The peaking potential of long-duration energy storage in the United States power system

In this work, we investigated the peaking potential for storage with durations of 4 h up to durations of 168 h (1 week). The peaking potential for a given storage duration is the amount of storage that can be added to a power system before that storage can no longer serve the peak net demand period at full rated capacity. We found that for the United States, 168 h of storage would be sufficient to serve about 27 % of peak demand, or about 215 GW in the current system. However, more than one-half of this amount could be served by storage with 12 h or less of capacity. As deployment of wind and solar grows, the peaking potential increases significantly, and under decarbonization scenarios, approximately one-half of the peak demand could be served by storage of up to 168 h; but again, the majority of this storage could be with durations of up to 12 h. The potential is also driven by the mix of wind and solar, and by storage efficiency, with the deployment of solar having the largest impact for both storage peaking potential and the mix of durations. •We examine the peaking potential of storage with durations of up to one week.•The peaking potential for storage up to 168 h is currently 215 GW in the United States.•Diurnal storage provides over half of the peaking potential of all storage up to 168 h.•There is limited (but non-zero) peaking opportunity for storage durations of 12–24 h.