https://phys.org/news/2019-11-self-assembled-microspheres-silica-cool-surfaces.html
"...Self-assembled microspheres of silica to cool surfaces without energy consumption
...
Cooling systems account for 15% of the global energy consumption and are responsible for 10% of greenhouse gas emissions.
...
novel two-dimensional material able to remove heat, cooling down the surface in which it is placed without energy consumption or gas emissions of any kind.
...
The material is inspired by the Earth's efficient temperature-regulation mechanism, named radiative sky cooling. Although the Earth is heated by the Sun, it also emits infrared radiation to the outer space, as this kind of radiation is not captured by the atmosphere...."
It is also possible to, without consuming energy, artificially generate radiative sky cooling to create a temperature difference that then can be used to generate electricity for the national grid; -a strange kind of 'back-to-front' alternative addition to solar power and one that can work even at night (and would work much better at night anyway).
@humy
Of course such solar systems would have to tune to IR frequencies which have a lower intensity but I guess it could work but we wouldn't see the 13mw/ha hitting the ground. and then 20% efficiency cells so maybe 3Mw/Hectare or so during daylight hours. If we got to 40% efficiency, 6 Mw/hectare.
I can see where you could have a dual sided solar cell, sunlight incoming to sun facing solar cells and on the other side of the cells, an IR tuned set of cells to capture outgoing radiation. It looks to me like the incoming daylight sun would give a LOT more energy per hectare than the downward facing IR cells though. So would the effort be worth it? I suppose if you reduce heating even by 1 % you have achieved something.
There would have to be massive ground installations to do any good plus power infrastructure if the systems were in the deserts around the planet. That is a huge project in itself, just building those high voltage power grid lines and towers.
Still, it could work. My guess is the IR side of the coin would still produce quite a bit of power by itself besides the topside getting direct sunlight so it would produce power during the day and during the night.