Pacific Gas & Electric, California’s largest electricity utility and one of the largest in the nation, is showcasing a Toyota Prius that it has converted into a plug-in hybrid at the Silicon Valley Leadership Group Alternative Energy Solutions Summit in California this week. The utility may be the first in the U.S. to demonstrate that a plug-in hybrid can power a home.

Like a traditional hybrid, plug-in hybrids have both an electric motor and a gasoline engine. But their larger batteries and ability to be charged with any 120-volt outlet allows for even better gas mileage than the 55 mpg average of a regular Prius. Since plug-in hybrid batteries can power the vehicle for up to 60 miles, about half of the cars in America could go everywhere they needed to go in a day without using any gas. Some estimates set the average fuel economy at 100 miles per gallon.

So what’s different about PG&E’s plug-in hybrid? Unlike most plug-ins that take in electricity from the grid and then are driven around during the day, the PG&E concept car demonstrated that any plug-in can also be used as a two-way generator.

These “vehicle-to-grid,” or V2G, cars are charged by plugging into a three-prong, 110- to 120-volt outlet. But if a home needs energy, like during a blackout or during high demand when electricity prices increase, a switch can be flipped to send the charge the other way, from the car to the home.

PG&E’s plug-in hybrid car powered a small electric heater and lights. The car could supposedly even run home appliances for several hours with a full battery charge. The utility hopes that the new concept car will demonstrate new ways to use hybrids and increase the demand for the cleaner vehicles. California’s renewable energy laws are pushing utilities to cut global warming emissions. Plug-in hybrids help them reach that goal by allow ing homeowners to use more energy at night – when wind power and cleaner fuels are available - and less energy during high-demand days when natural gas and coal plants produce the energy.

Prices for plug-in hybrids are expected to range from $3,000 to $5,000 more than typical hybrids, and it’s unclear how much money a homeowner would save by charging a hybrid with electricity. Although they would be buying more energy from their utility, they would save on gas costs. And although many areas of the country would be powering their plug-in hybrids with coal-fired power from the grid, governoment studies have shown that powering cars with electricity creates much less global warming pollution than power them with gasoline.

CalCars, a nonprofit organization that has converted about 20 hybrids to plug-in hybrids in the past three years, expects the two-way generator technology to be about 5-6 years away.

CalCars
PG&E
Plug-In Partners
Reuters
San Jose Mercury News, via Green@WorkToday