GM and Utilities to Study how Plug-In Hybrids Connect to the Grid
August 6, 2008
General Motors Corporation (GM) and the Electric Power Research Institute (EPRI) announced in late July that they will team up to study the integration of plug-in hybrid electric vehicles with the electrical grid. Plug-in hybrids run on battery power for short trips, but include an engine to recharge the batteries for extended trips. As a result, for most commutes the plug-in hybrid will use battery power only, burning no fuel at all, while on long trips the plug-in hybrid should have a fuel economy similar to today's hybrid vehicles. The cost of running on battery power is currently about one-fifth the cost of fueling with gasoline. But to meet the need for recharging these vehicles without straining the electrical grid, they must recharge during off-peak hours, such as late at night or early in the morning. Such "smart charging" was demonstrated by GridPoint, Inc. and Duke Energy in late March. The vehicles could also serve as an emergency power source, or they could provide supplemental power to the electrical grid during peak demand periods, such as unusually hot days. See the GridPoint press release.
The new collaboration between GM and EPRI will cover everything from codes and standards to grid capability of plug-in hybrids. While the collaboration will largely focus on safe and convenient vehicle charging, it will also examine how "smart grid" technologies can interact with plug-in hybrids. A smart grid is more interactive than today's electrical grid and could network with plug-in hybrids to optimize their charging times or to draw power from them when needed. Thirty four utilities from throughout the country will participate in the collaboration. GM is currently developing two plug-in hybrids: the Chevrolet Volt, which has been approved for production in 2010, and the Saturn Vue plug-in hybrid, which the company also intends to launch in 2010. EPRI formed a similar collaboration with Ford Motor Company in late March, and the Michigan Public Service Commission (PSC) has also launched a similar program. See the press releases on the GM agreement from GM and EPRI, the press releases on the Ford agreement from Ford and EPRI, and the Michigan PSC press release.
Electric vehicles produce no pollution while running, but of course they depend on an electric power system that does produce pollution. While some people have expressed concern that this is just shifting the pollution from one source to another, a study released last year by EPRI and the Natural Resources Defense Council (NRDC) found that plug-in hybrids have significant environmental benefits. In fact, the widespread adoption of the vehicles could reduce greenhouse gas emissions by more than 450 million metric tons per year by 2050, equal to removing 82.5 million of today's cars from the road. The study also found that if plug-in hybrids achieve 60% of the market for new cars by 2050, they will still consume only 7-8% of the nation's electricity. A separate study found that plug-in hybrids will have a small but significant benefit in terms on nationwide emissions of pollutants, while reducing petroleum consumption by 3-4 million barrels per day by 2050. Studies by DOE's Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) also concluded that a large percentage of U.S. vehicles could be powered using off-peak electricity. See the EPRI press release (PDF 40 KB), the EPRI reports, the ORNL press release, and the PNNL study (PDF 417 KB). Download Adobe Reader.