California pilot program turns GM's EVs into roving battery packs

Imagine a future where every car on the road doubles as an emergency power supply.

Mike Blake / reuters

While not nearly as much of a mess as Texas' energy infrastructure, California's power grid has seen its fair share of brownouts, rolling blackouts, and power outages caused by wildfires caused by PG&E. To help mitigate the economic impact of those disruptions, this summer General Motors and Northern California's energy provider will team up to test out using the automaker's electric vehicles as roving, backup battery packs for the state's power grid.

The pilot program announced by GM CEO Mary Barra on CNBC Tuesday morning is premised on birectional charging technology, wherein power can both flow from the grid to a vehicle (G2V charging) and from a vehicle back to the grid (V2G), allowing the vehicle to act as an on-demand power source. GM plans to offer this capability as part of its Ultium battery platform on more than a million of its EVs by 2025. Currently the Nissan Leaf and the Nissan e-NV200 offer V2G charging, though Volkswagen announced in 2021 that its ID line will offer it later this year and the the Ford F-150 Lightning will as well.

This summer's pilot will initially investigate, "the use of bidirectional hardware coupled with software-defined communications protocols that will enable power to flow from a charged EV into a customer’s home, automatically coordinating between the EV, home and PG&E’s electric supply," according to a statement from the companies. Should the initial tests prove fruitful, the program will expand first to a small group of PG&E customers before scaling up to "larger customer trials" by the end of 2022.

"Imagine a future in which there's an EV in every garage that functions as a backup power source whenever it's needed," GM spokesperson Rick Spina said during a press call on Monday.

"We see this expansion as being the catalyst for what could be the most transformative time for for two industries, both utilities and the auto automotive industry" PG&E spokesperson Aaron August added. "This is a huge shift in the way we're thinking about electric vehicles, and personal vehicles overall. Really, it's not just about getting from point A to point B anymore. It's about getting from point A to point B with the ability to provide power."

Technically, like from a hardware standpoint, GM vehicles can provide bidirectional charging as they are currently being sold, Spina noted during the call. The current challenge, and what this pilot program is designed to address, is developing the software and UX infrastructure needed to ensure that PG&E customers can easily use the system day-to-day. "The good news there is, it's nothing different from what's already industry standard for connectors, software protocols," August said. "The industry is moving towards ISO 15118-20."

The length of time that an EV will be able to run the household it's tethered to will depend on a number of factors — from the size of the vehicle's battery to the home's power consumption to the prevailing weather — but August estimates that for an average California home using 20 kWh daily, a fully-charged Chevy Bolt would have enough juice to power the house for around 3 days. This pilot program comes as automakers and utilities alike work out how to most effectively respond to the state's recent directive banning the sale of internal combustion vehicles starting in 2035.