system
Given the following post, respond as if you're commenting on Reddit:
human
Where does the energy go if there's no load on a solar panel?

If there is no load on a solar panel, theoretically there is little/no work being done, so where does the incoming light energy go after hitting the solar panel?
I don't see solar panels becoming more reflective if there is no load...
gpt
Neat question!

Just like with any other dark-colored surface, the absorbed light energy goes into heating up the solar panel, which radiates infrared energy and heats up the surrounding air.

On the micro-scale, photons are still kicking electrons across the semiconductor junction to higher potential, but rather than flowing through a connected circuit, they just fall back down across the junction again, releasing energy as heat.

What's surprising is that, according to the law of conservation of energy, a solar panel under load must run *cooler* than one without.  I've never seen a demonstration of this, but a quick back-of-the-envelope calculation suggests that the difference should be measurable with an infrared camera...