A more powerful charging box is mounted on the wall of a house in Mariefred. It is the only sign that Amer Kadić's car could be part of the solution to one of the world's major energy challenges.
The autumn sun is beating down on the area in early October, and the solar panels on Kadić's roof are generating more electricity than the house uses. At the same time, the spot price is zero kronor.
The price of electricity is low now for a reason: there is a lot of electricity available. So we store what is produced when prices are low and can use it later, when it is actually needed, he says.
The car battery is charged when prices are low. When the sun goes down and electricity prices rise, the battery can instead supply power to the house. If the spot price is high enough, it may even be worthwhile to sell electricity to the grid. In total, this can amount to thousands of kronor a year.
Like a nuclear power plant
There are almost half a million electric cars in Sweden. They are literally batteries on wheels that could be used when the vehicles are stationary, which is estimated to be 96 percent of the time. Klas Boman is co-founder of Energy Bank, whose business idea is to use these vehicles as power banks. What is needed is the right kind of electric car, charger and software.
A nuclear reactor has an average output of a thousand megawatts. That is as much as a hundred thousand cars. If we had that many chargers, they could produce as much power as a nuclear power plant, even though the nuclear power plant is more sustainable, he says.
The software controls when it is most profitable to charge the battery and use its electricity.
You will never have a car with less than 20 percent charge. But in the app you can set it so that "when I leave at seven in the morning, I want the car to be at 80 percent", says Boman.
Greater resilience
Anna Larsson is head of the electromobility unit at the state research institute Rise and sees several uses for the technology in addition to smoothing out electricity peaks and stabilising the electricity system. With the right equipment, electric cars can be used as backup power during a power outage, for example.
From a climate point of view, it is very good to use one as a backup instead of a diesel generator. In times of crisis, we may not have access to fuel, but energy can be produced locally, making us much more resilient, she says.
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