Assessing load flexibility in smart grids: Electric vehicles for renewable energy integration

Demand response can contribute to system stability and foster integration of renewable energy sources. In our work we model static residential electricity demand together with flexible electric vehicles (EVs) as charging loads. We develop a mixed-integer program to assess the ability of an EV fleet operator to coordinate charging in such a way that a maximum amount of renewable energy is used. Such coordinated charging still requires that all projected mobility needs are satisfied. EVs are modeled using empirical driving profiles of full time employees. Our results show that compared to uncoordinated immediate charging, an optimized charging schedule can nearly double the share of renewable energy used and achieve a yearly supply from wind power of up to 67.2%. In addition, we find that coordinated charging decreases load peaks and reduces the amount of conventional generation required as backup capacity.