“Notes on the Infra-Slim” by Marcel Duchamp (1945):

A transformer designed to utilize slight, wasted energies such as:
the excess of pressure on an electric switch
the exhalation of tobacco smoke
the growth of a head of hair, of other body hair and of the nails
the fall of urine and excrement
movements of fear, astonishment, boredom, anger
dropping of tears
demonstrative gestures of hands, feet, nervous tics
forbidding glances
falling over with surprise
stretching, yawning, sneezing
ordinary spitting and of blood
unruly hair, cowlicks
the sound of nose-blowing, snoring
whistling, singing
sighs, etc. […]

Although not nearly as poetic, here’s an image from Human Generated Power for Mobile Electronics by Thad Starner & Joseph A. Paradiso:

Possible power recovery from body-centered sources. (Total power in parentheses)

A poetic writing from mid-20th century on the everyday and the infra-slim evoking current research on energy harvesting seems to be another case where a once-marginal artistic idea turns (not entirely, but still) into a necessity, similar to Oulipo and Twitter.