FRANKFURT (Reuters) – German solar firm sonnen said on Wednesday it has successfully stored excess grid power in electric car batteries owned by its customers to help stabilise power networks operated by Dutch company TenneT, and will expand the business model.
The use of electric vehicle (EV) batteries builds on a project Shell-owned sonnen started in 2015 and provides a balancing mechanism to make sure supply and demand are matched in real time on TenneT’s network in Germany.
Sonnen supplies owners of photovoltaic (PV) installations for generating electricity from rooftop solar panels with storage batteries, to release power to the home when needed and to reduce purchases from the national grid.
It introduced a digital “community” for buyers of its residential batteries in 2015 who share home batteries which were aggregated into a virtual power plant (VPP) in 2019. Part of the community’s profits are shared by the members.
The project with TenneT, which operates 14,000 kms(8,699 miles) of high-voltage grids in Germany, extends to EV batteries as another storage medium, sonnen said in a statement.
Sonnen ran small-scale tests in November and December for customers who agreed to lend their car battery’s capacity for absorbing power over times defined by the two companies.
This worked well, prompting TenneT to make the agreement permanent, sonnen said.
“The private passenger car thus can transform from a mere mode of transport to become an active and stabilising part of the energy system,” sonnen said, adding the commercial inclusion of EVs was a first in Germany.
The agreement helps TenneT to balance frequency changes on its networks within 30 seconds.
Sonnen aims to sign up 5,000 customers for the scheme.
“Integrating electric cars into the power grid is an important milestone towards responding to the challenges of future power availability,” said TenneT chief operation officer Tim Meyerjuergens.
(Reporting by Vera Eckert, editing by Emelia Sithole-Matarise)
