California’s vehicle-to-grid experiments offer a glimpse of the future

The tech already exists for an EV battery to power your house. Now carmakers, utilities, and regulators are working out how that energy-storage tech could help bolster bigger things—namely, the power grid, as both the demand for electricity and reliance on renewables grow.

California has been the US leader in policies that support electrifying transportation, and is crafting regulations that would ban the sale of any new gas-powered cars in 2035. In October 2019, the state passed a bill that requires the California Public Utilities Commission (CPUC) to maximize the use of “feasible and cost-effective” vehicle-grid integration by 2030—one of only a few of its kind in the country.

Vehicle-grid integration (VGI) encompasses both what the industry refers to as V1G, meaning intelligently-managing EV charging, as well as vehicle-to-grid (V2G), which involves discharging power from the vehicle’s battery back to the grid.

“We’ve got a pretty volatile grid here, to say the least. We’ve got a lot of public safety power shut-offs and just a lot of renewables that we need to figure out how we can sustainably integrate that into the grid,” Sarah Woogen, head of US operations and analytics at charge management company Mobility House, told Emerging Tech Brew. “Because of that, and because California policymakers just tend to be a little more progressive than some other states, we are seeing a lot happen here first, which is expected.”

Since it passed its 2019 VGI bill, California has been backing programs to determine how to deploy and scale VGI technology.

“It runs the gamut from your sort of simpler off-peak charging rebates, to dynamic rates, up to demand-response programs, where you’re just shifting or modulating the charging of the vehicle or the fleet. And then all the way up to these bidirectional use cases where you’re providing backup power, or providing other services to the grid and providing other value to the customer,” Zach Woogen, policy specialist at the California-based nonprofit Vehicle-Grid Integration Council (VGIC), told us.

Testing, testing

The CPUC and California Energy Commission (CEC), along with other state agencies such as the California Air Resources Board, are working together on best practices for VGI. The state is funding pilot programs to figure out how to work EVs into the power grid, without draining drivers’ batteries and hampering their travel needs.

Last year, the CPUC expanded its Emergency Load Reduction Program (ELRP)—designed to manage energy supply and demand to avoid electricity outages—to include more EV participation. The program pays customers $2 per kWh for exporting energy from the vehicle’s battery, which VGIC’s Woogen said could amount to hundreds or thousands of dollars in earnings annually, depending on the type of EV and charger.

The ELRP now enables aggregation of residential and commercial EV battery capacity in order to create an energy source large enough for utilities to manage. This summer could see megawatt-scale participation from the new aggregator subgroup of ELRP (which will likely be composed of customers ranging from school buses to individual EV owners), according to VGIC estimates.

VGIC’s Woogen said that’s important because it’s the first program in the US that attempts to address the scalability of VGI.

“It’s allowing aggregators this opportunity to really construct a business model and really provide this value to their customers,” he said.

The CPUC is also facilitating funding for investor-owned utilities in the state to research VGI education and compensation for customers. PG&E and utility Southern California Edison have asked the CPUC to approve a combined $29 million in funding for seven different VGI pilots.

San Diego Gas & Electric, another major utility, is hoping to get approval from the CPUC for a V2G Export Rate that would compensate customers who discharge energy from EVs to the grid, though the application is still in the early stages, according to VGIC’s Woogen.

The state is interested in advancing vehicle-to-building (V2B) applications as well. The CEC is currently evaluating applications for $19.5 million in grants to fund pilot programs that use EV batteries as backup power for homes and other buildings.

These pilots will be focused on verifying the safety of V2B tech and testing how it might improve grid resilience during outages, Kiel Pratt, supervisor of the transportation planning and analysis unit at the California Energy Commission, told Emerging Tech Brew.

“[That program is] to move the ball forward with that kind of technology development, making sure there’s an ecosystem for not just equipment providers, but validating that these things can be installed safely and used by customers,” he said.

What’s next

VGI is still years away from a scenario where EVs can seamlessly supply power to the energy grid.

Using an EV battery as an alternative to a generator when you need backup power is one thing, but ensuring that electricity can safely be distributed to the grid requires considerations about complicated electrical issues like direct current vs. alternating current, interconnection, and interoperability.

Policy makers can encourage interoperability by making it a prerequisite for grant funding, Woogen from Mobility House said. But the main difference between using EV batteries as backup power in a V2B application and putting electricity back onto the grid is interconnection, she said. Independent systems operators (ISOs), which control the electrical power system, need to be able to bring energy from behind the meter (on the customer’s side) to front-of-meter (on the grid side).

"A lot of the ISOs are now going to start looking at, ‘What is the pathway to allow that?’ But even that’s five years in the future, maybe more,” she said.

And even if all the technology works together perfectly, convincing EV owners to participate is “where a lot of the work lies,” VGIC’s Woogen said. In addition to providing people with sufficient education and incentives, Pratt said participation must be easy.

“Maybe some of the early adopters are energy nerds, and they don’t mind looking at the stats or getting out their phone to configure something pretty often,” Pratt said. “But really, this stuff is not going to work at scale if it’s cumbersome for the customer.”