Unpacking Zap Energy's Novel Approach

How the startup's Z-Pinch technology stacks up against the competition

January 01, 2025

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In September 2024, Seattle-based startup Zap Energy announced that it had secured $130M in funding. This new funding round, led by Soros Fund Management LLC, underscores growing confidence in Zap’s novel approach to commercial fusion power.

Zap simplifies the engineering problem

The fundamental science behind fusion energy has been well understood for decades – make a plasma (hot ionized gas) of fuel (typically isotopes of hydrogen), compress it to make it both hotter and denser, and fusion will occur.

The challenge is generating more energy than it takes to achieve these conditions – essentially an engineering problem. Established approaches to the problem have involved using powerful magnetic fields to compress and retain the plasma, with heat exchangers producing steam to drive generator turbines.

Zap has reduced the complexity and cost by eliminating the powerful magnet systems entirely. Instead, they rely on electromagnetic effects – passing a large electrical current through the plasma generates a magnetic field, which compresses the plasma to achieve the conditions for fusion (a phenomenon known as Z-pinch).

In addition, Zap uses a liquid metal swirling around the plasma vessel to absorb the heat energy which is then passed on through heat exchangers to generate steam for the turbines; this also has the advantage that the neutrons liberated in the fusion reaction do not degrade the vessel because they are absorbed by the liquid metal.

Zap Energy vs. the competition

Other startups in the fusion energy race are testing different approaches:

  • Helion Energy uses a unique fusion fuel (D-He3) which, combined with a novel compression technique, allows them to harvest the electromagnetic energy from the fusion reaction directly, bypassing the steam generation cycle (akin to how regenerative breaking charges the battery in a car).

  • General Fusion is pioneering an approach they call Magnetized Target Fusion. This combines magnetic containment and inertial fusion – employing conventional engineering with a system of pistons to compress the plasma to reduce the number of new technical challenges that must be overcome.

  • Commonwealth Fusion Systems makes use of scientific advances in high-temperature superconducting magnets to achieve magnetic containment with stronger magnetic fields in a smaller reactor than traditional approaches.

The Road Ahead

Zap Energy's competitive edge lies in its engineering simplicity and cost-efficiency, thanks to its use of Z-pinch technology. By sidestepping traditional magnetic and inertial confinement methods, Zap (theoretically) can iterate faster and forge a quicker path to market. However, even with total funding exceeding $330M, it still trails behind competitors like Helion, which has raised over $600M to date. If Zap’s latest prototype delivers results, an even larger funding round is likely on the horizon.