Batteries on wheels: California to mandate bidirectional charging on EVs from 2027

Aug 08, 2023

California has introduced a bill that would require all EVs to have bidirectional charging from 2027. The bill would cover all light-duty motor vehicles as well as school buses.

The bill will convene a stakeholder workgroup to examine the challenges and opportunities associated with using EVs as mobile batteries to power homes with a report due by January 1 2025.

The workgroup is tasked with looking at costs and benefits associated with bidirectional charging, mechanisms to ensure interoperability as well as the resources needed from the electricity sector to facilitate vehicle-to-building and vehicle-to-grid practices.

The proposal says there is a unique opportunity to leverage the anticipated eight million EVs on California roads by 2030 to provide a significant reserve of dispatchable electricity to support the largely renewable grid. The state has already landed that all new car sales be fully electric by 2035.

"Supporting market scalability of bidirectional charging has the potential to lower electricity costs in California and maximize reliability and resilience benefits to consumers and the electrical grid, especially when bidirectional-capable electric vehicles are colocated with distributed onsite energy resources," the legislation says.

The SB 233 bill has been supported The Climate Center along with over 60 clean air, climate and environment groups who wrote a joint letter in April urging the Californian government to progress with the new legislation.

The Climate Center's joint letter says the electrification of transport creates a once-in-a-generation opportunity for EVs to not only decarbonize transportation, but also keep the lights on during power outages, and lower energy bills.

The new bill would require some big changes for EV makers wanting to sell cars in California as the Nissan Leaf is currently the only fully vehicle-to-grid capable vehicle on the market in the US.

The Californian car market is one of the largest in the world so if the bill is passes it would likely have global ramifications for carmakers.

The new bill on bidirectional charging comes in the same week that California unanimously approved its Advanced Clean Fleets rule requiring all new medium and heavy-duty vehicles sold or registered in California to be zero-emission by 2036. The ACF also bans new diesel trucks from shipping ports and railyards from 2024.

The Californian Air Resources Board (CARB) estimates the ACF will save $US26.5 billion in Californian health benefits from criteria pollutant emissions and provide net cost savings of $US48 billion truck fleets.

Daniel Bleakley is a clean technology researcher and advocate with a background in engineering and business. He has a strong interest in electric vehicles, renewable energy, manufacturing and public policy.