Power Sources

TVA IRP calls for additions of storage, solar

Among the recommendations included in a final Tennessee Valley Authority integrated resource plan is the addition of up to 2,400 megawatts of storage by 2028, between 1,500 and 8,000 MW of solar by 2028 and up to 500 MW of demand response by 2038, depending on availability and cost of the resource.

TVA on June 28 released its final IRP and associated Environmental Impact Statement that evaluates options to meet the region’s power generation needs over the next 20 years.

Under development since February 2018, TVA’s IRP is a power planning roadmap that examines a variety of economic, regulatory and market-driven scenarios and strategies – both within and outside TVA’s control – to help TVA respond to changing energy demands while continuing to provide reliable power at the lowest possible cost, TVA noted.

TVA said in a news release that it is updating its 2015 IRP “due to continuing dramatic changes in the utility industry. Such changes include abundant, lower-cost natural gas, decreased cost of renewable generation, and increased focus on energy conservation efforts.”

TVA said that during the IRP process, TVA — with significant input from stakeholders and the public — considered a wide range of future scenarios, various business strategies and a diverse mix of power-generation resources to build on TVA’s existing asset portfolio.

IRP study results show:

  • There is a need for new capacity in all scenarios to replace expiring or retiring capacity;
  • Solar expansion plays a substantial role in all futures;
  • Gas, storage and demand response additions provide reliability and/or flexibility;
  • No baseload resources are added, highlighting the need for operational flexibility in the resource portfolio;
  • Additional coal retirements occur in certain futures;
  • Energy efficiency levels depend on market depth and cost-competitiveness;
  • Wind could play a role if it becomes cost-competitive; and
  • In all cases, TVA will continue to provide for economic growth in the Tennessee Valley. 

Details on recommended planning direction

TVA said its recommended planning direction affirms its commitment to a diverse and flexible resource portfolio guided by the least-cost system planning mandate.

The ranges detailed in the IRP, stated in MW of capacity, provide a general guideline for resource selections.

In developing a recommendation from the study, TVA elected to establish guideline ranges for key resource types (owned or contracted) that make up the target power supply mix.

This general planning direction is expressed over the 20-year study period while also including more specific direction over the first 10-year period. “Meeting the Valley’s future needs in accordance with the resource technologies and ranges in this Recommendation will position TVA to continue to deliver low-cost, reliable and clean power to the people of the Tennessee Valley,” the IRP said.

Coal, hydro and nuclear

With respect to recommendations related to coal, the IRP calls for continuing with announced plans to retire the Paradise coal-fired plant in 2020 and the Bull Run coal-fired plant in 2023 and evaluate retirements of up to 2,200 MW of additional coal capacity if cost-effective.

All portfolios outlined in the IRP reflect continued investment in TVA’s hydro fleet to maintain capacity and the IRP recommends consideration of additional hydro capacity where feasible.

In the area of nuclear generation, the IRP further recommends pursuing the option for a second license renewal of Browns Ferry for an additional 20 years. The IRP also recommends continuing to evaluate emerging nuclear technologies, including small modular reactors (SMR) as part of technology innovation efforts.

Energy efficiency

Meanwhile, the IRP calls for achieving energy efficiency savings of up to 1,800 MW by 2028 and up to 2,200 MW by 2038. It also recommends that TVA work with local power company partners to expand programs for low-income residents and refine program designs and delivery mechanisms with the goal of lowering total cost.

Wind and solar

Noting that existing wind contracts expire in the early 2030s, the IRP recommends considering the addition of up to 1,800 MW of wind by 2028 and up to 4,200 MW by 2038 if cost-effective.

For solar, along with the recommendation of between 1,500 and 8,000 MW of solar by 2028, the IRP also calls for up to 14,000 MW by 2038 if a high level of load growth materializes. “Additions may be a combination of utility and distributed scale. Future solar needs are driven by pricing, customer demand, and demand for electricity,” the IRP said.

Storage

Along with the proposed target of up to 2,400 MW of storage by 2028, the IRP also calls for up to 5,300 MW of storage by 2038.

“Additions may be a combination of utility and distributed scale. The trajectory and timing of additions will be highly dependent on the evolution of storage technologies,” the final IRP notes.

Natural gas

The IRP also makes recommendations related to natural gas generation.

It recommends evaluating retirements of up to 2,000 MW of existing combustion turbines if cost-effective and adding up to 5,200 MW of combustion turbines by 2028 and up to 8,600 MW by 2038 if a high level of load growth materializes.

Future combustion turbine needs “are driven by demand for electricity, solar penetration, and evolution of other peaking technologies,” the IRP said.

With respect to combined cycle gas generation, the IRP calls for adding between 800 and 5,700 MW of combined cycle by 2028 and up to 9,800 MW by 2038 if a high level of load growth materializes. Future combined cycle needs “are driven by demand for electricity and gas prices, as well as by solar penetration” that tends to drive combustion turbine instead of combined cycle additions, TVA said.

Additional information about the IRP and EIS is available here.

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