Allentown - After more than half a century of generating electricity, two coal-fired units at PPL’s Martins Creek power plant in Northampton County, Pa., shut down permanently on Friday night.

“Built during the economic boom after World War II, these units have reliably produced electricity for the region’s homes and businesses for more than 50 years,” said Dennis J. Murphy, vice president and chief operating officer for Eastern Fossil and Hydro in PPL Generation.

When they were built in the 1950s, they were PPL’s largest generating units, each capable of producing 150 megawatts. When shut down for the last time, they were PPL’s smallest coal-fired generators but still generated enough power to supply about 240,000 homes a year.

Their retirement is part of a voluntary agreement reached in 2003 between PPL and environmental agencies in Pennsylvania and New Jersey to reduce sulfur dioxide emissions.

PPL is donating 70 percent of the units’ sulfur dioxide emission allowances and 70 percent of the nitrogen oxides emission allowances and emission reduction credits to the Pennsylvania Environmental Council. The allowances will not be sold or transferred to other generating units. Fossil fuel power plants receive emission allowances from the U.S. Environmental Protection Agency under provisions of the Clean Air Act.

After the coal-fired generating units are retired, PPL also will be closing a coal ash disposal basin that was repaired after a major release of water and ash in August 2005.

The Martins Creek power plant is located on the border of Pennsylvania and New Jersey, about 10 miles north of Easton, Pa. PPL operates two other generating units there, which can run on natural gas or oil. Adjacent to the Martins Creek plant is PPL’s newest generating facility, Lower Mount Bethel Energy, with advanced environmental controls that make it one of the cleanest natural gas power plants in the country.

“PPL continues to meet the region’s growing need for electricity in environmentally responsible ways,” Murphy said.