Power generation from ambient humidity using protein nanowires

No.11393754 ViewReplyOriginalReport
https://derpy.me/BlUqp

>Here we show that thin-film devices made from nanometre-scale protein wires harvested from the microbe Geobacter sulfurreducens can generate continuous electric power in the ambient environment. The devices produce a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimetre. We find the driving force behind this energy generation to be a self-maintained moisture gradient that forms within the film when the film is exposed to the humidity that is naturally present in air. Connecting several devices linearly scales up the voltage and current to power electronics. Our results demonstrate the feasibility of a continuous energy-harvesting strategy that is less restricted by location or environmental conditions than other sustainable approaches.

So, what's the catch here? Scalable continuous power generation from humidity, seems almost too good to be true. Every popsci site is buzzing with eye-catching titles like "power from thing air".