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At SXSW 2026, moderator Jacob Goldstein opened The Great Fusion Debate with three questions: “Is it going to work? When will it work? And what do we mean by that?”
On stage, SHINE founder and CEO Greg Piefer joined Melanie Windridge, founder of Fusion Energy Insights, and Luke Ward, investment director at Baillie Gifford.
The panel did offer timeline estimates. But the more revealing discussion moved past dates toward what it actually takes to make fusion work under real-world conditions and what counts as progress along the way.
Melanie Windridge addressed the “when” question directly, starting with a milestone often treated as a turning point: In 2022, the National Ignition Facility produced more energy from a fusion reaction than was put into it.
That result showed the science can work. But it also clarified something less comfortable: Demonstrating a net energy gain is not the same as building a system that can sustain it.
The next step, she said, is for private companies to reproduce that performance in their own systems. From there, the problem shifts from physics to engineering and into what she described as “phenomenal challenges” in building real power systems.
Those systems must run continuously and withstand extreme conditions. They must satisfy regulators and operate at a viable cost. Each requirement adds a constraint. Together, they compound.
That’s what makes timelines difficult to pin down. Melanie offered a rough progression for fusion companies, however -- technical milestones in the early 2030s, followed by initial electricity and broader deployment into the 2040s. But each stage depends on multiple factors advancing together.
As she put it, with complex systems, “Everything takes longer than you think it will, but … it seems really fast looking back.”
If engineering complicates timelines, capital can restrain them. From the investment side, Luke Ward extended the logic. As fusion approaches commercialization, the cost of de-risking rises. Each step forward requires more capital, not less.
“The biggest challenge,” he said, “isn’t selling electricity. It’s selling equity.”
Timelines, in other words, may be governed as much by financing as by physics.
The deeper issue may not be timing so much as the need to define our terms. More specifically, what does it mean for fusion to “work”?
If the benchmark is grid-scale electricity at competitive cost, everything before that point can look like delay. Greg offered a different lens. A system works when it creates value under real-world conditions—when it performs reliably, meets requirements, and customers are willing to pay for what it produces.
That perspective changes what counts as progress. It also shifts the focus from a distant endpoint to what systems can do now.
What does that look like in practice? Luke Ward offered a useful comparison. SpaceX didn’t begin with Mars. It built a business around low-Earth orbit—creating revenue, refining systems, and funding the next step.
Fusion may follow a similar pattern. The destination may be grid-scale energy, but the development path is likely to run through applications where fusion creates value along the way.
Greg made that approach explicit. “We've actually identified commercial applications of the technology today … and are using that as a path to practice and make fusion cheaper over time.”
He also pointed to earlier technology cycles—such as semiconductors—where performance improved and costs fell as systems scaled. In that context, early applications support continued development, helping drive costs down as systems improve.
If that model holds, the question shifts—from when will fusion work? to where is it already creating value? Greg pointed to applications that exist today—not as grid-scale power, but as systems built on the same underlying capabilities.
One example at SHINE is in aerospace and defense. The same expertise that underpins our fusion work—particularly in accelerator and target systems—also powers neutron sources used for imaging. These systems reveal internal defects in components such as jet engine turbine blades and pilot ejection seats—defects other methods can’t detect.
That level of visibility helps identify potential failures early, improving safety and performance. In these cases, customers aren’t paying for electricity but for a capability enabled by neutron sources.
Another area is medicine. Medical isotopes remain supply-constrained. Greg described a case close to home. His father went to the hospital with chest pain but, due to limited isotope availability, received a less precise diagnostic test and was sent home with the all-clear. Weeks later, he returned with a 99% blockage in a major coronary artery—a type of heart attack often referred to as the “widowmaker.”
The issue wasn’t diagnostic capability—it was access to the right drug at the right time.
At SHINE, neutron-driven systems produce medical isotopes. In addition, the company is building molybdenum-99 (Mo-99) production capacity to supply a significant share of U.S. demand. Mo-99 generates the technetium-99mused in most diagnostic imaging. The facility will use fusion-based systems to produce Mo-99 at scale, generating tens of millions of patient doses each year. SHINE also produces Lutetium-177 (Lu-177), a key isotope in targeted cancer therapies, using related neutron-driven processes.
In some cases, fusion itself is already being used and sold—for example, through SHINE’s FLARE platform, which provides fusion-generated neutrons for radiation testing of electronics and structural components in aerospace and defense systems.
Fusion in these applications isn’t theoretical. As Greg put it, “Fusion is already here.”
If timelines are hard and capital requirements are rising, it’s tempting to assume the answer is simply more funding. The panel pushed back on that.
In some parts of the world, that assumption is already being tested. China, for example, is investing heavily in fusion, with state-backed programs operating at a scale few private ventures can match. But funding alone does not resolve the underlying challenges.
“Infinite money is a terrible idea,” Greg said. His concern isn’t funding itself—it’s what happens without constraint. More capital can accelerate progress, but it can also distort incentives—reducing the pressure to prioritize, simplify, and design for cost from the outset.
Across the field, that shift is already visible. As Melanie described it, the industry is moving away from an “infinite money mindset” toward more commercially grounded development.
From an investor’s perspective, Luke framed the issue in practical terms. For a technology to scale, it has to compete—and that comes down to economics. Innovation, he argued, has to be both better and cheaper.
For grid-scale electricity, fusion remains a long-horizon challenge, likely extending into the2040s. But that’s only one measure of progress. In practice, the technology is beginning to take shape in systems operating under real constraints—technical, economic, and regulatory.
The question, then, isn’t just “when will fusion work?” It’s “where is fusion already working?” and “how does that change the path forward?”
