The effect of non-cooperative distributed energy storage on aggregated load profile under real-time pricing

Under real-time pricing (RTP) schemes for electricity, distributed energy storage (DES) can be used for arbitrage purposes in a deregulated electricity market by charging when price is low and discharging when price is high. Despite the various potential benefits that energy storage may bring to the grid, DES could significantly affect the aggregate load curve and create a load spike at the time when electricity price is lowest if the percentage of the active capacity of DES in all loads is too high. It is thus of crucial importance to model and analyse the effect that DES brings to the deregulated electricity market. In this paper we consider a deregulated electricity market where RTP is the only signal for load control and varies with load to reflect actual cost. We investigate a method for joint load rescheduling and energy storage operation planning under given price, and analyse the impact of increasing penetration of distributed energy storage on optimal RTP and aggregated load curve. Results show that distributed profit-making energy storage below a certain penetration rate helps to flatten the aggregate load curve under RTP scheme and increase social welfare. If the penetration rate exceeds a threshold, new load peaks could be created suggesting that using RTP alone is insufficient for load control in such cases.