A Seattle startup has taken a significant step toward creating a portable nuclear fusion device, operating its compact reactor at 300,000 volts for extended periods, a key technical breakthrough that could transform the clean energy landscape.
Who Is Avalanche Energy?
Avalanche Energy is a privately held company based in Seattle, Washington, founded in 2018 by Robin Langtry and Brian Riordan. The firm is focused on developing compact nuclear fusion reactors (small enough to fit on a desk!) under the product name “Orbitron.” Their long-term aim is to deliver clean, scalable energy solutions for everything from remote infrastructure to spacecraft.
While nuclear fusion has traditionally involved massive, multi-billion-dollar machines like ITER in France or laser-powered systems at the US National Ignition Facility, Avalanche is taking a radically different approach. Its system is designed to be low-cost, lightweight, and modular, using high-voltage electric fields instead of complex magnets or lasers to trigger the fusion process.
Milestone
The company’s latest milestone, sustaining 300,000 volts in a desktop-scale prototype, represents one of the highest voltage densities achieved in a fusion device of its size. This could prove a critical enabler in the race to demonstrate net energy gain from fusion, a feat that would mean the reactor produces more energy than it consumes.
Why A (Desktop) Fusion Reactor?
The global energy sector remains heavily reliant on fossil fuels, and while wind, solar, and battery technologies are progressing, they all face scalability, intermittency, and storage challenges. Fusion, which mimics the process that powers the sun, offers the potential for a virtually limitless source of clean energy without the long-lived radioactive waste or meltdown risks associated with conventional nuclear fission.
“Fusion offers the highest energy density possible,” Avalanche states on its website. “It’s clean, abundant, and sustainable—exactly what humanity needs as we scale into the future.”
However, making fusion practical has proven notoriously difficult. Traditional approaches require either extreme temperatures or massive magnetic fields to confine plasma. These methods are energy-intensive and require huge, expensive infrastructure, which has kept fusion perpetually 20 years away from commercial reality.
Avalanche believes that its ultra-compact Orbitron reactor, combined with recent advances in high-voltage electronics and materials science, could finally break the cycle.
How the Orbitron Works
Unlike tokamaks or laser-based fusion systems, the Orbitron uses a technique called electrostatic confinement. In simple terms, high-speed charged particles (ions) are trapped inside a vacuum chamber and guided into elliptical orbits around a central, negatively charged cathode.
As these ions accelerate and become more densely packed, they begin to collide with enough force to fuse, releasing energy in the process. The prototype achieved a voltage gradient of 6 million volts per metre, which is a level far beyond typical industrial equipment, and one that Avalanche says is “the real unlock.”
This compact design allows the entire system to operate without massive magnets or complex cryogenics. According to Avalanche, the key breakthrough lies in reaching ultra-high voltages in a small footprint, thereby enabling fast-moving ions to be packed into tight orbits with enough energy to spark fusion. The team says this is what allows the machine to remain physically small while delivering the energy densities required for meaningful power output.
The system is modular and scalable. Individual units ranging from 5 kilowatts (kW) to several hundred kW can be grouped together to create higher-capacity solutions, including mobile power sources, micro-grids, or even space-based applications.
What Makes Avalanche’s Approach Different?
Avalanche is part of a new wave of private fusion startups rethinking the architecture of fusion reactors. For example, rather than pursuing billion-dollar mega-projects, these companies are focusing on speed, agility, and commercial viability. Avalanche’s advantage lies in its compact, electrostatic design, which enables rapid iteration and prototyping.
The company says it can produce and test new components in days, rather than years, and expects this to dramatically reduce the cost of development. It also avoids the need for giant facilities or huge teams, which has historically slowed progress in the fusion field.
Another key difference is its target market. While most fusion developers are aiming to power grids, Avalanche is looking at decentralised applications, such as off-grid infrastructure, maritime systems, and lunar or planetary missions. These use cases demand small form factors, rapid deployment, and minimal support infrastructure, which are the criteria that Avalanche is specifically engineering for.
The Orbitron is also being designed to accommodate a range of fusion fuels, including deuterium-tritium and proton-boron-11. The latter has the potential to minimise neutron production, reducing shielding requirements and extending reactor life.
What Does the 300,000-Volt Breakthrough Mean?
Reaching and maintaining 300,000 volts in a compact machine is actually a pivotal achievement. It demonstrates that the Orbitron can sustain the extreme conditions required for meaningful fusion activity while remaining small, efficient, and robust.
Avalanche is now on track to use this capability to build FusionWERX, a planned neutron-production and testing facility in Richland, Washington. The company recently secured a $10 million Green Jobs Grant from the Washington State Department of Commerce to develop the site, which will allow third-party researchers and companies to test fusion components under realistic conditions.
FusionWERX
FusionWERX is intended to be a commercial facility, generating income through neutron production for radioisotope creation, materials testing, and IP-secure research. Langtry estimates Avalanche could become profitable by 2028, with projected revenues of $30–50 million in 2029.
Avalanche now aims to secure the remaining funding needed to match the 50 per cent cost-share requirement tied to its $10 million grant from Washington State. The company is actively preparing a Series B fundraising round to support the FusionWERX project and scale up its reactor development work. According to Avalanche, a significant portion of the matching funds is already committed, with further investment expected to follow as hardware milestones are met.
What Are the Broader Implications?
If successful, Avalanche’s technology could dramatically lower the barriers to fusion adoption. Rather than relying on centralised mega-projects, future fusion could emerge through a more distributed model, with small-scale reactors tailored to specific use cases and markets.
This could have particular relevance for UK businesses, especially those in energy-intensive sectors, remote infrastructure, or off-grid operations. For example, the potential to access compact, safe, and zero-emissions energy on demand would radically change planning and cost structures.
It could also disrupt parts of the existing nuclear sector. For example, traditional fission reactors are heavily regulated, expensive to build, and politically controversial. Fusion, especially in compact form, offers a way around many of these constraints. That said, whether governments will be prepared to adapt regulations quickly enough remains an open question.
For competitors, Avalanche’s milestone puts pressure on other private fusion firms to accelerate their own timelines. Notable players in the field include:
– TAE Technologies (California), which is pursuing proton-boron fusion using beam-driven plasma devices.
– Zap Energy (Seattle), developing a sheared-flow Z-pinch system with no magnets.
– Helion Energy (also based in Washington), which recently signed a deal with Microsoft to supply fusion-generated power by 2028.
– First Light Fusion (UK), using high-velocity impact fusion derived from research at Oxford University.
Each of these companies is using a different approach, but all share the goal of making fusion commercially viable in the near term. Avalanche’s unique angle, targeting small-scale, rapidly deployable systems, helps distinguish it in an increasingly crowded field.
Challenges and Criticisms
Despite the recent progress, fusion remains a tough nut to crack. While Avalanche’s voltage milestone is impressive, it has yet to demonstrate net energy gain, where the energy produced by the fusion reactions exceeds the energy required to initiate and sustain them.
Electrostatic confinement approaches like Avalanche’s have faced scepticism in the past. Earlier systems such as fusors and polywells showed promise but were ultimately unable to scale to net energy production. Whether Avalanche’s novel design can overcome those physics constraints remains to be seen.
There are also engineering hurdles ahead, including scaling up power extraction systems, managing heat loads, and extending component life under repeated bombardment by high-energy particles.
Some experts have also raised concerns about overpromising. With many fusion startups now forecasting delivery within five years, expectations are high, but public trust could suffer if those timelines slip. A measured, evidence-led approach will be key to sustaining momentum.
That said, the combination of technological progress, public funding, and early commercial pathways is helping to shift fusion from long-term aspiration to near-term opportunity. Avalanche Energy’s latest milestone brings that vision one step closer to reality.
What Does This Mean For Your Business?
Avalanche’s 300,000-volt achievement puts it ahead of many peers in demonstrating that fusion conditions can be created and sustained using a radically smaller and simpler system. While it does not yet mean net energy gain has been reached, the ability to operate a high-voltage, compact reactor continuously is a crucial step toward proving that desktop fusion is more than theoretical. This isn’t just a technical milestone, it’s a signal that fusion innovation is no longer confined to large institutions or national labs.
For investors, the company’s path to near-term revenue through neutron generation, radioisotope production and facility rentals helps to de-risk the commercial model. This gives Avalanche a clearer route to financial sustainability than most early-stage fusion firms, even before full-scale energy production is realised. That clarity may also allow it to attract more patient capital in a sector known for long development timelines.
For UK businesses, especially those in manufacturing, defence, remote operations and advanced research, the potential applications are considerable. Modular fusion systems that require little maintenance and produce no direct emissions could offer a stable and long-term energy alternative at a time when electricity prices and carbon pressures remain unpredictable. In high-value, energy-intensive environments where resilience and clean credentials matter, compact fusion could eventually shift how organisations plan infrastructure, supply chains and investment.
At the same time, regulators, utilities and energy planners will need to consider how small-scale fusion fits into existing frameworks. Questions about safety certification, licensing, integration with grid systems, and waste handling (even if minimal) will all need answering well ahead of any widescale deployment.
For the broader energy sector, Avalanche’s progress underscores a growing shift from slow, centralised fusion development toward smaller, faster, and more commercially agile models. This shift introduces competition and experimentation into a field once dominated by public-sector science programmes. But it also brings new scrutiny. Claims will need to be backed by results. Startups like Avalanche will be measured not just on vision, but on engineering performance, cost, scalability and real-world deliverables.
Avalanche’s milestone, therefore, offers a glimpse of what fusion could look like in practice, i.e., not vast tokamaks on government sites, but flexible machines that power remote labs, isolated communities or advanced industries. If the next set of milestones are met, and if the technology scales as claimed, fusion could become something businesses use, not just something scientists pursue. That would be a real shift, and this breakthrough brings that future closer than it has ever been.