Yes, but it works at night!

Not sure if you can get the MTBF on Stirling engines higher than on LFP batteries, though.

And in the day time, if transparent and applied to solar panels, the "efficiency" gain (~10W psqm) itself will dwarf other considerations.( Remembering that bulk of radiative cooling shouldn't happen below ~1300nm) And then there's beating the efficacy of carbon capture at mitigating warming by orders of magnitudes

Nothing to sneeze at. Just be careful of midbrow high-effort dismissals from the old and wise:)

These guys are applying them to solar panels:

https://www.i2cool.com/tideflow/uwJVdixI.html

  "Case Study 2: Solar Farm in Dubai
  Problem: Solar panels lost 15–20% efficiency at 55°C+ temperatures.
  Solution: Coated panels with i2Cool’s film.
  Results:
  Panel surface temperature: ▼25.7°C (from 58°C to 32.3°C)
  Power output: ▲8% (equivalent to adding 2,400 new panels to a 30MW farm)"

Thanks, that's staggering!

RF energy harvesting in urban areas results in about 0.5-5 mW/m^2. I would guess it would be about 1-2 orders of magnitude less in rural areas.

This is like shaving nickels to make money.

Certainly, there are better energy sources like the fusion reactor in the sky and building a fusion reactor (that's perpetually 30 years away).

TIL: Active nuclear reactors of all types around the world are mappable using antineutrino detectors. It would probably also expose the location of every stationary nuclear-powered ship and submarine too.

>400 milliwatts per square meter of mechanical power with a potential for >6 watts per square meter.

What miracle gets a Stirling engine to be 15x more efficient? Stirling engines have been around for over a century.