Project at a Glance
Project Status: complete
Title: Vehicle to grid demonstration project: grid regulation ancillary service with a battery electric vehicle.
Principal Investigator / Author(s): Alec N. Brooks
Contractor: AC Propulsion, Inc.
Contract Number: 01-313
Topic Areas: Mobile Sources & Fuels, Stationary Sources
Electric vehicles could potentially provide valued services to the power grid when not being driven, reducing ownership costs. This project evaluated the feasibility and practicality of vehicles providing a grid ancillary service called regulation. Regulation is especially well suited to battery electric vehicles: it involves fast-response changes in power above and below a baseline. With the baseline set at zero power, the power fluctuations above and below zero average out to approximately zero net energy over time. Hence, a vehicle's battery state of charge would vary in the short term, but would not become discharged over time. A test vehicle was fitted with a bidirectional grid power interface and wireless internet connectivity, allowing power flow to or from the vehicle to be dispatched remotely. An 'aggregator' function was developed to represent a commercial middleman between a grid operator and multiple vehicles. Power dispatch commands were sent wirelessly to the vehicle at 4-second intervals, and the vehicle response was monitored and recorded. Results showed that wireless data transmission times were within ISO system requirements, and that the energy throughput through the battery due to regulation is similar to that of typical daily driving. The value created by the service exceeds the battery wear out costs under most operating assumptions. The long term effects on battery life were beyond the scope of the study; however it was noted that battery capacity increased by about 10 percent during the testing.
For questions regarding research reports, contact: Heather Choi at (916) 322-3893
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