After announcing nearly a gigawatt of new clean-energy projects in February, APS is now seeking proposals to build two of them in different parts of the state.


Image: A power transmission line. Photo: courtesy of John Smith/

The first request for proposals (RFP) seeks partners to add batteries to existing APS solar plants in rural Arizona, storing their power for use after the panels stop producing each day. A second partner is being sought to develop a large new solar plant paired with storage, to bring more clean energy to customers after dark. Both of these projects will provide APS customers with more solar after sunset, serving their evening energy needs with an even cleaner resource mix.

These projects are the next step in APS’s goal to add nearly a gigawatt of new clean-energy projects by the summer of 2025. What does a gigawatt mean for the average customer? That is the equivalent of adding the power of more than 3 million solar panels or more than 9,000 electric cars to Arizona’s energy mix. This ambitious goal will be reached through a number of projects over the next few years, with today’s announcement a milestone toward that goal.

Arizona has unique and growing power needs that energy storage can help to meet. APS customers need almost double the electricity at peak times in the summer than in other, milder-weather seasons. During the summer, customers are coming home and relying on air conditioning almost nonstop to combat hot temperatures that last late into the evening. The simple challenge has been that solar panels go off the clock when the sun sets, just as APS customers are starting to use the most electricity. Batteries can now help solve that challenge.

“These projects aim to make solar work harder for APS customers and ensure our state’s peak energy needs are met with even more clean energy,” said Brad Albert, Vice President of Resource Management for APS. “Gone are the days of the sun dictating solar power’s hours. With our new energy storage projects, APS will be giving customers solar after sunset.”

RFP for Storage at Existing Solar Plants. APS is seeking partners to bring more storage to rural Arizona by installing batteries at existing APS solar plants in Chino Valley and Red Rock. The Chino Valley facility, located in Yavapai County, currently provides 19 megawatts of clean, solar energy. Red Rock, APS’s newest and largest owned solar facility, provides 40 megawatts and is located halfway between Phoenix and Tucson in Pinal County. Both of these batteries will be operational by 2021 and are the final portion of the 200 megawatts of battery storage systems for existing solar plants that APS announced in February.

RFP to Build New Solar Storage Plants. In addition to the new storage at existing solar plants, APS plans to build 500 megawatts of new solar generation plus storage and stand-alone battery storage by 2025. APS is seeking partners to build the first of these: a new 100-megawatt solar facility to be paired with a 100-megawatt battery.

Source: Company Press Release