Grid-unlock: Study shows plug-in hybrids could put idle power plants to work

Grid-unlock: Study shows plug-in hybrids could put idle power plants to work

Off-peak capacity in America's existing electric power grid could be used to power as many as 185 million plug-in hybrid-electric vehicles -- about 84 percent of the nation's passenger vehicle fleet -- according to a new study by the Department of Energy's Pacific Northwest National Laboratory in Richland, Wash.

AutoTech Daily reports that the study says large-scale use of plug-in hybrids also could help reduce electricity prices as electric companies improve economies of scale, noting that residential consumption of electricity would rise more than one-third under the report scenario.

The study says current battery technology is sufficient to satisfy the national average round trip daily commute of 33 miles, so it assumes most motorists would recharge their vehicles overnight.

Adding "smart grid" technology would ensure that vehicles are immediately disconnected if they overtax the grid.

Off-peak availability differs by region. The study found an abundance of idle generation, transmission and distribution capacity in the Midwest and East. But there is limited extra output available in the West, especially the Pacific Northwest, because of the region's large amount of hydroelectric generation, which depends on rain and snowfall.

The additional electricity for overnight recharging would be generated from coal-fired and natural gas-fired power plants. Although running these facilities at high output during off hours would generate more greenhouse gas emissions, the authors say this would be more than offset by fewer tailpipe emissions resulting from vehicles operating in all-electric mode.

The report calculates that the net effect of converting 84 percent of the vehicle fleet to plug-in systems would be a 5 percent reduction in carbon dioxide emissions.

The study says total sulfur dioxide emissions would increase in the near term due to the sulfur content in coal. However, urban air quality likely would improve since the pollutants are emitted from power plants generally located away from large cities.

And the researchers say it is far less expensive to capture emissions from factory smokestacks than from vehicles.

Another possible side effect: Increased electricity generation could hasten the replacement of aging coal-fired plants with newer, more environmentally friendly facilities.

Using industry estimates, the study says plug-in hybrids would cost $6,000 to $10,000 more than gasoline-only vehicles, mostly due to high battery costs.

Operating costs would be about one-third that of gasoline models, thus it would take five to eight years for owners to recoup the extra cost of a plug-in, depending on the price of gasoline and the cost of electricity.