Combining photovoltaic energy with electric vehicles, smart charging and vehicle-to-grid

Electric vehicles are expected to greatly increase their market share in the near future. Their impact on the energy system will depend also on the way electricity will be generated. Renewable energy sources and intelligent control strategies will offer relevant solutions to mitigate that impact. In this paper we study the combination of photovoltaic energy and electric vehicles under uncontrolled charging regime and under the application of smart charging and vehicle-to-grid strategies. The analysis assumes different levels of photovoltaic generation and different penetrations of the electric vehicles. The assignment is carried out by means of an open source linear optimization model named EVLS, which simulates the interactions between the electric vehicles and the upstream energy system by considering market, technical and behavioral constraints. The results show that a high photovoltaic capacity could cover only a small portion of the transportation demand, if the charge is uncontrolled. In such a case, the non-photovoltaic generation would be required to severely ramp up in the late afternoon hours. An intelligent control of the charge could better accommodate the photovoltaic energy and reduce the ramps. The vehicle-to-grid could additionally help harnessing the photovoltaic energy to shave the peaks of the conventional load profile.