Green Energy

Static electricity comes from the sun like every other source which is available in meaningful quantity (except geothermal which is kind-of-half-solar).

Corona motors are very simple and quite easy to make https://www.youtube.com/watch?v=vDRCKVUO8vw

Devices like this one are not going to gather that much energy as there is not all that much to harvest. It could be useful for small electronics and such though, or maybe even power lighting strong enough to read by without a battery.