Anti-solar panels pointed at space could generate power at night

[wiyosaya]

So sad to see respected sites like TechSpot and Extreme Tech repeating this garbage science. Solar panels don't produce electricity because "they're colder than the sun".

I guess you have a degree in basic thermodynamics, then? Pretty simple and basic thermodynamics. An engine cannot produce any work if its temperature is hotter than its sink. For your edification - https://en.wikipedia.org/wiki/Carnot_cycle

It amazes me how many come to TS that pretend to know something they don't.

It's pretty obvious that solar panels would not work if they were hotter than the sun.

 

[JimboJoneson]

...
It's pretty obvious that solar panels would not work if they were hotter than the sun.

Lol, yes, I agree with your sentiment.

At the same time, I do get dmeader's and others' complaint - which apparently was about they way it was written (yet that had to be assumed because of the way dmeader wrote his post); that the reason solar panels work is "because they aren't as hot as the sun". As I mentioned earlier this is toddler level description and I don't know how it ended up in the article written like this. That part I think is a somewhat valid complaint.

Everything is not hotter than the sun, but not everything creates electricity from solar energy, so even the "toddler level" description in the article simplifies it to the point of inaccuracy.

 

[Dmeader]

Look, here's what I meant. Solar panels generate electricity via the photovoltaic effect where a photon of light knocks an electron loose that flows off into a wire. What the article is attempting to describe is a thermal effect, harvesting heat from a warmer source like the panels people put on their roof to heat water. The article somehow conflates the two principles into one without clearly explaining either or how and if they are supposed to work together. I see that they have added an "in a nutshell" piece at the top which helps some, but even after edits the article is still poorly constructed, confusing, and shouldn't have been put up as it is now. THAT"S what I was criticizing, not solar energy.

Anyway, I don't see how it could work in the first place. A hot body absorbing energy from a cold body is not how I thought the second law of thermodynamics worked. Now, if you could design a panel that, via the photoelectric effect, could capture an IR photon and cause an electron to be liberated, well, then you might have something.

 

[John Galt]

Anyway, I don't see how it could work in the first place. A hot body absorbing energy from a cold body is not how I thought the second law of thermodynamics worked. Now, if you could design a panel that, via the photoelectric effect, could capture an IR photon and cause an electron to be liberated, well, then you might have something.

There are a couple of ways. All heat engines work on the same principle - interpose an "engine" of some kind between a hot and cold sources, harness some of that heat transfer (usually inefficiently), and convert it to another form (heat into pressure as in steam, or heat into electricity directly to be used in any number of ways remotely or locally).

Physics says all energy is fundamentally exchangeable (a neat trick if you can pull it off without losses). Thus, the photovoltaic effect COULD be thought of as a kind of heat engine too. Other processes DO directly convert heat to electricity - see RedWave technologies. I got so interested in that I went and visited Steven Novak, the original project manager who got the roll to roll printing process to work for the nanoantennas. So, it is theoretically possible to interpose "something" between a heat source and a cold sink and to capture some of the energy transfer. A process like theirs could be the holy grail of solar if they can scale the nanoantennas down small enough to capture visible light.

But - of course - I don't actually know what the author meant. They could have simply been wrong!