Searching for a way to provide unlimited clean energy to Earth's population, Japanese architecture firm Shimizu designed the "Luna Ring," a solar cell that would be wrapped around the Moon's equator and beam energy back to Earth.
Says Shimizu on their webiste:
A shift from economical use of limited resources to the unlimited use of clean energy is the ultimate dream of all mankind. The LUNA RING, our lunar solar power generation concept, translates this dream into reality through ingenious ideas coupled with advanced space technologies. Virtually inexhaustible, nonpolluting solar energy is the ultimate source of green energy that brings prosperity to nature as well as our lives. Shimizu Corporation proposes The LUNA RING for the infinite coexistence of mankind and the Earth.
In their proposal, they explain that robots will be sent to the Moon to prepare the surface for the giant solar ring, whose components will also be built by robots in space. Then the whole structure will be built on the Moon, supervised by a human colony. Just in case you were wondering how to build a colony on the Moon, Shimizu has a plan for that too.