NRG Energy (NYSE: NRG) is working on plans to convert its to-be-shut coal units at the Shawville plant in Pennsylvania to natural gas, and to convert the recently-shut coal units at the Portland plant in Pennsylvania to ultra-low-sulfur diesel.
NRG spokesman David Gaier told GenerationHub on June 27 that the four Shawville coal units, with a combined capacity of 597 MW, are to be shut in April 2015 to comply with the Mercury and Air Toxics Standards (MATS). Then there will be a conversion project to switch them to gas, including installation of a new gas pipeline to the site, with all four units due back up on gas in June 2016. The units will operate as peakers after the conversion, at a level that is generally less than when they ran on coal.
The two Portland coal units (158 MW and 243 MW) were shut earlier this year under a clean-air consent decree. Remaining in operation at the site are three combustion turbines fired with ultra-low-sulfur diesel. This means there is diesel-handling infrastructure already at the site, including tank storage and a rail connection for diesel deliveries, helping to drive the decision to use diesel in the two coal units. The coal units are due back up on diesel in June 2016. Gaier noted how the Portland conversion from coal to diesel will sharply reduce various emissions, like NOx by 95% and SO2 by 99%.
NRG is also working on coal-to-gas conversions at its Avon Lake plant in Ohio (by June 2016), the New Castle plant in Pennsylvania (by June 2016) and the Dunkirk plant in New York (by late 2015).