Ofgem chief executive Jonathan Brearley has been named as the new permanent secretary at the Department for Energy Security and Net Zero.
Brearley, who has led Ofgem since 2020, has been appointed by the cabinet secretary, Dame Antonia Romeo, with the approval of the prime minister.
He takes over from Clive Maxwell, the department’s second perm sec, who has stepped up as interim perm sec following Jeremy Pocklington's departure in October to become perm sec at the Ministry of Defence.
Brearley said it is "a real privilege" to be appointed to the role "at such a defining moment across UK energy".
"My time at Ofgem has been defined by the mission of protecting consumers and navigating the complexities of the UK energy transition," he said. "I am proud of what the team there has achieved, and I carry these lessons with me as I move into this new role.
"Working alongside the secretary of state, ministers and the dedicated civil servants at DESNZ, I look forward to continuing the department’s focus on bringing down bills and delivering clean, homegrown power."
Brearley joined Ofgem in 2016 as executive director, systems and networks, following a five-year stint as chief exec at the UK Regulators' Network.
His past civil service experience includes a spell from 2008-2014 at the then-Department of Energy and Climate Change, where he held several director-level positions. Earlier in his career, he was a deputy director in the Prime Minister's Strategy Unit, holding a senior adviser role from 2002 to 2006.
Energy secretary Ed Miliband said Brearley "has spent his career driving for Britain’s energy security and is a deeply experienced, dedicated and imaginative public servant".
"As we continue to deliver our clean energy mission to bring down energy bills for families and take back control of our energy with clean homegrown power, I am delighted to welcome Jonathan to lead the department," he added.
Romeo said Brearley "brings a wealth of energy experience from within the civil service and beyond".
Both also thanked Maxwell and praised his leadership of the department over the last few months.
The appointment follows an external recruitment exercise chaired by the independent first civil service commissioner Gisela Stuart.
DESNZ said the recruitment process for a new chief exec of Ofgem will be set out by the regulator shortly.