BMW i3 electric car charging in 'EV Charging Only' space, Santa Clarita, CA [photo: Steve J. Myung]Enlarge Photo
As the demand for electric cars grows, utility companies are considering their effect on local power grids—both positive and negative.
Recently, California's PG&E and BMW wrapped up a pilot program testing experimental vehicle-to-grid technology to see if electric cars could actually aid the grid—and they did.
The program showed electric cars were able to aid the grid during peak usage, which can lead to cost savings and greater flexibility for the utility.
Both partners worked in concert to lessen the strain of electric-car charging during periods of high grid demand, requesting a load reduction of 100 kilowatts on the grid, according to Current.
PG&E would forward the demand-response signal to BMW, which would select i3 electric cars taking part in the test for delayed charging.
The delay was limited to a maximum of 1 hour per day, with the notification to the car pushed through the BMW smartphone application.
2017 BMW i3Enlarge Photo
Participants were able to opt out of taking part at any time, but the program returned a high participation rate nonetheless.
About 100 BMW i3 owners were enrolled in the program in the San Francisco area over the course of 18 months.
To ease potential strain on those customers, BMW also provided supplemental solar-powered energy-storage systems to participants.
Those systems used lithium-ion batteries taken from earlier BMW MINI E demonstration vehicles as a back-up to support charging during the demand-response events as necessary.
At the end of the program, PG&E said it had dispatched 209 demand response signals to BMW, delaying 19,500 kilowatt-hours of use altogether and helping to stabilize the grid during those periods.
That's enough energy to power two homes for a full year. The program, the partners suggested, involved only a tiny fraction of the electric-vehicle owners in California.
2017 BMW i3
2017 BMW i3Enlarge Photo
Somewhat similar results were found in programs conducted in the state of Delaware.
The success of the PG&E and BMW program has led to a grant to conduct a second phase of the program.
The new V2G test will explore the possibilities for optimizing charging no matter where an electric car is located.
Tests of this sort are small and simple ways that electric-vehicle owners can do their part to keep the grid operating and ensure that power is delivered to the people.