we mostly rely on down on earth: the sun.
Big difference. The power of the sun has been stored and concentrated on Earth for hundreds of millions of years through organic carbon based life. We don't use this up just to run cars and lawn mowers. Without it, we work hard just to make clothing and shelter and to harvest and process food. Food that grows all by itself on Earth. Now add all the extra things you need to survive on the Moon. Pressurized atmosphere, oxygen, and water recycling. Burning enough energy/fuel, anything is possible. But you aren't going to have some self-sustaining habitat in such terrible conditions to human life without a huge input of energy. Even after you put up your little biodome or w/e, you don't have no Amazon to deforest, no coal mines or oil wells, no nothin to power the repairs and maintenance and to produce and shape any engineering/construction materials. And an extension cord doesn't quite reach that far. Solar won't cut it, at all, unless you keep it going with resources from the Earth. Spend all that energy on Earth to get the final products to ship to the Moon. The structural stuff, the replacement stuff, the maintenance things, the fuel. A colony would be 100% dependent on Earth to survive at all, let alone even think about growing/expanding.
uBeam for space, that's brilliant! :-D
That's essentially what it would be. These colonies would need fuel, as well as supply of unrenewable resources. And the efficiency after figuring the cost of getting it there would be uBeam level, if you're lucky.
There's zero chance of a self-sustaining human colony on the Moon unless/until the energy thing is figured out. Solar panels and batteries wear out. To make more of them you need a heck of a lot of energy. To refine metals from ore. To extract oxygen from moon rocks. To recycle your water. Lots and lots of energy. To use the word Eco-friendly in this thread (somewhere mentioned) is an oxymoron. Each of the humans living in this colony would have the carbon footprint of 10,000 people on earth, and it doesn't matter how many solar panels you ship up there. This would be like spending the equivalent Earth resources of a king for every space hippie living up there like a pauper. If this were a "second home," it would be a very expensive vacation home.