Is Fusion The Future Of Energy?

Nuclear fusion is a process whereby two light atomic nuclei collide and combine to form a heavier nucleus, releasing vast amounts of energy in the process. Fusion reactions power the stars, including our sun. Harnessing fusion on Earth could provide an abundant, safe, clean source of energy with several advantages over current power generation methods. Fusion promises to be more efficient, emitting no greenhouse gases, producing less radioactive waste, and reducing dependence on fossil fuels. If realized, fusion may become a revolutionary new energy source, capable of meeting global demand with reduced environmental impact. Many view fusion as the “holy grail” of energy, though significant scientific and engineering obstacles remain. This article will examine the physics behind fusion, progress in developing fusion reactors, timelines for feasibility, and fusion’s potential role in a future carbon-free energy mix.

Sources:

https://www.energy.gov/science/doe-explainsfusion-energy-science


https://www.iaea.org/bulletin/what-is-fusion-and-why-is-it-so-difficult-to-achieve

How Fusion Energy Works

Nuclear fusion is a reaction in which two light atomic nuclei combine to form a heavier nucleus, releasing enormous amounts of energy in the process. This is the same process that powers stars like our sun. Fusion differs significantly from nuclear fission, the typical process used in nuclear power plants. In fission, a heavy atomic nucleus like uranium splits into two lighter nuclei, also releasing energy.

In fusion, the nuclei need to get very close together before the strong nuclear force can fuse them. The nuclei are both positively charged, so they repel each other due to electromagnetic force. Only when the nuclei are extremely hot and moving very fast can they overcome this repulsion and get close enough to fuse. This requires temperatures of at least 100 million degrees Celsius. The sun’s core reaches 15 million degrees Celsius, allowing fusion reactions to occur.

Some promising fusion reactions combine isotopes of hydrogen like deuterium and tritium. When these isotopes fuse, they form helium and release a neutron. This fusion reaction releases roughly four times as much energy as a fission reaction. However, the extreme temperatures and volatile reactions make fusion incredibly difficult to control on Earth.1

The Challenges of Harnessing Fusion

One of the biggest challenges with fusion energy is the extreme temperatures required to fuse atoms together. In order for fusion to occur, the fuel must be heated to over 100 million degrees Celsius—hotter than the core of the sun. Containing a reaction this hot is incredibly difficult.

Most experimental fusion reactors use magnetic fields to suspend and insulate the plasma, keeping it away from material surfaces. But even the strongest magnetic fields have trouble fully containing the hot plasma. As noted in a GAO report, particles still escape and hit the reactor walls, causing damage and instability.

The plasma is so hot that it would melt through any physical material. Scientists must develop new materials and technologies that can withstand direct exposure to the extreme heat and radiation conditions inside a fusion reactor for long periods of time. This is one of the biggest obstacles to realizing a practical fusion power plant.

Major Fusion Reactor Projects

Several major projects around the world are pursuing fusion energy using various techniques and designs. Some of the most prominent include:

ITER – Based in France, ITER is an international collaboration building the world’s largest experimental tokamak fusion reactor. The goal is to achieve a sustained fusion reaction and produce 500MW of power. Construction began in 2010 and first plasma is targeted for 2025 (https://www.iter.org/).

NIF – The National Ignition Facility in the US uses lasers to heat and compress hydrogen fuel in hopes of reaching ignition. NIF set fusion energy output records in 2021, but has yet to achieve ignition (https://lasers.llnl.gov/).

Wendelstein 7-X – A German stellarator that achieved first plasma in 2015 and is testing an alternate magnetic confinement design. It set a world record plasma duration time of 100 seconds in 2021 (https://www.ipp.mpg.de/w7x).

Other major projects include JET in the UK, KSTAR in South Korea, EAST in China, and plans for a demonstration power plant called DEMO in Europe. Private companies like General Fusion, Helion Energy, and TAE Technologies are also pursuing fusion reactors.

Recent Breakthroughs and Progress

There have been several notable breakthroughs in fusion technology in recent years, bringing us closer to harnessing fusion energy. In 2023, scientists at the National Ignition Facility (NIF) were able to achieve a net energy gain from fusion for the first time, producing more energy from the fusion reaction than was put into the system to ignite it [1]. The NIF experiment used 192 high-powered lasers to bombard a pellet of deuterium-tritium fuel, briefly generating over 3 megajoules of energy output after 2 megajoules of laser energy input. This fusion ignition represented a major milestone, proving that net energy gain from fusion is possible.

Other key areas of progress include advances in superconducting magnets used to contain the hot plasma during fusion reactions. Scientists have developed new high-temperature superconductors that can create stronger magnetic fields for longer periods [2]. Containing the plasma is crucial to achieve fusion conditions. There have also been promising results in new plasma containment methods like stellarators, which use twisty magnetic coils instead of a simple tokamak donut shape.

While significant hurdles remain, these breakthroughs demonstrate the rapid pace of fusion technology development. With continued progress in magnets, lasers, computational modeling, and other areas, fusion may be poised to become a viable carbon-free energy source within the next few decades.

Timeline and Viability

The timeline for fusion energy becoming commercially viable has long been estimated at around 30-50 years away. However, recent breakthroughs in fusion technology have caused many experts to revise that estimate and suggest fusion may be viable on a commercial scale in a much shorter timeframe.

According to a 2022 Marketplace report, some in the fusion industry now believe the timeline could be as short as 10-15 years until commercial viability. Private companies pursuing fusion like General Fusion and Commonwealth Fusion Systems have announced timelines of 3-4 years for net energy gain prototypes, with commercial plants following sometime in the 2030s.

The Department of Energy’s ARPA-E program estimates that with sufficient investment, fusion could be commercially viable in the 2035-2040 timeframe. More conservative estimates still put fusion at least 30 years away from commercialization.

Ultimately, the timeline remains uncertain and dependent on factors like sustained funding, technological innovations, and successful demonstrations from major fusion reactor projects around the world. But there is growing optimism that fusion may be a viable energy source much sooner than previously thought.

Costs vs. Benefits

Fusion energy has the potential to provide vast amounts of clean, safe, and virtually limitless energy. However, developing fusion technology is extremely expensive. ITER, the largest experimental fusion facility currently under construction, has a projected cost of over $20 billion [1]. Building the first commercial fusion reactors could cost $10-15 billion each [2].

That said, the potential benefits are enormous. Once the technology matures, fusion energy is projected to have a levelized cost around $50-80 per MWh [2]. For comparison, natural gas and solar PV currently cost around $40-60 and $30-60 per MWh, respectively [3]. Fusion also offers effectively unlimited fuel with no carbon emissions or nuclear proliferation risks.

One analysis estimates the net present value of fusion energy could exceed $17 trillion globally through 2100 when accounting for factors like emissions avoidance [4]. While substantial investments are needed upfront, fusion energy could yield tremendous long-term benefits.

Fusion vs. Other Renewables

Fusion energy has some key advantages compared to other renewable energy sources like solar, wind, and hydro (source). The extremely high energy density of the fusion reaction means a very large amount of energy can be produced from a small amount of fuel. Fusion reactors could provide consistent baseline power, while solar and wind fluctuate based on weather conditions. The high energy density also means fusion plants require less space than massive solar and wind farms.

However, fusion is still likely decades away from being widely commercialized, while renewable sources like solar and wind are rapidly expanding today. Fusion faces engineering challenges like containing the fusion reaction that renewables do not. Renewables like solar and wind will be key to decarbonizing the grid more immediately while fusion continues to be researched and developed (source).

Ultimately, fusion will likely play a complementary role to renewables like solar and wind in building a carbon-free grid, rather than fully replacing them. Each has different strengths and weaknesses. Pursuing a diverse mix of clean energy sources will lead to the most robust decarbonized energy system.

Fusion’s Role in the Energy Mix

Fusion energy has the potential to play a major role in the future energy mix alongside renewable sources like solar and wind. According to ITER, fusion reactions release nearly 4 million times more energy than burning fossil fuels, providing an incredibly dense source of clean energy if harnessed. However, as noted by Re-examining the role of nuclear fusion in a renewables-dominated clean energy system, fusion may not fully replace baseload sources like fossil fuels and fission nuclear given the continued growth in variable renewables like solar and wind. Rather, fusion could complement and enable higher penetrations of renewables by providing flexible, dispatchable clean energy to fill in gaps when the sun isn’t shining or wind isn’t blowing. Its high power density combined with inherent load following capabilities could make fusion ideal for meeting peak demands. Fusion also provides constant output unaffected by weather fluctuations, acting as a reliable zero-carbon baseload source. While renewables will likely supply an increasing share of energy, fusion can act as a critical firming resource in a deeply decarbonized grid.

Conclusion

While fusion energy currently remains at the experimental stage, recent breakthroughs show promising potential for it to become a viable energy source in the future. Major projects like ITER aim to demonstrate the feasibility of fusion energy by the 2030s-2040s. If fusion reactors can be developed to operate continuously and provide net energy gain, fusion could have great advantages as a safe, sustainable, and virtually limitless energy source.

However, many scientific and engineering challenges remain before fusion can be commercialized. Building and operating economically viable fusion reactors will likely take many more decades of research and development. Fusion is therefore not expected to contribute significantly to mitigating climate change in the near term.

The outlook for fusion energy is optimistic but uncertain. With continued progress in plasma confinement, materials science, superconducting magnets and other key areas, fusion may play a major role in the global energy system by the end of the century. While other renewable sources will likely dominate in the coming decades, fusion could provide essential baseload power to complement renewables and ensure long-term energy security. The potential benefits of fusion make it well worth pursuing despite the remaining challenges.