[davidj]

I can't find the reference off hand, but I once heard that it takes 7 years of operation for a solar panel to generate the same amount of energy to build a panel, .. and the energy that it takes to build one comes from ... guess what .. coal and gas.

[kragen]

That used to be true, but efficiencies have improved dramatically, and current energy payback time is closer to 7 months than 7 years.

[rdl]

There are cases where a relatively maintenance free power source which can be installed a point of use is worth a lot more than you'd think -- it's basically like a primary battery cell -- a way to transport energy. It doesn't matter if it's less than unity efficient in recovering the power used to make it, if distribution and storage costs for that power would otherwise be really high.

On cellphone towers in the middle of nowhere with no wirelines linking them, a solar panel makes a lot of sense, even if it never recovers as much power as it cost to build. Or on a satellite. Or, apparently, on a shack in rural Africa.

I agree Africa probably could do better with natural gas, oil, hydro, or coal central plants for now, vs. big solar plants, but a combination of cheap big grid power sources and decentralized renewables seems like the best solution. Building out a grid in rural areas isn't really cost effective.

[sliverstorm]

Is that necessarily an ironclad reason not to use them? Can you not think of the panel as an investment of energy that is slowly returned over the course of 7 years? Like a battery, but with much greater charge density and a longer viable lifespan.

I mean, it's not like they can freely use coal and gasoline in their huts. It is also more efficient to burn the coal & gas in a plant.