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  • Author Author: gelmi
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Tap dancing? No – tap harvesting :)

gelmi

Today I did some successful trials with energy harvesting from a hot water  tap. This post is just a teaser, because it is almost midnight and I have to get up early. The photo below presents a bathroom battery with a TEG attached to and a multimeter (mV). The Peltier module is without load in the picture. When it is connected to LTC harvester chip and hot water runs from the tap, the voltage is about 55 mV.

image

As Victor stated and I also agree, energy harvesting is very tricky. You have to use unconventional ways and think outside of the box. However, I believe I have found the harvesting solution for my project and I will use this method in my batteryless carbon monoxide detector.

Stay tuned for my next post, in which I will describe in details this experiment, give some measurements data and energy estimation for my project.

  • in reply to vsluiter

    If you attach both hot and cold side to the pipes when both water streams run, you will get a lot more power than me. But what I miss from harvesting I have to catch up in EFM32 image Looking forward to your test with tap.

  • 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!