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I had this exact idea of using peltiers to reclaim energy from waste pipes. Think about big industrial systems. I knew from reading the specs that existing pelt

I had this exact idea of using peltiers to reclaim energy from waste pipes. Think about big industrial systems. I knew from reading the specs that existing peltiers wouldn't cut it. So I decided to let it go until progress in material science (maybe graphene) made it more efficient. There is a theoretical design that is radically more efficient. It uses an S shape design, but it's not possible at the moment. This looks to be using ordinary peltier designs but sliced up. This could be used like a stove-top heat pump that uses a peltier, and the heat from a stove to power a fan that helps circulated the warm air more efficiently. Of course this would add some insulation around the pipe too, so it may not be the free lunch it seems.

anonymouse008 5y ago
I have a prototype of an S Shaped design… supposedly there’s a layered design better than that. My friend is now at the DoE - do you have people with experience that could talk?
- irthomasthomas 5y ago
  That sounds great! Can you share anything about the materials and/or performance? I am only an armchair inventor. I once got as far as registering a company, and filing a business plan, but I noped out of it. I just like to follow the science and noodle with the equations, hoping for something interesting. The main problem for this application, I think, is maintaining a temperature gradient. So you add a heat sink to the cold side, but that only gets you so far. And then you have the extra cost and CO2 burden of manufacturing a heat sink (and aluminium is particularly dirty). My plan was to look for places with a sustained temperature gradient. So, I sandwiched a peltier between the hot and cold pipes in my old house, to power some LEDs. As long as the house was occupied, there was always cold running water on one side, and hot tap water on the other. So, if I was building, say, a power station, where cold water is being pumped in. I would arange the cold pipes close to the hot in one spot, insulate the outer surfaces, and stick a peltier generator in between. You can also use heat pipes (like on CPU fans) with coolant, to wrap the source hot/cold pipes, without needing a flexible peltier.
  - anonymouse008 5y ago
    Gosh this is cool - yeah, it's basically BiTe pressed wafers in S form. Test results never were validated so I can't put faith in the results unfortunately, they were pretty good though. Redesigning for temperature gradient is quite brilliant. My thinking was along the lines of an aerogel heat sync. In theory it could maintain a gradient much longer than current tech... at astronomical cost! Reach out if you'd like to continue the discussion, I miss this project.

anonymouse008 5y ago

I have a prototype of an S Shaped design… supposedly there’s a layered design better than that. My friend is now at the DoE - do you have people with experience that could talk?

irthomasthomas 5y ago
That sounds great! Can you share anything about the materials and/or performance? I am only an armchair inventor. I once got as far as registering a company, and filing a business plan, but I noped out of it. I just like to follow the science and noodle with the equations, hoping for something interesting. The main problem for this application, I think, is maintaining a temperature gradient. So you add a heat sink to the cold side, but that only gets you so far. And then you have the extra cost and CO2 burden of manufacturing a heat sink (and aluminium is particularly dirty). My plan was to look for places with a sustained temperature gradient. So, I sandwiched a peltier between the hot and cold pipes in my old house, to power some LEDs. As long as the house was occupied, there was always cold running water on one side, and hot tap water on the other. So, if I was building, say, a power station, where cold water is being pumped in. I would arange the cold pipes close to the hot in one spot, insulate the outer surfaces, and stick a peltier generator in between. You can also use heat pipes (like on CPU fans) with coolant, to wrap the source hot/cold pipes, without needing a flexible peltier.
- anonymouse008 5y ago
  Gosh this is cool - yeah, it's basically BiTe pressed wafers in S form. Test results never were validated so I can't put faith in the results unfortunately, they were pretty good though. Redesigning for temperature gradient is quite brilliant. My thinking was along the lines of an aerogel heat sync. In theory it could maintain a gradient much longer than current tech... at astronomical cost! Reach out if you'd like to continue the discussion, I miss this project.