>Are you saying if I heat my toaster it generates power ~` ?


Well, you would expect a small amount of DC power generation due to
the thermo-electric effect where different metals are used
eg elements and wires and lugs etc). Measuring this would be a real
challenge though :-).

Also, external to the toaster the potential would be canceled out by
the equivalent cell at the other end of the element so the element
will be offset to a dc mean voltage (vvv slightly) above or below
ground.

Now, about the dry ice in the fridge ....