TVA’s Most-Cost 2026 IRP, Joe Schiller
Like many in the TVA service area I had to rush to process as much as I could of the TVA preliminary IRP and submit my comments in the brief comment window TVA provided. While I may have missed some details, the broad outlines of the proposed IRP are clear—it is a disaster. TVA has drastically reduced the amount of renewable energy generation and increased the amount of fossil fuel and nuclear generation compared to the previous version of the IRP.
Why do I describe this IRP as a disaster? First, it is a climate disaster. Second, it is an environmental disaster. Lastly, it is a financial disaster. Allow me to explain each of these in greater detail.
My wife and I are retired professors of Biology now farming in Montgomery County Tennessee. Weather and climate play an important role in our farm’s wellbeing. We work outdoors every day, and we feel climate change and it is making our farming efforts increasingly challenging. In my lifetime (I will turn 71 this September) atmospheric carbon dioxide levels have increased over 115 PPM, rising from under 315 PPM when I was born to over 430 PPM this year (almost 37%). This is the highest level of atmospheric carbon in all human history. Since TVA conducted its last IRP the rate of these carbon level increases has accelerated. These rising atmospheric carbon levels have driven unprecedented climate disasters of ever-increasing financial cost. Events such as the winter storm Elliot three years ago, the devastating floods of last year’s hurricane Helene, and this year’s winter storm Fern are just a few local examples, but such events are occurring with increasing frequency everywhere. TVA’s IRP contemplates increasing carbon emissions, not reducing them. TVA’s refusal to include these costs in its least cost planning process enlists it as a willing contributor to climate disasters everywhere.
The science of climate change caused by emissions of climate warming gases is well understood and based on basic principles of chemistry and physics. Assertions otherwise amount to denial of the laws of chemistry and physics. The science of climate attribution has greatly improved and this science reveals with ever-improving precision the role carbon emissions play in causing climate disasters. Precise attribution of culpability will increase TVA’s future legal liability for increasing damages. TVA’s IRP is a climate disaster because in our current climate reality, intentionally increasing carbon emissions by continuing to run outdated coal plants and building more methane gas plants will exacerbate climate disasters.
TVA’s IRP is an environmental disaster not only because it will accelerate climate change, but because it will also increase many other environmental damages. Coal mining and gas drilling both have tremendous environmental impacts upon the local communities where they are extracted. Large quantities of air pollutants and water pollutants are produced along the fuel cycle by which they are extracted, processed, and transported to be burned. TVA does not include any of these costs in its IRP modelling. TVA lives in a magical world where only the environmental costs that occur within the fencelines of their generation plants matter.
On the other hand, TVA expresses great concern about the land cost of solar. They equate the acreage occupied by a wind farm or solar farm to the loss of land to a coal or gas plant, or a strip mine, ignoring the fact that farming continues in wind and solar farms but is impossible in a former mountaintop removal mine. TVA ignores the recent scientific evidence that solar farms have improved biodiversity of farmland hosting solar panels. TVA also ignores the fact that when a wind farm or solar farm reaches the end of its commercial life, it must, by law, be returned to its original condition. This will never happen to the millions of acres of farmland lost to urban and industrial development each year.
TVA’s IRP is a financial disaster because contrary to TVA’s own estimates, it emphasizes the costliest energy sources, nuclear, coal, and gas, at the expense of the least costly energy sources, renewables and battery storage. This is despite the many ways TVA has put its thumb on the scales to produce an outcome unsupported by both scientific and financial reality.
TVA’s previous IRP found that renewables and storage were competitive with gas and cheaper than coal and nuclear generation. In the brief couple years since that never completed IRP, renewables and storage have improved in capability and cost and now constitute the lowest cost, fastest to deploy, and most reliable energy sources in almost all parts of the world. Renewable energy accounted for over 88% of USA new electricity generation installed in 2025. Recent geopolitical events such as the Russia-Ukraine war and US Iran war have demonstrated the economic risks of fossil fuel dependence. Renewable energy and storage provide abundant domestic, safe, stable, reliable, and affordable energy resources that are immune to these vulnerabilities. TVA emphasizes that its IRP is an exploration of the best strategies to achieve a least cost resource plan under differing future scenarios beyond its control. Regardless of future scenarios, i.e., high electricity load growth, low electricity load growth, carbon emissions regulations, etc., this goal can only be achieved by installing the most proven, commercially available, and lowest cost technologies available. The IRP fails to do that by imposing arbitrary and unsupportable limitations on the amounts of the least cost technology options, renewables and storage, while allowing wildly optimistic and unsupportable assumptions about the costliest resource options, natural gas and nuclear generation. Renewables and storage are not only the cleanest, cheapest, and fastest to deploy options, they are also rated the highest in technological readiness, and acceptability scores compare to polluting, expensive, and slower to install nuclear, coal, and natural gas technologies according to TVA’s own data.
In the case of low technological readiness technologies such as Gen IV small modular reactors and Light Water SMRs such costs are impossible to know because these technologies, by TVA’s own acknowledgement, are at too low a level of technological readiness for cost assessment. No commercially successful versions of these technologies have been built to provide a reliable estimate. In the case of low adoption readiness technologies such as Carbon Capture and Storage, experts and the public are skeptical of both its technological feasibility and cost given that no commercially viable CCS plants have been built.
TVA uses overnight costs in its modelling, and this intrinsically biases the analysis of renewable and storage costs relative to fossil fuels and nuclear. This is because renewables have high up- front build costs, but very low operating costs, while fossil fuel plants have similar build costs but much higher operating costs due to their greater complexity and dependence on fuel. As noted above TVAs estimate of nuclear costs are speculative at best, but still much higher than renewables and storage. A new report from the Current Energy Group and Grid Lab finds that Utilities are not including up to 30% of the overnight build cost of gas plants by ignoring related mandatory financial commitments to the gas suppliers that enable the gas plants to operate (https://www.utilitydive.com/news/sticker-shock-gas-power-plants-pipeline- gridlab/824061/?utm_source=substack&utm_medium=email ).
TVA’s cost estimates in this IRP seem badly out of date. This is a critical flaw that calls into question the validity of the entire IRP. For example, TVA cites a cost for four-hour lithium ion battery storage of $2158/kW, whereas a Google search yields $400-600/kW. TVA cites solar single axis tracking costs at $1698/kw which is similar to the $1600/kW obtained through a Google search. However, TVA lists solar and storage costs separately whereas a Google search for solar + storage yields an estimate of $1300-1600/kW. This is because combining solar with storage captures synergies that TVA’s analysis misses. Perhaps more importantly, these costs are declining over time. TVA says it bases its solar estimate on its actual past solar costs but a retrospective cost estimate of a technology that is consistently declining in cost guarantees an inflated future cost estimate.
While neither TVA nor any other utility has ever built a Light Water SMR, TVA estimates costs of $17,263/kW for the first one ever to be built and confidently projects that costs will drop to $8743/kw by the time they complete the 9 th unit in a decade. These estimates are not only speculative and wildly optimistic given consistent long-term trends in the nuclear power industry, but they are also foolhardy, exposing TVA customers to undue cost risks. It is critical to note nuclear generating sources, by TVA’s own estimate, cost at least 5X more than solar, but these are only the costs to build (overnight costs) the plants that do not include costs of fuel, maintenance and operation which are greater than renewables by an even larger multiple!
Each of these three IRP disaster realms result in high future environmental and economic costs to TVA rate payers. TVA endlessly emphasizes its legal requirement to pursue a least cost planning process, yet it chooses the costliest, both financially and environmentally, resources in its IRP. I am compelled to ask, “How is this least-cost planning?