Lunar Source of³He for Commercial Fusion Power

TLDR

Solar wind deposits an abundant, easily extractable source of 3He on the lunar surface. Extracting 3He from lunar regolith and transporting it to Earth requires about 2400 GJ per kilogram. Apollo samples reveal ~10⁹ kg of 3He, which could supply ~10⁷ GW‑yr of electricity in a 50 % efficient D‑3He reactor, giving an energy payback ratio of ~250 and indicating commercial potential.

Abstract

An analysis of astrophysical information indicates that the solar wind has deposited an abundant, easily extractable source of 3He onto the surface of the moon. Apollo lunar samples indicate that the moon's surface soil contains ∼109 kg of 3He. If this amount of 3He were to be used in a 50% efficient D-3He fusion reactor, it would provide 107 GW(electric)·yr of electrical power. The energy required to extract 3He from the lunar regolith and transport it to earth is calculated to be ∼2400 GJ/kg. Since the D-3He reaction produces 6 × 105 GJ of energy per kilogram of 3He, the energy payback ratio is ∼250. Implications for the commercialization of D-3He fusion reactors and for the development of fusion power are discussed.