According to an excel file I have with 6500 power plants active in 2001 only 4 Photo voltaic systems were active and their output was tiny in comparison to the entire grid. There was total output of 437 kWT per hour.
There are two grouped in AZ and two grouped in CA
Agua Fria Maricopa AZ 85072 64KWT
Solar Sacramento CA 95638 373KWT
THe largest solar plant in the US in 2001 was not Photovoltaic it involved solar reflection to hear liquids to spin turbines.
http://en.wikipedia.org/wiki/Solar_E...rating_Systems
SEGS I San Bernardino CA 92327
SEGS II San Bernardino CA 92327
SEGS III San Bernardino CA 93516
SEGS IV San Bernardino CA 93516
SEGS V San Bernardino CA 93516
SEGS VI San Bernardino CA 93516
SEGS VII San Bernardino CA 93516
SEGS VIII San Bernardino CA 92347
SEGS IX San Bernardino CA 92347
Total output in 2001 was 70,815 kWT per hour.
Not the generation numbers do not reflect maximum capacity as for obvious reasons solar plants cannot operate 24 hours a day.