Google and Utility to Test Hybrids That Sell Back Power

MOUNTAIN VIEW, Calif., June 18 - Google and Pacific Gas & Electric have unveiled their vision of a future in which cars and trucks are partly powered by the country's electric grids, and vice versa.

Google’s founders, Sergey Brin, left, and Larry Page, plugging in a hybrid car Monday at the company’s California headquarters.

The companies displayed on Monday six Toyota Prius and Ford Escape hybrid vehicles modified to run partly on electricity from the power grid, allowing the vehicles to go up to 75 miles on a gallon of gas, nearly double the number of miles of a regular hybrid. They also modified one vehicle to give electricity back to the power company.

The highly unusual test takes the hybrid, which is now familiar on American roads, a step further by using extra batteries to hold energy made and distributed by a power company. The technology is eagerly awaited by energy experts and environmentalists, but is not yet ready to go commercial because the additional batteries are not yet durable enough.

Google's philanthropic foundation, Google.org, headed by Larry Brilliant, led the conversion and announced that it would be investing or giving away about million to accelerate the development of battery technology, plug-in hybrids, and vehicles capable of returning stored energy to the grid.

Speaking on a sun-splashed dais in Google's parking lot to an audience well shaded by one of its new solar arrays, Mr. Brilliant described the vehicle designed to give energy back to the grid as "a bit of a science project."

But some observers, like the Stanford professor Stephen Schneider, who was one of the authors of the recent United Nations report on climate change, said that just getting this embryonic technology demonstrated by a company with Google's heft was a victory in itself. "These guys have clout with hundreds of millions of young and middle-aged people," he said, adding that what was necessary to jump-start a new type of car was a combination of reliability, affordability and "cool."

The six vehicles are used by Google employees near the company's Mountain View headquarters, and sit under a carport with a roof of solar cells. The cells are connected to the power grid, so they make energy whether the cars are charging or not. Dan Reicher, Google.org's director for climate change and energy initiatives, said the carports were meant to demonstrate a switch from fossil fuels to solar power.

Google is using batteries from A123Systems of Watertown, Mass., a company that sells an aftermarket kit to convert the Prius to a plug-in vehicle.

The Prius that has been converted to allow two-way flows of electricity is a more speculative project. PG&E, the utility serving Northern California, will send wireless signals to the car while it is parked and plugged in to determine its state of charge. It can then recharge the batteries or draw out power.

The transactions will be tiny, a few kilowatt-hours at a time, worth a few cents each, but if there were thousands of such vehicles, a utility could store power produced in slack hours until it was needed at peak times, said Brad Whitcomb, PG&E's vice president for customer products and services.

Some researchers say that utilities pay billions a year to power plants to stand by, ready to produce extra power or to provide small quantities of energy to maintain the frequency of the system at precisely 60 cycles a second. Plug-in hybrids could fill those roles, annually earning thousands of dollars each, some experts say.

But if a car gave all of its energy back to the grid, it would be left to run on gasoline, giving up the environmental benefit.

A plug-in hybrid can lower emissions of carbon dioxide and smog-causing gases. It can go three to four miles on a kilowatt-hour, experts say. If that electricity came from natural gas, that may mean under a quarter-pound of carbon dioxide is emitted each mile. In contrast, a car that gets 20 miles a gallon on unleaded gas emits about a pound of carbon dioxide each mile.