Solving the climate crisis will require the world to move rapidly from greenhouse gas-emitting
fossil-fuel energy to abundant clean energy. That transition will be dramatically hastened if clean
energy sources are much cheaper than the fossil fuel alternatives. Over the past fifteen years, there’s
been extraordinary progress in intermittent renewable energy sources, specifically, solar and wind
power. In favorable locations, they are now cheaper than fossil fuels when the sun is shining and the
wind is blowing.
Today’s technologies, though, face certain fundamental limitations: Solar and wind are variable
energy sources, batteries are less energy-dense than liquid fuels, biofuels compete with food, etc. The
world also needs power sources that are dispatchable (non-intermittent and can be ramped up and
down on demand), ubiquitous (siteable anywhere), inexpensive (much cheaper than fossil fuels),
resource-light (e.g., small physical footprints, low water consumption, low critical material and
chemical inputs, etc.), and safe (have low risk to the environment, operators, and the general public).
Fusion is, in principle, an obvious answer. It’s the process that powers the stars, in which light
atoms (like hydrogen) are squeezed together to form heavier atoms (like helium), thereby releasing
massive amounts of energy with zero CO2 emissions. It fulfills the criteria above.1,2 And, thanks to the
astronomical energy density of fusion reactions (millions of times higher energy per unit mass than in
chemical reactions), fusion fuels are effectively limitless and free, with millions/billions of years of
easily-accessible energy reserves.