Re: So, a hard to repair solar panel..
... and a toxic battery that will wear out, be heavy and costly, and need replacing is a good idea for the target market?
You do get that this unit requires someone to lift a bag weighing a hell of a lot more than several laptop batteries several times a night, right?
Nonsense, pure nonsense. Their first design WAS to do exactly that, and then, like any sensible person, they realised that is basically handing a hopeless black box that will break down to people who cannot repair it or have it serviced easily.
Last week I picked up a half a dozen solar powered garden lights. Cost a couple of bucks each, (maybe) give more light than these "gravity" units do, and they come on when it gets dark enough at about 8:30pm and are still giving strong light at 2am. I couldn't tell you the actual wattage involved but it's enough that $10 worth of these will reasonably light a large room (normal Western house). How long they'll perform to the same level for is another matter, the batteries will probably start to fail in a few years depending on how cheap/nasty they really are.
Complexity? Solar panel, battery (admittedly nicad which was a bit of a surprise), wires, probably some basic voltage or charge regulation, and a plastic case. Oh, and a very complex mechanical part called a "switch". No gears, no belts and pulleys, and so much effort to run that a physically drained or disabled mother could get it to work.
Oh, and servicing? As much as I like to recycle and re-use, I doubt I would bother. The power used in heating up the soldering iron would almost outweigh the cost of a replacement.
This way, unless it is abused, it will give service for an extraordinarily long time, with nothing but simple lifting motion required when light is needed.
Simple. Several times a night. A bag weighing what, 5-10kg? In areas perhaps where there could be a large number of weakened or disabled people who will struggle to do that as much as needed? Also it is a mechanical device that relies on suspended weight. I would expect that the materials used are the most re
not to mention handing out tons of toxic batteries is not exactly a great idea in a poor region with no recycling capability.
Batteries can be contain quite nasty chemicals. Not sure on the chemistry of capacitors but guess they're not much better. But plastics can be quite bad as well, although I guess/hope these people are using something relatively "green".
That said, I do like the concept. Anything that is able to help people to a better life (while still being resource/pollution etc friendly) I am happy with. Just not sure about the work (energy) input and the light output.