91–100 of 174 posts
A possible application of this would be backup power for fuel based heating, so that as long as you have fuel, you can get enough power to run the fans and controls. For an energy storage system, though, 40% makes little sense.
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In a heat-based system couldn't you use more cells to absorb remaining heat?
Adding more cells won’t help for two reason. Let’s say the extra cells would help absorb, they can only capture 40% which means you’ve got exponentially increasing costs chasing after all the heat you didn’t absorb (+ physical location of where to put the cells). The real reason though is physics, namely the 2nd law of thermodynamics. If you could keep adding cells to capture the heat other cells couldn’t, you’d basi…
A source of free energy, a "perpetual engine", is indeed impossible.
Could this be used to create a nuclear power generator without moving parts? Some radioactive material in the center, some coating to absorb the radiation, and a shell of these cells to generate electricity.
https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_...
There’s a story about some loggers finding an abandoned RTG in Siberia and sleeping next to it for warmth. They woke up with severe radiation burns.
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And we also have this looming thing called climate emergency, which should conceivably motivate us to forge ahead with renewables and adjust our energy usage patterns to match production peaks, lest we doom humanity to extinction
I feel like this is one of the biggest missed opportunities. Why do we insist on our energy system to be infinitely flexible and full power available 24/7? Is a habit of doing the laundry at night worth more than additional millions of tons of CO2 in the atmosphere? I understand convenience, laziness and inertia (resisting change) but I also think changing the times when we click "power on" is a simpler solution than…
I like to heat my home during winter. We have a (modern, highly efficient) heat pump, so we need most electricity during January, just when the least amount of solar insolation is available [1] and when it sometimes stays cloudy and below 0°C continuously for days. But I guess we'll just have to be more flexible and turn off heating, light, and electricity in general for a week, no big deal.
[1] I wonder if there's a causal relation between cold weather and low solar insolation?
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They don't ever run those close to this hot, right? There's barely any turbine blade materials able to withstand half those temperatures. At those temperatures, even the best alloys lose a large percentage of their strength. And also, steam this hot is incredibly corrosive.
Gas turbines typically are limited to ~1300C to limit NOx production. However, if you have another heat source that doesn't involve combustion, that limit is taken away. And then you can run the whole thing hotter (increasing efficiency substantially). There is no need for blades to withstand the combustion temperature, because film cooling can keep blades far cooler in high speed laminar gas flow. The challenge is t…
As far as I know, combustion isn’t required for NOx formation. If you want to run hotter without producing NOx, you need to eliminate either nitrogen or oxygen. IIRC there are a couple of proposed designs for doing this: combustion in nitrogen-depleted air and chemical looping combustion.
Could this be used to create a nuclear power generator without moving parts? Some radioactive material in the center, some coating to absorb the radiation, and a shell of these cells to generate electricity.
Yeah, that’s a radioisotope thermoelectric generator: https://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_... There’s a story about some loggers finding an abandoned RTG in Siberia and sleeping next to it for warmth. They woke up with severe radiation burns.
Earlier quoted context omitted.
Gas turbines typically are limited to ~1300C to limit NOx production. However, if you have another heat source that doesn't involve combustion, that limit is taken away. And then you can run the whole thing hotter (increasing efficiency substantially). There is no need for blades to withstand the combustion temperature, because film cooling can keep blades far cooler in high speed laminar gas flow. The challenge is t…
> Gas turbines typically are limited to ~1300C to limit NOx production. However, if you have another heat source that doesn't involve combustion, that limit is taken away. As far as I know, combustion isn’t required for NOx formation. If you want to run hotter without producing NOx, you need to eliminate either nitrogen or oxygen. IIRC there are a couple of proposed designs for doing this: combustion in nitrogen-depl…
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We already have a fusion reactor at a relatively safe distance called the sun.
This looks like it has about 100x higher power density than what solar PV gives at peak. Combine that with 100% uptime and deployment pretty much anywhere, that are some pretty compelling advantages.