Why not use wasted heat from warm water pipes in a similar way? Pipes are round; generators that convert heat into electricity, generally flat.
Cue a research team from Penn State, and its new manufacturing process for flexible generators.
A dozen strips, each holding 6 current transformers, were fitted onto a metal foil with space inbetween.
This was filled with liquid metal to increase efficiency and preserve flexibility for wrapping the foil around pipes.
In tests, 56.6 watts were generated per ca. 20㎠. With power density 150% higher than conventional thermoelectric generators, the potential to create clean energy is enormous.
It, in turn, could be stored here.