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HEP- The water acts as a power source which is used to turn a turbine. This then turns a metal shaft in an electric generator that produces the electricity. The dam is built to hold the
water, and create pressure. The turbines are inside the walls of the dam.
Potential in Brazil
Industrial development and the high cost of alternative fuel, particularly oil means the demand for hydro-electric power is continuously growing. Trying not to use too much energy
during peak hours, between 6 and 9 PM, is currently necessary to avoid the need to build new energy plants only to serve the demand in that timeframe.
The 10 year Energy Plan is that Brazil aims to build 71 new plants by 2017, with a potential output of 29,000 MW.
48 new plants are predicted by 2020, totalling 42,157 MW of installed power.
Only a little more than a third of the country's hydroelectric capacity has been tapped.
The geological formation (e.g. relief and impermeable rock types) of some areas is ideally suited for the building of power schemes of enormous size and capacity.
To monitor the impact of projects, Brazil is also investing in improving assessment carried out by the Brazilian Institute of the Environment and Natural Resources (IBAMA) before
installation of any plant.
Small hydroelectric plants can produce energy in a decentralized way with small environmental impact. These can be implemented in several regions of the country making use of
natural waterfalls, which many Brazilian farmers have taken advantage of.
Source of renewable energy, not expensive to maintain one it has been built, the water can be stored then used at peak times.
They have a very long life of around 50- 100 years which is much longer than ex, Nuclear Power Plants.
They have low failure rates, making them a reliable and dependable source of energy.
Hydropower is very convenient because it can respond quickly to fluctuations in demand. A dam's gates can be opened or closed on command, depending on daily use or gradual
economic growth in the community. The production of hydroelectricity is often slowed in the night time when people use less energy. When a facility is functioning, no water is
wasted or released in an altered state; it simply returns unharmed to continue the hydrologic cycle. The reservoir of water resulting from dam construction, which is essentially stored
energy, can support fisheries and preserves, and provide various forms of water-based recreation for locals and tourists. Land owned by the hydroelectric company is often open to
the public for hiking, hunting, and skiing.
Modern hydro turbines can convert as much as 90% of the available energy into electricity. The best fossil fuel plants are only about 50% efficient.
When in use, electricity produced by dam systems does not produce greenhouse gases. They do not pollute the atmosphere.
A very large area is needed to build the dam.
Dams are extremely expensive to build and must be built to a very high standard; they must operate for many decades to become profitable.
Damming rivers causes changes in ecological cycles and surrounding landscapes; self-regulating ecosystems are changed into ones that must be managed.
People living in villages and towns that are in the valley to be flooded, must move out. This means that they lose their farms and businesses. In some countries, people are forcibly
removed so that hydro-power schemes can go ahead.
Dams can damage the surrounding environment and alter the quality of the water by creating low dissolved oxygen levels, which impacts fish and the surrounding ecosystems. They
also take up a great deal of space and can impose on animal, plant, and even human environments.
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Fish populations can be impacted if fish cannot migrate upstream past impoundment dams to spawning grounds or if they cannot migrate downstream to the ocean. Upstream fish
passage can be aided using fish ladders or elevators, or by trapping and hauling the fish upstream by truck. Downstream fish passage is aided by diverting fish from turbine intakes
using screens or racks or even underwater lights and sounds, and by maintaining a minimum spill flow past the turbine.…read more