Engineers in Ghana are working on building solar power panels/cells using fabbers to bring cheap electricity to the masses. This could very well be the killer app for fabbers. There was recently an article in Wired about printable solar cells.
Entrepreneurs promise that soon solar-energized "power plastic" will radically extend the battery life of laptops and cell phones. Ultra-cheap printed solar cells will enable construction of huge power-generating facilities at a fraction of today's costs. And technologies to integrate solar power-generation capability into building materials will herald a new era of energy-efficient construction.These technologies will soon be available commercially, according to the article. But how long will it take before you can print them on your fabber at home? Research are already working on this. When it becomes a reality, we can expect that people worldwide will start printing solar for many of their needs, whether they live in more developed or less developed regions of the world. This will make energy very cheap for most people, and will be almost as easy as downloading a PDF file and printing it on your printer. It will help to lessen the usage of fossil fuels even while giving a much better standard of living and quality of life to billions of poor people. It will be very useful on Luna, especially since Luna has the materials necessary in the regolith to make solar power collectors for a future Lunar base.