Is nuclear fusion a distant dream or a real option for the future?

With the global climate crisis becoming more urgent and energy demand only increasing, nuclear fusion is a better dream than ever: It can help solve both problems at the same time. Despite this promise, nuclear fusion is usually treated as a scientific curiosity rather than a real world-changing solution to a huge problem. why? Are we really nowhere yet? Or is there a light on the horizon?

The enormous potential of nuclear fusion makes it hard to ignore. It’s a technology that can safely deliver a massive, steady stream of electricity, using a plentiful fuel made from seawater to fuel the same reaction that powers the sun. This will not produce any greenhouse gases and produce minimal waste compared to traditional energy sources.

But building a fusion reactor essentially produces an artificial star. Scientists have been studying fusion physics for a century. With some of the most powerful machines ever built, they are striving to improve delicate subatomic mechanics to reach a crucial stage: getting more energy out of a fusion reaction than they put into it. Researchers say they are closer than ever. But why is it so difficult?

What exactly is nuclear fusion?

Let’s start with what exactly is nuclear fusion. We know something about nuclear fission and have been using it for decades in our nuclear power plants: This is what happens when large atoms like uranium and plutonium decay and release energy. Its power is enormous, just look at the nuclear weapons we have and they work on the same principle. Nuclear fusion is stronger. This is what happens when the nuclei of small atoms stick together, fuse together to form a new element and release energy. The most common form is that two hydrogen atoms fuse together to form helium.

The reason fusion generates so much energy is that the new element weighs slightly less than the sum of its parts. This tiny amount of lost matter is converted into energy according to Albert Einstein’s famous formula, E = mc2. The letter “E” stands for energy while the letter “m” stands for mass. The last part of the formula is “c”, which is a constant that measures the speed of light – 300,000 kilometers per second, which is then expressed as a square. So there’s a huge multiplier of matter being converted into energy, which makes fusion a very powerful interaction.

Why is it so difficult

These basic principles are well understood and researchers are convinced that they can be used in a useful way, but so far nuclear fusion has been elusive. We know for sure that the basic theory works. But trying to do it in the lab isn’t easy.

To prove nuclear fusion, just look at the sun during the day. Even at a distance of 150 million kilometers, our nearest star generates enough energy to warm the Earth through the vacuum of space. But the Sun has an advantage that we don’t have here on Earth: it’s very, very big. One problem with fusion is that atomic nuclei – the nuclei of positively charged atoms – usually repel each other. To overcome this repulsion and fusion, you have to make the atoms move very fast in a limited space, which increases the chance of collisions.

A star like the Sun, about 333,000 times the mass of Earth, generates gravity that accelerates atoms toward the center – heating them up, “trapping them inside” and igniting fusion. The fusion reactions then supply energy to speed up other atomic nuclei and start more fusion reactions.

Imitating the Sun on Earth is quite a task. Humans have been able to start fusion, but in uncontrollable ways, such as thermonuclear weapons (sometimes called hydrogen bombs). Fusion has also been demonstrated in laboratories, but under conditions that consume much more energy than is produced by the reaction. The reaction generally requires creating a high-energy state of a substance known as a plasma, but plasmas have quirks that scientists are still trying to understand.

Ramps: magnet and laser

To make fusion useful, scientists need to run it in a controlled way that produces far more energy than they put in it. This energy can then be used to boil water, spin turbines, or generate electricity. Teams around the world are studying different ways to achieve this, but the methods usually fall into two broad categories.

The first involves using magnets to keep the plasma in check. This is the approach he uses ITERCurrently, the largest merger project in the world under construction It is located in the south of France. Another approach is to confine the fusion fuel and compress it into a small area using a laser. This is the approach used, for example, by the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California.

Replicating a star requires extensive research, so fusion experiments often use the most powerful scientific tools ever made. For example, the central solenoid of ITER can generate a magnetic force strong enough to lift an aircraft carrier two meters from the water.

Why is it safe

Building devices that can withstand these extreme conditions pose enormous scientific and technical challenges. And managing such large-scale experiments is not easy. ITER started with an estimated initial cost of €6.6 billion, which has more than tripled since then. Construction began in 2007 and the first trials will begin in 2025.

One feature of the complexity of fusion reactions is that it is almost impossible to cause a rapid reaction or collapse of the kind that destroyed nuclear power plants like Chernobyl. If the fusion reactor fails, the reaction turns off quickly. In addition, the main “waste product” of hydrogen fusion is helium, which is an inert gas. The process can cause some reactor materials to become radioactive, but the radioactivity is much lower and the amount of hazardous waste is much smaller compared to conventional nuclear power plants. So fusion energy can become one of the safest sources of electricity.

Two problems: Politicians and money

But it is difficult for policymakers to invest in an expensive research project that may not pay off for decades. Scientific progress doesn’t always keep up with political timelines: the politician who gives the green light to a merger project may not live long enough to see it as a viable energy source – so it’s certainly not a useful political currency in upcoming elections.

The European Union currently spends about 680 million euros annually on nuclear fusion, which sounds like a lot of money, but dwarfs the more than 50 billion euros in subsidies for energy from fossil fuels. Americans spend about 400 million euros a year on nuclear fusion. This country spends more than $600 billion annually on defense.

The good news is that investors Jumping on the wagon more and more It currently invests billions in private startups developing their own merger strategies. One of their motivations is this: Research on nuclear fusion has already brought a lot of benefits to other fields, especially in plasma physics, which is widely used in the production of semiconductors for electronics.

More than just physics

Despite the obstacles, some real progress has been made recently. The team at China’s nuclear fusion facility – Experimental Advanced Superconducting Tokamak (EAST) stated – It’s December 30th In 2021 he was able to produce plasma with a temperature of 70 million degrees Celsius and hold it for 1056 seconds. This is the time record for nuclear fusion. Last summer, researchers from the US NIF reported that they Their best results so far 1.3 megajoules yields 1.9 megajoules — bringing them closer than ever to positive energy fusion.

As mentioned, the problem with nuclear fusion is that visualizing it is still an interesting scientific experiment. However, scientists and engineers believe that nuclear fusion is not only possible, but also inevitable. Just as space exploration is more than astronomy, nuclear fusion is much more than physics. It can be a leading tool in the fight against the world’s most pressing problems, from climate change to lifting people out of poverty.

Increasing access to energy is closely linked to improved health, economic growth, and social stability. However, there are still nearly a billion people on our planet without electricity and many of them have power only intermittently, so there is an urgent human need for more energy.

Not immediately, but if it works…

At the same time, the window for climate change mitigation is closing and electricity and heat production remain the dominant source of greenhouse gases in the atmosphere. To meet one of the goals of the Paris climate agreement – to limit warming to less than 1.5 degrees Celsius this century – the world must cut greenhouse gas emissions by half or more by 2030, according to the Intergovernmental Panel on Climate Change. Many of the largest emitters of greenhouse gases aim to focus on their contribution to climate change by mid-century. To achieve such a significant reduction in emissions, fossil fuels must be phased out as quickly as possible and much cleaner energy sources used.

The technologies we have today do not fit the task of solving the tension between the need for more energy and the need to reduce carbon dioxide emissions. A problem like climate change is an argument for focusing on all kinds of far-reaching energy solutions, but nuclear fusion is perhaps the technology with the most profit possible. And on longer time scales, it could be a real solution. The foundation must now be laid through research, development and implementation. Nuclear fusion could become humanity’s greatest achievement.

At the moment, major fusion experiments are continuing at NIF and ITER. At NIF, scientists will continue to improve their process and work steadily on the path of positive energy fusion. ITER is scheduled to become operational in 2025 and to begin hydrogen fusion experiments in 2035. So it will take some time. But if you succeed…

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