Nissan Leaf Will Power Homes in Japan

This week, automaker Nissan  announced a two-way charging system that will allow the new all-electric Nissan Leaf  to not only charge up, but also to reverse the flow of electricity to allow the car to power the home for brief periods during power outages or shortages.

Considering the recent calamity in Japan’s power generation system, and the numerous blackouts that occurred in the aftermath, this capability will certainly be appreciated. Meanwhile, energy saving measures in the wake of the disaster have reduced Tokyo’s electric demand by about a third.

The  Leaf’s lithium-ion battery can hold 24 kWh when fully charged, enough to power an average Japanese home for two days. For a typical American home, that would last less than a day. Of course, the consumer needs to be careful not to run the batteries all the way down to make sure that there is enough juice left in the car should it be needed.
This system can be used as a money-saving energy storage unit, if the batteries are charged overnight when the cost of power is low, and then used in the house during the day when power costs are higher. This system will be available in Japan in 2012 and in other locations as soon as the design can be localized. The announcement coordinates well with other recent announcements of more forthcoming electric vehicles.

Japan was not the first country to adapt such as system-- Denmark was.

Denmark’s program, which was announced in June, allows users to not only power their homes, but also to sell excess power back into the grid. An EV owner could theoretically make up to $10,000 over the life of the car. The technology is being provided by US manufacturer Nuvve, which chose Denmark as the best location to pilot their vehicle-to-grid based on Denmark’s enthusiastic embrace of both electric cars and renewable energy.

According to the company’s website:

Nuvve’s proprietary ‘Vehicle to Grid’ or ‘V2G’ Aggregation solution transforms electric vehicles from simple loads on the electric grid into dispatchable energy storage resources by enabling the vehicle to send excess energy stored in its battery back to the grid upon request.  The aggregation of hundreds of electric vehicles allows Nuvve to participate in ancillary service markets with power capacity comparable to traditional generators.

Nuvve’s solution includes both hardware and software as well as the services required to connect the vehicle to the electric utility infrastructure.

The system contains several modules including:

• Electric vehicle supply equipment (EVSE) - which interfaces the vehicle with the charging apparatus


• Aggregator – which collects power from several vehicles at a time in order to meet grid minimum capacity levels


• Vehicle Smart Link (VSL) – an embedded processor within the vehicle to reconcile participation opportunities with the vehicle owner’s driving needs.

Forecasts from Zpryme project that by 2020 there will be over one million V2G vehicles on the road. They predict a $43.8 billion market at that time, which is going to take a lot of jobs to create and provide a lot of opportunities for innovation.

This growth will be a boon to both the economy and the environment, since this additional capacity, when combined with new agile generating equipment will go a long way to facilitate the widespread use of renewables that should make a dramatic positive impact on reducing greenhouse gas emissions. I only hope that it’s not too late.

RP Siegel is the co-author of the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water.  Like airplanes, we all leave behind a vapor trail. And though we can easily see others’, we rarely see our own.

Follow RP Siegel on Twitter.