I've not encountered discussions of solar panels in firefighter training, but my intuition suggests it's probably not a big deal. For nighttime fires, the panels won't be generating any electricity anyway. For daytime fires, smoke and water will likely occlude the panels and decrease their voltage. Firefighters ventilating the roof would need to be trained to avoid HVDC wires connecting a series-connected panel array to the inverter. We might also just lob foam onto the panels and turn them off that way.