- Historic fusion project: The Tennessee Valley Authority (TVA) – the largest US public power utility – plans to build a first-of-its-kind 350 MW nuclear fusion power plant at a retired coal site in Tennessee, aiming to power about 300,000 homes nam.org. The project will use stellarator fusion technology developed by startup Type One Energy, backed by Bill Gates’s Breakthrough Energy Ventures, in a multibillion-dollar gamble on virtually unlimited, carbon-free energy.
- Stellarator advantage: Unlike conventional tokamak fusion reactors that run in pulses, the stellarator’s twisting magnetic design can confine superheated plasma in a steady-state (continuous) operation without constant adjustments typeoneenergy.com. This promises a more stable and efficient fusion process, which Type One says could deliver on-demand electricity at competitive prices with coal and natural gas typeoneenergy.com if the technology succeeds.
- AI boom driving demand: A surge in electricity needs from artificial intelligence and high-tech industries is spurring interest in advanced nuclear projects. TVA explicitly cites growing power demand from AI, quantum computing and advanced manufacturing as motivation for its fusion initiative typeoneenergy.com utilitydive.com. Tech giants are also betting on fusion – Microsoft signed the world’s first fusion power purchase deal to run its data centers on fusion by 2028 world-nuclear-news.org, and Google agreed to buy 200 MW from a planned fusion plant in the early 2030s datacenterdynamics.com. (Even OpenAI has explored buying “vast quantities” of fusion power for future AI supercomputers datacenterdynamics.com.)
- Parallel nuclear push: In addition to fusion, TVA is pursuing next-generation fission reactors to meet rising demand. In September 2025, it inked a landmark agreement with startup ENTRA1 Energy to deploy six small modular reactors (SMRs, developed by NuScale) across its service region – adding up to 6 GW of new nuclear capacity utilitydive.com. ENTRA1 will finance and build the SMR plants (enough to power ~4.5 million homes or 60 new data centers) and sell the output to TVA utilitydive.com. This dual approach highlights how utilities see advanced nuclear (both fission and fusion) as crucial for reliable, carbon-free power in the AI era.
- Challenges ahead: No fusion experiment has yet produced net-electricity output (continuous power greater than the energy input to the system) theguardian.com. Recent lab breakthroughs (e.g. a December 2022 shot that yielded more fusion energy than the laser energy applied theguardian.com) were momentary and consumed far more power overall. Commercializing fusion remains a formidable challenge – engineers must solve extreme heat, materials, and plasma control issues, and many experts don’t expect viable fusion power plants before the 2040s datacenterdynamics.com. Investors have poured billions into fusion startups regardless, amid both excitement and “FOMO” that fusion could revolutionize energy if it works datacenterdynamics.com. Skeptics caution that fusion is not a near-term climate solution theguardian.com, but each new project – like TVA’s – is an important step toward finally harnessing the power of the stars on Earth.
TVA’s Fusion Gamble at Bull Run
The TVA’s plan marks an unprecedented move by a US utility: building, owning and operating a fusion power plant (pending regulatory and board approvals) rather than just buying fusion power from a third party. In September 2025, TVA issued a letter of intent to Type One Energy, signaling its interest in deploying the company’s fusion reactor at TVA’s former Bull Run Fossil Plant site near Oak Ridge, Tennessee typeoneenergy.com. Bull Run was a coal-fired power station retired in 2023 – now its grounds may host a cutting-edge fusion facility, symbolically transitioning from fossil fuels to futuristic clean energy.
Type One Energy’s reactor design, called Infinity Two, is envisioned as a 350 MWe (megawatt electric) fusion pilot plant nam.org. That output is roughly the size of a small conventional power plant – capable of supplying around 300,000 homes in the region nam.org. The startup aims to complete the reactor’s final design and all licensing and environmental reviews by 2029, after which construction and testing could begin in the 2030s. If all goes well, TVA and Type One hope to have the fusion plant feeding power into the grid by the mid-2030s world-nuclear-news.org.
Crucially, the TVA project will use a stellarator-type fusion device – a less common approach that could offer significant benefits for power generation. “This really is a watershed moment in the history of fusion,” said Type One’s CEO Christofer Mowry, describing the TVA partnership as a major validation for fusion’s commercial prospects. Unlike previous fusion deals structured merely as power supply contracts, TVA’s intent to directly invest in fusion infrastructure indicates a high level of confidence – or at least willingness to take on risk – by a large public utility. TVA President and CEO Don Moul noted the agency is “strategically partnering with innovative companies like Type One Energy” to advance nuclear technologies, expressing excitement at the possibility of hosting “the first U.S. commercial stellarator fusion power plant” in the Tennessee Valley typeoneenergy.com.
Cost and funding: While detailed budgets haven’t been released, Type One estimates the first pilot plant will cost on the order of “several billions of dollars”. For context, another private fusion venture (Commonwealth Fusion Systems) recently announced a multi-billion-dollar investment to build a similarly sized fusion plant in Virginia governor.virginia.gov. These are truly moonshot projects – expensive prototypes that, if successful, could pave the way for a new era of energy. TVA’s model is to leverage public-private collaboration: it brings its utility expertise in siting, construction and operations, while Type One provides the fusion technology. The state of Tennessee and Oak Ridge National Lab are also involved (via “Project Infinity”) to support R&D and workforce development world-nuclear-news.org. Final go-ahead for TVA’s fusion plant will depend on hitting design milestones, securing regulatory approvals, and ensuring the project meets the utility’s cost and reliability requirements typeoneenergy.com typeoneenergy.com. In other words, TVA isn’t committing to build the plant until it’s confident the reactor will work as advertised – a prudent stance given fusion’s uncertainties.
What Is a Stellarator? A “Twisted” Path to Steady Fusion
Most fusion projects to date – including giant international experiments like ITER in France and private ventures like CFS’s SPARC – use the tokamak design. A tokamak traps hot plasma in a doughnut-shaped magnetic field and drives electric currents through the plasma to help stabilize it. Tokamaks have achieved high temperatures and fusion reactions, but they tend to run in short pulses and face challenges keeping the plasma stable and uniformly confined. In a tokamak, the magnetic field is stronger on the inner side of the donut than the outer side, which can cause the superhot plasma to drift and instabilities to grow world-nuclear-news.org. Engineers must constantly adjust and fine-tune the plasma conditions to prevent disruptions.
Stellarators take a different approach: they twist the magnetic torus into a pretzel-like shape (often a figure-8 or more complex geometry) using intricately wound coils. The twisted shape ingeniously evens out the magnetic field around the plasma, eliminating the need for large plasma currents and external tweaks to keep the reaction stable world-nuclear-news.org. In essence, a stellarator’s magnets do all the work of confinement, allowing for continuous operation without the pulsing or frequent control adjustments tokamaks require. This design was first conceived in the 1950s but was long limited by how difficult it is to design and build the complex 3D coils. Thanks to advances in supercomputing (for design optimization) and high-temperature superconductors (for stronger magnets), modern stellarators are making a comeback. Germany’s Wendelstein 7-X, the world’s largest stellarator, recently set records for plasma stability and duration, running for up to 8 minutes and demonstrating the type of steady-state operation needed for power production en.wikipedia.org indiandefencereview.com.
Type One Energy’s stellarator – called Infinity One (a prototype) and Infinity Two (the power-plant design) – builds on that progress. It is currently the only fusion technology to demonstrate inherently stable, continuous operation at high efficiency typeoneenergy.com. These qualities are extremely attractive for a utility like TVA: a steady-state fusion reactor could run 24/7 to provide reliable baseload power, just like a conventional coal, gas, or fission plant typeoneenergy.com. In contrast, many tokamaks (and other fusion concepts) operate in pulses or require intervals to recharge, which complicates grid integration. “The stellarator is currently the only fusion technology to have demonstrated stable, steady-state operation with high efficiency,” Type One notes, highlighting why TVA and others find it promising typeoneenergy.com.
That said, stellarators are technologically complex. Every magnet coil in a stellarator has a unique, non-planar shape – manufacturing and assembling these with the precision required is a major engineering challenge. Type One is mitigating this by partnering with experienced fabricators: TVA’s own Power Service Shops in Alabama will help develop modular fabrication techniques for the Infinity One and Two machines typeoneenergy.com typeoneenergy.com. Type One also licensed advanced superconducting cable technology from Commonwealth Fusion Systems to use in its magnets world-nuclear-news.org, indicating a collaborative approach among fusion ventures. If Infinity Two succeeds, it would effectively validate a new branch of fusion reactor design for commercial use. The upside is huge: a fusion plant that, once ignited, burns like a star continuously, sipping small amounts of hydrogen fuel to deliver a steady output of electricity with no greenhouse gases or long-lived waste.
Why the Fusion Frenzy? AI and the Race for Clean Power
TVA’s fusion gambit comes amid a broader groundswell of interest in fusion energy, supercharged by the world’s growing thirst for clean yet firm (always-available) power. A key driver frequently cited is the booming energy demand from artificial intelligence and other digital industries. Training AI models and running data centers devour enormous amounts of electricity – and those needs are projected to skyrocket in the coming decade. “This is the energy needed to power America’s economic prosperity and fuel artificial intelligence, quantum computing and advanced manufacturing,” TVA stated, underscoring why it’s investing in new nuclear capacity utilitydive.com. In other words, the rise of AI is putting pressure on power suppliers to deliver massive, reliable, round-the-clock electricity without the carbon footprint of fossil fuels.
Renewables like solar and wind are scaling up, but their intermittency and land footprint pose challenges for meeting the always-on power requirements of data centers and industries. Advanced nuclear technologies – both fission and fusion – are being pursued to fill this gap. Fusion, with its theoretical ability to provide “near-limitless, safe and clean” energy theguardian.com, has captured the imagination of both governments and tech leaders.
Notably, big tech companies are directly getting involved in fusion development. In May 2023, Microsoft shocked the energy world by announcing a power purchase agreement (PPA) with fusion startup Helion Energy: if Helion’s planned pilot plant is operational by 2028, Microsoft will buy 50 MW or more of fusion power to help run its cloud data centers world-nuclear-news.org world-nuclear-news.org. This was the world’s first-ever fusion electricity contract – essentially a bet by Microsoft on fusion coming to fruition within five years. Helion has since broken ground on its fusion plant in Washington state (named “Orion”), and it explicitly targets data center power as a market, promising “flexible, scalable, baseload power that is affordable” and carbon-free world-nuclear-news.org.
Google, not to be outdone, has invested in multiple fusion ventures. It is a backer of Commonwealth Fusion Systems (CFS) and recently agreed to purchase 200 MW of fusion power from CFS’s first commercial reactor (the ARC tokamak plant planned in Virginia with Dominion Energy) datacenterdynamics.com. That plant, slated for the early 2030s, would supply Google with clean energy for its facilities – showing Google’s interest in locking in long-term green power supply for its expanding server farms. Similarly, OpenAI (the AI lab behind ChatGPT) was reported to be in talks to secure huge amounts of fusion power from Helion down the line datacenterdynamics.com; OpenAI’s CEO Sam Altman is actually an investor in Helion, underlining his belief that fusion will be key to powering AI in the future.
This convergence of Silicon Valley and fusion research is a striking new development. Tech executives view fusion as a potential silver bullet: a source of massive, carbon-free energy to run energy-hungry technologies without exacerbating climate change. Their involvement is bringing fresh capital – and urgency – to an industry long dominated by government-funded labs. In 2023 and 2024, private investors poured extraordinary sums into fusion startups. Commonwealth Fusion Systems, for example, raised $863 million in a single funding round in 2025 (with backing from Nvidia’s venture arm and other big-name investors) datacenterdynamics.com datacenterdynamics.com. CFS has now raised about $3 billion in total datacenterdynamics.com, and is building a large team to commercialize its high-field tokamak. Dozens of other fusion companies worldwide – from TAE Technologies in California (which Google also backs) datacenterdynamics.com, to TAE’s UK rival Tokamak Energy, to startups in Canada, Europe, and Asia – collectively have secured over $6 billion in private funding in the past several years. This fusion gold rush is fueled by a mix of optimism and fear of missing out: as energy consultant Mark Nelson quipped, investors either “see what comes out of these experimental prototype reactors, or are terrified of being left out – maybe both.”
Government support is rising too. In the US, the Department of Energy launched a Milestone-Based Fusion Development Program to co-fund promising private fusion designs with the goal of a pilot plant in the 2030s fusionindustryassociation.org. The UK government is planning to build a fusion demo (the STEP program) by 2040, and China and Japan have increased fusion research budgets. Even oil companies and fossil energy players are investing in fusion as a hedge on the energy future climatechangenews.com. All of this momentum suggests a palpable “fusion fever” – a sense that after decades on the scientific fringe, practical fusion power might finally be within reach. However, enormous work remains to turn that hope into reality.
Fusion vs Fission: Betting on Two Horses
It’s important to put fusion’s prospects in context with the other nuclear technology experiencing a renaissance: advanced fission reactors. Traditional nuclear fission plants (which split atoms of uranium) already provide around 20% of US electricity, but they’re large, expensive and have faced public concern over safety and radioactive waste. Now, small modular reactors (SMRs) and other Gen-IV fission designs promise to reboot nuclear power with smaller, safer units that can be factory-built and perhaps more easily financed. TVA’s strategy shows it is hedging its bets on both fronts – fusion and fission – to meet future demand for clean energy.
On the fission side, TVA’s agreement with ENTRA1 Energy could lead to six SMR units (using NuScale’s 77 MW modular reactor technology) deployed across the TVA service area over the next decade utilitydive.com utilitydive.com. These would add up to 6 GW of capacity – roughly equivalent to 6–7 large conventional reactors, or about three-quarters of TVA’s entire current nuclear fleet utilitydive.com utilitydive.com. ENTRA1 will finance and own the SMRs, while TVA will buy the power, in what is being called the largest SMR rollout in U.S. history utilitydive.com. According to TVA, 6 GW could supply “60 new data centers” or 4–5 million homes, underscoring again how data center growth is influencing utility planning utilitydive.com. “No utility in the U.S. is working harder or faster than TVA” on new nuclear, said TVA’s CEO Don Moul, pointing to public–private partnerships like those with ENTRA1 and Type One as “vital” for advancing next-gen reactors utilitydive.com.
While fusion and fission both produce energy from atomic nuclei, they have very different risk–benefit profiles. Fusion (combining light atoms like hydrogen into helium) has the allure of “nearly limitless energy” from common fuels – a single kilogram of fusion fuel (isotopes of hydrogen from water or lithium) could yield as much energy as 10 million kilograms of fossil fuel theguardian.com. Fusion emits no greenhouse gases and produces no long-lived radioactive waste theguardian.com. There’s also no risk of a runaway reaction or core meltdown: if containment fails, the plasma simply fizzles out. These advantages explain why fusion is often called the “holy grail” of energy. Fission, on the other hand, generates some long-term radioactive waste and carries a (small) risk of accidents, as seen at Chernobyl or Fukushima decades ago. Yet fission has one huge edge right now: it works today. Proven reactor designs can be built now to deliver carbon-free power, whereas fusion still must clear fundamental feasibility hurdles.
TVA’s embrace of both SMRs and fusion reflects a dual strategy: SMRs can start adding reliable capacity in the 2030s (NuScale’s design already won regulatory approval in 2023 utilitydive.com), while fusion has the potential to be the ultimate game-changer in energy – but likely not until the late 2030s or 2040s. By supporting fusion R&D early, TVA positions itself to benefit if/when the technology matures, without abandoning nearer-term solutions. Governor Bill Lee of Tennessee praised this approach, noting it helps build a “nuclear ecosystem” in the state that creates jobs and expertise in both fission and fusion sectors typeoneenergy.com typeoneenergy.com. In a future where both advanced fission and fusion are available, they could complement each other and further strengthen grid reliability alongside renewables. For example, SMRs might handle baseload needs in the 2030s, with fusion plants coming online later to take over as the primary zero-carbon energy workhorses in the second half of the century.
The Promise and Peril of Fusion: Will It Pay Off?
The potential benefits of fusion power are undeniable – clean, abundant energy that could fundamentally reshape economies and help solve climate change. A successful fusion reactor would generate electricity by replicating the process that powers the sun, fusing hydrogen atoms into helium and releasing prodigious energy nam.org. Every major fusion milestone generates buzz: when U.S. scientists achieved a net energy gain in a fusion reaction for the first time in December 2022 (at Lawrence Livermore’s laser-driven NIF facility), it was hailed as a historic breakthrough theguardian.com theguardian.com. “A major scientific breakthrough decades in the making,” declared the U.S. Energy Secretary theguardian.com. That experiment proved that fusion is not just theoretically possible but can produce more energy out than in – at least at small scale and for a split second.
However, translating that kind of result into a practical power plant is an entirely different challenge. The Livermore experiment, for instance, yielded about 3 MJ of fusion energy from a tiny fuel pellet, but it required over 300 MJ of energy in total to fire the lasers – a huge net loss when considering the whole system. Similarly, today’s best magnetic fusion devices have come close to “breakeven” (JET in the UK produced 0.67 of the input power in fusion output in 1997), but none has reached the point of continuous self-sustaining burn where the reactor produces excess electricity. As the National Association of Manufacturers neatly summarized: “while scientists have produced fusion energy for brief periods on multiple occasions, they’ve yet to create a long-term sustainable power generator.” nam.org In other words, sustained, controlled fusion that feeds the grid is still unproven.
The engineering hurdles are enormous. Fusion reactors must heat fuel to over 100 million °C (hotter than the sun) and confine it long enough for sufficient fusion reactions to occur. This demands superconducting magnet coils, exotic materials, and precision controls operating at the extremes of temperature and pressure. The reaction also unleashes floods of high-energy neutrons (especially in the deuterium–tritium fuel cycle that most designs use). Those neutrons bombard the reactor structure, causing damage and radioactivity in materials – finding materials that can withstand this neutron flux for years is a major research area. Handling the intense heat flux exhaust (much hotter than a space shuttle reentry) without components eroding is another challenge datacenterdynamics.com. And then there’s the issue of economics: even if a fusion reactor works physically, can it be built and run at a cost competitive with other energy sources? Skeptics point out that fusion will likely be very expensive initially, and renewable energy plus storage is getting cheaper every year. To compete, fusion must not only break the scientific barriers but do so in a way that is commercially viable and scalable.
Because of these hurdles, many experts maintain that fusion is still decades away. A recent analysis noted that “major hurdles remain – namely, high costs, heat management, and plasma confinement – which have pushed most estimates for commercialization beyond the 2040s” datacenterdynamics.com. Even insiders of the fusion industry often acknowledge that widespread deployment may not happen until mid-century unless there are unforeseen leaps. And while fusion could be a game-changer for the second half of the century, it unfortunately won’t arrive fast enough to significantly help with the urgent task of cutting emissions by 2030 to meet climate goals theguardian.com. As The Guardian reported, scientists stress that fusion is “far from ready to turn into viable power plants – and is not about to solve the climate crisis” in the near term theguardian.com.
Yet the recent flurry of investments and prototype projects suggests a new optimism that fusion’s timeline can be accelerated. The influx of private capital and competition could spur faster innovation, much as SpaceX revolutionized the rocket industry. Already, we see multiple approaches being pursued: from tokamaks and stellarators to laser inertial fusion, magnetized target fusion, and novel concepts (like Helion’s pulsed non-ignition approach using direct energy conversion world-nuclear-news.org). Each has its pros and cons, and it’s unclear which (if any) will hit the mark first. This diversity increases the chances that someone will crack the problem. As one fusion CEO put it, “after more than a decade designing and building record-breaking fusion machines, [starting construction on a power plant] is a significant moment for us as we prepare to bring fusion power to the world.” world-nuclear-news.org The coming few years will see a race of prototype reactors: for example, CFS’s SPARC tokamak is set to attempt net power by 2027 datacenterdynamics.com, and multiple startups aim for demo reactors before 2035 with help from government milestone funding.
For TVA and the communities it serves, the fusion project at Bull Run is a bold long-term bet. If successful, it could make the Tennessee Valley a leader in the next revolution of energy technology. “Tennessee is ready-made to lead America’s energy independence,” Governor Bill Lee said, noting the state’s commitment to both fission and fusion initiatives typeoneenergy.com. The fusion plant would bring high-tech jobs and reaffirm the Oak Ridge area’s identity as an innovation hub (Oak Ridge National Lab, recall, was born from the Manhattan Project – a lineage fitting for another potentially world-changing nuclear project). On the other hand, if fusion takes longer than hoped or fails to materialize, TVA’s customers won’t be left in the dark thanks to parallel investments in SMRs, solar, and other resources.
In summary, the TVA-Type One Energy partnership exemplifies the new wave of fusion development: a public-private collaboration aiming to turn decades of laboratory science into a practical power source. It’s a moonshot with no guarantee of success – but the payoff, unlimited clean energy, is so great that many now deem it worth the risk. As one energy observer noted, the surge of fusion efforts shows that investors and utilities “are clearly excited… or terrified of being left out. Maybe both.” In the next 10–15 years, we will find out if that excitement is justified. If the stars align (quite literally), the mid-2030s could see the lights in Tennessee – and perhaps Virginia and elsewhere – powered by humanity’s first fusion power plants. That would indeed be, as TVA’s partner said, a “watershed moment” – not just in the history of fusion, but in the story of energy and technology itself.
Sources:
- National Association of Manufacturers – “TVA Partners with Startup on Nuclear Fusion.” (Feb. 19, 2025) nam.org nam.org
- Type One Energy press release – “TVA and Type One Energy Accelerate Fusion Commercialization in Tennessee.” (Sept. 19, 2025) typeoneenergy.com typeoneenergy.com
- Utility Dive – “Tennessee Valley Authority signs agreement for 6 GW of small nuclear.” (Sept. 2, 2025) utilitydive.com utilitydive.com
- World Nuclear News – “Helion begins work on fusion power plant.” (July 31, 2025) world-nuclear-news.org world-nuclear-news.org
- DataCenterDynamics – “Commonwealth Fusion Systems raises $863 m in Series B2 funding…”. (Aug. 29, 2025) datacenterdynamics.com datacenterdynamics.com
- The Guardian – “US scientists achieve net energy gain for second time in nuclear fusion reaction.” (Aug. 6, 2023) theguardian.com theguardian.com
