Drax CEO Dorothy Thompson will step down at the year end. She will be succeeded by current chief financial officer Will Gardiner.
The company said Gardiner, who joined the firm almost two years ago, was selected ahead of internal and external candidates.
Chairman Philip Cox said Gardiner was “a focused, innovative and engaging leader”, and thanked Thompson for an “enormous contribution to Drax” over her 12-year tenure at the helm.
“Dorothy leaves the group in a strong position with a clear strategy that lays the foundations for further success in a changing energy sector,” said Cox.
Gardiner said he was thrilled to step up during a period of “unprecedented change” in the energy sector.
Thompson said she would retire “knowing the group is in excellent shape: it has the right strategy, the right team and in Will, the right leader”.
Drax now seeks a new finance chief and said it may make an interim appointment.
The company, which owns the UK’s biggest power station, pushed strongly into biomass under Thompson and is now looking to convert at least one of the former coal station’s units to gas. It also has plans to build a large battery storage unit in order to capitalise on increasing balancing revenue opportunities, as well as four smaller rapid response gas plants for similar purposes.
Meanwhile, the company acquired business energy retailer Opus Energy earlier this year, adding a strong SME retail channel to its existing supply business, Haven Power, which predominantly supplies larger business customers.