Environmental Engineering Reference
In-Depth Information
Figure 1.10). This availability could drop further if there is an increase in annual
production. New deposits are being exploited in addition to known supplies. It is
estimated that the reserves will increase up to one-half times due to these additional
supplies. If production remains constant over the next few decades, the oil reserves
will last another 65 years. However, it is certain that we will no longer be using oil
as an energy source at the end of this century.
207
hard coal
198
lignite
64
natural gas
43
crude oil
42
uranium
0
50
100
150
200
years
250
Figure 1.10
Extent of availability (in years) of known energy reserves based on current
production.
The situation with natural gas and coal supplies is not quite so critical. Based on
current production levels, the known gas supplies will be depleted in 64 years. In
contrast to oil, the estimated additional supplies are considerably more extensive
than those known to date. This is partly because the deposits are located at a lower
depth than oil and also because industrial production and the search for new supplies
began much later. However, due to the continuing high level of consumption, natural
gas supplies will also be running out during this century. Coal is the only fossil fuel
that may still be available at the dawn of the next century.
1.5 The End of Fission
A key point about fuel supply, and one that most people are unaware of, is that even
uranium supplies are very limited. Although there is more uranium in the earth's
crust than either gold or silver, less than one percent of the purest natural uranium
can be used to create energy. Power stations can only use natural uranium after the
useable part of uranium has been enriched with uranium-235.
The share of ore must be higher than average to enable an effective exploitation of
natural uranium. Canada is the only country that has deposits with a uranium ore
content of more than one percent. If the uranium ore content drops, considerably
