This is the start of a mini-series of proposed ideas of making profit in space. Some have immediately return on investment, others will take a bit more time. These posts are just a snippet, full written articles are not being publicly published, but available.
BioFuel generation is done right now on earth. It can be highly efficient (bacteria/algae) or inefficient yet still supported by the hippies (corn).
On the moon, we get great sun energy with no atmosphere in the way. The basic idea is to build a lunar “greenhouse” with a self-healing film to ensure plenty of light enters the facility. We grow a mix of algae and other bacterias that consume these algaes (sugars) to produce a form of diesel oil. This oil can be used to produce plastics and any other raw material that is costly to make with earth gravity (nanotubes? battery packs?). Sterline engines powered by moltan salt ensures we have electricity. However, we will depend on nuclear energy for the first years while the facility is built. Part of the electricity usage will be used to power a large electromagnet to simulate the Earth’s magnetic field. This must be a very large electromagnet and may utilize the cold tempuratures found on the moon to ensure more efficiency in the coils.
The only raw material needed is the carbon. In theory, we could take any carbon from earth, transport it to the moon and return shipment of oils, plastics or other processed materials back to earth. The entire environment would be computer controlled as the environment will be 100% manmade. Living quarters will be underground (at least 1 meter or deeper) to protect from micro-meteorites, space debris and radiation. Work near the surface or in growing houses will be limited to reduce exposure.
Return trips to earth will be powered mostly by electricity. A large electric railgun will be fired with the cargo (and ship) on board and targetted on a return path to earth. The railgun will not fire at immediate escape velocities as the human body will not survive, but instead have multi steps to ensure a constant acceleration. Due to no atmosphere being in the way, we can attain escape velocity near the surface where the large railgun “track” is build towards earth. Conventional rockets will be available incase of miscalculations on the return flight path.