The Tennessee Valley Authority board of directors took action Nov. 14 to further diversify the federal utility’s power generating mix to keep pace with changing economic and regulatory conditions.
TVA President and CEO Bill Johnson said to the board: “This will support our focus on cleaner energy and bring additional, necessary balance into our portfolio for managing our current and projected load profile.”
He added: “Over the past months, we considered a number of capacity studies, including TVA’s 2011 Integrated Resource Plan and associated financial and environmental analyses. We also looked hard at the effect on rates, our employees and any potential economic impact to local communities.”
The board approved a coal fleet plan that will retire eight coal units at three plant sites with more than 3,000 MW of combined capacity. A number of these units were already idled or scheduled for idling and/or retirement based on an agreement with the U.S. Environmental Protection Agency and several nearby states to reduce air emissions.
The retirements affect:
- all five coal units at the Colbert Fossil Plant in Tuscumbia, Ala.;
- one of two operating coal units at the Widows Creek Fossil Plant in Stevenson, Ala.; and
- two of three coal units at the Paradise Fossil Plant near Central City, Ky. Paradise Unit 3, one of TVA’s largest coal units, will continue to operate.
TVA conducted detailed analyses including an Environmental Assessment to review options for meeting stricter air quality regulations at the Paradise plant, including installing additional emission controls on Units 1 and 2, building a new gas-fired generating plant at the site or taking no action.
Based on that review, the board on Nov. 14 approved the construction of a gas-fired plant at the Paradise site in western Kentucky. This will result in an investment of approximately $1bn at the site. The two coal units will be retired when the gas plant is available.
The new plan, which does not affect the FY 2014 budget approved by the board in August, moves TVA toward a more balanced generation fleet of about 40% nuclear, 20% coal, 20% gas and 20% hydro, renewables and energy efficiency. This more diversified portfolio is consistent with the range of options analyzed in TVA’s 2011 Integrated Resource Plan, which is now being updated.
The board delegated authority to Johnson to establish a schedule for the coal unit retirements.
Paradise to lose 1,408 MW of coal capacity
The approximately 2,500 MW of capacity provided by Paradise is important in maintaining an adequate and reliable power supply to the north-central portion of TVA’s service area. For particulate controls, TVA was considering before this decision to shut outright two of the units installing pulse jet fabric filter (PJFF) systems on Units 1 and 2.
TVA began construction of Paradise in 1959 and completed Units 1 and 2 in 1963. Construction of Unit 3 began in 1966 and completed in 1970. Paradise is located in Muhlenberg County in western Kentucky. The plant is on the west bank of the Green River.
Paradise Units 1 and 2 are coal-fired cyclone units with a rated capacity of 704 MW each. Unit 3, which is not in danger of being shut, provides a rated capacity of 1,150 MW. Combined, the three units have a generating nameplate capacity of 2,558 MW. Paradise typically generates 14 billion kilowatt-hours of electricity a year.
The units typically burn coals from nearby counties in western Kentucky and southern Illinois. Coal is transported to the plant by truck, rail, and barge. For rail delivery, a 2.2-mile-long railroad spur managed by CSX Transportation provides access to the plant. U.S. Energy Information Administration data shows that coal suppliers earlier this year were KenAmerican Resources, Armstrong Coal and Alliance Coal.
Paradise Units 1 and 2 are equipped with selective catalytic reduction (SCR) systems to remove NOx, and wet flue gas desulfurization (FGD) systems to remove SO2 and PM. Ammonia handling and storage is required to support SCR operations. The hydrated lime injection system was installed in the fall of 2011 to control SO3 emissions. Paradise Unit 3 is equipped with an SCR to remove NOx, an electrostatic precipitator (ESP) to remove PM, and a recently installed FGD system to control SO2 and acid gases.
Notable is the fact that TVA is not the only utility recently to talk about retiring FGD-equipped coal capacity, going against the previous conventional wisdom that such plants were safe from the ongoing wave of coal retirements due to MATS and other new emissions regulations.
The gas-fired alternative at Paradise includes a new combined cycle combustion turbine plant with a generating capacity of approximately 1,000 MW.
Colbert has five coal units with a total of about 1,184 MW (net summer), with all five of those units to be shut under this plan.
Widows Creek has two active coal-fired units with a summer net capability of 974 MW, with one of those units to now be shut. Units 1-6 at Widows Creek are already idle and will be retired by July 31, 2015.