Toyota develops mutual power supply system for electric vehicles and homes

TOYOTA CITY —

Toyota Motor Corp on Monday said that it has developed a vehicle to home (V2H) system for the mutual sharing of power between electric-powered vehicles, such as plug-in hybrid vehicles (PHVs) and electric vehicles (EVs), and homes.

The V2H system is to start testing, using Prius PHVs, at the end of 2012 in approximately ten households as part of the Toyota City Low-Carbon Verification Project (Toyota City Project) that began in April 2010.

The newly developed V2H two-way electric power supply system can supply power from home to vehicle as well as from vehicle to home. An AC100 V inverter onboard the Prius PHV converts stored power into AC suitable for home use, while power flow is controlled according to communication between vehicle, charging stand and the home.

With this new method, low-carbon electricity (“green” electricity) generated from regional or home solar generators, or low-cost late night electricity, can be stored in a vehicle’s drive battery and then used to supply power to the household during peak consumption times. This kind of optimal energy flow can be automatically controlled by a home energy management system (HEMS).

Vehicle batteries can also be used as a power source in times of emergency by manually setting the electricity flow to supply power from the vehicle’s drive battery through the charging stand to a home’s lights and power outlets. With a fully charged battery and full tank of gasoline, a Prius PHV can supply power for average Japanese household electricity use (approximately 10 kWh) for four days.

Interest in smart grid technology and expectations for the effective use of electric vehicle batteries has increased due to recent anticipated electricity shortages in Japan, the beginning of full-scale renewable energy introduction and an increased need for emergency power supplies.

Households participating in the verification tests in Toyota City will use Prius PHVs, which can use the V2H system to supply electric power to homes, as well as function as conventional gasoline-electric hybrid vehicles once onboard electricity supply depletes to a certain level.

In addition to the V2H system, TMC has also developed devices capable of supplying electricity from PHVs directly to home devices, for use at emergency shelters in the event of a disaster. The devices will be installed on the PHVs used in this round of the Toyota City Project tests.

The Toyota City Project awards eco-points to consumers who change their lifestyle habits to conserve electricity, and in 2011 there was an increasing trend toward households to use low-cost power to charge their vehicles. In light of the recent power supply shortages in Japan, the Toyota City Project is working to promote regional energy management that can respond to shifts in peak usage.

In response to the increasing need to control peak electricity use, the Toyota City Project will test synchronized automatic control between HEMS and regional energy data management systems (EDMS) this year. Existing energy usage optimization technology using household storage batteries will be expanded to V2H systems, making green electricity use even more effective while promoting a shift away from electric power consumption during peak-demand times.

JCN Newswire

  • 0

    NeverSubmit

    How much do you want to bet that despite being technically feasible, they won't allow a fully independent home, meaning off the grid system, as in a solar system connected to the vehicle battery for stable power.

    Everybody will still have to be connected to the main grid.

    And why not use a diesel-hybrid combo like Volvo has developed. It's much more efficient, especially to generate electricity.

  • -1

    kurisupisu

    It is all there isn't it?

    Homes in Japan have the capability to be 100% standalone and off the grid yet they are not being designed that way. Where are the charging stations for evs in my city? Where are the cheap solar panels? Central control is dooming Japan.......

  • 0

    Fadamor

    With this new method, low-carbon electricity (“green” electricity) generated from regional or home solar generators, or low-cost late night electricity, can be stored in a vehicle’s drive battery and then used to supply power to the household during peak consumption times. This kind of optimal energy flow can be automatically controlled by a home energy management system (HEMS).

    Umm. "Peak times" are usually in the middle of the day, when it's hottest out. The car will be in the workplace parking lot, or at the subway parking lot. How do they plan on getting power from the battery there back to the home? A 10-kilometer-long extension cord?

  • 0

    cleo

    The car will be in the workplace parking lot, or at the subway parking lot.

    In many parts of Japan people take the train to work and either walk or bike it to the station; the family car sits outside the house during the day.

  • 0

    Fadamor

    True, but then are you saying Toyota will ONLY attempt to sell this in their Japan market? Probably not a bad idea because if they tried it in the U.S., my comment would be the first one any potential buyer would raise with the salesman.

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