Prabhakar A.R. Bende, Former Managing Director, MP Power Transmission Company Limited and MP Power Generating Company Limited
Climate change and its global impacts on environmental security and safety are driving nations and organisations to reshape their policies and strategies to address the threat. To deal with this issue, governments and organisations are constantly working to incorporate climate resilience and adaptation strategies into their planning. Though existing renewable energy resources are crucial elements to mitigate climate change, they are not sufficient on their own. Solar, wind, hydro and geothermal sources have seen substantial growth over the years but they still account for only one-third of global electricity generation, thereby necessitating reliance on fossil fuels for baseload power requirements.
Nuclear fission power could serve as an alternative to fossil fuels for consistent energy supplies. However, they face several challenges, such as high initial costs, long development periods, geopolitical risks, and public concerns over radioactive waste and safety. The inherent constraints of nuclear fission technology make it less attractive, necessitating the development of new technologies that are equally efficient and capable of meeting base load power requirements.
Nuclear fusion technology, which is still under development, has the potential to be a game changer due to its ability to produce clean and virtually limitless energy without any significant environmental threats. Nuclear fission, on which present-day nuclear power plants operate, involves splitting a heavy atomic nucleus, such as uranium-235 or plutonium-239, into two or more smaller nuclei, and releasing neutrons and a significant amount of energy. On the other hand, the nuclear fusion process involves combining two light atomic nuclei to form a heavier nucleus, releasing a tremendous amount of energy, which is similar to the reaction that powers the sun and other stars. Fission reaction produces long-lived radioactive waste that requires careful management and storage, whereas fusion does not carry this risk as it produces minimal radioactive waste, most of which has a much shorter half-life. Geopolitical factors and international sanctions significantly affect the availability of nuclear fission material. In contrast, fusion fuel is abundant globally, as it primarily requires isotopes of hydrogen, which are readily available.
The first successful controlled thermonuclear fusion reactions in a laboratory were achieved in 1958 at the Los Alamos National Laboratory of the US Department of Energy. A major breakthrough occurred on December 2, 2022, when scientists at the National Ignition Facility, Lawrence Livermore National Laboratory in the US, achieved a self-sustaining controlled fusion reaction that produced more energy than it consumed. The inertial confinement fusion experiment achieved an energy gain factor of 1.5 (3.15 megajoules versus 2.05 megajoules). This is one of the most impressive scientific achievements of the 21st century, as fusion can generate four times more energy from the same amount of fuel compared to fission, and nearly 4 million times more energy than burning oil or coal.
Fusion energy is considered crucial for future climate change strategies because it is considered a potential source of boundless, clean and sustainable energy. Unlike fossil fuels, fusion produces no carbon dioxide or other greenhouse gases. Fusion fuel uses isotopes such as deuterium and tritium, which can be easily extracted from water and lithium respectively. Deuterium is abundant in water, and tritium is produced by neutron irradiation on lithium-6. Tritium is also produced as a by-product during both fission and fusion reactions. This could make the fuel supply for fusion more sustainable, as tritium can be bred within the reactor itself.
Fusion processes produce significantly less radioactive waste with shorter half-lives. This reduces the long-term environmental impact and challenges associated with radioactive waste management. Fusion energy also carries no risk of catastrophic accidents like meltdowns, because the extremely high temperature, pressure and confinement required to sustain fusion are very difficult to maintain. This inherent instability makes a runaway reaction less likely, as the reaction would quickly stop if the conditions were not maintained.
However, fusion reactions rely on powerful magnetic fields to confine the hot plasma, and uncontrolled instabilities in this field may disrupt the reaction and damage the reactor. Further, tritium is a radioactive isotope of hydrogen, and handling and storing tritium poses significant safety challenges and environmental risks, but not as high as managing fission fuels. Therefore, continued research and development are crucial to address the potential risks associated with fusion technology.
It is important to note that despite the abundance of fuel, harnessing fusion energy is a complex technological challenge. Fusion energy is generated by replicating the process that powers the sun and stars, where hydrogen isotope nuclei combine under extreme pressure and temperature to form helium, releasing vast amounts of energy.
The simplified overview of how this process is managed in fusion reactors, such as tokamaks and stellarators, is explained below.
Fuel preparation: The most common fusion reaction uses isotopes of hydrogen, deuterium and tritium. Deuterium can be extracted from water, while tritium is produced from lithium. There are substantial reserves of lithium on earth that could last for an immeasurable period of time.
Creating extreme conditions: Hydrogen isotopes must be heated to extremely high temperatures, exceeding 100 million degrees Celsius, to initiate nuclear fusion. At these temperatures, gas turns into plasma, an electrically charged state of matter where electrons are separated from nuclei.
Confinement methods:
- Magnetic confinement: Powerful magnetic fields are used in fusion reactors to contain and control the hot plasma, thus avoiding contact with the reactor walls.
- Inertial confinement: Inertial confinement fusion utilises lasers or ion beams to rapidly compress a tiny fuel pellet, creating the extreme temperature and pressure conditions required for fusion.
Fusion reaction: Under these extreme conditions, the nuclei of deuterium and tritium overcome their natural repulsion and fuse together. This reaction produces a helium nucleus, a neutron, and releases a tremendous amount of energy, mostly carried by the neutron.
Energy extraction: The high-energy neutrons, generated during the fusion process, escape the magnetic confinement field and are absorbed by a surrounding lithium blanket. The energy from the neutrons is transferred to the lithium blanket, causing its temperature to rise. This heat is then used to generate steam, which drives turbines to produce electricity, mirroring the process in traditional power plants.
We need specialised reactors, such as tokamaks and stellarators, to achieve fusion reactions on Earth. Both tokamaks and stellarators utilise a powerful magnetic field to confine plasma in a doughnut shape (torus) to facilitate a fusion reaction. Tokamaks use three large sets of magnetic field coils – toroidal field coils, poloidal field coils and central solenoids. The toroidal field coils are wound around the entire dough-shaped chamber, generating a strong magnetic field that runs along the length of the torus, confining the plasma in a circular path. The poloidal field coils are located around the outside of the chamber and generate magnetic fields that circle the plasma in the poloidal direction (the shorter path around the doughnut). The central solenoid is located within the centre of the torus and generates a powerful induced electric current running through the centre of the plasma itself. This induced current is crucial for plasma confinement and plasma heating. These three magnetic field coils work together to create a complex magnetic field within tokamaks to confine and heat the plasma, creating conditions for a controlled nuclear fusion.
In stellarators, an intricate arrangement of multiple magnetic field coils encircles the plasma, creating a complex three-dimensional twisted magnetic field that wraps around the doughnut shape without the need for a central current. Stellarators have major advantages over tokamaks. They need less power to sustain the fusion reaction, their design is more flexible, and the possibility of plasma disruptions is lesser. However, a major issue is that they struggle to confine the most energetic particles within the plasma, which are crucial for sustaining the fusion reaction. Scientists are working diligently on stellarator technology to fix this issue and make them more viable.
Both tokamaks and stellarators are effective at maintaining high temperatures and confining the plasma, which is crucial for achieving controlled fusion reactions. A tokamak’s symmetrical shape around an axis easily confines the particles and does not have the problems stellarators face. Tokamaks are among the most common types of magnetic confinement fusion devices, and most research is currently focused on them to create controlled nuclear fusion reactions. However, research in stellarators is also gaining momentum. France-based energy firm Renaissance Fusion is developing a stellarator, which they claim to be the most efficient, steady and stable fusion reactor. Researchers at the Princeton Plasma Physics Laboratory have also made a breakthrough in enhancing stellarator performance.
Several types of fusion reactors have been developed and are being researched to harness the power of fusion. These include the International Thermonuclear Experimental Reactor (ITER) (under construction in France), the Joint European Torus (the UK), the JT-60SA tokamak (Japan) and the Experimental Advanced Superconducting Tokamak (China), all focused on tokamak reactors. Inertial confinement reactors use high-powered lasers or ion beams to compress and heat small pellets of fusion fuel to achieve fusion. The National Ignition Facility (the US), HYLIFE-II (the US) and Laser Mégajoule (France) use these reactors. Magnetised target fusion is a hybrid approach that combines elements of magnetic and inertial confinement, with start-ups like General Fusion exploring this approach. Field-reversed configuration (FRC) reactors use self-generated magnetic fields to confine the plasma in a compact, typically cylindrical or spherical shape. Companies such as Helion Energy and TAE Technologies are developing FRC reactors. Compact fusion reactors are smaller, with modular designs that use advanced magnetic confinement techniques and high-temperature superconducting (HTS) magnets to improve efficiency. SPARC (a project developed by Commonwealth Fusion Systems [CFS] in collaboration with the Massachusetts Institute of Technology [MIT]) and Lockheed Martin are researching compact fusion reactors. Z-pinch reactors use electric current to generate a magnetic field that compresses the plasma, and Zap Energy is a company exploring this method.
Various designs are being explored worldwide to overcome the technical challenges of producing net energy gain from fusion reactions. Each reactor type has its own advantages and disadvantages, and it is likely that a combination of different designs will pave the way for successful commercial fusion energy.
Governments and private sectors globally are investing heavily in fusion energy research and development, with various projects and international collaborations under way to make this transformative energy source a reality. The International Thermonuclear Experimental Reactor (ITER) Organisation, a flagship project of international collaboration, is a massive international nuclear fusion research and engineering initiative involving the European Union, the US, Russia, China, India, South Korea and Japan. The ITER will be the world’s largest experimental tokamak, aiming to produce 10 times more fusion power than the heat energy used to initiate and sustain the reaction. Private companies, such as CFS, TAE Technologies, Novatron Fusion and Helion Energy, are also driving progress with innovative technologies.
The ITER Organization was officially established on October 24, 2007, after all partners signed an agreement. It is based in France and is responsible for designing, constructing and operating the ITER. This scientific experiment aims to demonstrate the feasibility of fusion power as a large-scale and carbon-free energy. The construction of the ITER tokamak complex started in 2013 and the machine assembly was launched July 28, 2020. The ITER central solenoid will be one of the largest superconducting magnets ever built, capable of generating a magnetic field of 13 Tesla, equivalent to 280,000 times the earth’s magnetic field.
Alcator C-Mod, a compact high-magnetic field tokamak developed by the MIT Plasma Science and Fusion Centre, has laid much of the research foundation for SPARC, the world’s largest near-commercial experimental fusion reactor being researched and developed by US-based CFS. The SPARC tokamak, a high-field compact fusion reactor designed to be the world’s first commercially relevant fusion device, is aimed at producing more power than it requires for operation. The SPARC reactor uses advanced HTS magnets, consisting of 18 magnets, each generating a field of 20 Tesla. Its success is intended to pave the way for ARC, a full-scale fusion power plant in Virginia, the US, capable of providing significant grid-connected power.
India is actively contributing to ITER research while simultaneously developing its own domestic fusion programme, focusing on advancing tokamak technology and fusion materials. Indian research institutions, such as the Institute for Plasma Research (IPR), have been central to advancing fusion science. The IPR operates the ADITYA and SST-1 (Steady-State Superconducting Tokamak) devices to experiment with plasma confinement and heating. These initiatives emphasise the country’s commitment to harnessing nuclear fusion as a future energy solution. The emergence of private sector players, such as Anubal Fusion – a start-up established in May 2024 – highlights India’s growing ambition to participate in advancing fusion technology. Anubal Fusion has formed partnerships with prominent institutions, including the Tata Institute of Fundamental Research, Hyderabad, and IIT Madras.
Two developments in the coming year could mark a significant shift from the public to the private sector in the pursuit of generating cheap and abundant clean power from fusion. The first is the commissioning of SPARC, the world’s first near-commercial 140 MW experimental tokamak, which is expected by late 2025 or early next year. Following the SPARC demonstration, CFS plans to construct ARC, the world’s first 400 MW grid-connected fusion power plant, marking a major milestone in the commercialisation of fusion energy. The ARC fusion power plant is targeted to be commissioned by the mid-2030s. The second issue is the significant delay in the commissioning of the ITER, which was originally scheduled for 2025. The ITER Organisation, in an announcement in July 2024, postponed the date due to several reasons, including pandemic-related supply chain and quality control delays, component faults, and a pause in construction demanded by the French nuclear regulator. As a result, the final stage of the ITER plan has been delayed from 2035 until 2039, with an additional €5 billion in cost overruns.
The cost of fusion energy is challenging to evaluate at present, but initial estimates suggest an end-consumer price of less than half that of conventional nuclear fission energy. The prospect of fusion becoming a primary energy source by mid-century is an increasing possibility. The first commercial fusion power plants may be developed soon, but widespread adoption will depend on sustained scientific and technological breakthroughs, combined with global investments and policy support. Until then, other clean energy technologies will likely continue to dominate the energy landscape.
As climate change accelerates, threatening ecosystems and human life, the greatest challenge lies in finding transformative solutions. Fusion energy stands as one of the most promising breakthroughs on the horizon. With recent advancements in magnetic confinement and high-temperature superconductors, the vision of harnessing the power of the stars no longer feels out of reach. It offers hope for a cleaner, more sustainable future, a potential game changer in humanity’s fight against climate change.