You'll get better efficiency running a Stirling engine from a lightweight solar collector. I actually wonder how it would compare if you equalize the weight.
Conventional solar cells also suffer from decreased efficiency (-0.45%/°C) as temperature increases, a the inclusion of TEGs could help dissipate this waste heat while simultaneously increasing solar panel efficiency.
I've done research on exactly this, and the efficiencies of TEGs makes this a tough prospect. It started to work out in our favor when using concentrated solar to reduce the amount of paneling needed, but that's no longer an economic driver, and you get a much better return on investment by skipping the TEGs and just plopping a few extra panels down in a lake.
Minor correction/note: most modern modules/cells have a temperature coefficient in the range of approx. -0.27 to -0.35%/°C. A little better than -0.45%.
See fig 14 in [1] for data through 2021/22, and then the more recent transition to n-type cells is helping more [2]. This database [3] doesn't list module release date, but filtering for modules with STC rating over 500 W (decent proxy for "modern") gives an average of -0.34%°C, with a lot at or better than -0.30.
That's still 2.5 watts per square meter in direct sun, 0.5 watts per square meter as a round-the-clock average. More than enough to keep your cellphone charged with a square meter. A section of a farm is 2.6 million square meters.
The bigger question is not what its efficiency is, which is to say, how much sunlight it needs per watt, but what its material consumption is—how much bismuth it needs per watt. Sunlight is abundant; bismuth isn't.
Thermoelectric devices are interesting because they can be manufactured using comparatively simple metallurgy. Not because their efficiency is competitive with semiconductor photovoltaics.
Solar panels enabling offgrid power is tagcloud-related to surviving human civilization collapse.
We're entering an era of decreased globalism, where megacorporation scale actually becomes a danger to society due to reduced warehousing/stockpiling and long extended supply lines, and of course offshored manufacturing that goes with that.
You'll get better efficiency running a Stirling engine from a lightweight solar collector. I actually wonder how it would compare if you equalize the weight.
Conventional solar cells also suffer from decreased efficiency (-0.45%/°C) as temperature increases, a the inclusion of TEGs could help dissipate this waste heat while simultaneously increasing solar panel efficiency.
I've done research on exactly this, and the efficiencies of TEGs makes this a tough prospect. It started to work out in our favor when using concentrated solar to reduce the amount of paneling needed, but that's no longer an economic driver, and you get a much better return on investment by skipping the TEGs and just plopping a few extra panels down in a lake.
Minor correction/note: most modern modules/cells have a temperature coefficient in the range of approx. -0.27 to -0.35%/°C. A little better than -0.45%.
See fig 14 in [1] for data through 2021/22, and then the more recent transition to n-type cells is helping more [2]. This database [3] doesn't list module release date, but filtering for modules with STC rating over 500 W (decent proxy for "modern") gives an average of -0.34%°C, with a lot at or better than -0.30.
[1] https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p... [2] https://www.nrel.gov/docs/fy22osti/82871.pdf [3] https://github.com/NREL/SAM/blob/patch/deploy/libraries/CEC%...
Efficiency of 0.25%. Like a dancing bear, the amazing thing is that it dances at all, not that it dances well.
That's still 2.5 watts per square meter in direct sun, 0.5 watts per square meter as a round-the-clock average. More than enough to keep your cellphone charged with a square meter. A section of a farm is 2.6 million square meters.
The bigger question is not what its efficiency is, which is to say, how much sunlight it needs per watt, but what its material consumption is—how much bismuth it needs per watt. Sunlight is abundant; bismuth isn't.
But presumably it can be improved.
Or just cover 1% of that area with PV.
Can you make PV at home?
Thermoelectric devices are interesting because they can be manufactured using comparatively simple metallurgy. Not because their efficiency is competitive with semiconductor photovoltaics.
Perovskite solar cells could be and dye sensitized solar cells can be[0]. The better question is why should one make solar cells at home?
[0]https://www.instructables.com/How-to-Build-Use-A-Dye-Sensiti...
Solar panels enabling offgrid power is tagcloud-related to surviving human civilization collapse.
We're entering an era of decreased globalism, where megacorporation scale actually becomes a danger to society due to reduced warehousing/stockpiling and long extended supply lines, and of course offshored manufacturing that goes with that.
> Can you make PV at home?
https://hackaday.com/2018/01/26/home-brew-solar-cells-for-th...
Not anywhere near as efficient as commercial PV cells, of course.
This is by the same person as the OP btw (and linked in the original article).
You can make Schottky solar cells too with bismuth but as others have pointed out optimum operating temperature is different for thermoelectrics.