Arizona Storm Knocks Out Solar Power, ACC Kevin Thompson Reveals Challenges During Peak Hours

A powerful dust storm that hit Arizona this week caused major problems for the state's solar power system, according to Kevin Thompson, who chairs the Arizona Corporation Commission.

Kevin Thompson shared surprising details about how Monday's storm affected electricity production across the state. When the dust storm rolled through, Arizona's two biggest utilities lost massive amounts of solar power right when people needed electricity most.

"APS & SRP lost a combined 1,585 MWs of generating power from utility scale solar during peak demand." Thompson explained. "That's roughly one reactor at Palo Verde."

Timing of Storm

The dust storm started around 3:30 p.m. in southern Arizona near Casa Grande and Eloy. The wall of dust moved north toward Phoenix, reaching the city about two hours later. NPR issued warnings for major highways including Interstate 10, Interstate 17, and Highway 60.

The storm brought more than just dust. Thunderstorms hit areas like Queen Creek, Chandler, and Gilbert. Flash flooding threatened parts of western Arizona near California.

NPR reported that by evening, over 39,000 homes in Arizona had lost power, with most outages in Maricopa County. The storm lasted about an hour as it moved through the area.

Blackout Prevention

Just as the solar panels stopped working properly, demand for electricity went up by 200 megawatts on the APS system. Thompson said this meant APS lost about half its solar power while SRP lost 45% of theirs during the worst part of the storm.

Fortunately, natural gas power plants quickly kicked in to make up for the lost solar energy, preventing blackouts across Arizona.

Thompson said this storm proves an important point about Arizona's electricity future. 

"The moral to the story is that natural gas, coal, and nuclear will continue to play a pivotal role in Arizona's diverse mix of generation, complimenting renewables and ensuring a reliable grid for the foreseeable future." He stated. 

Thompson discussed these events during a recent workshop about natural gas. He said the storm shows why Arizona needs to keep using traditional power sources even as the state adds more solar and wind energy.

For Arizona residents, Monday's storm was a real test of how well the state's power grid can handle extreme weather. The results show both the benefits of having multiple energy sources and the challenges of relying too heavily on weather-dependent power like solar.