Scientists are building a ‘second sun’ – can it save our dying planet?

Nuclear fusion. It’s integral to the time-travelling DeLorean in Back to the Future, and it enables Doctor Octopus to harness “the power of the sun” in 2004’s Spider-Man 2 (a film I watched so many times on VHS that the villain’s fiery origin story was quite literally seared into my eight-year-old brain). Now, though, the potentially revolutionary energy source looks set to exit the realm of fiction, and become reality.

Earlier this week, US scientists announced a new breakthrough in the development of nuclear fusion. For the first time, they achieved a net energy gain from a fusion reaction – in other words, the reaction produced more energy than it took in – signalling that the future of sustainable energy production could lie in the same reaction that “powers” the sun.

Unfortunately (although unsurprisingly) we’re a long way off actually harnessing the power of a “second sun” to keep our dying planet’s lights on. Many scientists believe that functioning fusion power plants are still decades away – far beyond the schedule we need to stick to if we’re to avert the worst effects of the climate crisis. This is despite Joe Biden setting a target of “a commercial fusion reactor within 10 years”. 

Below, we break down the new fusion breakthrough, how it could one day help pull us back from the brink of environmental devastation, and whether Joe Biden’s plan to make it happen before 2033 is actually viable. The President of the United States wouldn’t lie to us... would he?

WHAT IS NUCLEAR FUSION?

Ok, so conventional nuclear power plants work by nuclear fission, a process that generates energy by splitting heavy atoms such as uranium. Basically, nuclear fusion does the opposite: light elements, such as hydrogen, are fused together via a thermonuclear reaction that releases excess energy. This is the same process that causes the sun to produce heat and light.

SO... SCIENTISTS WANT TO CREATE A ‘SECOND SUN’?

Sort of. Scientists at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California have figured out how to recreate the thermonuclear reaction artificially. It’s a complex process involving lasers that heat a small gold cylinder to more than three million degrees celsius. Inside that cylinder sits a pellet of fuel encased in diamond. By heating this fuel, the NIF team managed to release 3.15 megajoules of energy using 2.05 megajoules – a net gain of just over a megajoule.

That isn’t much energy (just about enough to boil a kettle, apparently) and it was only sustained for a tiny fraction of a second, but it does prove that it’s possible to generate energy using laser fusion, a result that scientists have been working toward for decades. Essentially, supporters of fusion believe that this means we could use the same reaction that keeps the sun producing heat and light to fill our own energy needs.

Why’s that such an exciting prospect? Because there’s no associated carbon emissions or long-term radioactive waste, a cup of fuel could theoretically power a whole house for hundreds of years, and it could offer a consistent flow of energy, unlike today’s renewables.

IS THE CLIMATE CRISIS SOLVED, THEN?

Unfortunately, no, it’s not that easy. The terms of the Paris Agreement suggest that emissions need to be reduced by 45 per cent by 2030 and reach net zero by 2050 in order to limit the global temperature rise to 1.5 degrees celsius above pre-industrial levels. Many scientists believe that fusion-based power stations are still decades away. Dr Michael Bluck, director of the Centre for Nuclear Engineering at Imperial College London, tells the Guardian that 50 years is an optimistic timeline for commercial use, adding: “There are huge hurdles to overcome.”

That being said, US Energy Secretary Jennifer Granholm said on Tuesday that Joe Biden has a “decadal vision” for the technology, and wants a commercial fusion reactor up and running within ten years. Announcing the new breakthrough, she said: “This shows that it can be done.”

10 YEARS SOUNDS A BIT OPTIMISTIC...

It does. Who’d have imagined that a politician could overpromise and underdeliver? Well, basically everyone – even the director of the laboratory that ran the successful experiment says that the White House’s timeline is overly optimistic, and that transferring the technology from a lab setting to a real power plant will more likely take several decades.

On the upside, that timeline could be significantly shortened by a wave of investment in fusion technology, which will only be bolstered by the revelation that a net energy gain is actually possible. Already, Biden’s administration has pledged to pour nearly $370 billion into shifting away from fossil fuels as part of August’s Inflation Reduction Act. Meanwhile the UK is greenlighting new coalmines. Love that for us!

SO IS THE NEW FUSION BREAKTHROUGH REALLY A CAUSE FOR CELEBRATION?

Despite the unclear timelines and general pessimism from many credible scientists, it should be acknowledged that the successful use of nuclear fusion to produce energy is a remarkable feat. Since the 1950s, researchers have been attempting to figure out how to harness the same reactions that light up the big burning ball at the centre of the Solar System, and now they actually did it the absolute madmen.

In a video on the breakthrough, the Lawrence Livermore National Laboratory itself says: “Fusion ignition is one of the most significant scientific challenges ever undertaken by humanity.”

Now, it’s “just” a case of taking what they have learned in a controlled experimental setting, and figuring out how to reproduce the reaction in the real world, on a large scale. Currently, the NIF can apparently run the fusion reaction about ten times a week. It’s going to take a lot more reactions – as in many, many times a second – to power the Earth and pull us back from the brink of environmental collapse. For now though, at least the scientists can boil themselves a cup of tea while they think it over.