Getting Paid to Charge Your Car – First Steps
April 26, 2013
One of my more popular “solutions” videos starting to come true.
Basic idea, electric cars provide stability and storage to a distributed electrical grid, paying the car owner for the very valuable service.
I put this out before the Chevy Volt and other electrics hit the road, but the idea is still the same. Now we’re taking baby steps to make that vision become reality.
Finally, payback for the plug-in.
A line of Mini Coopers, each attached to the regional power grid by a thick cable plugged in where a gasoline filler pipe used to be, no longer just draws energy. The power now flows two ways between the cars and the electric grid, as the cars inject and suck power in tiny jolts, and get paid for it.
This nascent form of electric carcommerce will be announced on Friday by the University of Delaware, the regional grid operator and an electric company. They have developed a system to collect payments for work (balancing supply and demand moment to moment) that is normally the domain of power plants.
The possibilities of using electric cars for other purposes are being realized around the globe. Electric cars like the Nissan Leaf and Chevrolet’s plug-in hybrid Volt, are generally not sold in the United States with two-way chargers that could feed back into the grid. But Nissan is offering a similar device in Japan that allows consumers to power their houses when the electric grid is down.
In the Delaware project, each car is equipped with some additional circuitry and a battery charger that operates in two directions. When the cars work with the grid, they earn about $5 a day, which comes to about $1,800 a year, according to Willett M. Kempton, a professor of electrical engineering and computing. He hopes that provides an incentive to make electric cars more attractive to consumers, and estimates that the added gadgetry would add about $400 to the cost of a car.
The frequency of electric current in the United States is supposed to be stable at 60 cycles a second, but if the supply from a wind farm or solar plant changes suddenly, or demand shifts, frequency gets out of whack.
The market that Professor Kempton is tapping into, known as frequency regulation, has become increasingly important as the mix of generators on the grid has changed.
If electric cars become more popular, proponents say that a network of thousands of plug-in cars could help stabilize the grid.
The cars listen for a signal from the headquarters of the regional grid operator, the PJM Interconnection, in Norristown, Pa., that comes every four seconds. The signal could tell the batteries to charge, or to discharge, or to do neither. Alternatively, if the cars need charging, they can provide the same service by varying the amount of current they draw. For the grid, the effect is to add or subtract load in a coordinated way that aids stability.
With a relatively powerful two-way link, the idea is to branch out into another service the grid needs, known as “spinning reserve.” Power plants that offer that service keep a turbine spinning, but not generating power; they are ready to pick up load at a moment’s notice, if called on by grid operators. Providing spinning reserve burns substantial amounts of fuel, usually natural gas, but batteries could do the same work with no pollution, experts say.
At any given moment, a car could provide one service or the other; an aggregator could decide on an hour-by-hour basis which service to provide. So far, the system now being commercialized is nowhere near the point of absorbing surplus electricity at night and selling it back during the day; for the time being, the frequency regulation market would be more lucrative and the battery capacity is relatively small. Besides, peak demand hours often fall when the driver would want the car on the road.