Coordinated electric vehicle charging solutions using renewable energy sources

Growing concerns about global warming, air pollution, and fossil fuel shortages have prompted the research and development of energy efficient electric vehicles (EVs). The United States government has a goal of putting 1 million EVs on the road by 2015. The anticipated increase in EV usage, along with the use of renewable energy sources for EV charging presents opportunities as well as technical hurdles. In this work, we propose coordinated EV charging strategies for commercial charging stations in parking lots. The focus of the research is on minimizing energy drawn from the grid while utilizing maximum energy from renewable energy resources in order to maximize benefits to parking lot owners. We propose an optimal control theory based strategy for EV charging. Specifically we derive a centralized iterative control approach in which the charging rates of EVs are optimized one at a time. Through analysis and simulations, we demonstrate that optimizing the charging rate of one vehicle at a time and repeating this process for all vehicles iteratively converges to the global optimum.