After decades of being dismissed as perpetually 30 years away, fusion energy—power generated through nuclear fusion reactions—is increasingly viewed as a question of when, not if. Investor and public interest in fusion is driven in large part by surging electricity demand from the A.I. boom and the rapid expansion of data centers across the U.S. As Big Tech companies search for reliable, carbon-free baseload power, fusion has reemerged as a long-term solution with growing near-term momentum.
In September, Type One Energy, a startup backed by Bill Gates’ Breakthrough Energy Ventures, announced plans to develop a 350-megawatt electrical (MWe) fusion power plant in Tennessee in partnership with the Tennessee Valley Authority (TVA), the largest public power utility in the U.S. Type One Energy is one of dozens of companies racing to be first to bring fusion power into commercial operation in the U.S. Helion, a startup backed by Sam Altman, Peter Thiel and Reid Hoffman and valued at $5.4 billion, has set an ambitious goal of beginning commercial operation in three years. Startups such as Pacific Fusion and Proxima Fusion have each raised more than $100 million, while Commonwealth Fusion Systems recently announced collaborations with Nvidia and Siemens to apply A.I. to fusion development. Thea Energy, meanwhile, has completed a pre-conceptual design for a fusion power plant.
Despite the flurry of announcements, the central challenge facing the sector remains unchanged: demonstrating that fusion can generate electricity at a commercial scale and at a competitive cost. With global energy demand expected to at least double in the coming decades, industry leaders argue that fusion is not competing for a fixed slice of the energy market. “The market is big enough for all energy industries,” Matt Miles, senior vice president of marketing and external affairs at Type One Energy Group, told Observer. Fusion, he added, isn’t “fighting over the same megawatts” as existing sources such as fossil fuels, solar or wind. “Once the first fusion plant comes online, we can expect to see a dramatic capital influx,” Miles said.
How much will fusion energy cost?
Because no fusion power plant is currently in operation, both short- and long-term capital costs remain uncertain. Some estimates place costs as high as $8,000 per kilowatt (kW) by 2050. Still, modeling from fusion experts suggests that under favorable market conditions, even capital costs around $7,000 per kW could allow fusion to reach 100 gigawatts (GW) of capacity—roughly matching today’s U.S. nuclear fleet. In less favorable scenarios, where alternative energy technologies continue to scale aggressively, fusion costs would need to fall to less than half that level to achieve similar penetration.
A significant driver of fusion’s high costs is the extreme engineering environment inside a reactor. Reliable supplies of advanced materials, including tungsten alloys, silicon carbide composites, high-temperature steels and graphene-based coatings, are required to withstand intense heat and constant neutron bombardment. “In the race to unlock fusion and reinvent fission, graphene may be the missing material,” Kjirstin Breure, CEO of HydroGraph, told Observer. Graphene’s exceptional thermal conductivity helps prevent overheating, while its strength and radiation resistance protect reactor components from cracking and degradation, she explained.
Funding, however, remains the sector’s central constraint. Most of the capital invested to date in the fusion landscape is going into two primary technological approaches: Magnetic Confinement Fusion Energy (MFE) and Inertial Confinement Fusion Energy (IFE), said Christoph Frei, partner and head of energy at Emerald Technology Ventures. MFE, which uses powerful magnetic fields to confine superheated plasma, accounts for the majority of startup activity and has attracted roughly $30 billion in public and private funding. IFE, which relies on high-energy lasers to compress fusion fuel, accounts for approximately 20 percent of startup activity and around $7 billion in total investment.
Energy generation is only one piece of a much larger system. Grid infrastructure and energy storage pose equally significant challenges for emerging power technologies. In the U.S., the interconnection queue has become a major bottleneck, with more than 2.6 terawatts of generation and storage capacity seeking grid access. This represents more than twice the total installed capacity of the existing power fleet.
Miles argues this constraint may also present an opportunity. A U.S. Energy Information Administration report found that utilities plan to retire 12.3 gigawatts of generating capacity in 2025, a 65 percent increase from 2024, with coal accounting for two-thirds of those retirements. In 2022, the Department of Energy identified 157 retired coal plants and 237 operating coal plants as potential sites for “coal-to-nuclear transition.” These locations already have transmission infrastructure and grid connections in place—assets that fusion plants will require. Type One Energy’s proposed Tennessee project, planned for the former Bull Run fossil plant site near Oak Ridge, exemplifies this strategy. “We will plug in to the existing grid,” Miles said. “We won’t need any re-shuffling of how the grids are operated.”