Factorial Analysis for Evaluating the Effect of Energy Storage on Renewable Energy Accommodation

The integration of high-penetration renewable energy resources into the power system has posed increasing challenges to system operators if the strict constraints of solar and wind curtailments are taken into consideration. The energy storage could provide ancillary service to system operators as it temporarily stores renewable energy to deal with the variation of renewable generation, thus promoting the consumption of renewable energy. Its effect on renewable energy accommodation is well worth being evaluated so that suitable types and sizes can be chosen to minimize the investment of energy storage equipment. Moreover, other factors such as the flexibility of thermal unit could also influence the effect of energy storage on renewable energy accommodation. This paper utilizes analysis of variance-based factorial analysis method to evaluate the effects of energy storage on renewable energy accommodation. A case study is conducted to study the effect of four factors (power capacity, energy-to-power ratio, round-trip efficiency for energy storage and minimum power output for thermal units) on the rate of renewable energy curtailment in a sending-end system of HVDC transmission. The results of analysis could provide a clear guidance to system operators for subsequent planning of energy storage devices in the HVDC sending-end system.