"Urban transport systems based on a combination of rail lines, bus lines, bicycle pathways, and pedestrian walkways offer the best of all possible worlds in providing mobility, low-cost transportation, and a healthy urban environment." –Lester R. Brown, Plan B 4.0: Mobilizing to Save Civilization.
Chapter 5. Building the Solar/Hydrogen Economy: Turning Sunlight into Electricity
After wind power, the second fastest growing source of energy—solar cells—is a relatively new one. In 1952, three scientists at Bell Labs in Princeton, New Jersey, discovered that sunlight striking a silicon-based material produced electricity. The discovery of this photovoltaic or solar cell opened up a vast new potential for generating electricity.36
Initially very costly, solar cells could be used only for high-value purposes such as providing the electricity to operate satellites. Another early economical use was powering pocket calculators. Once run on batteries, pocket calculators now typically rely on a thin strip of silicon for power.
The next use to become economical was providing electricity in remote sites, such as summer mountain homes in industrial countries and villages in developing countries not yet linked to an electrical grid. In the more remote villages, it is already more economical to install solar cells than to build a power plant and connect the villages by grid. By the end of 2000, about a million homes worldwide were getting their electricity from solar cell installations. An estimated 700,000 of these were in Third World villages.37
As the cost of solar cells continues to decline, this energy source is becoming competitive with large, centralized power sources. For many of the 2 billion people in the world who do not have access to electricity, small solar cell arrays provide a shortcut, an affordable source of electricity. In villages in the Peruvian highlands, for example, village families spend roughly $4 a month on candles. For just a bit more, they can have much higher quality lighting from solar cells. In some Third World communities not serviced by a centralized power system, local entrepreneurs are investing in solar cell generating facilities and selling the energy to village families.38
Perhaps the most exciting technological advance has been the development of a photovoltaic roofing material in Japan. A joint effort involving the construction industry, the solar cell manufacturing industry, and the Japanese government plans to have 4,600 megawatts of electrical generating capacity in place by 2010, enough to satisfy all of the electricity needs of a country like Estonia.39
With photovoltaic roofing material, the roof of a building becomes the power plant. In some countries, including Germany and Japan, buildings now have a two-way meter—selling electricity to the local utility when they have an excess and buying it when they do not have enough.40
Newly constructed office buildings in the United States, Germany, and Switzerland have incorporated photovoltaic materials in their facades to generate electricity. Nothing in the appearance of these buildings would indicate to the casual observer that their glass walls and windows are in fact small power plants.
Growth in the sales of photovoltaic cells averaged 20 percent a year from 1990 to 2000. Then in 2000, sales jumped by 43 percent. Over the last decade, worldwide sales of photovoltaic cells have increased more than sixfold—from 46 megawatts of capacity in 1990 to 288 megawatts in 2000. (See Figure 5-3.)41
The big three in solar cell manufacturing are Japan, the United States, and the European Union. In 1999, production of solar cells in Japan alone jumped to 80 megawatts, pushing it into first place ahead of the United States. A large share of the solar cells produced in the United States, which reached 60 megawatts in 1999, was exported to developing countries. Europe is currently in third place, with 40 megawatts of production in 1999, but its capacity expanded by more than half when Royal Dutch Shell and Pilkington Glass opened a 25-megawatt solar cell manufacturing facility in Germany.42
When BP merged with Amoco, it also acquired Solarex, the solar cell arm of Amoco, making BP overnight the world's third-ranking manufacturer of solar cells after Sharp and Kyocera, both of Japan. Siemens/Shell is in fourth place. The world solar cell market is marked by intense competition among companies and among countries. One reason leading industrial countries have ambitious solar roof programs is to help develop their solar cell manufacturing industries.43
Japan, Germany, and the United States all have strong programs to support this industry. The new Shell/Pilkington manufacturing facility in Germany was built in response to a vigorous German program to increase the use of solar energy, particularly on rooftops. In contrast to the Japanese, which rely on a cash subsidy to the buyers of solar roofing systems, the German government offers a bonus price for solar cell electricity and uses low-interest loans to encourage investment. Germany has a 100,000 Roofs program, with a goal of installing 300 megawatts of solar cells by 2005. The U.S. Million Solar Roofs program was launched in 1997. Although it is an impressive goal, government financial support is not nearly as strong as in Japan and Germany. Italy, too, has begun to move forward on the solar front, with a 10,000 Solar Roofs program.44
The potential in the solar arena is enormous. Aerial photographs show that even in the notoriously cloudy climate of the British Isles, putting solar cells on the country's existing roofs could generate 68,000 megawatts of power on a bright day, about half of Britain's peak power demand.45
The costs of solar cells has fallen from more than $70 per watt of production capacity in the 1970s to less than $3.50 per watt today. And it is expected to continue dropping, possibly falling to only $1 per watt as technologies advance and as manufacturing capacity expands by leaps and bounds. Research designed to improve photovoltaic technology is under way in literally hundreds of laboratories. Scarcely a month goes by without another advance in either photovoltaic cell design or manufacturing technology.46
36. Christopher Flavin and Nicholas Lenssen, Power Surge (New York: W.W. Norton & Company, 1994), pp. 154-55.
37. Estimate by Paul Maycock, PV Energy Systems, discussion with Shane Ratterman, Earth Policy Institute, 15 July 2001.
38. "Power to the Poor," The Economist, 10 February 2001, pp. 21-23.
39. International Energy Agency, "Japan: Overview of Renewable Energy Policy," www.iea.org/pubs/studies/files/renenp2/ren/25-ren.htm.
40. According to North Carolina Solar Center's Database of State Incentives for Renewable Energy, 37 states now have some form of net metering; see www.dcs.ncsu.edu/solar/dsire/dsire.cfm; Germany and Japan from Paul Maycock and Steven J. Strong, in seminar at American Solar Energy Society Annual Conference, May 2000, Madison, WI.
41. Figure 5-3 from Paul Maycock, PV Energy Systems, discussion with Shane Ratterman, Earth Policy Institute, 28 May 2001.
42. Christopher Flavin, "Solar Power Market Jumps," in Lester R. Brown et al., Vital Signs 2000 (New York: W.W. Norton & Company, 2000), p. 58.
43. Maycock, op. cit. note 41.
44. Siemens Solar, "New German Government Announces 100,000 Rooftop Photovoltaic Program," press release, www.siemenssolar.com/german_rooftop_program.html, viewed 25 June 2001; Million Solar Roofs program from DOE, www.eren.doe.gov/millionroofs/; Italian program in Molly O'Meara, "Solar Cells Continue Double-Digit Growth," in Lester R. Brown et al., Vital Signs 1999 (New York: W.W. Norton & Company, 1999), pp. 54-55; German program in Christopher Flavin, "Solar Power Market Surges," in Worldwatch Institute, op. cit. note 3, p. 46.
45. R. Hill, N.M. Pearsall, and P. Claiden, The Potential Generating Capacity of PV-Clad Buildings in the UK, Vol. 1 (London: Department of Trade and Industry, 1992).
46. O'Meara, op. cit. note 44; prices for photovoltaic modules held steady at $3.50/watt for 2000-01, according to Christopher Flavin, "Solar Power Market Surges," in Worldwatch Institute, op. cit. note 3, pp. 46-47.
Copyright © 2001 Earth Policy Institute