Surplus electricity could 'fill up' plug-in vehicles

An added benefit of plug-in hybrid vehicles is their capacity to store energy, which allows them to serve as a back-up power unit. The battery of a typical PHEV can produce enough electricity to power a home for about 10 hours. So, while the vehicle is parked in the garage or at work, its energy reserves could be used by utilities for a fee.

Plug in your car. Unplug foreign oil, greenhouse gases and other emissions that contribute to urban smog. A new study by Pacific Northwest National Laboratory has found that off-peak electricity production and transmission capacity could fuel 70 percent of the 220 million cars, light trucks, SUVs and vans on the road today—if they were plug-in hybrid electrics.

The study, performed for the Department of Energy, also suggests that replacing gasoline-powered vehicles with vehicles powered by off-peak electricity could improve urban air quality and potentially reduce expected increases in electricity rates by using the current infrastructure more effectively without building new power plants and power lines.

Batteries for plug-in hybrid electric vehicles, or PHEVs, will easily store enough energy for the national average commute, about 33 miles a day. Researchers found that if drivers charged up overnight when demand for electricity is low, most regions of the country would have plenty of off-peak generation, transmission and distribution capacity to provide for that region’s PHEVs.

The impact on national security could be significant. “Since gasoline consumption accounts for 73 percent of imported oil, it is intriguing to think of the national security benefits if our vehicles switched from oil to electrons,” said PNNL energy researcher Rob Pratt. The extra electricity needed to power PHEVs would come from coal-fired and natural gas-fired plants. Even though these power plants emit greenhouse gases, overall levels would be reduced because it is more efficient to move a car one mile using electricity than producing gasoline and burning it in the car’s engine. Another long-term benefit is that the steady demand for electricity is likely to spur investments in cleaner coal-fired power plants.

“PHEVs would increase residential consumption of electricity by about 30-40 percent depending on how many PHEVs we will own. The increased generation could lead to replacing aging coal-fired plants sooner with newer, more environmentally friendly versions,” said PNNL scientist Michael Kintner-Meyer.