ABSTRACT
The electric motor showed a drastic improvement in fuel economy of vehicles for two reasons. One is that the efficiency of the electric motor at low vehicle velocity is better than that of the internal combustion engine. The second is that regenerative braking is very effective and this is possible only for an electric drive with battery, as the gasoline hybrid vehicles have been successfully commercialized in the last nine years. There are a few ways to supply renewable energy to drive vehicles. One of the realistic solutions is ‘plug-in-hybrid’, which is to increase the capacity of battery and to use electricity at home to charge the battery of gasoline hybrid vehicles. Regenerative braking and rooftop photovoltaics (PV) will increase vehicle cost, but the investment on hydrogen supply infrastructure will decrease. Technologies for innovative vehicle design such as battery, PV, water electrolysis and fuel cell are surveyed.
