Electric-drive vehicles for peak power in Japan

Electric-drive vehicles (EDVs), whether based on batteries, engine-electric hybrid, or fuel cells, could make major contributions to the electric utility supply system. Computer-controlled power connections from parked EDVs would provide grid power from on-board storage or generators. Kempton and Letendre conclude that, in the United States, battery EDVs can be cost-effective as a source of peak power (Kempton and Letendre, 1997) or as spinning reserves (1999). This option is even better matched to urban Japan, where vehicles are typically parked throughout peak electrical demand periods. Using Ministry of International Trade and Industry (MITI) forecasts for the number of zero emission vehicles in 2010, we estimate the maximum potential power from EDVs in the Kanto region (which includes Tokyo) at 15.5 GW, 25% of Kantoʹs 1998 peak demand. This paper calculates the cost to provide power from five current EDVs — both battery and hybrid vehicles — and compares those costs to current purchase rates for independent power producers (IPPs) in Japan. Battery characteristics are calculated from current manufacturer-provided data as well as the California Air Resources Board (CARB) projections. Given current vehicle battery costs and current utility purchase rates, no vehicles would be cost-effective peak power resources. Given CARB projections for batteries, the Nissan Altra is cost-effective as a utility power source. Using projected IPP purchase rates for peak power and CARB battery projections, the Nissan Altra and Toyota RAV4L EV are cost-effective. The net present value to the electric grid could be near 300,000 yen ($US 2500) per vehicle. If utilities take advantage of this opportunity to purchase peak power from vehicles, it would make the electric grid more efficient, enlarge the market for EDVs, lower urban air pollution, and facilitate future introduction of renewable energy.