Off-Peak Power Could Fuel Most Plug-In Hybrids
A new study for the Department of Energy (DOE) finds that off-peak electricity production and transmission capacity could fuel 84 percent of the country’s 220 million vehicles if they were plug-in hybrid electrics.
Researchers at DOE’s Pacific Northwest National Laboratory (PNNL) also evaluated the impact of plug-in hybrid electric vehicles (PHEVs) on foreign oil imports, the environment, electric utilities, and the consumer.
According to DOE’s Office of Electric Delivery and Energy Reliability, the first review of the impacts of very high market penetrations of PHEVs is important for baseline knowledge. As consumers look for more efficient vehicles, automakers are evaluating the market for PHEVs and battery manufacturers are working to improve battery life and performance.
Current batteries for these cars can store the energy for driving the national average commute–about 33 miles round trip a day–so the study presumes that drivers would charge up overnight when demand for electricity is much lower.
Researchers found that in the Midwest and East, there is sufficient off-peak generation, transmission, and distribution capacity to provide for all of today’s vehicles if they ran on batteries.
But in the West and the Pacific Northwest, there is limited extra electricity due to the large amount of hydroelectric generation that is already heavily utilized. Since rain and snow levels are not guaranteed, it is difficult to increase electricity production from the hydroelectric plants.
PNNL says the conservative estimates did not include hydro, renewables, or nuclear plants, nor did they include plants designed to meet peak demand because they do not operate continuously. The research still found that across the country 84 percent of the additional electricity demand created by PHEVs could be met by idle generation capacity. The added electricity would come from a combination of coal-fired and natural gas-fired plants.
Researchers found that even with today’s power plants emitting greenhouse gases, the overall levels would be reduced because the entire process of moving a car one mile is more efficient using electricity than producing gasoline and burning it in a car’s engine.
Total sulfur dioxide emissions would increase in the near term due to sulfur content in coal. Yet urban air quality is projected to improve since the pollutants are emitted from power plants that are generally located outside cities.
In the long run, according to the report, the steady demand for electricity is likely to result in investments in cleaner power plants, even if coal remains the dominant fuel for electricity production.
And with the PHEVs charging overnight, residential consumption of electricity would increase by 30 to 40 percent.
Since PHEVs are expected to cost about $6,000 to $10,000 more than existing vehicles–mostly due to the cost of batteries–researchers evaluated how long it might take owners to break even on fuel costs.
Depending on the price of gas and the cost of electricity, estimates range from five to eight years–about the current life span of a battery. Utilities could offer a lower price per kilowatt-hour on off-peak power, making PHEVs more attractive to consumers.
