Impact of Batteries' Energy Trading on Distribution Network Congestion: A Great Britain Case Study

This work investigates the potential effect on distribution network flows and congestion in Great Britain of wholesale market trading by grid-connected batteries. Using real network and windfarm data during three 5-week periods in 2022, the effect of battery trades on overall network flows at a chosen location is simulated. This study found that there are times of good alignment between patterns of network flows and wholesale electricity prices, during which trades by a suitably-sized battery would not cause congestion. However, more often, the timeseries pattern of wholesale price would encourage trades that fit poorly with network flows: at such times a battery, engaged in wholesale trades, would be likely to exacerbate distribution network congestion. This result may not hold for locations with distributed solar rather than wind generation. Possible responses could include more granular price signals, greater use of flexible connections, and suitable local flexibility products.