TEP to Build Tucson BESS

Tucson Electric Power (TEP) plans to build the 200 MW Roadrunner Reserve II, the company’s second large BESS, in southeast Tucson.

The system, slated to store 800 MWh, is scheduled to begin operation in 2026, a year after the similarly sized Roadrunner Reserve is expected to begin operating on the same site.

The side-by-side systems are slated to be the largest energy storage resources in TEP’s portfolio.

“Our new Roadrunner Reserve II system will help us make the most of intermittent resources, especially during the summer when usage is highest and customers are counting on us the most,” says Susan Gray, TEP’s President and CEO. 

“We need additional energy storage as part of a diverse energy portfolio to support service reliability.”

The projects will be built next to a southeast-side TEP substation. Construction of Roadrunner Reserve is ongoing, while construction of Roadrunner Reserve II is scheduled to begin later this year.

Currently, TEP has 50 MW of storage capacity, including a 30 MW BESS at the Wilmot Energy Center.

The company will own and operate both systems, which will be designed and built by Scottsdale-based DEPCOM Power. Both systems will use lithium iron phosphate battery units.

TEP and its parent company, UNS Energy, are subsidiaries of Fortis.