Introduction and Structure - Renewable Energy: Technology, Economics and Environment - page 5

considerable increase. It is also perceivable that the increase is by far not linear,
but has been noticeably influenced by the two oil price crises in 1973 and
1979/80. Also at the beginning of the 1990's, the increase of the worldwide en-
ergy consumption slowed down significantly. This is partly attributable to the
downturn of the global economy and the restructuring of the former Eastern block
including the former USSR. At the same time a significant increase of fossil pri-
mary energy consumption could be perceived for Asia. Only towards the middle
of 1990's, the worldwide primary energy consumption started to increase again
more quickly. Towards the end of the 1990s the increase of the primary energy
consumption slowed down again to increase noticeably at the beginning of the
first decade of the 21 st century.

500

450

400

Asia-
Pacific

350

300 Africa

Middle East

250

Europe and
Eurasia

200

150

Central- and
South Amerika

100

North-
America

50

0

65 70 75 80 85 90 95 00 05

Time in years

Fig. 1.2 Evolution of the worldwide consumption by regions of fossil primary energy car-
riers and hydropower (data according to /1-3/)

In 2005, the overall energy consumption of fossil energy carriers and hydro-
power was covered by 36 % by crude oil, by 24 % by natural gas, by 28 % by coal
and always by 6 % electrical energy generated by nuclear and hydropower respec-
tively. On a regional level these fractions are strongly dependent on local and na-
tional characteristics due to varying national energy politics or available primary
energy resources differing from region to region (Fig. 1.3). For instance, in Asia
the major share of the given demand for fossil primary energy carriers is covered
by coal (this applies in particular to the People's Republic of China), whereas this
energy carrier is of almost no importance in regions such as the Middle East. Due
to the abundance of crude oil and natural gas mainly liquid and gaseous fossil hy-
drocarbons are used. In line with this observation, the high use of natural gas in
Russia is attributable to its abundant natural gas resources.