QUOTE (Del Palmer @ Dec 14 2007, 08:24 PM)
You need both. A fuel cell is like a battery: it just stores energy. It would be useless without solar cells to 'charge' it up.
Yes, agree, as Phil has said, for a greater survavility, the key is the redundancy.
However, a solar panel on the crest of some high mountain of South Pole, not 100% sure since there are few mountains around S.P. might be, will be always exposed by the sun light in the round lunar orbit. So it is no needed to use the battery. However, I prefer to have both kind of power supplies and two independent circuits at the hand for just in the case if the circuitry of solar panel might get troubled after a very rare micrometeorit impact. Without electricity in the Moon, everybody will be dead by not having a proper A/C or heating, oxygen and water recycle filtering and etc.
Does the SMART-1 and other lunar probe has already identified an South Pole's montain in which crest is always exposed to the sun in all round lunar orbit? If not, maybe, the present probes around moon will be able to identify which ones?