Fusion energy is the ultimate goal of green energy production. This will probably occur about 90 years after being fully operational, or 55 years after the introduction of permanent residents.
We want to focus on Helium–3 (3He) and Deuterium (2H). Helium–3 can be found in the lunar soil. Deuterium can be found in Earth's oceans.
3He + 2H ⇒ 4H + 1 proton
3He + 2H ⇒ 3.6 + 14.7
3He + 2H ⇒ 18.3 MeV
Helium–4 is an alpha particle that can be used to generate electricity and the fusion reaction is mostly aneutronic (no neutrons generated), which means mostly no radiation hazard. However, some of the Deuterium particles will randomly fuse with other Deuterium particles, which produces neutrons (radiation hazard). Spin polarization is a theoretical solution to this problem.
The other bad news is that 100 million kilograms of lunar regolith is needed for every kilogram of Helium–3.
Even more bad news is that about 6,500 kg of seawater is needed for every kilogram of Deuterium.
The good news is that it is very easy to mine 3He on the Moon and that is very easy to mine 2H on Earth.
When the fusion breakthrough occurs, Spaceport America will retire its collection of solar panels.
Assembling a fusion reactor on the Moon will probably be more difficult. It would probably be easier to build a fusion rocket engine and transport the reactor there.
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