OK, so following that analogy, the electrons get excited, but have no place to go, so new incoming photons can’t excite them anymore, and it’s no different than if the photons had just hit my roof shingles.
I’m still curious about the heat thing. When a photon hits a non-connected solar panel, or just my roof, all of it’s energy (that isn’t reflected) is converted to heat. Does that mean a functioning panel is cooler, because some of that energy is instead converted to electricity?