Chief:

So far, cost-efficiency requires an energy density factor much higher than ambinet thermal gradients. Another generation of nano-scale engineering will probably overcome this and we should be able to micro-scavenge using sensor built into wall and roof tiles from ambient thermal, air, sound, static charge and mechanical vibration, using microscopic cells and accumulators like large capacitors that look something like steel-wool -- miles and miles of capacitative surfaces in a very small area.

But we have to bring the cost of design and production (and repair or replacement) down to be able to take advantage of such sporadic and low-density energy events.


A