Fusion Energy Is Finally Advancing. Here's What Changed

For billions of years, the sun reigned supreme as the only fusion reactor in our solar system, leveraging its immense gravitational pressure and intense heat to overcome atomic nuclei's natural repulsive tendencies. Now, something extraordinary is happening on Earth—big-brained primates called humans have decided to try their hand at this whole fusion thing, using an ingenious donut-shaped invention called a tokamak.

Now, a new kind of star is on the cusp of creation—and it holds the promise of providing near-limitless energy for Earth's 8 billion inhabitants.

A History of Impossible Dreams

Since its introduction in the 1950s, tokamak-powered fusion has earned an infamous reputation, with some experts saying fusion is "the energy source of the future, and it always will be" due to the immense temperatures and exotic materials needed to create such a machine. However, within the past few years, that feeling of impossibility has been slowly fading, as physicists and engineers around the world have begun to make serious progress toward fusing hydrogen isotopes into helium, similar to what the sun's been doing for 4.6 billion years.

What Makes Fusion So Powerful?

Fusion occurs when two light atomic nuclei combine to form a heavier nucleus, releasing enormous amounts of energy. The most commonly studied reaction involves hydrogen isotopes, such as deuterium and tritium. Fusion has several major advantages:

It produces no direct carbon emissions
It generates far less long-lived radioactive waste than fission
Fuel sources can be extracted from seawater and lithium
The reaction is difficult to run out of control

In theory, fusion could provide a nearly limitless energy supply. In practice, achieving the necessary conditions is extremely difficult.

The Main Challenge: Containing Plasma

To make fusion happen, fuel must be heated to temperatures above 100 million degrees Celsius, creating a state of matter known as plasma. At these temperatures, no solid material can touch the fuel, so scientists must use advanced confinement methods. The most developed approach uses strong magnetic fields to hold plasma in place inside a donut-shaped reactor called a tokamak.

Major tokamak projects include:

  • ITER (France)
  • JET (United Kingdom, now concluded)
  • EAST (China)
  • SPARC (United States, in development)

The big question remains: are we truly getting closer to practical fusion power, or are the toughest challenges still ahead?