Hydroelectricity+advantages+and+dis...

__Advantages-__ > > > > >
 * Once the dam is built, the energy is virtually free.
 * No waste or pollution produced.
 * Much more reliable than wind, solar or wave power.
 * Water can be stored above the dam ready to cope with peaks in demand.
 * Hydro-electric power stations can increase to full power very quickly, unlike other power stations.
 * Electricity can be generated constantly.


 * Hydro-electricity is renewable. The sun evaporates water from the sea that comes over and rains on the dam and will continue doing so.

__Disadvantages-__ > However, many dams are also used for flood control or irrigation, so building costs can be shared. > > >
 * The dams are very expensive to build.
 * Building a large dam will flood a very large area upstream, causing problems for animals that used to live there.
 * Finding a suitable site can be difficult - the impact on residents and the environment may be unacceptable.
 * Water quality and quantity downstream can be affected, which can have an impact on plant life.