Arizona Public Service this morning announced a major investment in solar battery, a historic shift in the utility’s approach to renewable energy.
The state’s largest electric company said it will add 850 megawatts of battery storage and 100 megawatts of new solar generation by 2025.
“Arizona is already a national leader in solar energy. The challenge is no one has figured out how to stop the sun from setting at night,” APS Chairman and CEO Don Brandt said in a news release. “As storage technology improves and declines in cost, we will increasingly be able to store the power of the sun cost-effectively to deliver when our customers need it.”
APS said it will add battery storage to its fleet of solar power plants, build new solar plants with battery storage, and then use the stored energy to deliver power during peak energy usage. The company said this will result in customers being able to use solar energy after the sun goes down, and lead to a cleaner energy mix.
Solar production usually declines late in the afternoon, and electric companies turn to natural gas to meet the energy demand. APS said it will use 150 megawatts of solar-fueled battery storage to partly meet that energy demand.
APS has also contracted with Calpine to provide 463 megawatts from natural gas.
APS said its contract with Calpine lasts only seven years, instead of the typical 20-year agreement, which the company said will allow it to take advantage of cleaner technologies in the future.
The investment has broad support.
Pat Graham, state director of The Nature Conservancy in Arizona, said investing in large-scale battery storage is a critical step toward reliable and affordable clean-energy solutions.
“Clean energy and clean air are important to the health of our communities and the lands and water upon which all life depends,” he said.
APS said it will upgrade its existing solar plants with 200 megawatts of battery storage systems. Invenergy, a company that specializes in large-scale battery systems, will install six new battery systems at APS’s solar plants in Maricopa County and Yuma by 2020. Two other upgrades will be completed by 2021, APS said.
APS also plans to build another 500 megawatts of solar storage by 2025, the first of which is a 100-megawatt solar-storage plant. APS said it expects to issue a request for proposals this summer.