Environmental Engineering Reference
In-Depth Information
Figure 9.16
Left: Stream in the area of the Donaukraftwerk Freudenau power plant in Austria.
Source:
www.verbund.at.
Fish bypass at Weserkraftwerk Bremen in Germany.
© Weserkraftwerk Bremen GmbH.
The newly built Three Gorges dam in China is often cited as a negative example of
the type of environmental damage hydropower plants can cause. Twenty cities and
more than 10000 villages, together housing more than one million people, were
sacrifi ced for the building of this plant. It is still not clear what the ecological impact
has been on the fl ooded area. It is expected that the many environmental sins of the
past will come back to haunt those who live in the area, for example by contaminat-
ing the groundwater. The fear is that the 600km-long reservoir is turning into a
cesspit of sewage and industrial waste.
On the other hand, when it is fi nished, the Three Gorges dam will produce 84 billion
kilowatt hours of electricity per year. This equates to more than one-sixth of total
German demand. If modern coal-fi red plants were used to generate the same amount
of electricity, they would be emitting more than 70 million tons of carbon dioxide
into the atmosphere each year. This corresponds to the total carbon dioxide emis-
sions of Austria.
In this sense it is important to weigh the benefi ts and disadvantages of all hydro-
power plants. It is possible to build ecologically viable plants. The main thing is
that ecological aspects are included in the equation along with protecting the envi-
ronment and providing reasonably priced energy.
9.7 Hydropower Markets
About 17% of the electricity generated worldwide comes from hydropower plants.
In 2004 Canada was still the leader in this fi eld (Figure 9.17), but in the meantime
it has been overtaken by China. The hydroelectric share of the power generated
varies substantially from country to country. Whereas 100% of Norway's electricity
comes from hydropower plants, this share is 84% in Brazil, 65% in Austria and
