A research collaboration in Europe has created a new alloy of silicon, germanium, and tin that can convert waste heat from computer processors back into electricity. It...
I suppose it’s a better idea than I initially gave it credit for. It’s a new type of thermocouple, and processors do run at a fairly high heat gradient compared to ambient temperatures.
The way I see it, every little bit helps. If even a little of the waste heat can be recaptured as electricity for operation, it's a good thing unless the conversion itself has a higher energy cost, and from what I can tell, that's not the case with this technique.
Data centers will probably be the only practical application. Consumer electronics will probably barely produce enough energy to power the regulator and tie-in circuit just to feed back into the pwm driver for fans nowadays.