Environmental Engineering Reference
In-Depth Information
Source:
Itaipu Binacional (2003)
Figure 1.17
Itaipu Hydro-electric Power Plant
Three Gorges hydro-electric power plant in China will generate 18.2 GW
when completed.
Such large hydro-electric power plants are not uncontroversial because
they also have a negative impact on nature and local conditions. For the Three
Gorges power plant in China, several hundred thousand people had to be
relocated. An example of adverse environmental effects is the Aswan dam in
Egypt. It stopped the Nile from flooding, and hence from replenishing the
nutrients in the intensively farmed flood planes. The artificial irrigation
required to make up for the missing fertilization caused salination of the
ground and harvests deteriorated. The area around the estuary also is affected
by increasing soil erosion.
Before planning large hydro-electric power plants, the advantages and
disadvantages should be considered carefully. On the one hand, hydro-electric
power is a technology that can generate electricity without carbon dioxide
emission at very low cost. On the other hand, there are negative impacts as
detailed above. Small hydro-electric power plants can be an alternative. Their
negative impacts are usually much smaller, but their relative costs are much
higher.
The tidal power plants described on p21 also utilize hydro power. Other
types of power plants that use hydro power are wave or ocean current power
plants. However, these power plants are still at the prototype stage at present.
Biomass
Life on Earth is possible only because of solar energy, a substantial
amount of which is utilized by plants. The following equation describes, in
general, the production of biomass:
