Fusion & Magic

Andrew Blum in Lapham’s Quarterly:

The first extrasomatic energy source was fire, mastered by prehistoric societies 250,000 years ago. Pack animals provided ancient humans with an order of magnitude more energy. But not until waterwheels came into common use in the medieval era was there any common inanimate source to master. The Canadian historian Vaclav Smil notes that the Domesday Book records 5,624 water mills in southern and eastern England in the late eleventh century, one for every 350 people. Yet it would take another eight hundred years, into the Industrial Revolution, for their performance to be increased by another order of magnitude. Then things sped up. By the 1880s, the electrical system as we know it was recognizable, and crude oil began its rise to dominance for transportation. Ox by ox, water­wheel by waterwheel, engine by engine, the peak capacity of individual generating units rose approximately fifteen million times in ten thousand years, with more than 99 percent of that rise occurring during the twentieth century. Of those leaps, the most dramatic was nuclear fission, the breaking apart of atoms. Fission weapons shaped the century’s geopolitics; fission power plants still supply 10 percent of the world’s electricity.

Except now fission has run its course. In the wake of the Fukushima disaster, society’s appetite for nuclear risk has diminished. The costs of engineering even greater safety make fission power less economically viable compared to the falling costs of renewable sources like wind and solar. Averting further climate catastrophe requires broad policy changes—and some key new technologies. A step-change improvement in energy storage would open up new ways of using renewable energy, like solar energy at night and wind energy on calm days. More efficient ways of removing carbon from the atmosphere, at scale, might help change the climate again.

But the greatest potential for innovation—the closest thing to a technological silver bullet—remains fusion. Fusion is what powers the sun: a self-sustaining reaction in which isotopes of hydrogen at tens of millions of degrees fuse to form helium, releasing vast amounts of energy in the process. Fusion carries none of fission’s catastrophic risks. Its raw materials are abundant and safe, derived primarily from seawater. Its waste is minimally radioactive—more like what’s produced by hospitals than fission power plants. And there is no risk of meltdowns: when a fusion reactor’s power is shut off, its reaction stops.

More here.