Electric vehicles that buy and sell their own power

Getting the most out of power consumption. That’s the idea behind the Edison Project: programming the recharging of electric vehicles at night and controlling how much electricity is needed and when.

The aim is to create a smart grid powered by renewable energies like wind energy to promote the use of electric vehicles. Louise is one of 30 Danish civil servants who are testing electric cars in Bornholm, Denmark. Next year they will be the first to test the smart grid.

Maja Felicia Bendtsen, Project Leader at the Bornholm Utility Company explains how the process works:

“The idea is that when you come home you plug in your electric car, but the car doesn’t start to charge. You have a smart charger on the wall where you can send messages to a program which controls the charge. Then you tell the programme ‘OK I will use my car, for example, next morning.’ Then the programme schedules when the car should be charged, it sends a message to the charger and the charging starts when the schedule fits, for example at two o’clock at night,” she told us.

Researchers in Copenhagen are part of an international effort to make this possible. At present, consumption controls production: the smart grid will work the other way round, creating a real time market where everybody will buy and sell energy when it is at its most profitable.

Anders Troi is the Head of Programme of Intelligent Energy Systems at the Technical University of Denmark. He says it can make money for drivers of electric cars:

“You’ll be able to participate on the market and buy energy when it’s cheap, so when the wind blows and the energy prices may be 10 cents per KWh, you’ll buy energy and fill up your electric vehicles. At peak demand, maybe the peak price will go up to one euro or even more per KWh, so you can sell it back to the grid, earning money.”

Idle electric vehicles will sell their surplus energy back to the grid, thus providing part of energy supply. This requires a much faster charging and discharging system than the one used today.

As Louise remarks:

“This car can go 100 km and then we have to go back and fill it again, and it takes about two hours or so to make a new filling”.

That’s two hours for Louise’s needs but an electric car takes about eight hours to be fully charged. The eventual goal is to get that down to just a couple of minutes. Cars will interact with the grid with new generation recharging cables, something Daniel Kullmann, a PhD student at the Technical University of Denmark, is working on. He explains:

“This is a very thick cable so it can transfer much more power over it, and because it’s a three phase system, you can also have much more power transferred to the vehicle, so in a shorter time you can put the same amount of energy into the battery.”

Oscar Forero, a Masters student from Colombia, is developing a software that will enable cars to tell the grid their recharge status and the amount of electricity they will need.

“We are trying to make this software platform more generic and flexible, in order to allow any kind of electric battery to be integrated into the grid,” he say.

More electric vehicles will be introduced in Bornholm over the next 12 months; it will be the first place to test just how stable the grid is as the number of electric cars using it rises.