Knut Karlsen designed the above trickle charge some NiMH batteries with a wraparound flexible photovoltaics.

Completely impractical, but the idea of simply laying some depleted batteries out on a table to recharge does appeal to me.

Since the relaunch, almost every post references solar panels. Solar is often billed as a cure-all for our climate and energy needs, but as Knut links to photovoltaics themselves are nonrenewable due to rare elements required for their manufacture.