Highlights from Seattle Fusion Week 2025

At the end of every September, the Seattle Clean Tech Alliance (CTA) holds Seattle Fusion Week. Seattle Fusion Week 2025 is the second of these events that The Fusion Report has been a part of. And just like last year, the program provided a lot of good information on the fusion ecosystem, particularly that in the Washington State area, which is a hotbed of fusion activity. One of the outputs of the CTA this week is their 2025 Washington State Fusion Energy Landscape Report (you can get it at this link). We will highlight some of the content from the various sessions at Seattle Fusion Week below.

Status Updates from Washington State Fusion Energy Companies

Several Washington-area companies presented their current status at Seattle Fusion Week. We will provide the highlights of these here.

Avalanche Energy (Kate Kelly, Chief of Staff): Avalanche’s goal is to build the world’s smallest fusion machine. Small fusion machines open up a lot of possibilities, including powering datacenters, extending the operational reach of the US military, and to power autonomous vehicles for deep-sea research and space exploration, while de-carbonizing these parts of the ecosystem. There are also important needs for fusion machines operating at Q<1, such as for the generation of neutrons. Avalanche recently opened up a commercial-scale test family in Richland, WA to test materials and systems for other companies. Avalanche also achieved one of their Series A technical milestones, operating their plasma confinement system at 300kV. The company also received a Washington State $10M cost-share grant for “Green Jobs”. Finally, Avalanche turned on their most recent fusion machine, which they believe will solve some of the instability issues that they were dealing with to achieve the plasma densities they need to reach for Q>1 fusion.

Helion Energy (Jesse Barton, Director of Communications): From a funding standpoint, Helion is the third largest fusion energy company (behind Commonwealth Fusion Systems and TAE), with nearly $1.04 billion in funding. But more interestingly, Helion Energy aims to be the first private company to field the world’s first fusion power plant  (Orion) in Malaga, Washington, which Helion expects to complete in 2028, and which will produce 50 megawatts (MW) of electrical power (or greater!) for Helion’s first customer (Microsoft). Helion’s current state of the art fusion machine (Polaris) is the precursor to Orion, and has been successfully operating since the end of 2024, paving the way for commercial fusion energy. While Helion’s schedule is aggressive (perhaps aspirational), let’s hope that they can actually achieve it!

Zap Energy (Alex Cheung, Director of Design Integration): Zap Energy today is the #8 fusion energy company by total funding, with a total of $330M raised in private funds to date. Zap utilizes a sheared-flow stabilized Z-pinch approach to produce fusion. The advantage of this approach is that it eliminates the need for complex lasers or magnetic coils, significantly reducing the cost of the overall system. Their current fusion machine has survived over 1,000 shots at a rate of 0.1 Hz (one shot per every ten seconds). The next step for Zap Energy is their “Project Century”, which will build upon their current solution by adding a heat exchange system which will enable the conversion of the heat g enerated by their fusion machine into electricity, combining and testing all of the pieces together for extended periods.

Kyoto Fusioneering (Bibake Uppal, Head of Kyoto Fusioneering America): Unlike the other companies presenting at Seattle Fusion Week, Kyoto Fusioneering is not building fusion energy machines. Rather, they are building the downstream systems required to support fusion machines in a way that is agnostic to the type of fusion. The company was founded in 2019, and has raised $110 million to date. Their three technology areas of focus today are the breeding/thermal blanket, fusion fuel cycle systems, and plasma heating systems. Kyoto has built a number of gyrotrons for plasma heating, many of which they have sold to private fusion energy companies and to government labs. On the thermal blanket side, their “Unity-1” system utilizes lithium-lead as the coolant/first wall/breeding medium, while “Unity-2” is their fuel cycle experimental setup.

General Fusion: Of all the companies that spoke at Seattle Fusion Week 2025, General Fusion perhaps has the most unique approach to fusion energy. Unlike other systems that are generally using magnetic confinement fusion (MCF) or inertial confinement fusion (ICF), General Fusion utilizes mechanical compression driven by hundreds of steam-driven pistons which drives a liquid-metal first wall which is 2 meters thick, that compresses the fusion fuel. They are currently working on the LM-26 machine.

Utility and Grid Integration

As we have pointed out numerous times, fusion energy without a way to get it to where it needs to be consumed is not very interesting. Making this more difficult, building new transmission lines is becoming problematic in urban areas; think of “Not In My Backyard” (literally). Fusion is interesting because you can site power plants where older power plant technology (coal, gas, etc.) is sited today. In addition to replacing existing (“brownfield”) generation resources, utilities are also looking at lower-power “distributed” fusion solutions, which could work “behind the meter” for high-power consumption sites such as datacenters.

Electricity pricing is also becoming a challenge for a larger number of rate-payers in Washington state, largely from the Washington Clean Energy Transition Act (CETA) of 2018 which focuses on phasing out fossil fuels in favor of alternative clean energy resources. It is especially problematic because many of these clean energy resources are not dispatchable, and often need new transmission infrastructure. This is also made worse by datacenters and crypto-miners, whose power needs can swing wildly and rapidly. Complicating matters worse is that medium/large transformers (which are critical to transmission of power from renewable sites to urban areas) can take 3 years or more to build, and shipping them is also difficult because of their size.

To be successful, utilities would like to see fusion power systems that are NOT “copies” of today’s power plants. They are also looking at how to derisk this new technology from a power reliability perspective, such as collocating fusion plants next to existing power plants to avoid blackouts. In any case, one of the most attractive features of fusion for electricity is that the marginal cost of fusion fuel is a strong positive, as it significantly reduces the cost of dispatchability, an issue for fossil fuels today. The impact of this cost can be seen in the replacement of coal by natural gas, which had a much lower marginal cost than coal. This also helps with the electricity pricing issue above. While the panelists pointed out that they are not in the business of inventing new power sources, they see fusion as being important to the future of electrical power.