Electric vehicles as storage devices for supply-demand management

The use of electric vehicles as storage devices is investigated, with a view to improving the supply/demand matching of electrical networks. Consideration is given to making this supplementary function compatible with the primary function as a means of transport. Case studies showed that, where solar energy is the primary energy source, daytime charging, combined with evening/overnight regeneration, provides the optimum matching. Large car parks, close to the place of work, would be used for charging. Conversely, for wind energy, charging is generally best carried out overnight. This would therefore be performed largely in residential areas. Network reinforcement would include extra transformers for MV feeders to car parks, and higher capacity LV feeders in residential areas.