Solar panels are on the left and embeded to the wall, yes. THey are wired to the door, yes. door is at the bottom, yes.
The change is imminent, so you don't need to wait for boxes to heat up. They will start emitting themselves as soon as they are sunbathed. The panels are activated as long as they are sunbathed by enough amount of energy as well.
I will make the intensity of the light stronger so it will be more obvious that they are heating up. I might better upload one of the solutions, coming in a min.