He3! Senator, Astronaut Harrison Schnitt wrote Return to the Moon. He is a geologist and analyzed lnar material and trained other astronauts to gather lunar materials. The amount of lunar materials would allow the building of a lunar colony, mining He3, building fusion reactors, generating and beaming the electricity to earth. This is proven technology which would provide electricity to all of Earth with NO pollution of our atmosphere.
Cost would be substatial but when you look at the RETURN ON INVESTMENT of 25% for the entire Apollo program's 25Billion dollar investment we should start the process yesterday!