Using Energy Storage to Mitigate PV Impacts on Distribution Feeders

This paper explores applications of energy storage on distribution systems, particularly for support of PV integration, using quasi-static time-series power flow simulation to assess both engineering and economic impacts. The methodology behind ES-GRID, a tool developed by DNV KEMA to assess and provide a valuation of energy storage on the distribution grid will be reviewed and results on a sample test case with be presented. Results indicate the potential for energy storage to mitigate component overloads, improve system voltage profile, and improve system equipment operations. Simulation results also illustrate the potential for storage to have indirect effects on the distribution system even where controls are designed to support one element for PV integration. For example, controls targeted at maintaining PV kW production thresholds can simultaneously result in voltage improvements. Overall, the research highlights the complexities of applying and valuing storage on the distribution system due to indirect effects and non-linear relationships between system impacts, storage sizing, and dispatch controls. Ultimately, this research highlights the need for robust systems analysis in evaluating storage impacts.