Developing alternative energy sources is one of the most important challenges the world faces today. Although using helium-3 as source of nuclear fusion is one proposal for an energy source, many hurdles remain to overcome before it could be realistically used.

Potential

Helium-3 (He-3) is an isotope of the element helium that is currently found only on the moon. Nuclear fusion harnesses the charged atoms of this isotope to create a heavier atom. When used as a fuel in nuclear fusion reactors, He-3 has a huge potential to be a source of safe energy.

Benefits

So far, most of the energy produced by nuclear fusion has been radioactive neutrons. Helium-3 does not create these pollutants and byproducts. It is also extremely dense, so one space shuttle load full of Helium 3 would be enough to power the energy needs of the U.S. for an entire year.

Considerations

He-3 is only located on the moon, because it is a byproduct of solar radiation that the moon is subject to. It is scarce on Earth because our planet's atmosphere protects it from this radiation.

Scarcity

Because it is so rare, Helium-3 is also extremely costly. Forty tons of Helium-3 is worth about $40 billion, whereas that same amount of crude oil is worth about $40. The cost of transporting this fuel is currently too high to make it economically viable.

Theories/Speculation

One issue is that it is still unclear how one nation or entity can achieve the rights to mine or exploit Helium-3 exclusively. Many nations with space programs are already in intense competition to gain access to He-3 and bring it to Earth.

Source:

Richard Bilder: A Legal Regime for the Mining of Helium-3 on the Moon: U.S. Policy Options

ListSeargent: Top 10 Alternative Energy Sources that Will Work

More Information:

IAEA: Nuclear Fusion