Germany must completely rework its system of financial compensation for energy firms hit by the nuclear power phase out, the Federal Constitutional Court ruled on Thursday. 

The court ruled in favor of Swedish energy firm Vattenfall in its case against the German government relating to the nuclear power plants Brunsbüttel, Krümmel and Mülheim-Kärlich.

The court found that the conditions for compensation payments were unclearly regulated and that previous amendments to the law could lead to a double reduction of claims. 

Read more: Germany's nuclear phaseout explained

A 2016 ruling forced the government to amend the Atomic Energy Act in 2018,  however, the court found the changes were insufficient and had not come into force yet due to a lack of approval by the European Commission.

Germany reversed its position on nuclear power after Japan's 2011 Fukushima nuclear disaster. Just a few months after extending approvals for 17 German nuclear power plants it withdrew them. By the end of 2022 at the latest, all nuclear power plants must be taken off the grid.

The 2018 legislation, which hinged on Commission approval, meant the power companies would only find the exact amount of compensation in 2023. The Karlsruhe court found this "unreasonable."

A lawsuit by Vattenfall is also still pending before the World Bank's International Centre for Settlement of Investment Disputes (ICSID) in Washington, concerning several billion euros for the permanent closure of Krümmel and Brunsbüttel.

aw/rt (dpa, AFP, Reuters)