FUSION ENERGY

Written by Ayesha Khan

For decades, scientists across the ever-populating world have been searching for more ways to solve humanity’s most crucial problem: finding a new, greener source of energy to replace fossil fuels The best possible solution to this has been to use the power of nuclear fusion, a ‘limitless energy source’ obtained by combining two nuclei together Although this feat seemed nearimpossible for decades, a significant step has recently been made as a team of scientists have managed to harness the power of fusion, releasing a more significant amount of energy

What is nuclear fusion?

To understand how this discovery will impact the future of renewable energy, we need to understand what makes nuclear fusion so sustainable, and a better alternative to current energy sources Nuclear fusion is the process by which two lighter atomic nuclei combine to form a single heavier nucleus while releasing massive amounts of energy

Fusion reactions take place in a state of matter called plasma a hot, charged gas-like substance made of positive ions and free-moving electrons [with properties different from solids, liquids or gases ] Normally, putting two positively charged nuclei next to each other will make them repel, similar to two positive poles in a magnet However, if enough energy is inserted into them, they can overcome this mutual repelling force, allowing them to fuse.

The sun, along with all other stars, is powered by this reaction constantly occurring in their cores, where extremely high pressures (due to its massive gravitational force) and temperatures of around ten million degrees naturally induce fusion. On Earth, however, without that extra pressure, a temperature even higher than in the sun is needed for the reaction to take place – temperatures of over 100 million degrees Celsius For many years, this has not been possible

Currently, the most widely used and produced process used to generate electricity in nuclear plants is nuclear fission Although nuclear fusion and nuclear fission both draw energy from the atom, they work differently Fission releases energy when heavy radioactive atoms such as uranium split and releases heat energy However, this creates nuclear waste, and thus is difficult to safely dispose of as it can cause mutations in living organisms through radiation, especially if it enters watersystems in habitats. Furthermore, fusion could generate four times more energy than fission and nearly four million times more energy than burning oil or coal

Fusion has been under development for more than 70 years, and while fusion of nuclei has been achieved before, it has ended quickly This has not been worthwhile as a massive amount of energy has been required to start the fusion process, with little output

This breakthrough, on the 5th of December 2022, is the first time they've produced more energy from a fusion reaction than they put in A total of 192 lasers at the National Ignition Facility (NIF), part of the Lawrence Livermore National Laboratory in California, fired about 2 megajoules of heat energy into the two ends of a tiny cylinder holding a pellet of frozen (deuterium and tritium, heavier forms of) hydrogen, and struck the inner wall of the cylinder. The pellet generated temperatures and pressures intense enough to cause the hydrogen inside it to fuse into helium In a tiny blaze lasting less than a billionth of a second, the fusion released about 3 megajoules of energy about 50% more than what had been used to heat the pellet.

Why is this so important?

If the technology can be replicated on earth at an industrial scale, nuclear fusion offers the possibility of "unlimited" fuel This is because the elements needed are easily available in seawater, and the process does not create the radioactive waste of nuclear fission, or produce the pollution caused by generators fueled by fossil fuels

Previous estimates have said that the first electricity-producing fusion power plant could be built and operating by 2050, and if this were to happen the world's shift to renewable energy would become supercharged, helping to fight climate change Although the significant scientific milestone proving a fusion reaction can generate more energy than put into it has been achieved, the research and resources invested has brought criticism from some: the major problem being that the experiment required 300MJ of electricity to power up lasers, producing 3MJ worth of energy from the fusion reaction As such, they had put in 99% more power into the than they had got out, so as a whole was actually a huge net energy loss Furthermore, billions of dollars have been invested into the project ($3 5bn in this California project) with only just enough energy to boil a few kettles. However, researchers argue that the promise of a limitless clean energy source is worth the short-term investment

Fusion energy is still in the early stages of development, and although it could take anywhere from two decades to a few generations, it could provide virtually limitless clean, safe, and affordable energy to meet the world’s ever-growing demands Columbia University estimates 83 million excess deaths by 2001 as a direct result of climate change (e g through flooding), but this could be lowered with alternative energy sources. Nuclear fusion is definitely one of the most exciting scientific developments to keep an eye on, and has the potential to save billions of people worldwide