Three new combined cycles improve efficiency, reduce emissions

Three new power plants officially began serving North Carolina customers at the end of 2012, representing a combined investment of nearly $3.65 billion and marking another significant milestone in Duke Energy's commitment to meet electricity needs with cleaner generation.

In addition to investing nearly $6 billion in new plants since 2007 and retiring as much as 6,800 MW of older coal capacity, Duke Energy has invested another $7.5 billion for plant upgrades to reduce emissions across its service area. These investments have reduced the regulated fleet's emissions of sulfur dioxide by 74 percent and nitrogen oxides by 57 percent since 2005.

Cliffside Steam Station Unit 6

Cliffside Steam Station Unit 6 in Mooresboro, N.C., reached commercial operation on Dec. 30 and provides 825 MW. This coal unit employs a combination of air quality controls to remove 99 percent of sulfur dioxide, 90 percent of nitrogen oxides and 90 percent of mercury. It burns less coal per MW-hour than most other coal units in the nation.

Duke Energy retired four 1940s-era coal units at Cliffside, totaling 198 MW, in October 2011 and committed to retiring another 1,469 MW of older coal generation in North Carolina associated with Cliffside Unit 6. Duke Energy also added a scrubber to its existing unit 5 in 2011. The site is now said to generate more than twice the electricity with 80 percent less sulfur dioxide and half the nitrogen oxides and mercury than it did previously.

H.F. Lee Plant

The 920-MW H.F. Lee Plant near Goldsboro, N.C., reached commercial operation on Dec. 31 and utilizes a natural gas combined-cycle design. This new facility, along with the five combustion turbines at the existing Wayne County Energy Complex, will be called the H.F. Lee Energy Complex, with a total generation capacity of 1,800 MW. Progress Energy Carolinas retired three older coal units (totaling 382 MW) and four combustion turbines at the H.F. Lee Plant earlier.

Dan River combined cycle station

The Dan River combined cycle station in Eden, N.C., with 620 MW of natural gas-fueled generation, reached commercial operation on Dec. 10 and has more than twice the 276 MW of coal capacity Duke Energy retired there in spring 2012. Duke Energy also retired all three older combustion turbines at the site.

Sutton Plant

Construction is also under way at the 625-MW natural gas combined-cycle facility at the Sutton Plant near Wilmington, N.C., where 575 MW of older coal-fired generation will be retired. The new gas plant is scheduled to be commercially available by the end of 2013.