Nuclear Fusion: Harnessing the Power of the Sun

December 13, 2022 will forever be etched as a seminal moment in the world of nuclear physics. The day will be remembered for an epoch-making event where laboratory scale nuclear fusion was declared successful, paving the way as a potential path towards green, non-polluting energy for earth and its inhabitants.

The Breakthrough

The U.S. government-funded National Ignition Facility at Lawrence Livermore National Laboratory in California announced that they were able to fire a laser carrying roughly 2 megajoules of energy into a tiny fuel pellet made up of two hydrogen isotopes, turning the atoms into plasma and producing 3 megajoules of energy — a 50% increase.

Challenges

While a successful experiment, the reactor as a whole did not produce a net gain of energy. Scientists posit that for a fusion reaction to be practically useful, the tens of megajoules drawn from the electrical grid, converted into the laser beams and fired into the reactor core would have to be significantly less than the energy released from the plasma.

The new plasma ignition milestone only accounts for the laser energy in and the plasma energy out, not the significant loss from converting electricity to light, making the reaction a net negative energy process.

For fusion to be commercially successful, the fuel has to be heated to more than a hundred million degrees Celsius — hotter than the core of the sun — which poses extraordinary engineering challenges when it comes to reactor design.

Further, this occurred in a tiny fuel pellet inside the world's biggest laser, lasting only a few billionths of a second, and can only be repeated every six hours, thus making scalability and commercial viability a certain impossibility.

Promises

Fusion does create radioactive waste, like fission, but it is less hazardous and could be recycled within 100 years, instead of necessitating storage deep underground for tens of thousands of years.

Fusion also yields several times more energy by weight than fission and millions of times more than the combustion of fossil fuels.

A few paper clips’ worth of hydrogen isotopes could produce enough energy for a person’s lifetime.

Last Word

As significant as this breakthrough is, huge technological and economic hurdles still have to be cleared before fusion reaches true scale and viability. Fusion start-ups are mushrooming and hope to provide fusion electricity to the grid sometime in the 2030s.

While the Livermore experiment has been compared to the Wright brothers’ first flight, it's more like a lab experiment demonstrating that air flowing over a wing can produce a little bit of lift. However, given the urgency of reducing greenhouse gas emissions, many climate scientists are dreaming big.

“Imagine, if everything goes right, a world where, in a quarter-century’s time, we can take down the solar panels and wind turbines we’re now erecting and replace them with elegant fusion reactors."

Dare to dream!