Electric cars are more expensive than petrol models because batteries cost so much. But new technology can turn those costly devices into an asset, offering owners benefits such as lower electricity bills, reduced lease payments or free parking.
Ford Motor, General Motors, BMW and other automakers are looking at how electric car batteries could be used to store excess renewable energy, to help utilities cope with fluctuations in power supply and demand. Automakers would make money by acting as intermediaries between car owners and power suppliers.
Millions of cars can be viewed as a giant energy system that will, for the first time, be connected to another giant energy system, the electric grid, said Matthias Preindl, an associate professor of power electronic systems at Columbia University.
“We're just in the early stages,” Dr. Prindle said. “In the future they will interact more, and they could potentially support each other — or put pressure on each other.”
A large screen on the wall of the Munich office of Mobility House (whose investors include Mercedes-Benz and Renault) shows one way carmakers can make a profit while helping to stabilise the grid.
The graphs and numbers on the screen paint a real-time picture of the European energy market where investors and utilities buy and sell electricity. The price changes minute by minute as supply and demand increase or decrease.
Mobility House buys electricity when solar and wind power is abundant and cheap, storing it in electric vehicles that are part of its system and plugged in across Europe. When demand and prices rise, the company resells the electricity. It's a classic play: buy low, sell high.
People in the automobile and energy industries have been talking about using car batteries for grid storage for years. As the number of electric cars on the road grows, these ideas are becoming more tangible.
French carmaker Renault is offering Mobility House technology to buyers of its R5 electric compact car, for which it began taking orders last month. Renault will begin deliveries in December of the car, which starts at 29,490 euros (about $32,000) in France.
Buyers who opt in will get a free home charger and sign a contract allowing Renault to take power from the vehicles when they're plugged in. R5 owners will be able to control how much power they give back to the grid and when. In return, they'll get a discount on their electricity bills.
“The more they plug in, the more they earn,” said Ziad Dagar, the Renault executive in charge of the program. Renault estimates that participants could cut their home energy bills by 15 percent.
Renault, which will offer the technology in France before implementing it in Germany, Britain and other countries, will share in the profits earned by Mobility House from energy trading.
If such services prove successful, the financial argument for electric vehicles, a vital tool against climate change, will become stronger.
“This will really drive EV adoption,” said Adam Langton, a BMW executive who works on energy issues.
BMW already offers software that allows owners to charge their electric cars when renewable energy is most abundant. This helps the company earn carbon credits and pay customers who participate in the program.
The new generation of electric vehicles to be sold by BMW next year, known as the Neue Classé, will have so-called bidirectional capability, meaning the cars will be able to draw in power from the grid and release it back as well as use the energy to power their motors.
Ford was a pioneer in two-way charging with the F-150 Lightning pickup, which Powering the Home During a BlackoutGeneral Motors, Hyundai and Volkswagen also offer or plan to offer cars with bidirectional charging. As such vehicles become more common, the potential for storage could become much greater.
By the end of the decade, it's estimated that there will be 30 million electric vehicles on US roads, up from about three million now. All of these cars can store as much electricity as dozens of nuclear plants produce in a day.
But of course those millions of cars could also put a strain on the grid, which is already dealing with rising power demand from heat pumps and data centers, said Aseem Kapoor, chief revenue officer at GM Energy, a unit of General Motors that provides services to electric vehicle owners. By helping smooth out demand, “EVs can be a vital resource,” he said.
But before this dream can become a reality, certain problems need to be resolved.
Owners may not be keen to drive their cars on the grid, as they worry that constant charging and discharging will wear out their batteries faster.
Some energy experts said the decline would be negligible, especially if utilities use only a small portion of the battery's capacity. Renault is tackling the issue by offering participants in its energy storage program the same eight-year, 160,000-km warranty that those who don't participate get.
Another challenge is that some U.S. utilities and the state regulators that oversee them prefer to run centralized grids, in which energy flows almost entirely in one direction — from power plants to homes and businesses.
To overcome resistance from utility companies, Maryland passed a law last month requiring them to accommodate bidirectional charging plans and offer financial incentives.
There is growing recognition that electric vehicle batteries are valuable investments that most owners will only actively use for a few hours a day.
“We want to realize the full value of electric vehicle batteries,” said Gregor Hintler, Mobility House's chief executive for North America.
“If all of New York City's electric cars were used as storage, those vehicles would be the most valuable power plant New York has ever seen,” said Dr. Prendl, the Columbia professor.
Consolidated Edison, the company that serves New York City and some of its suburbs, is exploring how managing charging times and using electric vehicles to store power could help it cope with the rapid growth of battery-powered cars.
Contrary to popular fears, electric cars “are not going to collapse the grid,” said Britt Reichborn-Kjenrud, director of e-mobility at Con Ed. “The big concern is that if we don’t plan differently for this very fast-growing load, the grid will not be ready in time to support the transition.”
Con Ed supplies power to the Bronx depot for New York City Electric school busesWhere the Mobility House software allows more vehicles to use the facility.
Fleets of electric vehicles owned by businesses or governments are a particularly promising form of backup energy storage. The vans or trucks have large batteries and their routes and schedules are predictable.
Ford Pro, the commercial vehicle division of Ford Motor, has started offering free chargers to customers who allow them to shut them off during peak power demand. Owners also save on their electricity bills.
Ford provides software to manage the chargers and meet customers' driving needs, and it manages relationships with utilities. Ford is testing the service in Massachusetts before expanding it to other states. The next step will be a two-way system that allows vehicles to send energy to the grid.
“Smart charging can cut costs,” said Jim Govern, director of charging strategy for Ford's electric vehicle division. “That's been a major barrier for customers.”