For a long time, humans have been pursuing the dream of fusion energy. We mastered fission decades ago, and nuclear power has served us well since, except that it has some terrible PR because when fission energy goes wrong, as at Chernobyl and Fukushima, the consequences are severe.
Despite the major accidents, nuclear energy is actually one of the safest power sources available, ranking alongside solar and wind. Nuclear causes 99.9% fewer deaths than coal. Oil and gas are almost as bad as coal. Nuclear, especially modern nuclear power, is far more efficient than any other power source.
Modern nuclear power is also highly efficient in terms of waste production. Much of the waste can be recycled, and by the end of one year of operation, nuclear plants produce just 3 cubic meters of waste. Compared to a coal plant, which makes 300,000 tons of ash and six million tonnes of CO2 in the same time.
All of that makes nuclear power sound pretty great. Now imagine if it were fusion power instead of fission power. Four times the energy of fission, and the only waste material is helium, which is not radioactive. Four million times the energy of coal.
You may have heard people refer to thermonuclear fusion as limitless energy. That’s not far off from the truth, except for the potential costs associated with it. But if that is overcome, if we could master fusion, we would change the entire world forever. But we don’t have it yet.
People were designing fusion reactors as far back as 1939, but obviously, no big progress has been made. We understand the benefits and the science, but the practical reality has never come to pass. We can even create fusion reactions, but sustaining and making use of them is still not happening. So will it ever happen? Let’s see!
What is Fusion?
Fusion power, hard though it may be to create on Earth, is very real and plausible. It’s what powers the sun. The high pressures and temperatures in the sun are able to fuse together atoms of hydrogen and create helium as a byproduct. The energy produced in this reaction is what causes the sun to be that giant, flaming ball of plasma we see in the sky every day.
Fission, which is what happens in modern nuclear reactors, as well as nuclear weapons, involves splitting an atom rather than fusing one. In both cases, incredible energy is released because the mass of the finished nucleus is smaller than the mass of the reacting ones.
One day, the sun will burn out when it runs out of fuel to keep it going, but it contains enough hydrogen right now to last it for another five billion years, so it’s not a big issue for us anytime soon.
To make fusion work here on Earth, we need a reaction that gives us more energy than we put into it. That’s where the problem is. It takes a lot of energy to start a fusion reaction. You need to make plasma, which is a very hot kind of gas filled with charged particles. Almost every attempt we have made so far to produce a fusion reaction has required more energy to make the pressure and temperatures required for the plasma than we were able to get out of the very minuscule fusion reaction that occurred afterwards. Remember, the sun is 333,000 times the size of Earth, so pressure and temperatures there (which reach 27 million degrees) are much easier.
Is a Fusion Generator Even Possible?
It’s possible to make fusion on Earth, but hard. The pressure in the sun is 24.7 million gigapascals. For some perspective, it made international headlines when scientists created a pressure of 770 gigapascals in a lab once. This is the fundamental roadblock in making fusion work here as easily as it does on the sun. We can’t come even remotely close to creating the same pressure. That means we need to increase the temperature, but that requires a lot more energy, which is what ruins the reaction. If you have to put so much energy into making it that you don’t get enough back, it’s useless.
Remember when we said the sun can generate temperatures up to 27 million degrees? That sounds amazing until you hear what we have to do in labs to try to create fusion. On Earth, using lasers to compensate for our lack of pressure, we heat up the plasma to 100 million degrees.
This process works and, in lab conditions, we have made fusion work plenty of times. The problem is that generating 100 million degrees requires more energy than the fusion gives us back. It’s also a safe bet that when fusion is developed in a way that makes it possible, it’s also going to be extremely expensive at first. That puts a real roadblock in front of that unlimited energy dream.
There are about 20 fusion reactors currently in the world working towards creating a sustained fusion reaction that doesn’t cost more energy than it produces. Back in 2022, scientists made this happen for the first time. They used two megajoules of energy to power 200 lasers focused on a single fuel capsule. The fusion reaction started and produced 3.15 megajoules of power. It’s a small reaction, but successful. It was repeated three more times, once generating 3.88 megajoules, proving it wasn’t a fluke.
Also in 2022, a lab in China broke the record for the longest sustained reaction. They made one last for 17 minutes at temperatures of 126 million degrees. Later, a lab in the UK produced 59 megajoules of sustained energy, double the previous record. In 2024, 69 megajoules were produced. That’s not a lot in practical terms, just enough for 4 hot baths. There are multiple plans to have working fusion generators by 2030.
The reactions need to be dramatically scaled up to make it viable. Much more energy needs to be produced if we plan to power cities. But the promise is there, and expectations are that it’s coming soon.
Why Do We Want It So Badly?
There’s a reason why people call fusion a potentially limitless energy source. It’s fueled by hydrogen, which is the most abundant element in the universe.
Suppose we had a machine, a kind of fusion reactor, that was stable and reliable and produced high-efficiency fusion energy. One gallon of seawater would provide enough fusion to make energy equal to 300 gallons of gasoline. No need for coal that creates dirty smoke, or uranium that gives off radiation. Just clean, abundant fuel and no dangerous byproducts.
Solar and wind can boast clear energy production too, but they can’t work on the scale of fusion. You need far more infrastructure for wind and solar in the form of solar panels and windmills. And both solar and wind rely on weather, which fusion would not.
The big benefit of using fusion power would be how it affects our climate. Fusion power effectively ends pollution from modern power sources, in particular fossil fuels. We could end the production of so many dangerous emissions. The climate crisis could potentially be solved with fusion energy. Companies investing in fusion are predicting that we can be carbon net-zero by 2050.
The fact that fusion is far more energy efficient than any current power production we have is also a great selling point. Producing energy four million times more efficiently than a coal-burning plant makes even considering coal look foolish.
While fission energy is the best option we currently have, fusion leaves it in the dust, not just in terms of the amount of power produced but also the safety. The biggest drawback nuclear plants have now is the fear of an accident and concern over the waste products. Fusion reactors eliminate both of these. There is no dangerous waste, and there can’t be an accident at the plant.
Fusion plants use an incredibly small amount of fuel; the deuterium or tritium used would be the size of a postage stamp. If something happened, the reaction couldn’t get out of control and cause a meltdown, it would simply burn itself out and stop.
Another point to consider is that, because these reactors use hydrogen, a lot of geopolitical tension could be laid to rest. Imagine if wars didn’t have to be fought over oil anymore because no one needed it. The potential for a new dynamic across the globe is very real. With that in mind, the potential economic impact on different parts of the world is not something to overlook, either.
What’s the Danger of Fusion Power?
Although not a danger, a potential downside of early fusion energy is likely to be the price. Everything new is expensive, whether it’s a new car, a new video game system, or a new energy source. Established power is just going to be cheaper. That’s why we still burn coal and gasoline and use nuclear power plants. The infrastructure is there, the method of making power is easy to understand, and customers are accustomed to paying for it at a certain price point.
It’s been predicted that the cost of fusion will need to be around $80-$100/MWh at 2020 prices. However, the more realistic likelihood is that it would cost much more, up to $150/MWh. As inflation increases, this will get higher. But that may only be realistic in a world where fusion is the norm. At its inception, researchers at Princeton have suggested fusion may have capital costs up to $7,000/KW.
The US Department of Energy estimated in 2021 that ITER, the international fusion research project that builds tokamak reactors to study and produce fusion, had already cost $65 billion. Originally plans were for a $5 billion budget. In other words, no one knows the cost of fusion yet, but it’ll probably be more than we think.
In terms of practical dangers, fusion reactors may not work the way people think. The sun fuses hydrogen, but on Earth, we’re looking at using deuterium and tritium, isotopes of hydrogen, because they are more reactive than hydrogen. Tritium can’t be found in nature. It’s radioactive and a by-product of fission. A fusion reaction could make its own tritium eventually, but a lot needs to be fed into it to start with. It costs about $30,000 per gram.
Making fusion with these isotopes creates neutron streams that are radioactive and could produce weapons-grade plutonium. So the “no waste” benefit is not technically true in terms of how we have to make fusion on Earth. That said, proponents point out tritium has a very short half-life and only the smallest amounts are needed in fusion plants. That could still ensure relative safety. In terms of neutron streams, a solution for how to shield and protect against those needs to still be determined, but it is possible.
Another drawback, heading back to the energy issue, is that maybe the statement about energy net gain is a bit of doublespeak. The 2022 fusion breakthrough neglected to mention that the lab used 300 megajoules of energy to charge up the lasers before firing them to generate the three megajoules of fusion energy. They just focused on the energy expelled in the actual fired burst, which was less than what they produced.
In terms of being a savior for the world, there’s also the time frame issue. If we need to save the world from a climate crisis, based on data from the UN, we need to be carbon-neutral around the world by 2050. Despite what companies have promised, it seems unlikely that fusion can be scaled that quickly at all. That’s not to say it’s not worth pursuing, but claiming it will solve a problem it’s going to be too late to fix is disingenuous.
It’s also worth noting that how much power a fusion generator can produce is often cloaked in sketchy language. The ITER facility in France has been touted as being able to produce 500 megawatts of output with just 50 megawatts of input. That sounds like a good trade, but the 500 megawatts is not electrical power; it’s fusion power in the form of neutrons and alpha particles. And the 50MW isn’t electricity used, it’s just the heat energy. The plant uses much more electricity, around 300 to 400 MW. So the efficiency they’re touting is not really there yet, and the PR and marketing are obscuring the truth.
The sun and the other stars in space certainly prove fusion power is an amazing source of energy. Whether mankind will ever harness it, and harness it in a way that makes it worth the time and effort, is something we’re not going to know for a few years yet, at the very least.
Other Articles you Might Like
