365
Power and Energy Directly from Water
13.2.4.2 disadvantages
While hydroelectricity offers many advantages as stated above, it also has some
drawbacks. Some of these drawbacks are briefly stated as follows
1. Hydroelectric projects can change the ecosystem and loss of the land. Dams
can have a serious effect on salmon and fish populations around the dams.
2. When water flows, it has the ability to transport heavier particles downstream. This has a negative effect on the operation of dams and subsequently their power stations.
3. High siltation can fill a reservoir and reduce its capacity to control floods
along with causing additional horizontal pressure on the upstream portion
of the dam. This can ultimately result in the failure of the reservoir due to
accumulation of large sediments [10,11].
4. When a dam is on the river, the change in river flow can affect the amount
of power supply to the neighborhood. This can be important as the temperature of the water and rainfall changes under different climates.
5. In tropical regions, reservoirs of power plants may produce a substantial
amount of methane. This is because of the decay of plant materials in anaerobic environment that results in methane production by microbiological reactions. This type of emission is higher when the reservoir is large compared
to its electricity-generating capacity, and the forests surrounding the dams
are not cleared [10,11].
6. The new dam projects also displace people. The capital costs for new dam
projects are high.
7. For large dams, failure of dam due to poor construction can be the largest
man-made disasters in the history. The Banqiao Dam failure in Southern
China resulted in the deaths of 26,000 people, with another 145,000 from
epidemics, and millions were left without homes [1–13,34].
13.2.5 environmenTAl iSSueS
Hydroelectric power is environment friendly. Some evidences toward this fact are
as follows
1. Unlike in coal- or gas-driven power plants, hydroelectricity eliminates flue
gas emissions, including pollutants such as sulfur dioxide, nitric oxide,
carbon monoxide, dust, and mercury. It also eliminates emissions of GHG
like methane and carbon dioxide.
2. It eliminates all the health hazards related to coal mining and coal dust
emissions.
3. It also eliminates all the negative consequences of “fracking process” to
recover unconventional gas for gas-driven power plants.
4. Compared to nuclear power, hydroelectricity generates no nuclear waste and
has none of the dangers associated with uranium mining nor nuclear leaks.
5. Unlike coal-, gas-, or uranium-driven power plants, hydroelectricity is a
renewable and carbon-free energy source.
Power and Energy Directly from Water
13.2.4.2 disadvantages
While hydroelectricity offers many advantages as stated above, it also has some
drawbacks. Some of these drawbacks are briefly stated as follows
1. Hydroelectric projects can change the ecosystem and loss of the land. Dams
can have a serious effect on salmon and fish populations around the dams.
2. When water flows, it has the ability to transport heavier particles downstream. This has a negative effect on the operation of dams and subsequently their power stations.
3. High siltation can fill a reservoir and reduce its capacity to control floods
along with causing additional horizontal pressure on the upstream portion
of the dam. This can ultimately result in the failure of the reservoir due to
accumulation of large sediments [10,11].
4. When a dam is on the river, the change in river flow can affect the amount
of power supply to the neighborhood. This can be important as the temperature of the water and rainfall changes under different climates.
5. In tropical regions, reservoirs of power plants may produce a substantial
amount of methane. This is because of the decay of plant materials in anaerobic environment that results in methane production by microbiological reactions. This type of emission is higher when the reservoir is large compared
to its electricity-generating capacity, and the forests surrounding the dams
are not cleared [10,11].
6. The new dam projects also displace people. The capital costs for new dam
projects are high.
7. For large dams, failure of dam due to poor construction can be the largest
man-made disasters in the history. The Banqiao Dam failure in Southern
China resulted in the deaths of 26,000 people, with another 145,000 from
epidemics, and millions were left without homes [1–13,34].
13.2.5 environmenTAl iSSueS
Hydroelectric power is environment friendly. Some evidences toward this fact are
as follows
1. Unlike in coal- or gas-driven power plants, hydroelectricity eliminates flue
gas emissions, including pollutants such as sulfur dioxide, nitric oxide,
carbon monoxide, dust, and mercury. It also eliminates emissions of GHG
like methane and carbon dioxide.
2. It eliminates all the health hazards related to coal mining and coal dust
emissions.
3. It also eliminates all the negative consequences of “fracking process” to
recover unconventional gas for gas-driven power plants.
4. Compared to nuclear power, hydroelectricity generates no nuclear waste and
has none of the dangers associated with uranium mining nor nuclear leaks.
5. Unlike coal-, gas-, or uranium-driven power plants, hydroelectricity is a
renewable and carbon-free energy source.