Arizona G&T Battery Project Gives Co-ops ‘A La Carte’ Options to Serve Members

Trico installed 15-megawatt batteries in August to establish its Chirreon Solar and Battery Energy Storage Facility. The battery project with AEPCO next summer will be the co-op’s second. (Photo Courtesy: Trico Electric Cooperative)

From enabling more renewable energy resources to saving consumer-members money during peak demand, three Arizona electric cooperatives anticipate significant benefits next summer from local energy storage made possible by their generation and transmission co-op.

Arizona Electric Power Cooperative in Benson and its sister organization, Sierra Southwest Cooperative Services, are buying three lithium-ion batteries totaling 35 megawatts to operate as 140 megawatt-hours of stand-alone energy storage on three rural co-ops’ distribution systems. The project marks the first of its kind for Arizona co-ops.

“Each co-op will be able to develop its own a la carte operating protocol for these batteries to meet the specific needs of their distribution systems while we still meet the reliability needs of our grid overall,” said AEPCO CEO Patrick Ledger.

The battery project plans include:

Mohave Electric Cooperative: 15-MW/60-MWh battery near its solar fields and distribution system in Fort Mohave.
Sulphur Springs Valley Electric Cooperative:10-MW/40-MWh battery near its Mesquite Substation.
Trico Electric Cooperative: 10-MW/40-MWh battery near its Sahuarita Substation.

The co-ops plan to charge the batteries during off-peak hours and distribute their stored power during summer peak periods to avoid buying electricity on the open market when prices are at their highest. The storage projects will also help back up intermittent solar power supplies.

“These local projects will help keep costs low for our members as well as sustain MEC’s commitment to reliability,” said Tyler Carlson, CEO of Mohave EC, based in Bullhead City.

The partnership with AEPCO will “allow us to take advantage of new technology in a responsible way, work with our co-op partners and cover our members’ needs,” said Eric Hawkins, chief operating officer and general counsel at Marana-based Trico, which recently installed its first 15-MW battery system.

“We plan to couple our battery storage with existing solar generation resources,” said Daniel Wilson, senior vice president of operations at Willcox-based SSVEC. “This technology will allow us to shift that energy production into peak demand hours when it is needed the most. Having dependable sources of energy during extreme weather events is critical.”

SSVEC currently utilizes approximately 7% solar energy with plans to exceed 20% by 2025. “Battery technology will allow us to optimize renewables into our power mix without sacrificing reliability,” Wilson said.

Bolstering grid reliability while diversifying the location and type of generating sources and providing co-ops flexibility to serve their members are “long-term goals for AEPCO” that the battery project will help fulfill, Ledger said.

“Our members know their systems best, and we’re here to collaborate on solutions that can meet their specific needs while benefiting our membership as a whole and contributing to the stability and reliability of our state and region,” he said. “It really showcases the value of the G&T and distribution cooperative partnership.”

Cathy Cash is a staff writer for NRECA.