Over years, cars have developed as comfortable means for going anywhere anytime. However, after the recent Great East Japan Earthquake, we saw many instances of cars being used as emergency power generation or electricity storage device. Can cars be incorporated in social infrastructure as a new “source of power” in future? In this second installment of the series of total 3 installments on cars as a source of energy, I will share information on the experiments done by some automobile manufacturers (Click Here for the first installment）.

In future when hybrid vehicles (HEV), plug-in hybrid vehicles (PHEV) or electric vehicles (EV) driven by high capacity rechargeable batteries would become widely used, couldn’t they be collectively utilized as mega power storage devices? The concepts of ’V2H (Vehicle to Home)’ and ’V2G (Vehicle to Grid)’, where cars would be bi-directionally connected to homes and power grids to exchange power, are being animatedly discussed.

This concept was originally thought of in the US at the time of building “Smart grid” - the next generation power grid. If PHEV and EV become widespread, most of the users would probably start recharging the batteries en mass once they return home at night. In the US, power grids in many places are aging and in order to sustain this en mass recharging, it will become essential to install more and more transformers on power poles which would be an expensive measure.

In order to curb this cost, a technology is now being studied to manage and put a check on en mass recharging of vehicles thus ensuring that no load is put on the power grids. However, as the smart grid thing was heating up, an idea came up that if recharging is anyway to be controlled, couldn’t the vehicle batteries rather be used as power source when the power grids have insufficient power or to level the load of highly fluctuating power generated from renewable energy sources like wind and solar energy?

Proactive support from automobile manufacturers

The idea has now caught hold of Europe and China who are aiming at facilitating the spread of electric vehicles and the topic is increasingly being discussed globally as well. However, before the Great East Japan Earthquake, the power companies in Japan insisted that the “power grids in Japan were of high quality and they did not feel any need to get power from electric vehicles.” Initially, the automobile manufacturers in Japan too did not take this seriously as they felt that it would involve major issues like “who will guarantee the quality of the batteries” when batteries would deplete due to the power supplied from them for any other purpose besides driving.

However, the heat from US, Europe and China has radiated to the automobile manufacturers in Japan too and they seem to have aggressively adopted a positive approach in recent couple of years. This may be because they have now realized that they themselves should rather have rights pertaining to the power supplied from vehicles. Hence now even in Japan, under the “Next-Generation Energy and Social System Demonstration Areas” project of the Ministry of Economy, Trade and Industry, Toyota and Nissan Motor companies are about to start conducting the verification tests.

Specifically speaking, Toyota Motors will start the verification tests in Toyota city, Aichi prefecture, while Nissan will start it in Yokohama city, Kanagawa prefecture. For example, Toyota plans to verify by actually selling 70 storage battery equipped houses to general consumers and lending each such home a PHEV or EV with rechargeable batteries installed and collect data from them.

The characteristic of Toyota Motors’s experiment is that it considers a set of ‘car and home’ as the basic unit and first aims at constructing a V2H system. Furthermore, the company is working on enhancing its housing department to strengthen its link with ‘homes’. In October 2010, the housing business of Toyota Motors was merged into Toyota Home and 9 companies of the Toyota group, namely Denso, Aisin Seiki, Toyota Industries Corporation among others newly invested in Toyota Home.

Toyota Motors aim at having an integrated control over the electric vehicles with rechargeable batteries installed and houses equipped with storage batteries. The figure above is an excerpt from the feature “Towards an energy storing society starting from home” published in Nikkei Electronics of November 1, 2010.