219
LAS VEGAS
221
LOS ANGELES
225
TRIPOLI
229
DAKAR
232
NAIROBI
234
CAIRO
237
GAMBIA
240
ADDIS ABABA
243
HONOLULU
248
OUAGADOUGOU
251
MOGADISHU
252
BAMAKO
254
987 1015 1021 1050
1177 1194 1212 1240 1252 1263 1275 1298 1321 1338 1350 1367 1385 1402 1431 1448 1454 1465
266
DJIBOUTI
1535
273
NOUAKCHOTT
0
1575
500
1000
1500
2000
Average incident solar power on a horizontal surface, converted to power outputs from solar cells and thermal solar collectors.
Solar energy 2010
25
INSOLATION Insolation is a measure of solar radiation energy received on a given surface area in a given time. A common measure of this energy is kWh/m² and year, or per day. Insolation con-
In Sweden, about 45–65 % of insolation over the year is which means that it is possible to capture solar energy even
zenith, the angle of incidence is 90° and direct insolation is at a maximum. Direct insolation is reduced in the atmosphere
choice of solar collector and its siting: read more on this in the following chapters.
INCIDENT RADIATION AND REFLECTION
mosphere is 1373 W/m². At the surface of the Earth, the incident radiation depends on the angle bet-
26
ANNUAL INSOLATION
m
The map shows average values of annual insolation at ground level. A south facing roof, with a slope of 30° to the horizontal, receives between 900 and 1100 kWh/ m², year, depending on latitude and the local climate.
Solar energy 2010
ANNUAL INSOLATION (kWh/m²/day)
1,5–2,0 2,0–2,5 2,5–3,0 3,0–3,5 3,5–4,0 4,5–6,0
1,5–2,0 2,0–2,5 2,5–3,0 3,0–3,5
The map shows average insolation at ground level, based on monthly measurements over the period 1983–1993.
3,5–4,0 4,5–6,0
ANNUAL INSOLATION (W/m²) kWh/m2/day 0
januARy 1984–1993
>8,5
APRIL 1984–1993
Source: NASA Visible Earth http://visibleearth.nasa.gov/view_rec.php?id=1683.
Solar energy 2010
27
Solar energy technologies There are several different ways of capturing solar energy, using appropriate collector technology. Some technologies are well developed, tried and tested, while others are still in process of development.
Efficiency = How efficiently we utilise energy at different times or for different applications.
Solar electricity Solar cells. Sunlight can be converted into electricity in solar cells – a technology that was developed as long ago as the 1950s in order to provide the first satellites with electricity. A solar cell consists of a thin layer of a semiconductor material, often silicon. When sunlight strikes the cell, it is polarised so that the front acquires a negative charge and the back acqui-
SOLAR CELLS
28
res a positive charge. This creates a voltage difference, which can drive a current flow via metallic contacts on the front and back of the cell. The voltage of a single cell is only about 0.5 V, and so 30–36 cells are normally connected in series in a single module in order to supply a useful voltage that can be used to charge batteries or be connected to an inverter. Silicon solar cells have an efficiency of about 15 %, and can produce a specific energy output of about 50–150 kWh of electrical energy per m² and year. There are two different types of module: crystalline silicon solar cells and amorphous silicon solar cells, which are generally referred to as thin-film cells in everyday language. The crystalline solar cell module is the more common type, with about 80–90 % of the market. The thin-film modules consist of a film that is only a few μm thick, thus reducing the amount of semiconductor material required and so also reducing the cost of manufacture in comparison with that of crystalline cells. Solar cells are today competitive for use in areas where it would be too expensive or complicated to provide a supply from the normal electricity mains. Common application areas are holiday cottages, on boats or in inaccessible areas. Another common application area is that of traffic monitoring equipment on roads. It is also possible to create systems connected to the normal electricity mains, and several larger installations of this type have been built on public buildings in Sweden. One example of such a larger installation is that of the Ullevi sports arena in Göteborg, where 750 m² of solar cells produce about 65 000 kWh of electricity per year.
Solar energy 2010
Electricity from solar cells is at present very much more expensive than electricity from, say, wind power, which is due mainly to the fact that solar cells are manufactured and used on a relatively small scale, and that wind power has a longer annual utilisation time. However, in actual capital cost in terms of SEK/kW, the cost of wind power is much the same as that of solar cells. To assist the move towards a renewable energy system, and to create jobs and companies in the energy technology sector, the Swedish Government has introduced a grant for installation of all types of mains connected solar cell systems. The aim is to increase the use of solar cell systems, and the number of parties involved with them, in Sweden, in order to reduce system costs and increase annual electricity production from solar cells by at least 2.5 GWh over the period June 2009–December 2011, during which the grant is available.
CONCENTRATING SOLAR ENERGY
A SOLAR CELL MODULE
Solar cells are often referred to as photovoltaic cells.
Solar energy 2010
CONCENTRATING SOLAR ENERGY. Concentrating solar power (CSP) is a system using mirrors to concentrate solar thermal insolation on to a particular point. The heat is used to produce steam to drive a turbine to produce electricity in the same way as in a traditional power station. There are also CSP installations that deliver energy using solar cell technology or other hybrid solutions. Nevada Solar One is one of the world’s largest CSP installations, with a nominal output power of 64 MW, and producing an annual energy output of 134 GWh/year.
29
SOLAR ENERGY TECHNOLOGIES
THERMAL SOLAR ENERGY The principle behind all thermal solar energy systems is simple. Insolation is capture by a surface, raising its temperature, with the heat being transferred to a medium, which can be either a liquid or a gas. The heated medium can then be used either directly, as for heating swimming pools, or indirectly via a heat exchanger. Thermal solar collectors can deliver heat for a wide range of applications, such as for heating domestic hot water, space heating or the drying of timber. Another interesting application is to use thermal solar energy for producing cooling: this application is particularly attractive, as about 15–20 % of all world electricity is used for various types of cooling or heat pump systems, and because it is particularly in areas where insolation is high that cooling requirements are likely to be greatest. Under Swedish conditions, a thermal solar collector can deliver 350–700 kWh/m² and year. Thermal solar collectors can be divided up into glazed and unglazed collectors.
GLAZED SOLAR COLLECTORS
GLAZED FLAT PLATE SOLAR COLLECTORS
There are two types of glazed solar collectors: Flat plate solar collectors and Vacuum tube solar collectors. FLAT PLATE SOLAR COLLECTORS. Flat plate solar collectors consist of a thermally insulated case with a cover glass. The case contains an absorber, which absorbs the incident radiation, and which usually heats up a glycol mixture circulated in contact with it. The cover sheet and thermal insulation behind the absorber minimise heat losses to the surroundings. The heat is transported in a closed circuit to a heat store, which might be, for example, a domestic hot water tank or a hot water tank for space heating purposes, forming part of the solar energy system.
30
Solar energy 2010
VACUUM TUBE SOLAR COLLECTORS
VACUUM TUBE SOLAR COLLECTORS. Vacuum solar collectors consist of various types of vacuum tubes. The commonest of these is the Sydney type, which is double glazed, with the outer tube being transparent and the inner forming the actual absorber. There are two ways of converting the incident solar radiation into heat in vacuum collectors: either lector, or through the use of a heat pipe. A medium in the pipe collects the heat from the absorber by evaporation, and then delivers it by condensation in a heat exchanger at the top of the tube.
Solar energy 2010
A VACUUM TUBE SOLAR COLLECTOR
The inner tube in a vacuum solar collector absorbs sunlight, while the outer tube provides insulation.
31
Solar energy technologies
Pool solar collectors
Unglazed solar collectors There are two types of unglazed solar collectors: Pool solar collectors and Air solar collectors/Ventilation solar collectors.
Air solar collector/ventilation solar collector
Cover glass
Pool solar collectors. A pool solar collector consists of an absorber made from UV resisting polymer that can withstand chlorinated water. As the collector heats up in the sun, it transfers its heat to a liquid circuit, which is often the pool water itself. These collectors are uninsulated and have poor efficiency due to being considerably warmer than their surroundings. However, as a result of their low price, they are very suitable for low temperature applications such as heating swimming pools.
SOLAR CELL
ABSORBENT
INLET AIR
INSULATION
OUTLET AIR
Air solar collectors/ventilation solar collectors. An air solar collector provides a simple means of ventilating and drying buildings such as holiday cottages or barns. Heat from the sun is absorbed by a dark back panel, behind which an air gap with ducting provides a passage through the collector from one end to the other, warming the air as it passes. The warm air can them be discharged through a thermostatically controlled fan, either directly into the building or into its ventilation system.
32
Solar energy 2010
SOLAR ENERGY SYSTEMS When considering solar energy applications, it is important to concentrate on the entire energy system, and not solely on the solar collectors or solar cell modules. A solar energy system can be built up in essentially the same way as all other energy systems, involving the main stages of energy production, energy distribution and energy use.
Schematic arrangement of a large scale solar heating system integrated into a district heating system.
Solar energy 2010
An example of two local solar energy systems. Solar cells for electricity production and solar collectors for heat. In principle, the system architecture is the same for both applications.
33
CLIMATE CHANGE STRATEGIST MARTIN HEDBERG ON THE THREAT TO THE CLIMATE Martin Hedberg is a meteorologist and the founder of the Swedish Weather and Climate Centre (SWC) and (with the European Commission) of the Climate Broadcasters Europe Network. His work concerns climate matters, and he is a frequently-consulted advisor to companies and public authorities. In recent years, he has been producing information and advising on strategies concerning climate change for the public, local authorities and companies, as well as performing future analyses and investigating the processes of change. What is the greatest consequence of climate change? We can’t say what is the greatest consequence, as this depends on what you’re concerned with: melting ice, rising sea levels, decline in biological diversity or tipping points, such as when nature itself starts to produce greenhouse gases. And climate change can also have humanitarian or security consequences, as well as causing changes to business and industry. So what’s the solution, in your view? You need first to decide which problem you’re going to solve before you can talk about a solution. Yet even major international contexts go for simplism and present solutions without defining just what particular concrete problem they’re supposed to be tackling. If you ask the scientists, many of them say that we should concentrate on avoiding tipping points, which are the stages when nature itself starts to produce feedback that accelerates the changes. It’s absolutely essential that this doesn’t happen, they say. Perhaps we should concentrate on saving something like the climate that we have today. Many scientists say that this is where we must start to draw the line. The problem is that no-one can say exactly what the dangers are if we cross the line, but we do know that things will be very different, and that many of the changes will be to our detriment.
34
You’ve previously said that there’s no shortage of energy on this planet of ours. Quite right: there’s no shortage of energy, or more exactly, of power. The Earth receives far more than we need from the sun, but it’s up to us to build the infrastructure to capture and use it. There are more than enough major energy streams from nature, but we’ve simply not created the necessary energy capture systems to capture and use the energy, which could provide the basis for the living conditions, security and other features that we today base on fossil energy. Once we’d found that there was oil there for the taking, and had built the necessary infrastructure, oil had such a high energy content, and was so versatile, easy to store and transport, that we’ve simply continued to do so, creating an enormous industry around this fossil fuel. It’s not so difficult for alternative energy forms, based on renewable resources, to gain a foothold as is sometimes represented by the media, but the established fossil fuel industries are not going to give up of their own volition. The main problem with trying to reduce carbon dioxide emissions, for example, is not that of supplying alternative energy, but of displacing the old fossil-based energy. Unfortunately, as users we’re stuck with the existing system. Perhaps there isn’t any realistic alternative for us as consumers if we want to get away from fossil energy. So which renewable energy sources would you recommend, and why? Solar energy. That’s how the energy arrives here: it’s the raw material for the other energy sources that we utilise in various ways. Wind power, wave power or biofuels: they all originate from the sun, but we can’t rely only on solar power, we also need the other forms of energy supply. And there’s no reason to concentrate on only one source: we must look to a diversity.
Solar energy 2010
Martin Hedberg, meteorologist and founder of the Swedish Weather and Climate Centre (SWC) and the Climate Broadcasters Network Europe.
What are your views on solar energy as a future energy source? Unfortunately, a lot of people are prejudiced against solar energy. As it doesn’t supply much in the way of heat in the winter here in Sweden, they simply write if off entirely, and overlook all its summertime benefits. Solar energy provides both heat and electricity. Many other countries are making major advances in both small-scale and large-scale electricity production from solar energy. Whether utilised as heat or as electricity, solar energy is many times more efficient per unit of land area than, for example, biofuels. But we should utilise the diversity of biofuels, solar energy and wind energy. What advice would you give to the construction and property sectors concerning their choice of future energy systems? Property-owners and developers should aim to build properties that produce more energy than they use. This is an aim that is recognised here and there, but it needs to taken up more widely. It was originally seen as a silly idea, but it’s not if you think about it a bit. Buildings receive a steady supply of solar energy, and the wind blows around them, so why not make use of these potential energy sources? Which means starting to use the technical innovations that exist in order to capture this free energy. And solar panels, for example, can serve the dual purposes of serving as façade cladding and providing energy.
Solar energy 2010
As a property-owner, you could be a net producer of energy when seen over the whole year. If you’re connected to the district heating system, why not supply heat back to it at times? The very least that you could ask for would be for the energy that you feed into the system to be credited against that which you receive from it at other times. How can solar energy be developed in Sweden? We’ve been very successful in Sweden in building up industries based on iron ore and steel, forest products, goods vehicles, aircraft, computer games and mobile telephones – so why not solar, wind and wave energy? We need individuals and companies to give a lead and forward-looking state and local authorities to provide support. With relevant and correct information on the potential, such establishment and growth should occur naturally. There’s such a lot to gain from it: strategic and economic benefits, energy supply benefits, reduction in environmental impact and so on. Industry understands that this is important, but many companies haven’t yet appreciated that it’s strategically important. It’s not just a matter of tackling problems, but a business opportunity, My experience is that it usually starts with a few individuals in a company who are personally involved in the problem, and who finally manage to get the whole company moving.
35
20 000 18 000 16 000 14 000 12 000
PV-ENERGY GWh/year
10 000
02 20
20
98 19
96 19
94 19
00
THERMAL ENERGY EUROPE GWh/year
8 000 6 000 4 000 2 000 0
Market development 20 000 18 000 16 000 14 000
02
20
00
20
98
19
96
19
19
94
China dominates the world solar heating market, with about12 000 largest solar heating installation is in Marstal in Denmark, ENERGI PV-VÄRDEN GWh/år three quarters of the world’s total installed capacity. This is10 000 with 18 000 m² of collectors. ENERGI ST EUROPA GWh/år 8 000 because solar heat is often the only alternative available for 6 000 4 000 hot water supply in residential buildings. Europe is in second 2 000 Solar cells place, with the greatest number of solar collectors in Ger- 0 Globally, the solar cell industry has a turnover of about SEK many, although Cyprus, Greece and Austria are far ahead of 100 000 million per year. In 2008, installed capacity amounother European countries in terms of number of units per ted to 5.95 GW. capita. However, all these countries have an energy policy that supports solar energy. World FIGUR 12solar electricity production Sweden has about 15 000 solar heating systems in opeITALY 0,24 GW ration, with new ones being added at a rate of about 2000 JAPAN 0,23 GW SOUTH KOREA 0,28 GW USA 0,36 GW per year. Most of these are smaller systems. Although Sweden REST OF EUROPE 0,31 GW REST OF THE and other colder countries have fewer hours of sunshine than WORLD 0,21 GW countries around the Mediterranean, it is likely that installation of solar heating systems will be relatively substantial due to the steadily rising prices of energy. Sweden also has some of the world’s largest installations: the largest collector array in the country is in Kungälv, with 10 000 m² of collectors SPAIN 2,46 GW supplying 4000 MWh of district heating per year. The world’s GERMANY 1,86 GW
Solar energy production [GWh/year] 20 000 18 000 16 000 14 000 12 000
PV-ENERGY GWh/year
10 000
06 20
04 20
02 20
00 20
19
96 19
94 19
98
THERMAL ENERGY EUROPE GWh/year
8 000 6 000 4 000 2 000 0
The market for solar cells and solar heating equipment has a steeply rising growth curve, although the actual volumes are still quite modest in comparison with other energy forms. 20 000 18 000 16 000 14 000 12 000
36
10 000 8 000 6 000 4 000
ENERGI PV-VÄRDEN GWh/år ENERGI ST EUROPA GWh/år
Solar energy 2010
Thermal solar energy
Sweden. Sweden has about 375 000 m² of glazed solar collectors, to give a nominal output of 270 MW. In 2008, they delivered over 100 GWh. In addition, there are about 120 000 m² of pool solar collectors, delivering an output of about 85 MW. There are also about 65 000 m² of solar cells, producing an output of about 8 MW, and generating about 7 GW of electricity in 2008.
In 2007, world thermal solar energy production capacity amounted to about 150 GW of heat, corresponding to about 210 million m² of solar collectors. In terms of installed capacity, the solar heating market today exceeds the wind power market.
Installed capacity – thermal solar energy
79 898
Total capacity [MWth]
7 105
8 000
6 054
7 000
4 866
6 000
5 000
4,3
3,7
2,4
1,0
LITHUANIA
ESTONIA
8,0
NORWAY
LATVIA
12
FINLAND
NAMIBIA
14
13
MACEDONIA
LUXEMBOURG
21
IRELAND
19
HUNGARY
MALTA
31
25
ALBANIA
BULGARIA
48
35
ROMANIA
58
49
THAILAND
61
SLOVAKIA
CANADA
79
69
CZECH REPUBLIC
BARBADOS
82
79
SLOVENIA
NEW ZEALAND
153
POLAND
102
SOUTH AFRICA
TUNISIA
173
164
SWEDEN
SWITZERLAND
ITALY
FRANCE
AUSTRALIA
USA
INDIA
GREECE
AUSTRIA
ISRAEL
BRAZIL
JAPAN
GERMANY
CHINA
Solar energy 2010
TURKEY
0
BELGIUM
197
176
PORTUGAL
231
213
NETHERLANDS
UNITED KINGDOM
311
278
MEXICO
DENMARK
557
321
CYPRUS
684
593
SPAIN
JORDAN
878
847
TAIWAN
1 178
1 000
1 014
1 734
2 000
1 505
2 501
2 511
3 000
2 094
3 456
4 000
37
Notes
38
Solar energy 2010
S-Solar is a Swedish world leading solar energy company with an extensive experience of developing solar thermal systems and technology for heating and cooling. S-Solar has participated in the development of more than 50% of the large installations currently in use in EU.
Solar energy 2010
39
40
Solar energy 2010