If you are a regular reader of CleanTechnica, you probably think of vehicle-to-grid technology — commonly referred to as V2G — as the greatest thing since maple syrup on pancakes. What’s not to like? You buy a car with a 75 kWh battery and you use that battery to power your TV while camping, or keep the A/C on if there’s a blackout in your area, or send some of the electricity stored in it back to the grid when needed in exchange for some financial considerations.
The state of California has been making lots of waves lately as it continues pushing ways to reduce carbon emissions from transportation within its borders. Last year, it announced a plan to prohibit the sale of conventional cars and light trucks by 2035. Recently, it upped the ante by proposing to prohibit the sale of diesel-powered medium- and heavy-duty trucks by 2036. Now a bill has been filed in the state legislature that would mandate that every electric vehicle sold in California have V2G capability built in.
First, let’s define our terms, because there are several different technologies associated with using the battery in an electric vehicle to power stuff. The first is called vehicle to load, or V2L. That feature allows drivers to tap the power in their batteries to run electric devices like power tools, TVs, or lights in a campground.
Vehicle to home, or V2H, permits homeowners to use their car’s battery to keep the lights (and A/C and heat) on when there is a grid outage. V2H requires a disconnect switch between the house and the electric meter to isolate the home from the grid. Without it, when the grid comes back to life, a surge of electricity could do serious damage to an EV battery. Not only that, the people who repair downed power lines don’t want to be placed at risk if they are splicing wires together when a jolt of electricity from the battery in your car comes zinging their way.
Vehicle to grid, or V2G, is more complex. Your household appliances can tolerate minor variations in voltage or frequency but both those parameters are carefully managed on the grid. Hundreds or thousands or tens of thousands of EV batteries connected to the grid can perform all sorts of useful services for grid operators. They can supply electricity to the grid when demand spikes, eliminating the need to fire up so-called peaker plants. They also can help deal with voltage or frequency variations — a service that is very valuable to utility companies and which they are willing to pay for.
But for V2G to work, the electronic equipment that sits between the battery in an EV and the grid has to be able to supply alternating current electricity that meets the voltage and frequency standards required by utility companies.
California May Require V2G On New EVs
Senate bill 233 in the current session of the California legislature would require automakers to equip the electric cars they sell in the Golden State with V2G capability. At the present time, only the Nissan LEAF, Hyundai Ioniq 5, Kia EV6, and Ford F-150 Lightning have V2G systems their owners can take advantage of. By plugging them into bi-directional charging stations at home, EV owners can sell the power in those batteries to utilities during peak demand, buttressing the grid and reducing their utility bills.
“When the grid is stressed, wouldn’t it be great if instead of firing polluting fossil fuel peaker plants typically located in disadvantaged communities, we were using our electric vehicles?” said Kurt Johnson, community energy resilience director at the California nonprofit The Climate Center. “Even the smallest commonly available EV battery is a multi-day energy storage asset for everybody,” he told Canary Media. “A Nissan LEAF can run your house for days.”
California already has 1.5 million EVs on the road. By 2030, that number is expected to reach 8 million. Combined, all the batteries in all those cars would have a total capacity of 80 gigawatts of power, Johnson said. That’s nearly 30 times the capacity of the state’s largest power plant, the Diablo Canyon nuclear generating station, which has a power output of “only” 2.3 gigawatts.
In a Senate Transportation Committee hearing on the proposed bill last week, state senator Nancy Skinner said the mandate would ensure that vehicles sold in the pivotal years when the state’s electric vehicle incentive programs are in effect are equipped with V2G capability. “I appreciate that manufacturers don’t like mandates, but we need to make sure the cars have the capability while the rebates still exist,” said Skinner, who introduced the bill.
Industry Pushback On V2G
Skinner is right about the industry’s distaste for mandates. The Alliance for Automotive Innovation is an auto industry advocacy group whose members include manufacturers such as BMW, Ford, General Motors, Honda, Hyundai, Jaguar Land Rover, Mazda, Mercedes Benz, Mitsubishi, and Nissan along with many Tier 1 automotive suppliers. It opposes the bill. In a letter to state senators, the group said a V2G mandate is premature and does not consider the associated costs or the regulatory changes needed to make vehicle-to-grid technology work.
“Mandating bidirectional hardware on the vehicle will not ensure that bidirectional charging will take place or will even be capable of taking place,” the letter said. The Alliance estimates the V2G technology could add about $3,300 to the cost of a new vehicle.
The Alliance also argued that using an EV to deliver power could adversely impact battery life and undermine battery warranties, which are based on years and mileage. However, the bi-directional charger approved for use with the Nissan LEAF manages several battery parameters to preserve battery life.
Even if every EV had bi-directional capability, getting the energy flowing into a home or the grid requires an expensive array of hardware. In addition to a bi-directional charging station, the car owner would need an inverter to convert the car’s DC power to AC, a switch to isolate the system from the grid, and a small battery to get the system going during an outage. Ford offers an all-in-one package that costs more than $5,000, not including the cost of hiring an electrician to install it. (Far less than the cost of a whole house generator, by the way.)
If an EV owner is just interested in powering a residence, the cost can be as little as $1,500, which includes the cost of a bi-directional charger and a manual transfer switch to disconnect the home’s electrical service from the grid.
For those who can afford all the hardware, the framework for connecting with the grid and selling electricity back to the local utility does not yet exist. “We’re not even effectively interconnecting stationary batteries, much less mobile batteries,” said Johnson. Also, for it to make financial sense for EV owners to offer up energy to the grid, there need to be pricing mechanisms for selling the electricity to the utility. While a few California utilities have begun vehicle-to-grid pilot projects, no official programs exist yet.
Johnson said the state is working on both interconnection and pricing. There are about a dozen bills addressing interconnection issues pending in the legislature, and the California Public Utilities Commission is studying new pricing frameworks. He said SB 233 is meant to be a starting point. “If the vehicles themselves don’t have the bidirectional capacity, which is the point of the bill, then none of that opportunity can be realized. So it all starts with the vehicles.”
Lazing around the CleanTechnica sundeck, this proposal from California sparked a lot of debate. On one hand, it makes a lot of sense to prepare for the future today. But the price of new cars is astronomically high as it is. Adding expensive new capabilities seems to be the last thing hard-pressed consumers need.
Perhaps California could encourage manufacturers to develop V2G systems and make them available to customers who want them. Our hearts are with the proposal, but our brains say this may in fact be something the marketplace should decide.
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