Environmental Engineering Reference
In-Depth Information
1. other
renewables
0.4%
1
2. nuclear 6.5%
2
3. natural gas
20.9%
3
7
4. large hydro
2.2%
4
6
5
5. coal 25.1%
6. biomass and
waste 10.6%
7. oil 34.3%
Figure 1.1
Percentage contribution to world primary energy
consumption. The pie chart in Figure 1.1 shows the percentage contribution to world primary
energy from the different energy sources according to data taken from the International
Energy Agency (IEA) Key World Energy Statistics, 2006.
The world demand for oil and gas is increasing signifi cantly each year. The major part of
this increase is currently taken up by India and China where industrialization and the demand
for consumer products is escalating at an unprecedented pace. The world consumption in
2006 increased by more than twice Britain's total annual energy use and is the largest global
yearly increase ever recorded. China alone accounted for roughly 40% of this increase. The
IEA forecasts that by 2030 demand for energy will be some 60% more than it is now.
1.1.3 Finite Resources
It is extremely diffi cult to determine precise fi gures on the ultimate availability of fossil fuels.
According to the major oil and gas companies, still signifi cant new resources of oil are being
developed, or remain to be discovered. A safe assessment is that there is enough oil from
traditional sources to provide for the present demand for 30 years. The latest fi gures for global
gas reserves indicate that these are approximately 50% higher than oil at some 60 years of
current demand, and gas is far less explored than oil so there is probably more to be found.
There are, however, unconventional hydrocarbon resources such as heavy oil and bitumen,
oil shale, shale gas and coal bed methane - whose total global reserves have been assessed
very roughly to be three times the size of conventional oil and gas resources. These are more
expensive to extract but may become exploitable as the price of fossil fuels increases due to
the steady depletion of the more easily accessible reserves. Fortunately for fossil fuel depen-
dent economies, coal reserves are considered to be many times those of oil and gas and could
