Solar power producing heat
4 marks · NormalFigure 1 shows a diagram of a simple solar heating panel.
Name the main energy transfer that takes place in the solar heating panel.
Suggest one reason why the pipes in the panel are often painted black.
Describe one way the panel’s design helps to reduce heat loss to the surroundings.
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(a) thermal (infrared) radiation to heat · must show thermal radiation (from Sun) heats the water
(b) to absorb more heat · must show increases absorption of radiation/heat
(c) glass cover or insulation · must show glass cover traps heat, insulation at the back/sides reduces conduction/convection losses
Show mark scheme and worked solution
Marking points
A1 (a) · 1 mark · Correctly identifies energy transfer as thermal/infrared radiation heating water.
A2 (b) · 1 mark · States black pipes absorb more heat/infrared radiation.
M1 (c) · 1 mark · Identifies a way to reduce heat loss (e.g., insulation/glass cover).
A3 (c) · 1 mark · Explains HOW this reduces heat loss (e.g., 'glass traps radiation', 'insulation slows conduction').
Worked solution
a) The main energy transfer is thermal radiation from the Sun being absorbed and then heating the water.
b) Black pipes absorb more heat energy from the Sun because black is a good absorber of thermal radiation.
c) The panel may have a layer of insulation at the back/sides to prevent heat loss. A glass cover on the front also helps trap heat by preventing loss of thermal energy by convection and reducing infrared emission.