SpaceX's Elon Musk Talks Rockets, Moon Base and Colonization

sailor.barsoom wrote:> If ground-based PV becomes more efficient, then the PV used on powersats also gets> more efficient. Also, places like the UK or Norway have bigger problems with> ground-based solar than the Sahara or even (most of) the US.Improvements in cost would hardly affect the cost of SBSP, almost all of whichof course, would be the enormous cost of getting the PV arrays up into space.Not making them.Improvements in efficiency would hardly make a dent in making SBSP as affordableas ground-based solar, because of said cost. Yes it would reduce the amount ofvolume and weight needed to be carried into space by a corresponding ratio. Butanywhere near enough? Like someone trying to empty Lake Tahoe with a waterbucket, by saying they now have a water bucket twice as large.Nor would those efficiency improvements reduce the size of the rectenna arrays.Also, the types of PV panels used in space are not the same types as the onesused on earth. Space presents a far harsher environment. They're many times asexpensive. And they effectively last about half as long as ground-based ones. Sosome new cheap or efficient type of PV might -- or might not -- be adaptable tospace.> As for what to put under the rectenna: factories, greenhouse agriculture, production> of synthetic hydrocarbons. You've got some basic structure there, and scads of> electricity.You can do the same for ground-based solar right now. Unlike SBSP, you own the power instead of having to buy it from someone else. Unlike SBSP, you can putthe structure anywhere, or anywhere there is enough sunlight. You can make thestructure as big or little as you want. Which is another advantage of ground-based solar: it is the most decentralized power source there is, whereas SBSPwould be *highly* centralized. And depending on your views of such things, you don't have to worry about notgoing onto the roof.SBSP would offer the advantage of continuous power. However if it's for theproduction synthetic hydrocarbons, this is would be a kind of energy storage.