[Knut Karlsen] put together a prototype set of solar rechargeable batteries. He always seemed to have batteries laying around on his worktable and figured they might as well be charging. The flexible solar cells were given to him by researchers at the IFE and are rated at 1.8V. He used superglue to secure them to the C cells. A silver conductive pen plus flat wires from a Canon lens connect the solar cells to the battery terminals. The batteries just trickle charge for now, but he’s going to try to build cells with built in charge controllers in the future.
I used the Ambigrid Plans to build a solar pales for under $100, as well as a solar water heater for less than $10! I can’t say enough good things about them!
Beautiful to look at, but the inefficiency would annoy me – it’s impossible to have all of the panel facing the sun at the same time. The good news is that flexible solar panels are on the way, and people will find all sorts of places to affix them.