The decision to shut down the plant came because of the comparatively low price of electric power generated from natural gas and the high cost to bring the aging power plant in line with environmental regulations, according to EquiPower Resources, which is a unit of Energy Capital Partners.
EquiPower notified ISO New England of the decision on October 7. The power plant has a staff of about 240 workers. It is located about 50 miles south of Boston.
EquiPower bought the power plant and two others from Dominion Resources in August 2013 for $650 million.