The holding company behind an energy group which employs about 110 people has gone into administration.
Calon Energy Limited is the holding company of Calon Energy Group, with sites at Severn Power Station, Newport, Baglan Bay Power Station in Port Talbot and Sutton Bridge, Lincolnshire.
It had plans to build a new combined cycle gas turbine at the former Willington power station in Derbyshire.
All staff remained employed, administrators KPMG said.
The company's three sites all operate combined cycle gas turbines.
KPMG said the operating companies underneath Calon Energy which ran Severn, Baglan Bay and Sutton Bridge power stations were not part of the insolvency process and continued to trade under the control of their directors.
Jim Tucker, joint administrator with David Pike at KPMG's restructuring practice, said: "We will be working with the directors and senior management in the coming months to develop a new business plan for the power stations, before finalising the timeline to commence a sales process."
The company had obtained consent to construct a gas turbine at Willington on the site of a former power station which has been out of operation for more than 20 years.