Energy

The headline stands at 0.5% by 2071. If one of these settled tomorrow and nothing else changed, the whole tree is played out again and the headline lands where the figure says. This is the site saying in advance what a milestone is worth, before it happens: when one of them lands, the entry that records it quotes what was predicted here. These come from playing the tree out 20,000 times per scenario, which is a throw of the dice: anything smaller than about 0.10 points is inside the noise, so read the order rather than the last decimal.

• A site on the Moon has a hundred kilowatts of electricity through the lunar night, for a year, from any source too small to tell apart from chance if yes 0.5% today · 0.5% if it happened · 0.0% if it turned out no (−0.5 points)
• A nuclear reactor runs on the lunar surface for a year too small to tell apart from chance if yes 0.5% today · 0.4% if it happened · 0.5% if it turned out no (too small to tell apart from chance)
• Solar panels with storage keep a lunar polar site powered through a whole year too small to tell apart from chance if yes 0.5% today · 0.4% if it happened · 0.5% if it turned out no (too small to tell apart from chance)
• Power sent down from orbit keeps a site on the Moon running for a year too small to tell apart from chance if yes 0.5% today · 0.4% if it happened · 0.5% if it turned out no (too small to tell apart from chance)

6 other open steps under this factor are worth nothing to the headline, because the headline does not rest on them at any remove: A single spacecraft generates and uses a megawatt of electricity in orbit, High-temperature superconducting wire costs a tenth of what it does today, A fusion power plant delivers net electricity to a grid, A power source makes a hundred megawatts of electricity while weighing no more than a hundred tonnes, A fission-electric power system built for spaceflight makes a hundred megawatts of electricity, A radiator system sheds a megawatt of waste heat in vacuum for thirty days. Most belong to the tiers above the one the headline asks about.

• Solar panels with storage keeping a lunar polar site powered for a year was raised when I checked the first estimates: every south-pole base plan starts on solar 2026-10-02 Changed my mind
• Forty-one steps had their criteria tightened so that two readers would agree when each has happened, with no number moved for that alone 2026-09-20 The tree itself changed
• A company broke ground on a fusion power plant that already has a signed customer for its electricity 2026-09-19 Settled

• A radiator system sheds a megawatt of waste heat in vacuum for thirty days E-megawatt-heat-rejected-for-thirty-days-in-vacuum
  80%baseline scenario, as of 2026-09-20
  By 2031 Not yet
• A single spacecraft generates and uses a megawatt of electricity in orbit E-megawatt-spacecraft-operates-in-orbit
  85%baseline scenario, as of 2026-09-19
  By 2031 Not yet
• Construction begins on a fusion plant built to sell electricity to a customer E-construction-begins-on-a-fusion-plant-meant-to-sell-electricity
  happened2025-07-30
  By 2031 Happened
• A fusion power plant delivers net electricity to a grid E-fusion-plant-delivers-net-electricity
  60%baseline scenario, as of 2026-09-19
  Within 20 years Not yet
• A nuclear reactor runs on the lunar surface for a year E-fission-reactor-runs-on-lunar-surface
  70%baseline scenario, as of 2026-09-19
  Within 20 years Not yet
• A site on the Moon has a hundred kilowatts of electricity through the lunar night, for a year, from any source E-power-through-the-lunar-night-at-a-surface-site
  90%baseline scenario, as of 2026-09-25
  Within 20 years Not yet
• High-temperature superconducting wire costs a tenth of what it does today E-superconducting-wire-price-falls-tenfold
  55%baseline scenario, as of 2026-09-19
  Within 20 years Not yet
• Solar panels with storage keep a lunar polar site powered through a whole year E-solar-with-storage-powers-a-lunar-polar-site-for-a-year
  65%baseline scenario, as of 2026-10-02
  Within 20 years Not yet
• A fission-electric power system built for spaceflight makes a hundred megawatts of electricity E-fission-electric-space-power-system-reaches-a-hundred-megawatts
  4%baseline scenario, as of 2026-09-25
  Whole window Not yet
• A power source makes a hundred megawatts of electricity while weighing no more than a hundred tonnes E-compact-power-source-at-fast-drive-scale
  8%baseline scenario, as of 2026-09-25
  Whole window Not yet Long shot
• Power sent down from orbit keeps a site on the Moon running for a year E-power-delivered-from-orbit-to-the-lunar-surface-for-a-year
  8%baseline scenario, as of 2026-09-25
  Whole window Not yet