Solar after Sunset Arrives in the Arizona Desert

APS energizes nine energy storage systems to keep solar energy flowing after sunset  


With record-setting July temperatures and more soaring temperatures in the forecast, Arizona Public Service (APS) customers are benefitting from solar energy at night, thanks to nine large-scale energy storage systems connected to existing APS solar power plants. As customer energy use broke records, these systems helped support the grid during peak hours.


Solar after sunset helps balance the electric system, improving reliability and resiliency while maximizing renewable resources. These systems capture and store excess clean solar energy when the Arizona sun is shining bright, for use on cloudy days or after sunset to meet customers’ needs.


“When families are making dinner or watching TV in the evening, they need the lights to be on and the air conditioner running,” said Ben Cluff, APS Director of Renewable Generation. “Solar after sunset helps enhance reliability when our customers need it most. We just came through the worst heatwave in Phoenix history, delivering reliable electricity, and serving our customers with this exciting new technology as part of APS’s all-of the-above approach in maintaining a diverse mix of energy.”


So how much energy will these new systems provide? The nine locations will provide about 200 megawatts (MW) of power, enough to serve 32,000 Arizona homes for 3-4 hours. For reference, one MW is about enough to power 160 homes in Arizona. On top of that, 13 more energy storage systems are planned in the next two years through power purchase agreements. Those systems will bring more than 2,000 additional megawatts to the grid, supplying another 320,000+ homes with electricity.


APS Solar Power Plants and Energy Storage Facilities

                                 Size                 Location

Chino Valley          17MW             N. of Prescott

Cotton Center       17MW            N. of Gila Bend

Desert Star            10MW             S. of Buckeye

Foothills                 35MW            Yuma

Gila Bend               32MW            Gila Bend

Hyder I & II            30MW            Hyder

Paloma                   17MW            N. of Gila Bend

Red Rock                41MW            Red Rock

solar panel field

APS serves approximately 1.4 million homes and businesses in 11 of Arizona’s 15 counties, and is a leader in delivering affordable, clean and reliable energy in the Southwest. The company is committed to serving customers with 100% clean power by 2050. As owner and operator of Palo Verde Generating Station, the nation’s largest producer of carbon-free electricity, and with one of the country’s most substantial renewable energy portfolios, APS’s current energy mix is 51% clean. With headquarters in Phoenix, APS is the principal subsidiary of Pinnacle West Capital Corp. (NYSE: PNW).

Related stories

The Heat is on and APS is Ready to Serve Customers
More clean energy for APS customers: what to know and why it matters
Local Veterans Give Back, Help Generate Solar Power for Arizona
View up to date news, articles and stories related to APS in the community.
Copyright © 2024 APS.  All rights reserved.
Current server address is