Up to 100 BMW i3 owners in the San Francisco area are being offered $1,000 to hold off on charging during hours when the electricity grid is stressed the most. The 18-month trial, which is being run by BMW and Pacific Gas & Electric Company, started this week. It was originally announced at this year's CES.

The process sounds simple, according to a customer who spoke to Bloomberg. "My understanding is that we’ll get a text message that says, 'Hey, you’re charging your car right now, can you back off for an hour?’" BMW customer Peter Berman told the publication.

The chosen customers will also be eligible for an additional bonus of up to $540 at the end of the program, but that amount "will be determined by individual participation levels throughout the 18-month program," according to BMW. (Drivers have the ability to opt out of participation for one day at a time, which would presumably lower the amount they're eligible for.) About 400 people have applied and the last few spots are still being filled, according to BMW. Applications can be submitted at the BMW i ChargeForward website.

The deal is another in a long line of incentives offered to buyers of electric vehicles. The United States government offers tax rebates on more than a dozen different models of electric cars. Power companies have also made a habit of incentivizing customers not to use power during peak hours by offering time-of-use pricing and a number of other rebates. The i ChargeForward program is unlikely to spark sales of the i3 specifically, but by piloting the new program BMW is helping make the idea of purchasing an electric vehicle even more attractive.