Remember when we told you electric cars might actually make some money for their owners? Looks like it's officially happening now.

A small fleet of Mini Coopers at the University of Delaware both draw electric power from the grid and return it, based on the needs of the moment. (PHOTO: UNIVERSITY OF DELAWARE)

The feds have dubbed it “tiny but promising,” but “vehicle-to-grid” electrical regulation officially has gotten off the ground in a small way. Last Friday the University of Delaware flipped the switch connecting—via car charging stations—a small fleet of electric-powered Mini Coopers to electric-grid managers PJM Interconnection. (Actually, the switch was flipped on February 27; last week’s event was a sort of debutant’s coming-out party for the technology.)

In a piece subtitled "A New Spin on Car Payments," Dan Ferber told us in the November 2011 issue of Miller-McCune (the precursor to Pacific Standard) about regulating electric current using stationary electric cars plugged into the system; the cars give and take electricity based on the real-time needs of the region and get some money from the utility for their pains. This is that project, headed by the heroes of Ferber’s piece, professor Willett Kempton and theV2G lab at the University of Delaware.

It’s not quite the same as selling electricity straight back to the utility, as you might with feed-in tariffs from home solar panels. These vehicles are selling a service as much as they are juice, offering both to regulate the flow and frequency of power and at the same time drawing from their batteries when the need for electricity peaks. What started Friday is indeed “tiny,” as Michael Gent, the former president of the North American Electric Reliability Corporation, told the New York Times. But when electric vehicles become more popular, or even the norm, the impact of those cars and their millions of batteries on the grid as generators, storehouses, and regulators could be huge.

As we said two years ago, that point is still a ways off. Not all electric vehicles have the guts, so to speak, to do this two-way exchange. But much of the preliminary research has been done, and laws have been amended to allow Mini-sized players, at least in Delaware, to compete with the big boys in the power world.

And the incentive for the electric car owner is profit—the Times quotes Kempton suggesting utilities could pay as much as $5 a day back to each plugged-in car’s owner. Given that electric cars tend to cost more than gas-powered ones, that's a welcome development.

And there’s another driver: renewable sources of power (which may help restore a bit of EV's green cred). As Ferber explained:

As more and more wind and solar plants are introduced into the grid, balancing supply and demand gets more complicated, since wind and sun don’t necessarily produce electricity when it’s needed. In PJM’s territory today, wind supplies three percent of PJM’s typical load, but an equal amount is under construction. And if half the wind farms already proposed come to fruition, wind could supply up to one-fourth of the region’s power by the 2020s, Huber says. “If we want a future with very high penetration of renewables, we need to have the ability to control the flow of energy they create,” says Chris Shelton, president of AES Energy Storage. Two large-scale ways to store electricity exist today. The most widely used method involves pumping water uphill into a reservoir and releasing it to drive turbines when electricity is needed. One utility, based in Alabama, stores energy by compressing air into a huge underground cavern, then releasing the pressure to drive an electricity-producing turbine. Both of these methods, which require a very specific natural infrastructure, can replace a downed generator for hours or days at a time. But they can’t produce energy quickly enough to provide spinning reserves or frequency regulation. Batteries can. Which is why Huber, who directs a team that searches for technological fixes to grid-operator problems, partnered with Kempton in 2005 to test vehicle-to-grid.

Friday, that test entered reality—at least in a small way.