Study: E-cars as energy storage devices

Would Electric cars as energy storage According to a study, the costs of the energy system could be reduced by up to 22 billion euros annually across the EU – and consumers could also save a lot. With the so-called bidirectional charging The vehicles absorb excess and therefore cheaper solar and wind power from the grid during the day and feed it back in in the evening or at night.

The cost advantages that this two-way charging could bring for network operators and consumers were examined by the Fraunhofer Institutes for Solar Energy Systems (ISE) and for Systems and Innovation Research (ISI) on behalf of the EU interest group Transport & Environment (TE). of all things.

Accordingly, in the most advantageous scenario, the extensive use of electric cars as electricity storage would reduce the need for investment in the European energy network between 2030 and 2040 more than 100 billion euros will fall. To achieve this, however, around half of all electric cars and battery trucks would have to be able to feed electricity back in by 2030. If this flows directly into the overall network, it is called vehicle to grid (v2g, i.e. from the car to the network).

Owners also have the option, especially in single-family homes, of using the electricity stored in the car battery for their own household (vehicle to home, or v2h). The electric car could then become an energy supplier in the particularly energy-intensive evening hours and reduce electricity costs. It then charges again at night when demand is low and electricity is cheap.

In Germany, savings of more than 700 euros per year would be possible in this way for a four-person household, the study authors calculated. If it is fed into the overall network, any remuneration for the wagon keepers would also be incurred.

Obstacles

But there are some people in favor of the widespread dissemination of two-direction technology Obstacles. On the one hand there is the problem with that Electricity conversion. When charging electric cars, the alternating current in the network must be converted into direct current and vice versa. On some models this happens in the car. Others require a more expensive wallbox to connect the car to. The study authors recommend a uniform standard that manufacturers can adapt to.

There were also missing regulatory and political framework conditionsin order to make the existing niche technology marketable on a large scale. At an industry meeting a few days ago, the German Economics Minister Robert Habeck (Greens) announced that bi-directional vehicles and services could be commercially available from 2025.

“As mobile electricity storage devices, electric cars can make an enormous contribution to stabilizing the electricity system,” said Habeck. “Their batteries can be used to temporarily store electrical energy, creating additional flexibility.”