ECP acquisition of Calpine in 2017 for $5.6 billion and sale to Constellation for profit of $25 billion. In 2017 the market seeing the shift to renewable energy missed that it would take 20-30 years to make the transition and in the meantime natural gas had a big role to play as a low cost less polluting fuel than coal. ECP in 2017 saw good cash flow and an opportunity to improve it with some changes. Blackstone's $16 billion made on buying Hilton Hotels is the second best deal ever for such a sale, buying of private companies and making improvements to sell them at a profit.