Car batteries will soon provide storage for the electrical grid, powering up when demand is low and sending energy back onto the grid in a power emergency.
The scenario might sound like science fiction but the technology is already in place, said Willett Kempton, a senior policy scientist and professor at the University of Delaware. Vehicle-to-grid, or “V2G” technology was one of many topics discussed Friday during the Annual Meeting of the American Association for the Advancement of Science, which drew 3,700 to the San Diego Convention Center.
“Electricity is the new auto fuel,” Kempton said.
Electric cars are also a promising solution for increasing the grid’s storage capacity. Once dismissed as too small to provide a significant impact, scientists are looking to electric cars for grid storage due to their growing numbers, Kempton said.
With the existing number of electric cars in the United States, the potential grid storage capacity is huge -- 2,865 gigawatts. The current load of the entire U.S. grid is just 400 gigawatts, Kempton said.
The technology would enable owners of electric cars to purchase power from the grid and sell back capacity. Customers would have the option to charge their cars during off-peak hours at a cheaper rate and earn money by keeping cars plugged in because of the storage capacity they provide.
Policies that allow such interaction between electric cars and the grid are not widespread. However, PJM International, the world’s third largest utility, which serves Pennsylvania through Virginia and areas as far west as Illinois, offers net metering for electric cars, said Ken Huber, manager of advanced technology at PJM Interconnection.
Customers with electric cars in PJM territory were paid 30 times last year, when the utility experienced reduced capacity due to a malfunctioning nuclear unit. The grid’s Independent Power Operator (ISO) communicated with electric cars and shut down charging for 10.5 minutes, during which their owners were paid by the utility, Huber said.
The grid also communicates with PJM customers as to when rates are lowest for charging electric cars. In PJM territory, the point of lowest demand is typically around 3 a.m. During that time wind energy is producing peak load, which often pushes rates into the negative – meaning customers actually get paid to charge their electric cars during that time, Huber said.
San Diego Gas & Electric offers electric vehicle rates, which allow customers to charge cars for less during periods of low demand; however net metering for electric cars is not yet in place, said Jennifer Ramp, an SDG&E spokesperson.
In order for V2G to become widespread, battery technology must become more reliable and longer lasting, said Jeff Stein, a professor of mechanical engineering for the University of Michigan.
“Batteries are the heart and soul of the V2G system,” Stein said.
Working under an National Science Foundation grant, Stein is studying the way in which batteries lose their storage capacity over time. He hopes the research will help develop longer-lasting batteries.
The federal government continues to invest in developing such technologies, including a recent investment of $2 billion in federal funds for battery manufacturing, said Raymond Boeman, Director of the Advanced Transportation Systems Program at Oak Ridge National Laboratory.
“This provides a very good path to energy security and greenhouse gas reduction,” Boeman said.
As the technology continues to improve utilities are taking note.
“There’s a growing interest by utilities to learn about ‘V2G’, if only to learn how it will impact them,” said Jasna Tomic, fuels program manager at CALSTART, a nonprofit focused on promoting use of alternative fuels.
The Annual Meeting of the American Association for the Advancement of Science began Thursday and continues through Sunday, Feb. 21.