Nuclear fusion, the holy grail in near-limitless and environmentally friendly energy production is one step closer as of 30 July 2023. Scientists at the National Ignition Facility (NIF) of California’s government-funded Lawrence Livermore National Laboratory have successfully re-created an energy-gaining (more energy was created than was put in) fusion experiment for the second time. This announcement, made in August, was not accompanied by the fanfare that the original breakthrough in December 2022 had – but represents the next stage in the process of harvesting the power of the stars on earth.

In the near century, since the theory of nuclear fusion was understood in the 1930s, scientists have attempted to recreate it on earth for the purpose of energy generation (and some, I suppose, for the destruction it may wreak without the radioactive fallout of conventional nuclear weapons). And for good reason: the fuel that would be used – hydrogen (in the forms of deuterium and tritium, which contain extra neutrons) – is extremely plentiful on earth in the form of seawater. Deuterium is extracted through electrolysis and tritium is extracted using lithium (also plentiful on earth).

It may sound complex to remove the hydrogen atoms from seawater, but the point is it can be done – and at a scale to power the earth for millions of years. Per kilogram of fuel, fusion could generate four times the energy of fission (what takes place in reactors today) and 4 million times the energy of burning the same amount of coal or oil. For anyone interested in clean energy generation, this is an incredibly seductive prospect.

Since earnest research began in the 1950s, scientists have been attempting to build a reactor that can contain the enormous heat required to initiate a fusion reaction. Stars, which are essentially fusion reactors, have the advantage of mass. This mass creates an enormous gravitational force in the centre of the star, which naturally induces fusion. As any fusion reaction on earth would take place in a relatively small reactor, enormous temperatures of over 100 million degrees Celsius are required to make deuterium and tritium fuse. For perspective, the core of the sun is around 15 million degrees Celsius.

To contain heat multiple times that of the sun, incredibly strong magnetic forces need to hold the plasma in place and away from the reactor walls – which would melt instantly. Magnets capable of containing this have simply not been constructed until recently. Commonwealth Fusion Systems (a fusion start-up financed by Bill Gates and various oil companies among others) demonstrated in September of 2021, their superconducting magnet technology.

Private investment in fusion technology has also widened the array of reactor designs under development, the most common of which is the Tokamak reactor, the one being constructed in southern France called ITER (Latin for “the way”). ITER is the result of a collaboration of 35 countries and was initiated in 1988. However, construction of the reactor only began in 2020. ITER will start conducting its first experiments in the second half of this decade and is scheduled to demonstrate sustained fusion in 2035.

There are over a dozen reactor designs for fusion but the NIF in California uses Inertial Confinement Fusion (ICF). Scientists fire a high-powered laser at a pellet of deuterium and tritium inside a capsule that scientists call a hohlraum. Inside the hohlraum, X-rays squeeze the hydrogen at pressures and temperatures high enough to initiate fusion.

The reaction in December 2022 produced 3.15 megajoules of fusion energy, while the lasers used 2.05 megajoules - an energy gain of 1.5. Though the results have not been released from July’s experiment, they are apparently higher. A commercially run reactor providing energy for the electrical grid would need to achieve an energy gain of 100. There’s also another problem: though the lasers injected 2.05 megajoules, the whole device needed 300 megajoules from the grid.

Advances in computing power as well as machine learning have also had major impacts in speeding up research. Nevertheless, despite the noticeable speed with which fusion research is making progress, the date at which our electrical grids will be powered by energy generated from fusion is still a while – and many billions of dollars – away. The consensus among those in the field is that a fusion power plant could be built and produce electricity by 2050 – which would put fusion almost … 30 years away (there is a joke that fusion is always 30 years away). This means nuclear fusion won’t arrive in time to stop climate change, but it can certainly be used to undo some of the damage in the future by powering machines that extract carbon from the atmosphere.

Private companies, such as Commonwealth Fusion Systems (CFS) of the United States, are targeting more ambitious timelines in the 2030s. With more than $4.7 billion invested in fusion start-ups, they are making significant progress. CFS is constructing SPARK (a compact Tokamak design), which the company says will be completed by 2025 and will produce 50 to 140 MW of fusion power – aiming for a net gain of 10 times what is put in. Helion Energy (another American company) has already agreed to provide tech giant Microsoft with 50 MW of fusion electricity, which the company says will be done before 2030.

Governments are also stepping up their investment. After December’s demonstration, the 2023 Appropriations Bill in the U.S. provides record funding for fusion research. Altogether, 2023 will see the U.S. government spending around $1.4 billion: $763 million from the Department of Energy (DOE) will go towards research and $630 million, from the National Nuclear Security Administration (NNSA), will go towards funding for Inertial Confinement Fusion research specifically. The Biden administration wants to see a pilot demonstration within a decade as it seeks to cut emissions and provide clean energy. The DOE has selected multiple companies to fund over 18 months in public-private partnership modelled on the collaboration between NASA and the commercial space industry which has worked so well.

Within a decade, there could be working prototypes. As the effects of climate change are increasingly felt, it’s likely the level of funding will massively increase as angry citizens demand solutions. The world already spends 10% of global GDP on procuring energy – with fusion funding only a tiny fraction of this there is substantial room for investment growth. If all goes according to plan, a century after nuclear fusion was theorised, it may become a reality.