Congratulations to the folks over at LLNL for their news yesterday on achieving fusion ignition. From the linked announcement:
LLNL’s experiment surpassed the fusion threshold by delivering 2.05 megajoules (MJ) of energy to the target, resulting in 3.15 MJ of fusion energy output, demonstrating for the first time a most fundamental science basis for inertial fusion energy (IFE).
So, why is this milestone exciting? Let's dive in.
Looking at the U.S. Energy Information Administration's electricity generation by energy source in the United States for 2021, roughly 4.11 petawatt hours were generated with ~60% coming from fossil fuels, ~20% from nuclear energy, and ~20% from renewables.
Fusion energy, often relegated to the realm of science fiction, has significant advantages over the nuclear and fossil fuel categories.
In comparison to nuclear energy, there is no risk of catastrophic meltdown, the raw materials are abundant, and the nuclear waste is minimal and decays relatively quickly.
When considering the looming effects of climate change, traditional fossil fuels like oil, natural gas, and coal become a lot less attractive.
So fusion energy, when available, could easily fit inside a portfolio of cleaner energy solutions like wind, hydropower, solar, biomass, and geothermal.
One of the more popular approaches (with a few dozen around the world), tokamak devices work to study fusion by generating a powerful magnetic field to confine the fusion fuel.
On the other hand, LLNL's National Ignition Facility (NIF) pursues fusion by means of inertial confinement (i.e. using energy from lasers instead). I'm not a nuclear physicist, so I won't go into more details than magnets vs lasers, but check out LLNL's article on How NIF Works for some interesting background.
In the announcement yesterday, NIF successfully created 3.15 MJ of energy by delivering only 2.05 MJ to the target. This is an awesome milestone, with the big caveat that in order to deliver 2.05 MJ of energy, the laser system needed ~300 MJ from the grid.
So, what's next? Like a tech tree in a video game, achieving fusion energy as a long-term power source requires prerequisite research advances in many areas. How do we fire shots at a higher frequency? How can we increase the yield from the lasers to require less energy from the grid? How do we further increase the energy yield? And so on.
The joke has been that fusion energy is always a couple decades away, but yesterday's milestone truly feels like we've moved one step closer. Who knows... ask me again in 2040.