We all know that people can plug their electric car into a building's electrical system to juice up the batteries, but what about reversing the flow and using the car's battery capacity to power the building? That's what Nissan engineers are testing in Japan with a technology that they call "Vehicle to Building."
While it's not a common practice in the United States, most electric power utilities around the world charge far higher rates during peak hours than they do at night when the demand is low. So the folks at Nissan figured that if they could use the cheap night time power to charge up their electric car's batteries, then they could tap into that stored energy to reduce their thirst for the expensive stuff during the day.
The system is being tested at Nissan's Nissan Advanced Technology Center in Atsugi City, where they have reduced their peak power draw by about 2.5 percent, saving around $5,000 per year on the electric bill. For the test, Nissan has been using six of their Leaf electric cars, connected to modified versions of the charging stations normally used just to charge the cars.
An electric car isn't much use if the batteries are dead when you need them, so Vehicle to Building uses software to ensure that the car is charged when you're likely to be driving it. That's fine if your schedule runs like clockwork every day, but could be a problem if your plans change and you have to make an emergency trip. I also wonder whether all of that extra cycling of the battery packs could negatively impact their useful life. I think most EV drivers would be nervous about draining their car's battery just to save a few bucks, if it might leave you stranded at the side of the road on an unplanned trip. It would certainly be handy however if there's a power outage.