Wojchiech Gelmunda of Poland, an element14 member, created one of the winning designs, a carbon monoxide detector. The design uses warm water for energy and an EFM32 microcontroller to gather and maintain energy from the excess heat of water pipes. An electrochemical sensor reacts to carbon monoxide. (Source: Newark element14)
Elizabeth, the harvesting of energy from hot water seems interesting, but this implies that the device has to be near a hot water pipe that is hot. In systems in the US, with a large tank hot water heater, this would limit the system to be near the heater. In Europe there are on-demand, tankless systems in use. If you were away for a while there would be no hot water in the pipes. I assume that there is some storage mechanism.
Right off I'm going to say... Elizabeth don't get me wrong... I'm glad to see people are thinking and trying to save energy. And as an exercise these are pretty good.
The reality is though that some of these examples take heat that was created to do something... then convert it into electricity to do a new something else... before it could do its intended job.
Originally, the heat used to power these devices was created with losses based on the level of inefficiency of a system. They used electricity, or gas, or oil, or coal to create the heat, and... it was turned into 'heat' because that is what the job required.
Then... the heat was parasitically intercepted before it could do that work, and converted again, with losses from another imperfect system.
I would not call his harvesting... It is outright theft!
I would call it harvesting if the energy was captured from a source that was not already in a stream to do some other work... Or if it was waste heat taken after the work was done (For example the Australian homebrew monitoring kit powered by excess heat generated during the fermentation process. Great effort that one)!
Had the faucet attachment or pot lid modifications bled off a little hot water to do something that required hot water no one would act like this was a 'harvesting' event...
If on the other hand they were capturing 'waste heat' then it would be a different story.
I'll suggest a quick fix to my complaint for one of these... Instead of stealing heat from the faucet, the heat should be taken from the drain pipe... I would call that harvesting.
At that point the water has done it's job and is taking heat with it; heat that can be saved from being wasted.
Yes, I guess there are considerations like that to think about when it comes to different standards and mechanisms in different parts of the world, naperlou. I'm not sure about the storage system. Perhaps there could be some kind of modification to the design to accommodate different hot-water accessibility scenarios. These are all prototypes, after all. :)
Points well taken, Ralphy Boy, thanks for your comments and your suggested workaround. Obviously none of these designs are meant to be perfect and usually there is some tweaking to prototypes before they would be put into practice or commercial development. But as you point out, it's good for people to be thinking in this direction and inventing devices toward this end.
You're very welcome, vimalkumarp. I find this very interesting technology to write about and it's fascinating to see the different methods clever people are designing to re-channel existing energy so it's put to good use.
Yes, vimalkumarp, I think we exchanged messages before in comments about your PhD work. It's fascinating. You're definitely doing research in a really promising and potentially world-changing area of technology. I think I said it before, but I will definitely be interested in seeing what you publish about your work. Good luck!