RE: Tap dancing? No – tap harvesting :)

vsluiter — Mon, 13 May 2013 08:07:15 GMT

Nice experiment!

It's a bit different from what I was planning to do with my shower tap; there I have thermostatic tap, so I can use both the hot and the cold water. I've been thinking a lot about the Peltier application lately, and especially about one of the comments in the paper I linked to. It talked about the 'thermal impedance' that also has to match, just like the electrical impedance. To get power from a Peltier, you need both heat difference (like potential difference in electrical domain) and heat flow (like current in electrical domain). Power is again the product of both. The thermal impedance of a peltier is quite low, so to get power you'll need a lot of heat flow; hence the need for a heatsink, so the impedance to the ambient temperature is also low (this can be seen as a series resistance; no heatsink would increase the thermal resistance).

I'll try to mount to my thermostatic tap; then I can get a lot of flow from the heat side to the cold side; could be quite a good harvesting place!