Blue Origin Making Solar Cells from Lunar Regolith• https://www.nextbigfuture.com, by Brian Wang
Using regolith simulants, their reactor produces iron, silicon, and aluminum through molten regolith electrolysis, in which an electrical current separates those elements from the oxygen to which they are bound. Oxygen for propulsion and life support is a byproduct.
Above – Molten regolith electrolysis extracts iron, then silicon, and finally aluminum by passing a current through the molten regolith. The rising oxygen bubbles in one of our reactors show metals and metalloids being separated from oxygen. Our reactor geometry, metal extraction approach, and materials selection will enable sustained lunar operations.
This process purifies silicon to more than 99.999%. This level of purity is required to make efficient solar cells. While typical silicon purification methods on Earth use large amounts of toxic and explosive chemicals, their process uses just sunlight and the silicon from their reactor.
The harsh lunar environment means lunar solar cells need cover glass. They would only last for days without glass. This technique uses only molten regolith electrolysis byproducts to make cover glass that enables lunar lifetimes exceeding a decade.