A new solar-plus-storage system planned for Cochise County will help Tucson Electric Power provide more clean energy when the sun goes down.
Winchester Solar, located about 18 miles west of Willcox, will include an 80-megawatt photovoltaic array and an 80-MW battery system and is expected to come online in 2027.
Virginia-based Torch Clean Energy will build, own and operate the facility and sell the power to TEP, which estimates the solar farm will produce enough energy to power about 11,000 homes annually.
Selected through an all-source request for proposals TEP issued in 2022, the Winchester Solar project is part of the company’s plan to reach net-zero direct greenhouse gas emissions by 2050.
The company’s latest integrated resource plan calls for expanding storage capacity from 51 MW currently to 1,361 MW in 2038.
TEP plans to charge Winchester Solar’s grid-connected batteries in the morning and early afternoon, to allow delivery of stored energy later in the day, when customers’ energy use typically peaks.
The 320 megawatt-hour battery system can provide 80MW of alternating-current energy for four hours when fully charged, the utility said.
Not far from the Winchester site near Willcox, TEP already buys energy from the Red Horse Solar and wind project, which was built and is owned by Torch Energy. The 51-MW solar array and 30MW wind farm went online in 2015.
TEP and sister utility UniSource Energy Services are currently evaluating proposals submitted in response to a joint all-source request issued in December 2023, calling for up to 625 MW of renewable and energy efficiency resources and up to 825MW of “firm capacity” resources that could be called upon at any time.
Meanwhile, development work continues on the 200-MW Roadrunner Reserve battery storage system near South Rita Road south of Interstate 10, which will be TEP’s largest energy storage system and among the largest in Arizona when it comes online in 2027.
