Solar power producing heat
4 marks · NormalA student suggests painting the inside of a solar panel white instead of black.
Predict the effect this would have on the efficiency of the panel.
Explain your prediction.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Efficiency would decrease · must show efficiency decreases
(b) — · must show white surfaces reflect more heat, less radiation absorbed, less energy transferred to water
Show mark scheme and worked solution
Marking points
A1 (a) · 1 mark · Predicts efficiency would decrease if panel painted white.
M1 (b) · 1 mark · Explains that white surfaces reflect more radiation/heat.
M2 (b) · 1 mark · States less radiation/heat would be absorbed by the panel.
M3 (b) · 1 mark · Links this to less energy being transferred to the water.
Worked solution
a) The efficiency of the panel would decrease.
b) White surfaces reflect more thermal radiation, so less of the Sun’s energy would be absorbed. As a result, less heat energy is transferred to the water inside the panel, making the panel less efficient.