Renewable energy may be clean, but it’s not always available when needed, so a major power transmitter has kicked off a project using blockchain technology to manage the flow of power.

Tennet announced last week that it was running the first European blockchain-controlled power stabilization scheme, in a partnership with battery supplier Sonnen, using IBM’s blockchain software.

The two partners announced test pilots in May, as CoinDesk reported at the time. That work has now entered the phase of practical application.

Urban Keussen, Tennet’s board chairman, said the project allowed the company to lead the way on the integration of renewable energy into the power supply of Europe.

He said in a statement:

“As a grid operator, we are taking a new approach here to better integrate decentralized renewable energy sources and secure supply. At the same time we offer citizens the opportunity to actively participate in the energy transition.”

Blockchain technology makes it easier to securely and efficiently manage flow as new sources of power get added to the grid, Tennet said.

Sonnen provides batteries to homeowners that allow them to store power generated at their homes when they aren’t there and using it. These batteries are networked, in the SonnenCommunity. By connecting that network to Tennet’s transmission system, the power distributor can tap stored power nearby as needed or offload excess power into the batteries.

“Instead of firing up power plants in the south of Germany we just draw the required electricity from our storage systems,” Sonnen Managing Director Philipp Schröder said in a statement.

A spokesperson for Sonnen explained in an email to CoinDesk that this isn’t simply energy trading. Rather, it’s making home equipment a part of the real infrastructure of the grid, not just an endpoint.

Currently, European transmission operators manage congestion on the network using expensive techniques like varying output at the power plant level, contracting with third-party plants for extra electricity and curtailing wind power output. Such approaches cost the system roughly 800 million euros across Germany in 2016, according to Tennet.

Tennet transmits power to 41 million users in the Netherlands and Germany.

Power lines photo from Shutterstock.