The Duration of Utility-scale Battery Energy Storage: All depends on how you want to use it
Utility-scale battery storage is growing at tremendous pace in the U.S., and it provides a variety of services from grid to load shifting.
How long the battery energy storage systems (BESS) can deliver, however, often depends on how it’s being used. A new released by the U.S. Energy Information Administration indicates that approximately 60 percent of installed and operational BESS capacity is being exerted on grid services.
To break it down, 40 percent is performing both grid services and electricity load shifting applications. Another 40 percent is performing only load shifting, while 20 percent is delivering only grid services, according to to EIA.
Those short-duration batteries which can discharge for less than two hours are ideal to help with grid stability in limited periods. With grid services, these assets sometimes discharge power for only seconds or minutes at a time. The contributed generation helps keep frequency and voltage levels stable.
Batteries with long duration potential of four to eight hours are used to shift electricity from times of relatively low demand to times of higher demand, such as peak evening use. In areas with higher solar capacity, such as California, these once-daily cycling batteries can store electricity from solar power during the middle of the day and then discharge later when demand is high and solar power is declining, the EIA release shows.
All told, the U.S. operational utility-scale battery storage capacity exceeded 4.6 GW at the end of last year, according to the EIA. Those systems dating prior to 2020 focused more on grid services, while those coming more recently are of higher duration and often co-located with solar facilities to shift electricity loads.
Some battery-energy storage systems are on-site components of a microgrid, such as the Kodiak Island Microgrid in Alaska. Others are much more expansive and paired with massive solar projects, such as Florida Power & Light’s Babcock and Manatee systems.
FPL announced the startup of the Manatee solar-storage hybrid late last year, calling it the world’s largest solar-powered battery this week.The battery storage system at Manatee Solar Energy Center can offer 409 MW of capacity and 900 MWh of duration.
Duke Energy also expanded its battery energy storage technology with the completion of three battery storage projects with a combined 34 MW in Florida.
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(Rod Walton, senior editor for EnergyTech, is a 14-year veteran of covering the energy industry both as a newspaper and trade journalist. He can be reached at [email protected]).