> 10 gallons of water an hour on 500 watts of electricity.
Maybe this has changed, but it's perhaps silly to talk about bringing clean water to a lot of dirt poor communities with this kind of energy requirement. People barely have enough fuel to cook with. They can't feed a generator and they can't order parts for it either.
I think the generator uses a Stirling engine. It's been designed to require little maintenance, so the need for parts is vastly reduced. Additionally, Kamen stated that you could power it using a variety of fuels. If indeed it is a Stirling engine, then a variation could even be adapted that merely used a large parabolic reflector to generate the necessary heat to power the generator, without any other fuel requirement.
I also think it's easy for us in developed countries to underestimate the amount of effort required to bring potable water to individuals in undeveloped areas. I've been working to help send an acquaintance back to Uganda to do work on water systems there -- analyzing the water, as well as clearing the simple spring wells and teaching the locals that it's better to get water from the pipe than from the pool on the ground. In his presentation, he noted that it's not unusual for many villagers to make a four-hour hike to a water source, and then carry that water back again.
I would think that a trip like that would consume rather more than 500 watts of power.
Maybe this has changed, but it's perhaps silly to talk about bringing clean water to a lot of dirt poor communities with this kind of energy requirement. People barely have enough fuel to cook with. They can't feed a generator and they can't order parts for it either.