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Post by besoeker3 on Apr 12, 2023 14:36:49 GMT
I have given you explicit answers. Now why does Germany not use energy from hot sand? You told me it is expensive to heat sand to 1700C. I disagree. You would get 100% efficiency converting from electrical energy into heat and you can do it via simple ohmic heating. If you make a claim it is expensive, then don't expect me to just take your word for it. I don't consider you as a a reliable reference. So why don't we use sand for hearing if it is that prolific? It is world wide not just British. Your move sunshine. |
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Post by Baron von Lotsov on Apr 12, 2023 14:48:27 GMT
You told me it is expensive to heat sand to 1700C. I disagree. You would get 100% efficiency converting from electrical energy into heat and you can do it via simple ohmic heating. If you make a claim it is expensive, then don't expect me to just take your word for it. I don't consider you as a a reliable reference. So why don't we use sand for hearing if it is that prolific? It is world wide not just British. Your move sunshine. You mean heating I presume. Well we do. We use a similar principle for storage radiators, although I can't say whether it is sand or some other substance, but the principle is the same.
The higher the temperature the greater the conversion efficiency back to electrical energy and higher energy storage density, hence why 1700C. It's a good number to use. |
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Post by besoeker3 on Apr 12, 2023 15:10:03 GMT
So why don't we use sand for hearing if it is that prolific? It is world wide not just British. Your move sunshine. You mean heating I presume. Well we do. We use a similar principle for storage radiators, although I can't say whether it is sand or some other substance, but the principle is the same.
The higher the temperature the greater the conversion efficiency back to electrical energy and higher energy storage density, hence why 1700C. It's a good number to use. Well your claim was about sand and the 1700C and I don't know that is any applications with those. Yes, we do have radiators for domestic applications but those are typically around 40C. And they don't have electrical storage.. |
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Post by patman post on Apr 12, 2023 16:00:02 GMT
Isn’t the melting point of Sand 1577 °C?
Silica’s would be high if around in sufficient quantities…
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Post by jonksy on Apr 12, 2023 16:16:15 GMT
Perhaps he means temperature. I can't think how that would work well if he did Super conductors. We don't have the means the money or the technology to make this option viable. If we did electricity would last for ever going around in a loop that would have to be kept at minus 200 degrees C or even less. |
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Post by jonksy on Apr 12, 2023 16:18:31 GMT
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Post by besoeker3 on Apr 12, 2023 16:19:53 GMT
Isn’t the melting point of Sand 1577 °C? Silica’s would be high if around in sufficient quantities… Apparently to make sand melt, you need to heat it to roughly 1700°C (3090°F), Not my forte.Power electronics for me is usually 125C. |
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Post by Baron von Lotsov on Apr 12, 2023 16:52:29 GMT
You mean heating I presume. Well we do. We use a similar principle for storage radiators, although I can't say whether it is sand or some other substance, but the principle is the same.
The higher the temperature the greater the conversion efficiency back to electrical energy and higher energy storage density, hence why 1700C. It's a good number to use. Well your claim was about sand and the 1700C and I don't know that is any applications with those. Yes, we do have radiators for domestic applications but those are typically around 40C. And they don't have electrical storage.. You use a heat engine to convert the heat to mechanical power and then use a generator. The higher the hot temperature the greater the efficiency. It's all about entropy. Electricity has a lower entropy than heat which is the highest entropy energy, and that is why all forms of energy will eventually find their way to heating something up, even if it is light. This is in accordance to the second law of thermodynamics applied universally. So the trick is to keep the energy as ordered as possible so it can convert more efficiently into electricity, and once you have the electricity you can use it for anything just via a wire. You save in all that gas pipework. You use a heat pump at the other end if you want heat. This will more than double up the heat you get. The law is disordered can not go to ordered, the best you can do is keep the order unaffected. That's you optimum efficiency, delta S = 0. |
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Post by besoeker3 on Apr 12, 2023 17:48:55 GMT
Well your claim was about sand and the 1700C and I don't know that is any applications with those. Yes, we do have radiators for domestic applications but those are typically around 40C. And they don't have electrical storage.. You use a heat engine to convert the heat to mechanical power and then use a generator. What kind of heat energy did you have in mind? |
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Post by Toreador on Apr 12, 2023 19:47:39 GMT
Isn’t the melting point of Sand 1577 °C? Silica’s would be high if around in sufficient quantities… Sand will melt at 1700C, it's how fiberglass is made. Once in a liquid state, it's spun just like candy floss. |
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Post by Baron von Lotsov on Apr 13, 2023 10:19:35 GMT
Isn’t the melting point of Sand 1577 °C? Silica’s would be high if around in sufficient quantities… Sand will melt at 1700C, it's how fiberglass is made. Once in a liquid state, it's spun just like candy floss. I know. That's why I chose that number to do the calculations. Much hotter than that you run into engineering problems because the thing holding it might melt. |
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Post by Orac on Apr 13, 2023 10:39:26 GMT
The sand will be white hot and radiating like crazy. My intuition tells me you would be far better off selecting a much lower temperature - say 400 C
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Post by Red Rackham on Apr 13, 2023 14:31:38 GMT
Here's the problem. We could have cheap energy if only we want to use it at certain times of day or times of year. Wind and solar are definitely cheaper than burning hydrocarbons, but we need to store it. For solar you get 10x the energy in the peak of summer as you do in the middle of winter. That's a huge amount of energy to store if you need to store the summer energy for using to heat in winter. You can reduce the storage needs if you configure industry to use the energy when it is plentiful (=cheap) but you don't really win because you really need to run your industry without these constraints or it will become inefficient. So here's the question - how can we store all of this energy and how do we propose to deal with it? Electricity storage is the holy grail, the fact that electricity cant be stored is the reason renewables are expensive and unreliable. As soon as someone comes up with a way of storing electricity in such volumes to satisfy industry and domestic users then costs will fall. However, I suspect that wont be for decades yet. As an aside, at the power station I used to work at excess electricity was 'dumped' or pumped down an earthing spike into the ground. |
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Post by besoeker3 on Apr 13, 2023 14:39:57 GMT
Electricity storage is the holy grail, the fact that electricity cant be stored is the reason renewables are expensive and unreliable. As soon as someone comes up with a way of storing electricity in such volumes to satisfy industry and domestic users then costs will fall. However, I suspect that wont be for decades yet. As an aside, at the power station I used to work at excess electricity was 'dumped' or pumped down an earthing spike into the ground. That's exactly right, old fellow. Electricity isn't stored. Energy can be. |
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Post by Baron von Lotsov on Apr 14, 2023 11:30:40 GMT
The sand will be white hot and radiating like crazy. My intuition tells me you would be far better off selecting a much lower temperature - say 400 C Your efficiency roughly halves at that temperature. You would waste more than your stored. Yes it would radiate like crazy, but you can devise insulation that insulates like crazy .You can use some of the tricks employed on low temperature physics. For radiation you reflect it, and then the bit that gets through you reflect again and so on. |
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