Environmental Engineering Reference
In-Depth Information
longer distances, and interconnections mushroomed to
embrace centrally controlled systems with capacities of
10
1
-10
2
GW.
The only major departure from earlier trends was the
location of fossil-fueled power plants away from cities, a
shift spurred by stronger air pollution regulations and
scale economies of huge mine-mouth stations. In fact,
post-WW II growth has been so rapid that some compo-
nents of power generation clearly overshot the opera-
tional optima. Global generation has grown smoothly,
with just a short break in the early 1930s. Between
1900, when worldwide output was about 8 TWh, and
1930, when it stood at 180 TWh, the average annual
expansion rate was approximately 10.5%, and between
1935 and 1970 just over 9%. Later the growth was
roughly halved, to 4.5% for the years 1970-1985, a
reflection of declining demand throughout
During the first century of fossil-fueled electricity gen-
eration, installed capacities of the largest power plants
rose from a few hundred kW to several GW, and individ-
ual utilities grew from enterprises serving a handful of
city blocks to regional and national systems with capaci-
ties up to 10
10
-10
11
W serving areas of 10
4
-10
6
km
2
.
Moreover, international interconnections in Europe and
North America make it possible to trade electricity at
multi-GW levels on semicontinental scales. But electricity
trade amounts to less than 5% of global generation, and a
large part of it derives from one-way sales of hydroelec-
tricity (see section 9.2). In contrast, international fuel
sales have steadily increased. During the early years of
the new century, some 15% of coal, nearly 60% of crude
oil, and 25% of natural gas, amounting to some 120 EJ
(or one-third of global
fuel extraction), were traded
the rich
internationally.
Coal exports are dominated by fuel for electricity gen-
eration (steam coal) while coking coal sales have steadily
declined; by 2005 they were only about one-quarter of
the traded total. The fuel is now the world's most impor-
tant seaborne dry-bulk commodity (after surpassing iron
ore), and hence its exports set the freight market trends.
Australia, with more than 200 Mt of steam and coking
coal shipped annually, is the world's largest exporter, fol-
lowed by Indonesia, Russia, South Africa, and China
(WCI 2006). Japan is the largest importer of steam and
coking coal (over 150 Mt by 2005), followed by the
South Korea, Taiwan, and in a shift unforeseeable a gen-
eration ago, by the two former leading coal producers,
Germany and Britain, using cheaper foreign coal for elec-
tricity generation.
Crude oil leads the global commodity trade both
in terms of mass and value. In 2005, 47% of total crude
oil production (just over 1.8 Gt) was sold abroad, and
world.
The roles of primary electricity in this growth (hydro-
generation, geothermal, nuclear, solar) are appraised
in section 9.2. Although many countries have always
produced most of their electricity from falling water,
fossil-fueled generation has been globally dominant, ac-
counting for just short of 60% in the 1920s, 67% in
1950, 70% in 1975, and just over 60% in 2000 (the rela-
tive decline was caused largely by rising nuclear genera-
tion). Assuming an average e
1
of 33% global fossil-fueled
electricity generation would have consumed about 30%
of worldwide production of fossil fuels in 2000. Fossil-
fueled electricity generation is even more unequally dis-
tributed than fuel extraction. In 2000 the U.S. share
was nearly 30% of the world's fossil-fueled generation,
and the five largest producers (United States, China, Ja-
pan, Russia, and India) claimed about 57% of the world
total.
