[Udik]

This makes me wonder how do you stop generating with a solar farm that is made of PV panels. They're entirely passive, right? The light hits them and they output electricity. How do you stop them?

I guess the process is somehow invertible, and once reached a certain static charge each panel stops absorbing energy?

In which case you're sort of already dumping the (non)produced energy in the environment- as heat, on each single panel?

[imtringued]

Photons excite electrons. If a photon doesn't have enough energy it will be reflected.

[beachy]

It's electricity. Break the circuit and it stops flowing.

[Udik]

When I stop a turbine I'm not simply breaking the circuit- I stop converting some fuel into energy, and keep it for later. If I break the circuit on a solar panel, the "fuel" keeps hitting the panel anyway. I guess the panel just reaches a different thermal equilibrium. Which is the same as dumping the energy in the ground, only more distributed.

[beachy]

According to this https://physics.stackexchange.com/a/71445:

> Electric power is the product of voltage and current. If there is no external circuit, there can be no current and thus no electric power can be delivered by the panel, i.e., the "electricity" is never developed and thus, there is no need to consider "where it goes".

There's also an interesting discussion in the linked post in more depth about electron hole-pairs.

My takeaway is that the temperature in the panel will not rise due to it absorbing any power that would otherwise go down the wires were the circuit complete.

[Udik]

Thanks for the find! The second comment to the first answer says:

"The equilibrium temperature of the connected panel should be slightly lower than the disconnected panel, because those hole recombinations introduce heat. But the efficiency is only something like 12% to begin with. So the temperature difference isn't like the difference between a white and black surface. More like the difference between a dark and slightly darker surface"