The archive · Climate & Energy · Technical decision · 2017–2025
Zap Energy bets magnet-free Z-pinch fusion; DOE certifies Century milestone, 39 kW
Zap Energy bets a sheared-flow Z-pinch needs no magnets or lasers; DOE certifies Century's 1,080-shot milestone, then 39 kW sustained operations.
Zap Energy
What the business is
Zap Energy is a Seattle fusion startup building power modules that confine and compress plasma with a sheared-flow-stabilized Z-pinch — no superconducting magnets or lasers — and Century, its 100 kW-scale repetitive test platform, to prove the plant's pulsed-power, liquid-metal-wall and electrode systems.
Starting capital：$130M Series D led by Soros Fund Management, closed October 2024; total funding surpassed $330M
How it started
Founded in 2017 by University of Washington professors Uri Shumlak and Brian Nelson with entrepreneur Benj Conway, Zap set out to commercialize sheared-flow-stabilized Z-pinch research. It joined DOE's Milestone-Based Fusion Development Program in May 2023, betting that engineering repetition — not a single physics breakthrough — is the fastest path to a commercial plant.
What happened
Century began operations in June 2024 and within weeks ran 1,080 consecutive plasma shots at 0.1 Hz into a chamber lined with flowing liquid bismuth. In October 2024 Zap closed a $130M Series D led by Soros Fund Management, with new investors including Emerson Collective and Mizuho, taking total funding past $330M. In February 2025 DOE certified Zap's first Milestone Program milestone: three hours of continuous operation with 1,080 shots, each at least 100 kA, in a liquid-metal environment. By September 2025 Century was firing more than one hundred shots at 0.2 Hz with up to 500 kA per pulse, reaching 39 kW average chamber power (57 kW total input) — a 20x gain over the 2024 commissioning run — while firing over 10,000 shots in a year with a 2,500-pound liquid bismuth loop.
No ending yet — it is still running.
Background
Zap Energy is a Seattle fusion startup founded in 2017 by University of Washington professors Uri Shumlak and Brian Nelson with entrepreneur and investor Benj Conway. Its bet is that fusion power does not need the giant superconducting magnets or high-power lasers that dominate other designs: a sheared-flow-stabilized Z-pinch compresses plasma with the magnetic field generated by its own current, letting each power module be compact and far cheaper to build.
To test the unglamorous engineering, Zap built Century, the first 100 kW-scale repetitive Z-pinch system. It fires pulsed power into a flowing liquid-bismuth chamber to validate the three subsystems a plant needs: repetitive pulsed power supplies, plasma-facing circulating liquid-metal walls, and electrode protection. Within weeks of its June 2024 commissioning it ran 1,080 shots; in February 2025 DOE certified Zap's first milestone under its Milestone-Based Fusion Development Program — a three-hour continuous run: 1,080 shots at 0.1 Hz, each at least 100 kA, in a liquid-metal environment.
By September 2025 Century had reached 39 kW of average chamber power at 0.2 Hz — one shot every five seconds, each up to 500 kA — a twenty-fold gain over its 2024 commissioning run, with more than 10,000 shots fired in a year. Zap closed a $130M Series D led by Soros Fund Management in October 2024, bringing total funding past $330M, and planned to ramp Century toward 100 kW while advancing its FuZE-Q plasma device toward scientific breakeven.
What has to be true
- The Z-pinch geometry removes the two most expensive components of fusion — magnets and lasers — making the technology's whole economic case orders-of-magnitude lower capital.
- Zap treats fusion as a systems-integration problem: Century runs on hydrogen so engineers can perfect pulsed power, liquid metal walls and electrodes before fusion neutrons complicate everything.
- DOE certification under the Milestone-Based Fusion Development Program gives independent validation of progress, which is what investors and future customers can actually underwrite.
- Repetition is the business model: a plant would fire thousands of times a day, so Zap's 10,000-shot year de-risks the machine in a way a single physics demo never would.
- A funding base spanning Soros Fund Management, Breakthrough Energy Ventures, Chevron and Shell backed the parallel track of physics and engineering that Zap says is essential to commercial timelines.
What can be applied
In capital-heavy deep tech, credibility comes from repeatable milestones: DOE-certified runs and 10,000 shots keep capital coming while the bet — magnet-free fusion — is still unproven.
Aftermath
As of September 30, 2025, Zap Energy continued ramping Century toward 100 kW average power and higher repetition rates, planning upgrades to its liquid-metal loop and cooling systems, while its FuZE-Q device works toward scientific breakeven. The company had raised over $330M in total funding and employed about 150 people in Seattle and San Diego, but had no fusion-grade machine, no grid contract and no revenue; its bet on a magnet-free Z-pinch plant remained unproven.
Sources
- DOE Certifies Zap Energy Fusion Technology Milestone
- Lightning Strikes 12 Times Per Minute on Zap Energy's Century Platform
- Zap Energy attracts $130M in fresh capital as demo power plant system begins operations and aims for first milestone
- Zap Energy Fires Lightning-Strength Plasma Shots Every Five Seconds in Engineering Test That Deliberately Skips Fusion
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