Heating houses by sunlight
When is it appropriate to use PV cells?
- PV cells are particularly appropriate in situations where maintenance is difficult, as they dont have any moving parts. For example, lighthouses in the UK are being converted to solar electricity, because its easier and cheaper to maintain PV cells than diesel generators in inaccessible, stormy places.
- PV cells are ideal for calculators, which need a tiny amount of power and are used in daylight.
- In many isolated parts of Africa, there is little water and not enough wind to generate electricity. The only choices are to use diesel generators or PV cells, and in the long run PVs often prove cheaper.
- To produce large-scale power, PV cells can be put on south-facing roofs in built-up areas. The electricity can then be used in the buildings and any extra fed into the mains. In a project near Amsterdam, 2500 square metres of solar cells have been put on the roofs of 72 houses, delivering 200,000 kilowatt-hours per year (enough for 150 families).
However, PV cells are not always an appropriate solution and in Europe it is important to investigate wind, tidal and other energy sources, which work when there is less sunlight and are much cheaper.