Solar heating
Solar energy is energy from the sun.
It arrives on Earth from the sun as light energy and heat energy.
It can be used to generate electricity or heat water.
Solar cells
Solar cells are devices that convert light energy directly into electrical energy.
Small solar cells are used to power calculators.
Larger arrays of solar cells are used to power roadside speed warning signs, parking ticket machines and satellites in orbit around Earth.
Light energy from the sun \(\rightarrow\) electrical energy.
Advantages
- Solar energy is a renewable energy resource and there are no fuel costs.
- No harmful polluting gases are produced.
Disadvantages
- Space is needed for installing solar cells.
- Solar cells do not work at night.
Solar panels
Solar panels are devices that make use of heat energy from the sun.
Solar panels do not generate electricity, but rather they heat up water.
They are often located on the roofs of buildings where they can receive heat energy from the Sun.
The diagram outlines how they work:
Cold water is pumped up to the solar panel, it heats up and is transferred to a storage tank.
Heat energy from the sun \(\rightarrow\) heat energy of the water.
Advantages
- Solar energy is a renewable energy resource and there are no fuel costs.
- No harmful polluting gases are produced.
Disadvantages
- Solar panels only produce very hot water in very sunny climates.
- Solar panels do not work at night.