Electric cars don’t need weekly trips to the gas station, but they still need fill ups in order to operate. Instead of gas, they’re filled up at electric charging stations at one’s home or popular thoroughfare. There are lots of different types of EV chargers, including some that are completely wireless. But none really address the question: “What happens when a storm knocks out the grid?”
Toyota decided to answer this question using a variation on the Prius, their popular electric hybrid. Using new vehicle-to-home (V2H) technology, Toyota turns what was once a one-way conversation (how will my home charge my Prius?) into a two-way discussion (how could my Prius possibly charge my home?).
The V2H charging tech is part of the Toyota City Project, an ongoing research project on smart grid technology supported by Japan’s Ministry of Economy, Trade and Industry.
According to this review, the V2H system equips the Prius Plug-in with an AC100 V inverter that converts the car battery’s direct current into the alternating current used in homes. Communication between the car, the charger and the Home Energy Management System (HEMS) facilitates power flow between the car battery and home.
Now before you get any grand ideas about going completely off-grid using your car as a permanent power source, it’s important to know that the the Prius Plug-in’s small lithium-ion battery isn’t powerful enough to power a home all on it’s own. At best it could provide essential power to a Japanese home for about four days.
But it’s a great start to a battery storage discussion that we hope Toyota will continue with further development. If engineers can figure out a way to make EV batteries more robust without a drastic price increase, it could become possible to use the Prius Plug-in as a reliable backup generator during storms or other emergencies that leave us without grid power.
The company also envisions further iterations of the Prius Plug-in with the ability to draw power during off-peak hours and then feeding that stored power back to the home during peak times, helping to lower total home energy costs.