4 ms·

Thermoelectric generator. Take the differential and output a voltage? Why hasn't this been done? Why do we go to the steam stage when we could just exploit the

Thermoelectric generator. Take the differential and output a voltage? Why hasn't this been done? Why do we go to the steam stage when we could just exploit the termoelectric properties of temperature and current? 1. Thermoelectric generator: https://en.wikipedia.org/wiki/Thermoelectric_generator https://en.wikipedia.org/wiki/Thermoelectric_generator 2. Thermocouple https://en.wikipedia.org/wiki/Thermocouple https://en.wikipedia.org/wiki/Thermocouple 3. https://en.wikipedia.org/wiki/Thermoelectric_effect https://en.wikipedia.org/wiki/Thermoelectric_effect

snaily 4y ago
> The typical efficiency of TEGs is around 5–8% A steam turbine is many times more efficient.
- pyinstallwoes 4y ago
  But it has way more parts... And it moves. This other path has no moving parts.
lambdatronics 4y ago
It's been considered, for a variety of heat sources. I'm long-term bullish on a related technology (thermophotovoltaics), although presently the efficiencies are not great & the compatibility with nuclear radiation is probably poor.
- pyinstallwoes 4y ago
  It seems relatively accessible too, at least as a technology and conceptual model it shows a simplicity that allows the majority to get their hands on it and thus a potential for more growth and innovation. It’s interesting that it also allows refrigeration. If we could combine heating, refrigeration, with a configurable output of either end on top of it being a generator of voltage… is quite amazing.
  - lambdatronics 4y ago
    The power density is much higher than traditional photovoltaics (more in line with concentrating photovoltaic power), so in theory the cost should be low, although one probably needs more sophisticated cells to achieve reasonable efficiencies. On the other hand, since there are no moving parts, the temperature can be very high, which increases the maximum theoretical efficiency. (Carnot limit applies.) The major issues I can see are (1) achieving sufficient efficiency at a reasonable cost, by recycling the low-energy photons instead of absorbing them as heat (2) avoiding radiation damage to this sophisticated device - maybe this isn't too hard with a liquid salt heat exchanger?
    - pyinstallwoes 4y ago
      What about mercury?

snaily 4y ago

> The typical efficiency of TEGs is around 5–8% A steam turbine is many times more efficient.

pyinstallwoes 4y ago
But it has way more parts... And it moves. This other path has no moving parts.

lambdatronics 4y ago

It's been considered, for a variety of heat sources. I'm long-term bullish on a related technology (thermophotovoltaics), although presently the efficiencies are not great & the compatibility with nuclear radiation is probably poor.

pyinstallwoes 4y ago
It seems relatively accessible too, at least as a technology and conceptual model it shows a simplicity that allows the majority to get their hands on it and thus a potential for more growth and innovation. It’s interesting that it also allows refrigeration. If we could combine heating, refrigeration, with a configurable output of either end on top of it being a generator of voltage… is quite amazing.
- lambdatronics 4y ago
  The power density is much higher than traditional photovoltaics (more in line with concentrating photovoltaic power), so in theory the cost should be low, although one probably needs more sophisticated cells to achieve reasonable efficiencies. On the other hand, since there are no moving parts, the temperature can be very high, which increases the maximum theoretical efficiency. (Carnot limit applies.) The major issues I can see are (1) achieving sufficient efficiency at a reasonable cost, by recycling the low-energy photons instead of absorbing them as heat (2) avoiding radiation damage to this sophisticated device - maybe this isn't too hard with a liquid salt heat exchanger?
  - pyinstallwoes 4y ago
    What about mercury?