A recent report from
the U.S. Department of Energy’s Power Outage Study Team, titled “Findings
and Recommendations to Enhance Reliability from the Summer of 1999,” identified
six major power outages. These outages occurred when high, heat wave-driven
local demands causing stress on distribution systems, resulted in an inability
to generate, purchase, and/or distribute enough electrical power.
An analysis of the solar
resource during these outages, based upon satellite remote sensing data,
shows that the output of local solar electricity systems would have been
above 90% of ideal clear day output during five of the six outages and
above 80% for the remaining one (as shown below). An analysis for a recent
outage in San Francisco has also been included. All show that local availability
of solar electricity can mitigate the conditions that lead to, and reliably
prevent, this type of outage.
 “Residential Customer-Sited Photovoltaics Niche Markets 1999,” Herig et al., and “Mapping the Value of Commercial PV Applications in the US—Accounting for Externalities,” Perez et al., American Solar Energy Society Conference Proceedings, Portland, Maine, June 1999.