A study of electric vehicle battery charging demand in the context of Singapore

Continuing environmental concerns are moving electric vehicles into high gear of development. Plug-in type electric and hybrid vehicles are expected in the market anytime. The EV battery-charging load can potentially increase the demand on the utility distribution systems considerably. It is desirable that the EV battery charging load be contained during system off-peak hours without affecting the peak demand, thus utilizing the low cost electricity for charging EV. However, a sizable EV load can introduce a new peak in the early off-peak period. Optimization of the EV charging during the low cost off peak period is formulated to minimize the cost of EV charging in the context of Singapore system. The case studies presented show that significant saving is possible even at reasonable low levels of EV penetrations.