For eons, humanity has yearned to tap into the energy that fuels the sun and stars. Thankfully, nuclear fusion provides a modern means to do it. Easy, right? Not so fast—there’s yet to be a viable commercial solution for nuclear fusion. The old adage says it’s only 30 years away, but there’s a reason the adage is old: people have been saying that for generations.
Good news: recent breakthroughs (plus a massive surge of investments) may lead to the commercialization of fusion power much faster than we think.
So what does that mean for humans, society, the world as a whole?
We’ll get to that. First, a common question:
Wait, Don’t We Already Have Nuclear Power?
We sure do, but not the kind this article is concerned with. Nuclear fission power plants have been around since the 1950s. Nuclear fusion, on the other hand, was first theorized back in the 1920s; however, it has not yet proven to be practical—hence, there are (currently) no nuclear fusion power plants.
Proposed fusion reactors don’t have the same drawbacks as fission reactors—for instance, there is no risk of meltdown, nuclear proliferation, and long-term nuclear waste. What’s more, nuclear fusion releases four times as much energy as nuclear fission and about 4 million times as much energy as coal-burning sources.
So yes, we do have nuclear power plants—just not the kind this article is concerned with.
So What’s Nuclear Fusion?
A nuclear fusion reaction occurs when two or more light (i.e., low atomic number) nuclei merge to form a single heavier nucleus. (In contrast, nuclear fission involves splitting a large atomic nucleus into smaller nuclei).
The nuclear fusion process releases energy as the mass of the resulting nucleus is less than the sum of the two nuclei. This should break some kind of rule! However, when we look at Einstein’s famous equation (E=mc2), we can see how mass may be converted to energy (and vice versa). Thus, the missing mass is converted into energy—a lot of it. Through the process of fusion, just 1kg of deuterium-tritium fuel (i.e., the most common fuel for fusion) would release 3.37×1014J of energy, which could power a 3900MWt power station for a day.
Deuterium (which is found abundantly in seawater) and tritium (which, on the other hand, is extremely rare) are two isotopes of hydrogen considered the most common fuel for fusion experiments and reactors. When a D-T (deuterium-tritium) fusion reaction occurs, the reaction produces a helium atom (also known as an alpha particle) and a high-energy neutron. The excess energy (i.e., the missing mass converted into energy) propels this hot, highly energized neutron into lithium capture devices. Lithium is used as it splits on impact from the neutron and forms more of the rare tritium fuel, helium, and heat energy. We can then use this heat energy to power steam engines and generate electricity.
Fusion requires light nuclei (such as deuterium and tritium) due to the interplay of two opposing forces. The “nuclear force” is the force that attracts protons and neutrons together, while the “Coulomb force” is that which repels protons away from each other. Light nuclei (i.e., smaller than Iron) are relatively small and lack protons, which allows the nuclear force to overcome the Coulomb force under a sufficient speed or temperature.
The Promise of Nuclear Fusion
The IPCC reported that carbon dioxide emissions need to be reduced by 45% by 2030 to keep the rise of global temperatures under 1.5°C.
Many countries are quickly enacting “net zero” emissions targets, which will eliminate their reliance on fossil fuels in favor of more sustainable energy sources. This leads to a significant dependence on renewables such as solar photovoltaics and wind turbines. However, many countries are held back by financial, political, and geographical limitations. As a result, some countries may not find it feasible to switch to renewables.
Continued development of nuclear fusion energy sources is essential to bring the technology out of R&D and into the market as a commercially viable option. Nuclear fusion (like nuclear fission) does not produce carbon dioxide or other greenhouse gases and could be a viable long-term source of low-carbon electricity. However, proof-of-concept studies are still underway, leading many to believe that commercial power plants could begin supplying energy to the grid from the second half of this century.
Nuclear fusion could supply baseload energy to the grid as a complement to renewable energy sources (e.g., solar photovoltaics, wind turbines, hydro, geothermal). The energy produced by a fusion reactor would be similar to a fission reactor at about 1 to 1.7 gigawatts, though such reactors would be much more efficient. Nuclear fusion releases four times as much energy as nuclear fission and about 4 million times as much energy as coal-burning. The major by-product of fusion is helium, which is inert and non-toxic.
On the other hand, nuclear fission reactors have long been polarizing due to: (1) the risk of meltdowns, (2) radioactive waste, and (3) nuclear weapon proliferation. Nuclear fusion reactors can nullify these issues. Fusion reactors cannot melt down as the thermonuclear conditions required to sustain fusion is incredibly difficult to sustain. Any disturbance would immediately stop the fusion reaction in seconds, as the technique has stringent heating requirements. Additionally, all fuel within the chamber is limited, eliminating the risk of uncontrolled chain or runaway reactions. Fusion reactors don’t produce a significant amount of radioactive waste, and what little is produced can be stored and repurposed. Finally, with fusion reactors, there is a limited risk of proliferation. Common reactor designs, such as the Tokamak, do not utilize fissile materials like uranium and plutonium. Additionally, there are no enriched materials used in the reactors that could be applied to nuclear weapons.
In fact, research surrounding fusion technology and plasma physics has led to innovations in advanced materials from ceramics to metals and coatings, as well as industrial processes (e.g., welding and waste removal).
Nuclear fusion rockets have also been an unsung hallmark of sci-fi novels—a futuristic technology that enables humans to explore the outer reaches of space and contact alien lifeforms. However, such rockets may soon be a reality as NASA is investigating fusion propulsion systems that could allow humans to reach deep space destinations faster with increased payloads.
While nuclear fusion represents a long-term, sustainable, economic, and safe energy source for electricity generation, its development paves the way for new advanced technologies.
Harnessing Nuclear Fusion on Earth
Nuclear fusion is a constant process within the sun’s core, largely assisted by gravitational forces which keep the core in a state of hot, dense plasma at a temperature of 15 million degrees Celsius.
The pressure of the sun’s core is about 200 billion times that of the Earth’s surface. On Earth, we lack the massive pressures and gravitational forces required. Thus, to compensate, we need to maintain a much higher temperature and density to reach and sustain the state of plasma—around 150 million degrees Celsius. Plasma is a superheated state of matter where the heat rips away electrons and forms an ionizing gas. The fusion fuel must be kept and handled in a state of plasma for thermonuclear fusion to occur.
The International Atomic Energy Agency (IAEA) describes the thermonuclear conditions required for nuclear fusion: extremely high heat, high ion density, and close proximity to ensure that the ions have enough energy to fuse at a high enough rate.
Two notable experimental approaches have been designed to achieve these conditions: magnetic confinement fusion and inertial confinement fusion.
Magnetic Confinement Fusion (MCF)
Magnetic confinement reactors confine D-T plasma by applying magnetic fields under high pressure and temperature. Magnetic fields are optimal for confining the plasma as the ions and electrons carry electrical charges that follow planned magnetic field lines. As they follow the magnetic field lines, they’re directed to avoid the reactor walls. A failure to confine the ions would result in them losing heat and speed, which would prevent fusion reactions. The ideal magnetic configuration shape is a torus/toroid (or a doughnut shape) where the magnetic field lines form a closed loop and plasma travel in a helical (or spiral) shape. Importantly, in this configuration, the magnetic field will become stronger on the inner section of the torus and weaker on the outer section. (Note that twisting the magnetic fields proves to create a suitable magnetic equilibrium.)
The two leading magnetic confinement reactor designs (i.e., the tokamak and stellarator) have different approaches to twisting the magnetic field lines and creating magnetic equilibrium within the torus. The tokamak (an abbreviation of “torus-shaped magnetic chamber” in Russian) induces perpendicular electrical currents around the plasma, which twists the magnetic field. In contrast, the stellarator uses an additional external magnetic field to twist the plasma.
Experimental tokamak reactors include the ITER tokamak, T-15, and STOR-M tokamak, while experimental stellarator reactors include the Wendelstein, HSX, and LHD.
Inertial Confinement Fusion (ICF)
The main characteristic of inertial confinement fusion is the confinement of the D-T fuel, which uses the particle’s own inertia to confine itself. The process works by focusing laser or ion beams onto the surface of a tiny D-T fuel pellet. The lasers heat the outer layer of the material, creating an outward explosion, which also induces a reactive compression force that compresses the inner layers of the material. This powerful shock wave compresses and heats the fuel, which induces fusion. In addition, the surrounding fuel may also be ignited and induce fusion chain reactions. The reaction time takes less than a microsecond.
While there are many different approaches for inertia confinement fusion, most have used lasers, such as the US National Ignition Facility (NIF) and HiPER.
Key Differences Between MCF and ICF
MCF uses magnetic fields to hold and sustain the plasma, where fusion can occur. Magnetic equilibrium is sustained in a tokamak through an induced current, while a stellarator will use external magnets.
On the other hand, ICF relies on the ignition of spherical fuel pellets and their associated compression forces to create a sphere of plasma in which fusion can occur. Pellets are ignited one by one as they are introduced into the ICF reactor chamber. The ignition of the pellets is a key difference among various ICF approaches—though laser ignition is the most popular method.
Governments, universities, and private research institutions are investigating both methods, though each has pros and cons. The prevailing argument is that of scalability. Proponents of MCF suggest that as magnetic confinement reactors are scaled up to industrial levels, the geometry also scales accordingly, which does not greatly affect the complexity of the design. However, the upscaling of ICF would increase pellet size, which would impact the size and complexity of ignition systems (e.g., laser systems). Although, ICF supporters may point to the difficulty required to produce long sustained fusion burns in magnetic confinement, which may limit its scalability.
Both methods have encountered breakthroughs, though the jury is still out on which method will reach the energy grid first.
Vulnerabilities of Nuclear Fusion
The two greatest concerns of nuclear fusion are energy output and fuel supply. Nuclear fusion so far has been expensive and time-consuming. However, the promise is that commercial fusion reactors will be feasible by the second half of the century, producing a baseload of power to the grid in combination with renewable energy sources.
Yet, the fusion reactor itself is power hungry and leeches its output to operate plasma confinement processes, refrigerators, vacuum pumping, heating, and ventilating, among other systems. So far, very few reactors have reached plasma breakeven (i.e., equal or greater energy produced for the energy required to heat the fuel). However, an inertial confinement fusion reactor at the NIF has reported energy output greater than that absorbed by the fuel. In addition, the much-anticipated multinational ITER aims to reach and exceed plasma breakeven with their new reactor. The device aims to produce 500 MW of fusion power for 50 MW consumed by the heating systems.
The limited supply of tritium (estimated at only 20kg) is also a threat to nuclear fusion, as it is considered the most effective fuel supply for fusion energy. Theorized alternative fuels, such as deuterium-deuterium, are about 20 times less efficient and require much more stringent thermonuclear conditions. However, tritium can also be produced within a tokamak reactor when the high-energy neutrons that escape the plasma interact with lithium. In fact, ITER has proposed concepts for “tritium breeding modules” using lithium blankets to catch neutrons and tritium. This is a key step to commercialization as fusion power plants would require at least 300g of tritium per day to produce 800MW of power.
Private Companies and Startups Are Heating Up
Over the past few decades, two mega-government initiatives have paved the way for fusion energy research: the US NIF (based in Livermore, California, US) and the international ITER collaboration (based in Southern France). ITER is a collaborative effort funded by the EU, China, India, Japan, Russia, South Korea, and the US. The ITER is expected to generate energy from 2035. However, such energy won’t supply the grid until subsequent plants are built around 2050.
There is a high degree of interest in this potentially groundbreaking technology. Yet, more and more private companies and investors have joined the marathon to unlock the potential of fusion energy. In fact, over 20 privately held companies and start-ups (backed by the likes of Jeff Bezos and Bill Gates) have begun making waves in the fusion space.
The University of Oxford spinout, First Light Fusion, recently demonstrated an early proof of concept for their inertial fusion method before UKAEA (UK Atomic Energy Agency) inspectors. The method reached this point in record time and for a cost-effective price. The company was founded in 2011 and has spent less than $59 million to get there. This is contrasted with ITER, which sits at around $20 billion.
General Fusion, a Canadian privately held firm (funded by Jeff Bezos) recently landed a $400 million deal with the UKAEA, hoping to make a breakthrough in fusion technology.
Similarly, Bill Gates’ Breakthrough Energy Fund (which includes investors such as Sir Richard Branson and Jack Ma) and Tiger Global Management have backed MIT spinout Commonwealth Fusion Systems (CFS). CFS recently set records for achieving a magnetic field strength of 20 teslas in their new superconducting magnet. CFS has also secured nearly $2 billion in funding from investors.
The Road to Green Energy
Energy independence is as important as ever, as geopolitical feuds and dependencies have shown how difficult it is to be independent while relying on fossil fuels.
Nuclear fusion holds huge energy-generating potential. However, harnessing the power that fuels the sun is no easy feat. Many experts agree that nuclear fusion is decades away and should not be the sole hope for the next generation of energy production. Renewables will continue to be instrumental in bridging us to commercialized nuclear fusion and beyond.
Many popular renewable sources are intermittent and dependent on uncontrolled factors such as wind currents, ocean tides, and sunlight visibility. However, such renewables have a massive energy-generating potential today and contribute significantly to many grids worldwide.
Traditional power plants require a consistent, predictable baseload level of energy, which nuclear fusion may be able to deliver. Once nuclear fusion methods have achieved a proof of concept for sustaining such loads, the next steps involve commercialization and economies of scale to bring the price of nuclear fusion power plants down to an affordable level.
For more than a decade, High Touch Group has partnered with companies from the advanced materials, climate technology, and renewables industries. We focus our marketing and communication strategies to help secure venture capital, foundation, and government funding to move emerging technologies out of the lab and into the commercial sector. We have coordinated effective public and media relations campaigns, developed community outreach programs, and supported multi-million-dollar governmental funding proposals for R&D programs. Our team is passionate about supporting energy independence and works hard to drive our clients’ climate and energy technologies forward.
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