The sun is the source of all energy supplies on earth
(with the exception of nuclear energy). Solar radiation brings heat and light to the earth.
We can use solar energy in three ways:
- By directly using the heat: dwellings and other buildings can be designed and built to make the most of the beneficial effects of the sun for heating in winter. That is what is called passive solar architecture.
Sunlight can also be used to heat buildings
as well as the water in water heaters and swimming pools. Such equipment is called an “active solar system”.
- By transforming light into electricity, by means of
photovoltaic cells.
- By transforming heat into electricity, using solar electric power plants and the high temperature process.
The energy we receive from the sun is intermittent: it stops during the night and in daytime it is often substantially restricted by clouds. Of course it varies depending on the latitude of the region, and the annual amount of sunshine received. But solar energy can be captured everywhere on the planet, including the most northerly countries. The energy received at the earth’s surface is known as the solar flux: it varies according to the place where it is measured. |