Utility-scale battery installations on US grid reach 700 megawatts

Utility-scale battery installations on the U.S. electric grid reached approximately 700 megawatts (MW) by the end of 2017, about 0.06 percent of U.S. utility-scale generating capacity, according to the U.S. Energy Information Administration (EIA).

Most of these installations occurred within the last three years. The EIA reported that 69 MW of new utility-scale battery capacity is currently planned for 2018.

Energy storage technologies such as batteries can act as both energy suppliers and consumers at different times, making direct comparisons to other generation technologies difficult, EIA explained in a news release.

Battery projects have a relatively low average construction cost but must buy electricity supplied by other generators to charge and to make up for the round-trip efficiency losses experienced when charging and discharging.

Battery’s technical characteristics can be described in terms of power capacity or rating, the maximum instantaneous amount of power that can be produced on a continuous basis in megawatts, and energy capacity, the total amount of energy that can be stored or discharged in megawatt hours (MWh). A battery’s duration is the ratio of its energy capacity to its power capacity.

EIA noted that while batteries have relatively low capacity factors, they “can uniquely capture a range of value streams, which can sometimes be combined to improve project economics.”

EIA highlighted numerous uses for batteries including balancing grid supply and demand, peak shaving and price arbitrage, storing and smoothing renewable generation, deferring large infrastructure investments, reducing end-use consumer demand charges and acting as back-up power.