An engineer designs a hybrid photovoltaic-thermal (PVT) solar collector by attaching a water-cooling pipe system to the back of a standard silicon solar panel. The flowing water absorbs thermal energy, reducing the operating temperature of the solar panel and providing hot water for a building.
How does the addition of this water-cooling system affect the electrical efficiency of the silicon panel and the overall efficiency of the PVT collector?
Both the electrical efficiency of the panel and the overall efficiency of the PVT collector decrease because energy is diverted to heat the water.
The electrical efficiency of the panel decreases due to the cooling effect, but the overall efficiency of the PVT collector increases because of the useful thermal output.
The electrical efficiency of the panel increases because silicon solar cells operate more efficiently at lower temperatures, and the overall efficiency of the PVT collector increases.
Both the electrical efficiency of the panel and the overall efficiency of the PVT collector remain unchanged, as the total energy of the system is conserved.