MEA, Chugach install new battery system to keep regional power grid stable

Two Southcentral electric cooperatives, Matanuska Electric Association and Chugach Electric Association of Anchorage, have taken steps to strengthen the regional power grid against upsets that could disrupt service.

The two co-ops have commissioned a new $65 million Battery Energy Storage System, or BESS, that will provide short-term power to keep the grid stable. The BESS will be capable of supplying 40 megawatts of electricity for two hours, which will give managers of MEA and Chugach time to adjust their systems, MEA and Chugach said Monday, Oct. 7, in a statement.

Chugach will own 75 percent of the system and MEA will own 25 percent, an arrangement similar to the partnership with the Southcentral Power Project in Anchorage, where the power that is generated is shared.

The BESS is in south Anchorage at the Southcentral power plant. It consists of 24 Tesla Megapack battery modules.

“We’re excited to see this project contribute to our region’s energy future,” said MEA CEO Tony Izzo. “We understand that reliability of power is the number one priority for our co-op members, and this initiative will improve power quality from the Bradley Lake Hydro project while reducing costs and increasing generation options for the entire region.”

“The BESS enhances system flexibility, boosts reliability, saves fuel, and brings cutting-edge technology to the Railbelt,” said Chugach CEO Arthur Miller. “It’s a crucial step as we work to diversify power generation and create a more dynamic system.”

The BESS will serve as a backup resource for both Chugach and MEA during disturbances, such as transmission line interruptions, generation issues, or other load shed events. It can instantly respond to power disruptions, injecting or absorbing power as needed to stabilize the grid. It will also increase the resiliency of the Bradley Lake Hydroelectric Project, which benefits the Railbelt.

Another advantage is its ability of the BESS to reduce reliance on “spinning reserve,” or generation capacity that is now kept operating in reserve on natural gas and hydro power generators.

If there is an upset power can be supplied from the spinning reserve. By moving spinning reserves to the BESS from existing generators, the BESS system will lower natural gas consumption by about 5% annually for both Chugach and MEA, with cost benefits as well as a reduction of greenhouse gas emissions.

The $65 million project may also qualify for federal Investment Tax Credits. The current BESS footprint also allows for potential future expansion of up to 70 megawatts from 40 in the current system.

Two other electric co-ops in the Southcentral-Interior “railbelt” power system have BESS units. Golden Valley Electric Association of Fairbanks has had a unit in place for several years that can store and deliver 20 megawatts of power for 15 minutes or 40 megawatts for a shorter period.

Homer Electric Association also has a BESS unit at its power generation station in Soldotna that can deliver 46 megawatts for two hours.

Meanwhile, Golden Valley in Fairbanks is working with Westinghouse on a larger energy storage system that could supply power for much longer periods. Unlike the BESS systems, which involve batteries, the Westinghouse technology will store surplus heat with a ceramic tile system. When needed the heat is tapped to generate power.

The U.S. Department of Energy has awarded a grant to GVEA to help develop the Westinghouse storage system at Healy, south of Fairbanks, but the Interior cooperative must raise funds for its share of funding.