Electric vehicles (EVs) represent both a new demand for electricity and a possible storage medium that could supply power to utilities. The "load shifting" and “vehicle-to-grid” concepts could help cut electricity demand during peak periods and prove especially helpful in smoothing variations in power generation introduced to the grid by variable renewable resources such as wind and solar power. This paper proposes a method for simulating the potential benefits of using EVs in load shifting and "vehicle-to-grid" applications for four different regions – the United States, Western Europe, China and Japan – that are expected to have large numbers of EVs by 2050.