Their request followed the release of the GAO’s biennial High Risk List in 2019, which found that “neither global efforts to mitigate climate change causes nor regional adaptation efforts currently approach the scales needed to avoid substantial damages to the U.S. economy, environment, and human health over the coming decades.”
TVA’s “accelerating” climate challenges
The GAO examined the climate resilience of TVA facilities from August 2021 to December 2022 — in other words, the ability to prepare for, recover from and adapt to the effects of climate change.
The report said that increasing temperatures, changing precipitation patterns and more frequent extreme weather events pose a number of risks to TVA’s operations.
“Because TVA is the nation’s largest public power provider, potential climate change effects on TVA’s infrastructure and operations could have significant economic and social consequences,” the GAO said.
The authors said the effects of regional warming may include increased demand for electricity, along with a decrease in capacity for hydroelectric, gas, and nuclear power generation.
Intensifying heat and rainfall patterns can also damage transmission lines, and cause problems for worker health, according to the report.
The GAO also interviewed an unidentified source, who said that tornadoes are increasing in frequency, which could damage transmission lines. An Oak Ridge National Laboratory report found that increasing wildfire risk threatens electrical transmission and distribution systems. Since utilities can be held liable from fires linked to power lines, the TVA could hold serious financial liability, the GAO said.
To punctuate its claims, the GAO referenced a climate-connected series of shutdowns at the TVA’s Browns Ferry Nuclear Plant near Athens, Alabama. In 2007, 2010, and 2011, the TVA had to shut down the nuclear facility because water temperatures were too high to cool the generator “without significant environmental impact.”
The authors said these challenges may lead the TVA to buy power from other suppliers, hiking rates for their more than 10 million customers across Alabama, Georgia, Tennessee, Kentucky, Mississippi, North Carolina, and Virginia.
Steps towards resilience
The GAO credited the TVA for taking a number of steps in identifying and assessing climate-related risks, including integrating climate-related risk assessment into its strategic planning.
The GAO also pointed out that the TVA has done assessments for the flood resistance of infrastructure near the Tennessee River, and collaborated with both the University of Tennessee and Oak Ridge National Laboratory on climate-based river management strategies.
Furthermore, more than $160 million has been spent on moving substations and bolstering flood resistance at the TVA’s nuclear plants since 2009, according to the GAO report.
However, the auditors found that the utility has not conducted a full inventory of “its assets and operations vulnerable to climate change.”
They cite that in TVA’s 2016 Climate Change Adaptation Action Plan, TVA officials state that major planning processes for the utility should identify all significant climate risks, which could “significantly impair, obstruct, or prevent agency success.”
But the utility has not assessed broader climate risks in its major projects or assets, like the risk of flooding to its substations.
“This is particularly important as these vulnerabilities become more acute and as new and better climate information becomes available, thereby reducing uncertainty,” the report said.
The authors also found that the TVA does not maintain an overarching climate resiliency plan for all of its at-risk operations and assets.
Instead, the utility relies on a series of “resiliency documents,” which include no portfolio of climate-based risks, action steps, or plans for how and when to mitigate those vulnerabilities.
“This (larger climate resiliency plan), in turn, would help TVA fulfill its mission of providing reliable and affordable power to its customers,” the authors said.
The GAO auditors recommended that the TVA conduct a complete inventory and assessment of climate-vulnerable assets and operations, along with developing a periodically updated “resilience plan” with a portfolio of mitigation measures and action plans.
However, the TVA Board of Directors position did not accept or reject the GAO’s recommendations. Instead, the TVA argued that it is already working on most of the actions advised in the federal audit, but that an overarching resilience plan would be impractical for the utility.
The Tennessee Valley Authority faces no legal obligation to act on GAO recommendations.
“The GAO’s recommendations to the TVA for improvement are appreciated,” said Rebecca Tolene, chief sustainability officer at the Tennessee Valley Authority, in a written response included in the GAO report.
“It is important, however, to note that as it relates to these recommendations, that the TVA uses a constant, ongoing risk process to ensure that each TVA major business unit identifies significant climate change risks on an ongoing basis.”
Tolene said that while the TVA does not have one consolidated inventory of climate-vulnerable assets and operations, “we continually evaluate climate-related risk to each area of operations.”
She added that the TVA has partnered with Oak Ridge National Laboratory and the Department of Energy to create an asset-specific risk management system, and a “corporate-level initiative” to monitor climate resilience and associated efforts began at the start of 2022.
With regards to the recommended TVA resilience plan, Tolene said that the TVA issues an annual climate adaptation report, which receives periodic updates.