4 ms·
Heat is energy. In summer, the sun (rudely) gives me excess unwanted heat in my house. I need to expend even more energy to get that heat from inside to outsid
by billpg 5y ago
Heat is energy.
In summer, the sun (rudely) gives me excess unwanted heat in my house. I need to expend even more energy to get that heat from inside to outside my house. (We call this process "Air Conditioning".)
What would be ideal is if the heat energy could be converted into some other form of energy that I could dispose of. Maybe if I could turn it into electricity I'd put a lightbulb in my window and shine the converted heat energy away.
I don't really care if that process is inefficient because that heat was completely free and unasked-for. I don't need to do anything useful with the converted heat energy, I just want it gone. If the process of converting heat to a disposable form of energy can be done for less energy than air conditioning needs, then its worth doing.
- elzbardico 5y agoI don't see why people are downvoting you, as you are basically wanting to avoid wasting good energy with air conditioning. Maybe people thought your tone was blasfemous?
- bernulli 5y agoPeople are downvoting because billpg essentially wants a perpetuum mobile, something that creates useable energy just from the presence of a high temperature reservoir. This violates the 2nd law of thermodynamics. Heat does not equal usable energy, what you need to extract something useful is a temperature difference.
- billpg 5y agoI don't care if the energy is useful, I just want it gone.
- Ajedi32 5y agoBecause what GP is proposing is thermodynamically impossible. The second law of thermodynamics states that heat naturally flows from hotter to colder regions. You can't just magically convert a static pool of heat to light and beam it somewhere else with no energy input. It's like suggesting that we generate electricity by rolling stones uphill; it just doesn't make sense.
- billpg 5y agoI don't know about blasphemy. My intended tone was "telling a joke". I know what I proposed would require our understanding of thermodynamics to be wrong, but this is in response to an article about a material that converts heat into electricity. I would love to hook up this material to a lightbulb in my window and save money!
- foobarian 5y agoI did get your snark but also half-thought that you were alluding to covering the house in solar panels. Which would, in an indirect way, remove the heat from your house and convert it to electricity :)
- oehpr 5y agoIt sure is tempting to think of heat as just energy. I mean it is. Of course. But the kind of device you're talking about is like Maxwell's Daemon. The article is talking about a step towards making an inexpensive thermocouple. These require temperature differentials, not just heat. And you don't want to be drawing power from the temperature differential in your house ;)
- tialaramex 5y ago> What would be ideal is if the heat energy could be converted into some other form of energy That would be nice, wouldn't it. If you ever build a universe, you should definitely implement that. In this universe the laws of thermodynamics specifically forbid destroying heat, or converting it into something else. Heat will naturally spread out evenly over time, but if we would prefer to do the opposite, moving heat where we want it (or away from where we don't want it), we need to use a heat pump which expends energy to do that, and that energy produces further waste heat which, yes, we also need to move. This is a core principle of how our universe works. Nobody is going to invent a new material that violates the laws of thermodynamics, for the same reason nobody is going to find an even integer that was hiding between 2 and 4 somehow without us noticing it.
- grishka 5y ago> In this universe the laws of thermodynamics specifically forbid destroying heat, or converting it into something else. But wait, what does a Stirling engine run on? Or a steam engine? You clearly can get some energy out of heat. Also, objects that are hotter than absolute zero radiate infrared light — and you, in principle, could convert light, regardless of its spectrum, into electricity.
- bernulli 5y agoThey run on temperature differences, that's how you get usable energy out of it. Google Carnot engine, there's even a super simple way to find the maximum efficiency just from the temperatures!
- SigmundA 5y agoTemperature difference is caused by heat. A heat engine converts heat into mechanical work. A Carnot heat engine is an idealized form of heat engine vs say a Diesel heat engine. You can most certainly convert heat into something else. It's called the law of conservation of energy, not heat, which is just one form of energy.
- grishka 5y agoOr you could have a battery and store that energy to supply your house with electricity, thus reducing your bills.
- Meandering 5y agoHeat is call "Low Quality" energy in thermodynamics. Heat is basically disorganized particle movement. It is very hard to convert disorganized energy to organized energy like electrical current.