Grid operators shut down solar systems, blocking on-site power use

Grid operators are increasingly switching off large solar installations remotely, preventing businesses from using the electricity they generate on site, BR reports. Companies say modern control technology could avoid the problem.

Greilmeier, a freight company in Obertaufkirchen in the Mühldorf district, invested in electric trucks, a large rooftop solar installation and a battery storage system to reduce its exposure to rising diesel prices. But when strong sunshine puts pressure on the grid, operator Bayernwerk remotely switches off the company’s solar system.

Company owner Christian Greilmeier says he does not understand why a grid shutdown also prevents the site’s refrigeration system and electric trucks from using solar power that would not flow into the public network. The system is switched off at the rooftop inverters rather than at the grid connection, said Christoph Strasser, whose company MaxSolar installed it.

Strasser said the same problem affects customers in different grid areas. Bayernwerk told BR that its network still uses radio ripple-control receivers, a technology based on analogue signals dating from the 1990s. As a result, the company said, local bottlenecks can lead to solar systems being switched off, including in cases where businesses want to use the electricity themselves.

A Bayernwerk spokesperson said differing legal requirements create contradictory demands in practice and hinder the rollout of intelligent control technology.

Mühldorf district administrator Maximilian Heimerl, of the CSU, has asked Federal Economics Minister Katherina Reiche, of the CDU, to change the law and give priority to self-consumption. Green Party state parliamentarian Martin Stümpfig has also called for clearer rules after receiving complaints from businesses in his Ansbach constituency whose solar systems are switched off by grid operator N-Ergie.

Reiche’s ministry told BR that current law already takes the protection of self-consumption into account. It said the Federal Network Agency could review cases in which businesses have problems with their grid operator. The ministry did not answer BR’s question about whether grid operators should face penalties for delays in digitalising their systems.