Energy entrepreneur Trevor St Baker and coal investor Brian Flannery will sell their Vales Point coal-fired power station in NSW for several hundred million dollars to a private Czech firm in what represents a further upheaval in the fast-changing sector.

The pair, who famously bought the generator for $1 million from the NSW government in 2015 and then revalued it at $722 million two years later, agreed to sell their respective 50 per cent stakes in Delta Electricity, the owner of the plant, to the family company Sev.en Global Investments.