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Can this technology work in an airconditioned room? I was thinking if this technology can provide enough electricity to even just lighting up a single room. It
by MojoJolo 13y ago
Can this technology work in an airconditioned room? I was thinking if this technology can provide enough electricity to even just lighting up a single room. It can use the heat outside, and the cool air (form air condition) inside the room.
All in all, very good invention! And also inspiring. I hope more teens will be involve in inventing things. I hope she wins. Also, (totally unrelated) I think she's cute. :)
- relix 13y agoSorry, what you're talking about is a perpetual motion machine, which the laws of thermodynamics forbid. The AC will just have to work harder to get the extra heat added by the thermoelectric device back out, no free energy here.
- ISL 13y agoIt should be provable that thermodynamics guarantees that it will be more power-efficient to generate the light directly with electricity instead of using electricity to cool the room, then exploiting a thermal gradient with even a lossless Peltier element.
- tekromancr 13y agoTrue, and it is. However, if you are going to be using that energy to cool the room anyway, why not try to reclaim that 'spent' energy?
- ISL 13y agoIf you wish to have 1) a cool room at temperature T 2) enough light, L, to see by 3) a happy human at temperature H Assuming that T,H, and L are fixed, you're going to use more energy with a less-efficient process. So, you'll 'spend' more energy to get there. If you're trying to run the process at fixed energy, you're going to wind up accepting a slightly higher T. If that's the case, you'd be able to use even less energy by powering the LED directly and moving the setpoint for T up to that same temperature.
- vidarh 13y agoI think what you are forgetting is that in doing so, you would be heating the room up again. So to keep the temperature where you want it, you'd need to cool the room even more.
- tekromancr 13y agoAhh, you are right.
- pocketstar 13y agoIt would 'work' but it would be grossly inefficient. Your room is cooled by a heat pump(air conditioner) a Peltier is just a different heat pump, a very inefficient one at that. You would end up spending much more money cooling the room than it would cost to just power lights normally.
- dwyer 13y agoTFA: due to the temperature reliance of Peltier tiles, the flashlights worked better in colder temperatures (tested at 41 degrees Fahrenheit). The flashlight still worked in warmer temperatures (50 degrees, for instance), but the colder the surrounding temperature, the more the hand’s body heat can help the Peltier generate electricity.