California Commission Approves Plug-In Electric Vehicle Submetering Protocol

The California Public Utilities Commission on Aug. 5 approved a plug-in electric vehicle submetering protocol for Pacific Gas & Electric, Southern California Edison, San Diego Gas & Electric, PacifiCorp and two smaller utilities. The commission demands the stated utilities implement the submetering protocol for all customers with plug in electric vehicles and customer owned submeters. The companies have been given two years to integrate submetering into their billing systems.

The submetering protocol is an essential step in accelerating the growth of electric vehicles. The protocol reduces the cost of electric vehicle charging, as consumers can prevent having to install a single utility meter and can as an alternative use the technology to have their electric vehicle charging assessed and charged independently from their primary utility meter. Submetering, as a result, encourages the adoption of electric vehicles, the deployment of vehicle grid integration and the realization of the subsequent electric grid benefits. Moreover, the commission’s approval will facilitate enhanced integration of electric vehicles into the grid, which involve having bidirectional car batteries charge from and discharge into the system.

The approval also implements electric vehicle supply equipment communication protocols for the utilities applying to electric vehicle supply apparatus installed through future transportation electrification endeavours. Moreover, the commission has also agreed to communication protocols to enable electric vehicle owners to optimize charging and take part in compensation plans that aid grid reliability, such as demand response.

A key discussion point has been submeter ownership. Pacific Gas & Electric have recommended an ownership model where the utility owns implanted submeters independently from the electric vehicle supply equipment, or EVSE. The ownership model would deal with a number of outstanding issues, such as meter accuracy, network reliability, data transfer, and cybersecurity.

The submetering protocol reinforces California’s commitment to accelerate electric vehicle growth. California added over 250,000 electric vehicles in 2021, bringing the total to more than one million. California aims to achieve 8 million electric vehicles by 2030 and will veto the sale of new gas powered vehicles as of 2035. As of earlier this year, electric vehicles accounted for 16 percent of car sales in the state.