Environmental Engineering Reference
In-Depth Information
Fossil Energy Sources - Stored Solar Energy
Fossil energy sources are concentrated energy sources that evolved from
animal and plant remains over very long periods of time. These sources
include oil, gas, hard coal, brown coal and turf. The base materials for fossil energy
sources could only develop because of their conversion through solar radiation over
millions of years. In this sense, fossil energy sources are a form of stored solar energy.
From a chemical point of view, fossil energy sources are based on organic carbon com-
pounds. Burnt in conjunction with oxygen, they not only generate energy in the form of
heat but also always produce the greenhouse gas carbon dioxide as well as other exhaust
gases.
In around 1530, coal mines in Great Britain were producing about 200 000 tons of
coal annually. By 1750 it was about 5 million tons and in 1854 an astonishing 64
million tons. By 1900 three countries, Britain, the USA and Germany, had an 80%
share of world production (König, 1999).
Renewable Energies - Not That New
The supplies of fossil energies, such as oil, natural gas and coal, are limited.
They will be depleted within a few decades and then cease to exist. Renewable
energy sources, on the other hand, 'renew' themselves on their own. For example, if a
hydropower plant takes the power of the water from a river, the river will not stop
fl owing. The energy content of the river renews itself on its own because the sun evapo-
rates the water and the rain feeds the river again.
Renewable energies are also referred to as 'regenerative' or 'alternative' energies. Other
renewable energies include wind power, biomass, the natural heat of the earth and solar
energy. Even the sun will eventually disappear in around four billion years. Compared
to the few decades that fossil energy sources will still be available to us, this time period
seems infi nitely long.
Incidentally, renewable energies have been used by mankind for considerably longer
than fossil fuels, although the current systems for using these fuels are vastly more
advanced than in the past. Therefore, it is not renewable energies that are new but rather
the knowledge that in the long term renewable energies are the only option for a safe
and environmentally compatible energy supply.
At the end of the 20th century worldwide coal production reached almost 4 billion
tons. With an overall share of less than 3% of the world market, Germany and
Britain had lost their former position of supremacy in the coal industry. Today
power stations use most of the available coal. China and the USA are currently the
main coal-producing countries by a considerable margin.
1.1.2 The Era of Black Gold
Like coal, oil consists of conversion products from animal and plant substances, the
biomass of primeval times. Over millions of years plankton and other single-celled
