Electromobility makes sense only if car batteries are charged using electricity from renewable energy sources. But the supply of green electricity is not always adequate. An intelligent charging station can help, by adapting the recharging times to suit energy supply and network capacity.
Germany aims to have one million electric vehicles — powered by energy from renewable sources -on the road by 2020. And, within ten years, the German environment ministry expects “green electricity” to make up 30 percent of all power consumed. Arithmetically speaking, it would be possible to achieve CO2-neutral electromobility. But, in reality, it is a difficult goal to attain. As more and more solar and wind energy is incorporated in the power grid, the proportion of electricity that cannot be controlled by simply pressing a button is on the increase. In addition, there is a growing risk that the rising number of electric vehicles will trigger extreme surges in demand during rush hour.
“What we need is a smart grid that carries information in addition to power,” says Dominik Noeren of the Fraunhofer Institute for Solar Energy Systems ISE. The structure of the grid has to change from a push system based on energy demand to a pull system based on production output. In Noeren’s opinion, “electric cars are best equipped to meet this challenge.” Introduced in large numbers, they have the capacity to store a lot of energy. On average, a car is parked for at least 20 hours out of 24. That is more than enough time to recharge them when the wind picks up or the demand for electricity is low.