Germany’s energy state secretary Rainer Baake has quit after four years in charge of the country’s flagship Energiewende policy.

Baake made his stand as Germany’s democratic limbo was finally resolved, 162 days after the 2017 federal election. A grand coalition of conservative and Social Democrats (SPD) will return, along with chancellor Angela Merkel.

Baake, a Green Party politician whose appointment by then economy minister Sigmar Gabriel was a surprise at the time, criticised the new government’s energy and climate plans in a resignation letter seen by Clean Energy Wire.

The plans for the energy transition (Energiewende) in the new coalition agreement were a “bitter disappointment”, Baake wrote to incoming energy and economy minister Peter Altmaier.

The new government was “missing out on the opportunity to thoroughly modernise Germany’s economy”, Baake said, adding that forces who wanted to preserve old and “climate-damaging” structures had apparently been stronger.

During his time in office, Baake oversaw the reform of the core Energiewende legislation, the renewable energy act EEG, which included the shift from feed-in tariffs to a tender system, a move heavily criticised by the renewable energy industry.

Baake, who has been dubbed “Mr Energiewende” by German media for his expertise and his key role in the country’s energy policy, also repeatedly locked horns with utilities and the coal miners’ union. He proposed a “coal levy” in order to cut emissions from coal power plants. Instead, some lignite plants were transferred to a paid “security standby” reserve, before being closed down permanently.

Ever since Merkel decided to hand the energy ministry in the coalition government with the Social Democrats to her close ally Altmaier, Baake’s future at the ministry had been uncertain. Saxony’s state premier Michael Kretschmer called for Baake’s resignation last week, saying that he was responsible for “ideologically charging up energy policy”.