[layoutIfNeeded]

You can’t. The second law of thermodynamics prohibits it.

“It is impossible to devise a cyclically operating device, the sole effect of which is to absorb energy in the form of heat from a single thermal reservoir and to deliver an equivalent amount of work.”

[jodrellblank]

How does having a hot side of a piece of material and a cold side of a piece of material come under "cyclically operating"?

[rpmisms]

Perhaps not an equivalent amount of work, but if we could capture some of the waste....