 |
|
|
 |
A source for everyone interested in energy, business and the environment  |
|
 |
"...an invaluable guide to a more helpful future..."
-Walter Cronkite |
|
|
|
|
|
 |
|
SOLAR:
After years of promising development, the key to affordable, widespread use of solar photovoltaics - which convert sunlight directly into electricity - are the new paper-thin PV cells that were created using advances discovered by semiconductor manufacturers. It's been a long time coming: Bell Laboratories invented the first practical PV cell in 1954. Investments by NASA, the Pentagon, the National Science Foundation, and the Department of Energy helped to sustain the technology. Since 1980 PV cells have come down in price by a factor of ten as production climbed from three megawatts in 1980 to 120 MW by 1997. Their market continues to grow at over 15 percent a year. Installed on a building, PV can reduce peak summer electricity loads and provide back-up for uninterruptible power supplies.
- One of the country's first large arrays of thin-film PV modules is a 17-kilowatt system on top of a warehouse operated by the New York City Transit Authority in Queens.
- A New York City Department of Sanitation building on Riker's Island uses 216 translucent PV modules for its roof. Besides providing electricity, the modules have a 17 percent light transmittance that provides daylight for the facility.
- The Austin, Texas Convention Center has a 20-kilowatt PV system mounted on a motorized rooftop tracking system that follows the sun throughout the day.
- By 1997, the Sacramento Municipal Utility District (SMUD) had installed more than five megawatts of distributed PV systems on its customers' buildings. SMUD has signed contracts to triple that capacity by 2002.
- Interface Carpets, with Solarex and AC Battery, is installing a 109-kilowatt solar array to generate the electricity for making tufted carpet at its Bentley Mills plant in City of Industry, California.
- An Applebee's Restaurant in Charlotte, North Carolina, has a small, 1.7-kilowatt photovoltaic array that replaces part of the roof. It includes a heat-recovery system that uses the array's excess heat to preheat water. The project had a payback of under two months with state tax credits.
|
|
|
