Nuclear fusion: the game-changing energy revolution

Just 30 miles (48 km) outside Boston, in a quiet industrial park, engineers are working on a revolutionary machine designed to replicate the energy of the stars. If successful, it could pave the way for virtually limitless, clean electricity in the US within the next decade.

This effort is part of a decades-long quest by scientists to create what would be an infinite source of clean energy, one that could completely remove our dependence on fossil fuels and finally make a significant positive impact on the climate change crisis.

Nuclear fusion holds massive potential for a planet increasingly plagued by the environmental consequences of fossil fuel use, but it can be a bit intimidating to learn about. Click through to get a straightforward explanation of everything you need to know about this new form of nuclear energy that may be the world's biggest power source in the future.

What is it?

Nuclear fusion is humankind's attempt at copying the most powerful energy in our universe: the sun. The sun is a natural fusion factory, consisting of a giant burning ball of plasma that fuses several hundred tons of hydrogen into helium each second, providing a constant source of heat and energy. The man-made nuclear fusion process tries to replicate the same energy that powers the sun.

On a more miniscule level

Nuclear fusion occurs when two or more atoms are fused into one larger one. This process generates a massive amount of energy as heat because the two particles that are being forced together actually repel one another by nature.

It's clean

Nuclear fusion promises a virtually limitless form of energy that, unlike fossil fuels, emits zero greenhouse gases. Additionally, unlike nuclear fission power used today, it produces no long-life radioactive waste. Picture a world running on clean, carbon-free energy.

Nuclear waste from fission

According to the Department of Energy, nuclear energy is a zero-emission energy source, but with fission it does produce radioactive waste that must be stored safely and carries safety risks—i.e. nuclear meltdowns like at the Fukushima and Chernobyl reactors.

How could it be limitless?

The source elements for nuclear fusion are mainly deuterium and tritium—two isotopes of hydrogen. Deuterium is abundant in both fresh and saltwater, and the deuterium from just 500 ml of water, with a little tritium, could power a house for a year, CNN reports. Tritium, on the other hand, is rarer and more difficult to obtain, although it can be made synthetically.

How the energy could make it to your home

The heat produced from fusing two atoms can subsequently be used to warm water, create steam, and turn turbines to generate power.

It holds incredible potential

If we master nuclear fusion, there's no reason it couldn't power much of the world. A single gram of fuel as input can reportedly create the equivalent of eight tons of oil in fusion power—that's a yield of eight million to one!

It needs to be on a bigger scale

“It's about what it takes to boil 10 kettles of water,” Jeremy Chittenden, co-director of the Centre for Inertial Fusion Studies at Imperial College in London told CNN of the net energy gain in the breakthrough experiment. “In order to turn that into a power station, we need to make a larger gain in energy—we need it to be substantially more.”

Tokamaks in the UK and France

In the UK and the ITER project in France, nuclear fusion scientists are working with tokamaks, which are huge donut-shaped machines outfitted with giant magnets. After a small amount of fuel is put into the tokamak, its magnets are turned on and the temperature inside is cranked unbelievably high to create plasma, often called the fourth state of matter. Plasma is a matter so hot that the electrons are ripped away from the atoms and form an ionized gas, like a soup that is electrically charged, according to the Plasma Science and Fusion Center.

A lot of heat to sustain

It's hard to wrap your head around how much heat the tokamak must contain, but for reference: 150 million degrees Celsius is approximately 10 times hotter than the core of the sun. So how can that exist on earth? Fusion energy scientists and engineers have impressively overcome this hurdle already by designing giant magnets that create a strong magnetic field that keeps the heat bottled up. Any other material would easily melt.

A bigger tokamak in the works

In May 2022, CNN reported that ITER's new tokamak will weigh 23,000 tons—which is equivalent to three Eiffel towers. It will consist of a million components that further differ into 10 million smaller parts, and will include some of the largest magnets ever created—some with diameters of up to 24 m (79 ft).

The hydrogen bomb was the first nuclear fusion

The first demonstration of nuclear fusion, the hydrogen bomb, was conducted by the military. The isotopes of the hydrogen fusion reaction were placed around a regular fission bomb whose explosion released the energy needed for the fusion process. Since the bomb was approximately 1,000 times as powerful as an ordinary atomic bomb, it made the general public less enthusiastic about nuclear fusion research.

Using lasers at the National Ignition Facility

In the US, much of the nuclear fusion work is happening at the National Ignition Facility, where they're using a process called “thermonuclear inertial fusion.” Essentially, as CNN reports, scientists fire pellets containing hydrogen fuel into an array of 192 lasers, which creates a series of rapid, repeated explosions at the rate of 50 times per second.

Why the recent breakthrough is important

Though there's a long way to go before making nuclear fusion commercially available, this breakthrough was the first time scientists have been able to show that they can create more energy than they started with—an essential trait for a potential commercial energy source.

Finding funding

The European Union is reportedly covering 45% of ITER's construction costs, and the other member countries are estimated to be contributing a little over 9% each. The construction was initially estimated at US$6.4 billion, but has more than tripled since.