Solar eclipse will obscure but not disrupt solar generators across United States

Published on August 09, 2017 by Chris Galford

An eclipse will briefly steal the power source from utility-scale solar photovoltaic power plants across on August 21, but the North American Electric Reliability Corporation (NERC) recently said that it should not affect the power system at large.

For those plants in the eclipse’s direct path–from Oregon east to South Carolina–solar-powered generators will find their power source blocked by the moon for up to three minutes, though they will likely be affected to a lesser extent over the entire three hours surrounding the event. Naturally, those further from the path of totality will be less affected. The eclipse itself will take about 90 minutes to cross the United States.

For the path of direct effect, however, 17 utility-scale PV generators will be hit. More than 10 gigawatts of capacity from hundreds of plants will be affected to lesser degrees, with 70 percent obscuration and up. At present, such solar PV operations provide 0.8 percent of the total U.S. electricity generation. California,
while outside the eclipse’s path of totality, faces the greatest burden, as such solar collection methods make up 40 percent of the country’s total capacity and 14 percent of the state’s generation. Normally it generates 8.8 GW through these sources–a number that will be more than halved during the eclipse, according to the California Independent System Operator (CAISO).

Accordingly, electricity generators in affected areas will be called on to increase output from other electricity sources to supplement the dip in solar power availability.