I agree, and I think the focus here on the battery is misplaced. What is enabling this to work is the availability of low cost LEDs, which require very little c

I agree, and I think the focus here on the battery is misplaced. What is enabling this to work is the availability of low cost LEDs, which require very little current to operate. These open the door of all kinds of lighting with low power sources, like galvanic batteries, or as you suggest solar panels (though I am guessing the cost for solar is higher). Whether this is the optimal power source is TBD, but the core idea that lighting can be brought to developing countries at very low cost by looking at non-traditional power sources is an important one.