Demonstrating Electric Vehicle Sub-Metering Solutions (DEVS)
Project Update
The project began in December 2025 and is currently in the planning phase, with partners preparing to initiate technical and analytical work. UC Davis is developing analytical frameworks for cost, tariff, and grid impact modeling for submetering, and Santa Barbara County has confirmed demonstration sites and is coordinating data access for the pilot. Subrecipients are in the process of executing their contract plans and timelines.
The Issue
High EV charging costs remain a major barrier to EV adoption in California, particularly at commercial sites, multi-unit dwellings, and public charging locations subject to demand charges. Although utilities offer EV-specific and dynamic electricity rates that can reduce charging costs and drive grid-supportive behavior, access to these rates can require expensive utility-grade meters or physical submeters. Existing EV submetering solutions rely on a limited number of Meter Data Management Agents (MDMA) and costly or proprietary systems, limiting widespread adoption, and there is limited research on using embedded EVSE submeters across key use cases such as fleets, workplaces, and public charging. Property owners and fleet operators also face administrative challenges in fairly allocating EV charging costs when chargers are connected to building meters.
Project Innovation
This project introduces a software-defined EV submetering solution that replaces costly utility-owned meters with embedded and customer-owned metering. The solution allows flexible, software-based grouping of EV chargers into billing and tariff categories without new electrical infrastructure. This enables direct utility billing, dynamic tariffs, and vehicle-grid integration at multi-tenant and fleet sites, and digitally separates EV loads rather than physically.
Project Goals
Project Benefits
This project will reduce the cost and complexity of EV charging by allowing EV electricity use to be metered separately from building loads without installing expensive utility meters. Site hosts such as the County of Santa Barbara will gain accurate, automated cost allocation across departments, fleets, and public users. EV drivers and fleets will gain access to EV-specific and dynamic electricity tariffs that significantly reduce charging costs. By enabling better price signals and load separation, the solution supports vehicle-grid integration and grid-responsive charging. This improves grid reliability and helps reduce peak demand. The solution also lowers barriers for multi-unit dwellings and other multi-tenant sites to deploy affordable charging infrastructure. Lastly, the project will provide data and models to support statewide adoption of submetering and improved EV rate design.
Consumer Appeal
By enabling access to EV-specific and dynamic rates, customers can realize cost savings from off-peak charging. Clear, fair billing at shared sites makes EV charging costs easier to understand for customers.
Affordability
This project will reduce EV charging costs by eliminating the need for expensive utility-owned meters and enabling access to EV-specific and dynamic electricity rates. Software-based submetering reduces both capital and ongoing administrative costs for site hosts and drivers.
Reliability
This project will improve grid reliability by enabling EV charging loads to be separated from building loads and managed independently. This allows EV charging to respond to time-of-use, dynamic pricing, and demand response programs independent of other site loads. By enabling better load forecasting and controlled charging, the project could help reduce peak demand and grid stress.
Key Project Members
Subrecipients
Match Partners
