Lee Steam may see additional upgrades


Duke Energy Carolinas recently filed an application for a Certificate of Environmental Compatibility and Public Convenience and Necessity (CECPCN) with the Public Service Commission of South Carolina (PSCSC) seeking approval to construct and operate a 750-megawatt natural gas-fired combined cycle plant at the existing Lee Steam Station in Anderson County.

The filing was in partnership with North Carolina Electric Membership Corporation (NCEMC), which will be a minority owner of 100 megawatts of the project if constructed.

According to a Duke Energy news release, no final decision to build at Lee has been made, but it states, “it is prudent to continue with the regulatory actions necessary to keep the project moving forward.”

“The energy needs of our customers are significant over the next 15 years,” said Clark Gillespy, Duke Energy state president — South Carolina. “Our commitment is to meet our customers’ needs in a way that balances affordable, reliable and increasingly clean electricity, and this project will help us satisfy that need.”

The utility’s request is part of a comprehensive, long-term plan to add new generation, modernize the fleet, maintain a diverse fuel portfolio, and manage customer costs while delivering a high-quality, reliable power supply.

According to the release, natural gas-fired combined cycle plants are a good match to meet needed base and intermediate load demands because of their high efficiency and flexibility. Their emissions of sulfur dioxide and nitrogen oxide are very low, and natural gas emits about half the carbon dioxide as coal.

A combined cycle unit uses combustion turbine generators, boilers and a steam turbine generator to produce electricity. In the process, natural gas is burned in the combustion turbines to produce mechanical power that is converted into electrical power by the generators. For increased efficiency, the hot exhaust gases from the combustion turbines are used to create steam in the boilers that spins a steam turbine-generator and creates additional power.

The proposed project would represent a substantial long-term investment by Duke Energy Carolinas in the Lee Steam Station site and surrounding community, adding about 500 jobs during the height of construction.

“The Lee site is a great location for a combined cycle plant,” Gillespy said. “Duke Energy will be able to leverage existing site infrastructure to minimize new generation project costs and impacts to the community and environment.”

Construction could begin after the company receives the necessary regulatory approvals. The new plant could begin commercial operation as early as June 2017.

The William States (W.S.) Lee Steam Station is a three-unit coal-fired generating facility located on the Saluda River in Anderson County. The facility is named for Duke Power co-founder William States Lee and is one of two Duke Energy coal-fired generating facilities in South Carolina. W.S. Lee operates as a cycling station to supplement supply when electricity demand is highest.

In 2004, Duke Energy entered into a voluntary agreement with the South Carolina Department of Health & Environmental Control to install additional nitrogen oxide emission controls at W.S. Lee Steam Station. The controls support the Greenville/Spartanburg/Anderson Early Action Compact to reduce smog-forming emissions in Upstate South Carolina.

In January 2007, Duke Energy began commercial operation of two new 42-megawatt combustion turbine units. The two units replaced three existing combustion turbine units that were decommissioned at that time.