Solar Panels for Heating Buildings
Solar panels come in two distinct types. The first type is where the sun heats water that is pumped through pipes on a roof. The other type consists of solar cells which convert the sun's radiation directly into electricity.
In this flashcard, we're talking about the first type - heating water in pipes. The panel which contains the pipes is usually a dark colour so that it absorbs the sun's radiation well (remember that dark, matt objects are good absorbers of infra-red radiation).
How does it work and what are the advantages of this method over, say, gas heating?
The sun's radiation is used to heat water directly during the day. This water can then be stored in hot water tanks and used either for supplying hot water to taps, or for heating a building by pumping it though radiators.
One advantage is that once the system has been installed, it is cheap to run with no fuel required - it's free energy! This renewable energy source means that fewer fossil fuels (non-renewable) will be needed to heat the building.
However, disadvantages are that the solar heating panels are expensive to buy and install. It may take several years to pay back the original cost of the system. Also, the panels will not heat water at night, or in bad weather.
GCSE Physics Keywords: Solar Heating Panel, Sun's radiation, Cost to run, Buy, Installation, Cost, Renewable