Nuclear fusion, once thought of as a mere pipe dream, is now seemingly on the horizon of attainability, as new experiments performed by some of the brightest minds in the scientific community have indicated increased promise within fusion technology, setting it apart as a leading contender for the title of ‘The Future of Clean Energy’. By far the most recent and groundbreaking discoveries occurred in the final stretch of 2022, when the world was blindsided as scientists at Lawrence Livermore National Laboratory achieved the major triumph of producing net-positive nuclear fusion. 

Immediately, there was a buzz in the air—nuclear fusion was only a decade away, nuclear fusion was going to end climate change, nuclear fusion was going to mutate us into Ninja Turtles. Although the hype has died down significantly since the initial announcement, the debate surrounding nuclear power has been re-ignited among politicians, activists, and everyday people alike, and I think now is the perfect time to clear up some misconceptions.

How does it work?

Nuclear fusion is the process by which smaller, lighter atoms are fused together to create heavier atomic nuclei, a process that produces significant quantities of energy. The recent experiment, in particular, utilized two different types of hydrogen nuclei to produce a larger helium atom. This can be seen in the simplified equation:

D + T → He + n

The D (deuterium) and T (tritium) are two types of hydrogen, also known as isotopes. When fused together, these hydrogen isotopes produce helium. However, the mass of deuterium plus tritium is actually larger than that of helium, meaning some mass has gone missing. This mass, of course, did not magically disappear; as anyone familiar with the laws of thermodynamics is well aware, neither matter nor energy can be created or, in this case, destroyed. For nuclear fusion, the difference in mass between the fuel input and helium output can be accounted for using the most famous mathematical equation ever written: E=mc2. This simple relationship states that if something has mass, it has energy and that the two can be converted from one to the other. But what about this little “c2” term? This correlates to the speed of light squared. But, the speed of light is equal to 299,792,458 m/s, meaning that even the tiniest of masses, when multiplied by this mind-bogglingly large term, equals a massive amount of energy. Hence, we may put away our Dora the Explorer hat as the mass wasn’t lost at all, but converted into usable energy in the form of a very, VERY fast-moving neutron (most prototype fusion reactors work by using these neutrons’ momentum to boil water and spin a turbine, similar to fission reactors).

The Livermore Laboratory was able to successfully complete the fusion process by aiming immensely energetic lasers at a fuel pellet that contained the deuterium and tritium mentioned. Then, with only a little over 2 megajoules of energy added into the system, the fusion process produced 3.15 megajoules—just enough to heat a tea kettle. In an exciting fit of energy, these scientists had achieved the world’s first net-positive nuclear fusion reaction. Put simply, more energy was released during the reaction than was put into the system to instigate it.

But while it is, indeed, a major triumph in physics, there are downsides to the team’s findings.

The reaction was not actually net-positive.

This seems self-contradictory, considering I just said the exact opposite, so let me explain. It is absolutely true that more energy was released by the fuel pellet than was put into the fuel pellet. However, this is not taking into account the rest of the system. When factoring in the 300 megajoules of energy the lasers had to accumulate as well as the energy of the equipment itself, the reaction drained considerably more energy than it gave back. This represents a significant hurdle in developing practical fusion power, where the efficiency of the surrounding equipment matters just as much as the reaction itself. 

Also worth noting is that the method used by Lawrence Livermore to achieve fusion is far from the only possibility and that there may be more efficient avenues to explore. For example, while Livermore used a confinement scheme in which the explosive force of a fuel coating hit by the lasers generates fusion in the Deuterium-Tritium core, many teams prefer a magnetically-confined plasma ring (typically referred to as “Tokamaks”), and others use a duel plasma injector system to rotate an inductive generator. Essentially, there are a lot of different ways to achieve fusion, each with its own advantages and limitations, and significant amounts of time, research, and monetary investment will be needed to find the most scientifically and economically efficient ways to achieve fusion.

It’s gonna be a while, folks. And that’s okay.

If there’s one thing we need to keep in mind moving forward with nuclear fusion technology, it’s that it will not be ready for a long time; and it will not be the saving grace that puts a stop to climate change, because by the time it is ready and implemented on a large scale, the fate of the world, and of humanity, may have largely already been decided. 

Do not misunderstand. In the distant future — decades or centuries from now — nuclear fusion will almost certainly be the crux of humanity’s energy production. It has the potential to produce more energy than any other known method, short of building a Dyson Sphere or shooting asteroids into a black hole.

But today is not that future. Today, nuclear fusion is simply not what we need. What we need is to develop the green energy technologies we already have at our disposal. We need to implement more renewable energy: wind, solar, hydroelectric, tidal, geothermal—all of which are rapidly becoming economically viable and have the potential to provide enormous amounts of power. We need to expand nuclear fission, which can adapt to the inherent inconsistency renewables face (solar power only works during the day, and wind only when it’s windy, for instance) and pick up the slack in the electrical grid to keep the lights on all day long. 

And we need, most of all, continued governmental and civilian action to put these technologies into practice and eliminate fossil fuels once and for all. Fusion will have its time to shine tomorrow, but only if we can make it through today.