‘Vehicle-to-X’ experiments in Japan, an opportunity to promote EV development

Résumé:

 Consumers expressing a need for longer range, the capacity of EV batteries will be increased in the future. But, except for goods delivery or public transport, the daily use of EVs for urban trips is not expected to grow; statistics on car use clearly show that a private car is used only one hour par day on average. This means a large amount of the electricity stored in the battery will not be used and could be assigned to other purposes. Thanks to devices authorizing a two-way charge, two main utilizations are experienced up to now.

The first one is a local one, which is using the battery as an additional storage capacity, both for reducing electricity purchase during peak periods, and to increase the share of renewable energy sources for houses and building. For example, Vehicle-to-Home (V2H) devices increase the storage capacity by 4 for houses equipped with solar panels, which encourages households to “produce and consume locally”, rather than selling the solar electricity to power supply companies. Vehicle-to-Building (V2B) or Vehicle-to-Factory (V2F) experiments were done using the companies’ car fleet and gave interesting results, in reducing peak period consumption up to 1/3.

The second one or Vehicle-to-Grid (V2G) concerns the use of EV batteries for the micro regulation of electricity supply (frequency control). Through a specific contract with an aggregator, EV owners agreed the use of a part of the capacity of their car batteries when the vehicle is plugged, for such a regulation, in return for fees which reduce the total cost of ownership (TCO). With the development of the e-car fleet, the size of the storage capacity will be enough to substitute to traditional regulation systems with a better quality (response time) and a lower cost.

This paper will present some results of these experiments in the case of the Japanese demonstrations of ‘Next Generation Energy and Social Systems’ (2010-2015) and discuss their interest for promoting Electromobility. Such devices are already commercialized in Japan and many other experiments are developing in other countries (US, Europe).