New Orleans-based Entergy Corp. plans to sell its 583-megawatt Rhode Island State Energy Center in Johnston, Rhode Island, to Carlyle Power Partners for $490 million.

The natural gas-fired plant began operating in 2002. One megawatt is roughly the electricity needed to power 1,000 homes.

Entergy’s wholesale generation division, Entergy Wholesale Commodities, bought the plant for $346 million in December 2011.

The power plant’s sale will mean a net gain of about 50 cents per share for Entergy, if the sale closes during the fourth quarter.

“Our strategy for EWC is focused on being disciplined about reducing risk and freeing up financial resources for other opportunities,” said Entergy Chairman and CEO Leo Denault. “RISEC has been a very good investment for us, and its sale is consistent with that strategy.”