Hank.Walker@CMU-CS-VLSI.ARPA (04/26/84)
According to a March Spectrum article, RCA achieved 10.1% efficient amorphous cells in 1982. This technology was licensed to Solarex. Fuji, Sanyo, and Sharp have plants, the latter in a joint venture with Energy Conversion Devices of Troy, Michigan. Sharp is using it to build solar-powered calculators. The cost is about $7 per peak watt, about the same as solar modules (cells in assemblies) made with commercially-available single-crystal cells. Low price per peak watt for the cell isn't the goal, it's low price per kilowatt hour. This takes into account balance-of-plant costs such as power conditioners, and as an example, for a typical plant, 12.6% cells could cost $400M, 10% cells could cost $320M, and 5% cells would have to cost -30M for the same busbar power cost. So efficiency does matter for power plants. This example comes from Southern California Edison, the utility with more solar experience than anyone. So NASA's goals aren't all that different than those of the real world.