Nuclear fusion has long been considered the holy grail of clean energy. It can generate virtually unlimited power with very little waste and no carbon emissions. Unlike nuclear fission, which splits atoms apart, fusion works by joining hydrogen atoms, similar to the process that powers the sun. This reaction releases enormous amounts of energy. 

Despite its promise, fusion energy has been difficult to achieve on a commercial scale due to major scientific, engineering, and cost challenges. Only recently has fusion achieved net energy gain—producing more energy than it took to initiate. However, recent advancements and increasing private investment have sped up progress, making fusion seem closer to reality than ever before. 

1. TAE Technologies: The Field-Reversed Configuration Approach

Founded in 1998, TAE Technologies is among the most well-established players in the fusion energy sector. The company employs a field-reversed configuration (FRC) method, which refers to trapping plasma using fast-moving particles to keep the reaction going. Unlike conventional tokamaks, which rely on massive superconducting magnets, FRC aims for a more compact and cost-effective solution.

TAE’s latest prototype, Norman, has shown that it can sustain high-energy plasma for extended periods. The next step is Copernicus, a reactor that aims to produce more energy than it consumes. The company has received significant investment from Google and other private investors, highlighting the role of private funding in advancing fusion research. However, some experts argue that FRC is still unproven on a large scale, and keeping plasma stable at an affordable cost remains a significant challenge.

2. General Fusion: The Magnetized Target Fusion Model

General Fusion, a Canadian company, is working on magnetized target fusion (MTF). This method combines two fusion techniques: magnetic and inertial confinement. It uses liquid metal to squeeze plasma and start the fusion reaction.

A key advantage of MTF is that it could be cheaper and simpler to build than large fusion reactors like tokamaks. General Fusion has received significant financial support, including backing from Jeff Bezos. Its pilot plant, currently under construction in the UK, aims to prove that this method can generate net energy. However, the company still faces significant challenges, including creating the extreme pressure and temperature conditions needed for a stable fusion reaction.

>>>READ: The Fusion Energy Fast Forward

3. Tokamak Energy: Leveraging the Spherical Tokamak Design

A UK-based company, Tokamak Energy, is advancing a compact spherical tokamak design that enhances plasma confinement efficiency. Traditional tokamaks, like ITER, require enormous infrastructure and complex superconducting magnets, making them costly and slow to develop. By contrast, Tokamak Energy’s ST40 reactor is designed for a more compact and efficient setup, achieving plasma temperatures exceeding 100 million degrees Celsius—an essential threshold for sustained fusion.

Tokamak Energy’s approach also incorporates high-temperature superconducting (HTS) magnets, which help improve efficiency and reduce reactor size. While promising, proving that spherical tokamaks can sustain stable fusion remains a challenge. Another concern is whether this design can generate enough electricity to scale for the power grid.

4. Commonwealth Fusion Systems (CFS): High-Field Tokamak Innovation

A spin-off from MIT, Commonwealth Fusion Systems (CFS) has garnered significant attention for its work on high-field tokamaks with its flagship project, SPARC, leading the way. SPARC uses high-temperature superconducting (HTS) magnets to improve plasma confinement and reactor efficiency.

CFS has successfully built and tested powerful HTS magnets, which make fusion reactors smaller and more efficient. The company plans to build a full-scale fusion power plant, ARC, by the early 2030s. With funding from Bill Gates’s Breakthrough Energy Ventures and other investors, CFS is a strong competitor in the fusion industry. However, it still needs to prove that its method can sustain a stable reaction for long periods—one of the biggest challenges to making fusion a practical energy source.

5. Zap Energy: The Sheared-Flow Z-Pinch Method

Unlike tokamaks and other fusion reactors that rely on strong magnets, Zap Energy is testing a different approach called sheared-flow Z-pinch. Instead of using expensive superconducting magnets, this method depends on the natural movement of plasma currents to create confinement. This approach makes fusion energy more affordable and scalable.

Zap Energy’s FuZE-Q reactor is designed to reach scientific breakeven, meaning it will produce as much energy as it consumes. This method could provide a cheaper way to generate fusion power if successful. However, some experts doubt its reliability because Z-pinch technology has historically struggled with plasma instabilities. Whether Zap Energy can solve these challenges and make its technology practical for large-scale energy production remains uncertain.

>>>READ: Zap Energy is Leading the Future of Fusion

Comparative Analysis and Future Outlook

Each of these five companies represents a distinct technological pathway to fusion energy, highlighting the diversity of approaches companies are exploring. From an economic standpoint, the fusion industry has attracted substantial investment, reflecting the growing confidence in its potential. However, commercialization remains uncertain, with key technical challenges such as plasma stability, material durability, and energy efficiency still unresolved. While some optimists predict commercial fusion within the next 20 years, others caution that significant breakthroughs are still needed before fusion can compete with existing energy sources.

The next decade will determine whether fusion energy can transition from experimental prototypes to a viable power source. Governments, private investors, and research institutions must continue collaborating to accelerate innovation and address the remaining scientific and engineering barriers. If successful, fusion energy could revolutionize the global energy landscape, providing an abundant, clean, and sustainable power source for future generations.

The views and opinions expressed are those of the author’s and do not necessarily reflect the official policy or position of C3.