Germany's €2.6 Billion STEAG Sale Puts 2026 Coal Phase-Out at Risk

The sale of German municipal power utility STEAG to private equity firm Asterion Industrial Partners for approximately €2.6 billion threatens to extend the company's hard coal operations by up to eight years beyond its own 2026 phase-out target. IEEFA is calling for a reassessment of the sale process, or at minimum a condition that the buyer publicly commit to implementing STEAG's coal exit plan.

STEAG, owned by KSBG KG — a consortium of six German municipal utilities — operates 4.1 GW of coal-fired capacity across North Rhine-Westphalia, Saarland, and Baden-Württemberg, making it the second most polluting power utility in Europe among the 25 analysed by IEEFA. In May 2023 STEAG published a sustainability report committing to phase out coal at its German plants by mid-2026, well ahead of Germany's national coal exit deadline. Just three months later, in August 2023, Madrid-based Asterion announced it had agreed to acquire STEAG for approximately €2.6 billion, with the transaction expected to close by end of 2023.

Asterion's press release stated support for Germany's coal phase-out plans but made no mention of adhering to STEAG's specific 2026 target. IEEFA warns that a private equity buyer focused on maximising returns may instead operate the coal fleet until each plant is compulsorily decommissioned by the Federal Network Agency — which may not be completed until 2034 under current estimates. At present, 1.2 GW of STEAG capacity will still be operating beyond 2025 and 0.75 GW beyond 2030 under compulsory timelines, meaning the sale could add eight years to STEAG's coal operations compared with its own voluntary commitment.

IEEFA analyst Jonathan Bruegel warns that STEAG risks becoming a climate laggard benefiting its new private owner while Germany accelerates renewables deployment. The institute recommends postponing the sale until all STEAG coal plants have binding decommissioning dates, which would lock in the coal exit before ownership transfers. An alternative would be to condition the sale on a firm, public commitment from Asterion to implement STEAG's 2026 coal phase-out target. The case illustrates a broader pattern in which the sale of polluting assets to private equity can undermine voluntary sustainability commitments made by prior owners.

Key figure — Asterion Industrial Partners agreed to acquire STEAG for approximately €2.6 billion in August 2023.