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CONVERTING SUNLIGHT
INTO ELECTRICITY
Chapter 9. Cutting Carbon Emissions in Half
Lester R. Brown, Plan B: Rescuing a Planet Under Stress and a
Civilization in Trouble (W.W. Norton & Co., NY: 2003).
When a team of three scientists at Bell Labs discovered in 1952
that sunlight striking a silicon surface could generate electricity,
they gave the world access to a vast new source of energy. No country
uses as much energy as is contained in the sunlight that strikes
its buildings each day, writes Denis Hayes, former Director of the
U.S. government's Solar Energy Research Institute.26
Solar cells were initially used to provide electricity in remote
sites in industrial countries, such as in national forests or parks,
offshore lighthouses, and summer homes in remote locations. In recent
years, a vast new market has opened up in developing-country villages
that are not yet linked to an electrical grid. In many such situations,
the cost of building a centralized power plant and a grid to deliver
relatively small amounts of electricity is prohibitive, which helps
explain why 1.7 billion people in developing countries still do
not have electricity. As the cost of solar cells has declined, however,
it is now often cheaper to provide electricity from solar cell installations
than from a centralized source.27
In Andean villages, solar installations are replacing candles as
a source of lighting. For villagers who are paying for the installation
over 30 months, the monthly payment is roughly the same as the cost
of a month's supply of candles. Once the solar cells are paid for,
the villagers then have an essentially free source of powerone
that can supply electricity for decades. In villages in India, where
light now comes from kerosene lamps, kerosene may cost more than
solar cells.28
At the end of 2002, more than 1 million homes in villages in the
developing world were getting their electricity from solar cells.
If families average six members, then 6 million people are getting
their residential electricity from solar cells. But this is less
than 1 percent of the 1.7 billion who do not yet have electricity.
The principal obstacle to the spread of solar cell installations
is not the cost per se, but the lack of small-scale credit programs
to finance them. As this credit shortfall is overcome, village purchases
of solar cells could climb far above the rate of recent years.29
The residential use of solar cells is also expanding in some industrial
countries. In Japan, where companies have commercialized a solar
roofing material, some 70,000 homes now have solar installations.
Consumers in Germany receive low-interest loans and a favorable
guaranteed price when feeding excess electricity into the grid.
In industrial countries, most installations are designed to reduce
the consumer's dependence on grid-supplied electricity, much of
it from coal-fired power plants.30
The governments with the strongest incentives for the use of solar
cells are also those with the largest solar cell manufacturing industries.
In Japan, for example, residential installations totaled roughly
100 megawatts in 2001. The comparable figure for Germany was 75
megawatts. The United States, a far larger country, was thirdwith
32 megawatts of installations. India was fourth with 18 megawatts.
Japan leads the world in solar cell manufacturing, with some 43
percent of the market. The European Union, led by Germany's vigorous
program, has moved into second place with 25 percent of output.
The United States, with 24 percent, is now third.31
The cost of solar cells has been dropping for several decades, but
the falling cost curve lags wind by several years, making solar-generated
electricity much more costly than power from wind or coal-fired
power plants. Industry experts estimate that with each doubling
of cumulative production, the price drops roughly 20 percent.32
Over the last seven years, solar cell sales have expanded an average
of 31 percent annually, doubling every 2.6 years. (See Table 9-2.)
Since there is little doubt that solar cells will one day be an
inexpensive source of electricity as the scale of manufacturing
expands, the challenge for governments is to leapfrog into the future
by accelerating growth of the industry. Only very modest government
incentives are needed to do that. If we can quickly reduce the cost
of solar cells, they will join wind as a major player in the world
energy economy.33
| Table 9-2. Trends in Energy Use by Source,
1995-2002 |
| Energy Source |
Annual
Rate of Growth
|
|
(percent)
|
| Solar Photovoltaics |
30.9
|
| Wind Power |
30.7
|
| Geothermal Power1 |
3.1
|
| Natural Gas |
2.1
|
| Oil |
1.5
|
| Hydroelectric2 |
0.7
|
| Nuclear Power |
0.7
|
| Coal |
0.3
|
|
1Data available through
2000. 2Data available through 2001.
Sources: See endnote 33. |
ENDNOTES
26. Denis Hayes, "Sunpower," in Energy Foundation, 2001 Annual Report
(San Francisco: February 2002), pp. 10-18.
27. Population without electricity in World Summit on Sustainable
Development, Department of Public Information, Press Conference
on Global Sustainable Energy Network (Johannesburg: 1 September
2002).
28. "Power to the Poor," The Economist, 10 February 2001, pp. 21-23.
29. Bernie Fischlowitz-Roberts, "Sales of Solar Cells Take Off,"
Eco-Economy Update (Washington, DC: Earth Policy Institute, 11 June
2002).
30. European Photovoltaic Industry Association and Greenpeace, Solar
Generation (Brussels: September 2001).
31. Fischlowitz-Roberts, op. cit. note 29.
32. Robert H. Williams, "Facilitating Widespread Deployment of Wind
and Photovoltaic Technologies," in Energy Foundation, op. cit. note
26, pp. 19-30.
33. Paul Maycock, "Annual Survey of PV," Photovoltaic News, March
2003, p. 1. Table 9-2 from the following: wind power from Worldwatch
Institute, Signposts 2002, CD-rom (Washington, DC: 2002), updated
with AWEA, op. cit. note 13; solar photovoltaics from Maycock, op.
cit. this note; geothermal power from Worldwatch Institute, op.
cit. this note; oil from DOE, EIA, "World Oil Demand," International
Petroleum Monthly, April 2003; natural gas and coal from Janet L.
Sawin, "Fossil Fuel Use Up," in Worldwatch Institute, op. cit. note
13, pp. 34-35; nuclear power from Nicholas Lenssen, "Nuclear Power
Rises," in ibid, pp. 36-37; hydroelectric power from BP, Statistical
Review of World Energy 2002 (London: Group Media & Publishing, June
2002), p. 36.
Copyright
© 2003 Earth Policy Institute
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