Europe must harness EV batteries' potential for improving electricity grids, Germany says

Europe needs common standards to make better use of electric vehicle batteries and home storage systems to improve electricity grid stability, according to an industry summit organised by Germany's economy ministry. "There was a consensus that the European regulatory framework for bidirectional charging must be further simplified, existing barriers removed, and a European single market for bidirectional charging developed," the ministry said.

Flexibility is key in an electricity system that relies on intermittent renewable energy sources. Storage, flexible demand management and flexible back-up power plants will all play an important role in ensuring security of supply as well as optimising the electricity system's operation and costs. Renewable energy industry association BEE called on Germany last year to remove obstacles for bidirectional charging to leverage the transport sector’s potential to make electricity consumption more flexible.

By enabling electricity flows in both directions - from grids into batteries and from batteries back into grids -, charging could be optimised to make use of periods of high renewable energy generation, with electricity to be fed back into the grid during times of low wind and solar energy output. “One EV could supply 19 households for one night or a single household for several days or weeks,” the ministry said. 

At the Berlin summit, representatives from automotive, energy, and digital industries presented recommendations for the market and grid integration of bidirectional electric vehicles and home storage systems, to ensure they benefit the electricity system as a whole by making it more flexible, the ministry said. It added that industry agreed to launch new bidirectional charging tariffs for customers in Germany this year.

The industry proposals included a standardised and dynamic EU grid status signal to help distribute load more efficiently across the region, the ministry said. In addition, industry stressed the advantages of combining bidirectional charging with users' solar panels. Such “energy sharing” concepts would allow drivers to use self-generated electricity to charge an electric car at the workplace, and would also provide emergency supply in case of power outages. 

An expert working group convened by the European Commission has drafted a report detailing the legal and technical requirements for data sharing in an internal European energy sharing market for bidirectional charging technology, the ministry added.