Enligt Wiki är det ett patent från 46.

Och -
"A recent analysis [3] showed that the evaporative heat flux driving a small bird was about 0.5 W, whereas the mechanical power expressed in its motion was about 50 microwatts, or a total system efficiency of about 0.01%. More practically, about 1 microwatt can be extracted from the bird, either with a coil/magnet or a ratchet used to winch paperclips."

http://en.wikipedia.org/wiki/Drinking_bird

Fågeln dricker än..........