California first in nation to offer independent submetering of electric vehicles

A major electric vehicle milestone was set in California last week when the California Public Utilities Commission (CPUC) decided to allow car owners to measure their own vehicles energy use without relying on expensive utility meters — a first for the United States.

The process is known as submetering, and proponents maintain that it could accelerate the growth of EVs throughout California, by helping owners — be they individual drivers, fleet owners or otherwise — avoid paying for expensive extra meters just to measure the electricity used by their vehicles. Given that cost has been one of the big hindrances to electric vehicles, anything to chip away at upfront investments required could only benefit the industry.

“Submetering makes EV charging cheaper and will help spur the growth of electric vehicles throughout the state,” Commissioner Clifford Rechtschaffen, who is assigned to the proceeding, said. “It’s a practical solution to one of the important barriers to widespread EV adoption.”

At the heart of the decision was the knowledge that utilities allow special rate structures for EVs, offering power at lower cost for charging during off-peak times. Without a main utility meter, taking advantage of those offers could be tricky at best, and those meters required an entirely separate purchase. By being able to submeter, the commission contended, EV charging will also be able to participate in demand response programs, decreasing their charging load and potentially feeding power back into the grid when in dire need.

“Taken together, the submetering and communication protocols enable customers to realize greater electric grid benefits by allowing them to optimize charging and to participate in programs such as demand response — for both their and the grid’s benefit,” CPUC President Alice Busching Reynolds said.

The decision also laid out communication protocols for EV chargers, to ensure they are interoperable with publicly funded EV charging infrastructure and aid statewide expansion of integrated charging, rather than conflict. The commissioners agreed that these efforts support widespread Vehicle-Grid Integration (VGI), working to shape vehicle charging behavior in ways that will aid consumer and grid alike, as well as state climate goals.