Environmental Engineering Reference
In-Depth Information
Plate 1
Solar panel providing household hot water in Myrthios, Crete.
Photo: Peter Smithson.
Much energy is received from the sun. It has been estimated that, on a global scale, ten
weeks of solar energy are equivalent to all the fossil fuel reserves on Earth. However, it is
effective only during daylight hours and cloud can reduce the quantities considerably. In
sunny climates, energy from the sun can be converted into heat by a solar panel (Plate 1)
for warming water or houses, or it can be converted into electricity using photovoltaic
cells.
Wind is also a potential source of energy, often in areas where solar energy potential is
less. It has been used from historical times when windmills ground corn or pumped water,
but now large-scale wind 'farms' have appeared to utilize the energy from moving air.
They are most effective where winds are steady and of moderate strength. In Britain they
are usually sited on high ground to take advantage of the higher wind speeds there, but in
low-lying Denmark there are proposals for offshore towers. Shortage of land sites and the
significantly higher speeds over the sea are reasons for this movement. At present most
power generation by wind is in the United States (mainly California), Germany, Denmark
and India. The use of wind power does have some environmental problems as well as
visual impact but in the right areas there is the potential to increase energy generation by
this method.
LANDSCAPE TRANSFERS
Many of these transfers influence landscape processes, for the movement of water
through the landscape is one of the main ways Earth's surface is altered and moulded.
