Natural gas figures prominently in the Tennessee Valley Authority's (TVA) final 2015 Integrated Resource Plan (IRP), which calls for the addition of gas-fired generating capacity along with greater reliance on renewable energy and efficiency measures in the coming decades.
The IRP, which lays out a plan to 2033, will be presented to the TVA board of directors for approval in August.
"The recommendations in the IRP meet the dual objectives of ensuring flexibility in our energy sources while providing guidance on least-cost power options," said Joe Hoagland, vice president of TVA stakeholder relations. "The plan also reinforces the importance that TVA power remains reliable, affordable and sustainable."
The update of TVA's 2011 IRP was brought about by "dramatic changes in the utility industry. Such changes include abundant, lower-cost natural gas, decreased cost of renewable generation, decreased demand, and increased focus on energy efficiency efforts," TVA said.
"The new IRP examined various scenarios of load growth and environmental regulations in the future. Those scenarios were then used to assess five strategies that focus on various themes: current goals, an emphasis on emission targets, a reliance on power purchases, maximizing energy efficiency or renewable energy. For the first time, this IRP also looked at energy efficiency as a generation resource, similar to traditional sources like coal and gas, to compare future pricing and availability."
Under every scenario, TVA found a need for new generating capacity, and in every scenario new natural gas-fueled capacity is necessary, according to the IRP.
The IRP proposes adding between 700 and 2,300 MW of gas-fueled combustion turbine and combined cycle capacity by 2023 and between 3,900 and 5,500 MW by 2033. "The key determinants of future natural gas needs are trajectories on natural gas pricing and energy efficiency and renewables pricing/availability," the IRP said.
TVA currently operates 87 gas-fueled combustion turbines at nine power plants with a combined generating capability of about 5,400 MW and 11 combined cycle units at five plants with 3,900 MW of capability. TVA is also currently a party to a long-term lease of a 700 MW combined cycle plant.
According to the report, natural gas use has contributed to emissions reductions at TVA. Emissions of carbon dioxide (CO2) were reduced 32% between 2005 and 2013, the IRP said. "We project approximately a 40% reduction in CO2 emissions by 2020 from 2005 levels. TVA is also reducing water use and waste production from its operations as it retires coal plants, increases generation from natural gas and renewable sources, and converts coal combustion residuals management to dry handling and storage."
The agency found that there is "no immediate need" for new baseload generating capacity beyond the completion of Unit 2 at its Watts Bar facility and power upgrades being evaluated for the Browns Ferry Nuclear station.
TVA is a U.S. corporate agency that provides power to business customers and local power distributors in parts of seven southeastern states.