It is a renewable source of energy Produces energy through hydroelectric power http://www.tehrantimes.com/News/10506/03_GEORGIA%20HYDRO.jpg
There is minimal pollution Reduces greenhouse gases It is renewable and clean The water used to power the plant is free from nature http://upload.wikimedia.org/wikipedia/commons/f/fd/Haditha_dam.png
How it functions http://www.electrical-res.com/EX/10-16-08/hydroelectric_power_plant.gif
The sluice gates measure the flow rate in open channels and regulates the water flow The penstock is the pipe inside the structure that delivers water to hydraulic turbines The turbines spin when the water is let through How it functions
The generator turns the water’s kinetic energy into energy we can use The powerhouse lets the dam be self- sustaining The transformer takes the energy produced and makes it into useable energy for homes and businesses
There aren’t many big places left to install hydropower plants. They can install low head hydropower plants almost anywhere. http://www.green-trust.org/hydro.htm
The pond builds up sediment It keeps the pond from storing water The sediment has to be dredged to get rid of this problem http://www.gina.gov.gy/dailyphoto/081215/The%20dam%20being%20constructed%20aback%20Buxton,%2 0East%20Coast%20Demerara%20to%20prevent%20water%20entering%20residential%20areas.JPG
50-100 years http://cleantechlawandbusiness.com/cleanbeta/wpcontent/gallery/cache/496__570x420_johnstown-dam-breaks.jpg
The risk of failure: When the Big Bay Dam in Mississippi broke in 2004, it destroyed over 50 homes. Dams can destroy wildlife habitats, which means that all the species living there are without homes. Dams can also drain wetlands and cause river pollution by reducing the river flow to such a low level that the river is not able to self- cleanse any longer.
Must have river with place for water to go upstream Must have room for machinery Must have resources to build it If machinery malfunctions the dam is pointless! Must have way to get electricity to homes If machine rooms flood an electric SHOCK can occur!!!
Average reconstruction cost: $5 million Reconstruction is a two-phase process Secondary spillway built (first phase) Granite blocks fixed because tree roots ruin them
The U.S. generates only 7-10% of the electrical supply by hydropower http://www.electrical-res.com/EX/10-18-08/hw_power_line.jpg
Water Turbidity Flooding Fish migration is disturbed Insect disease abundance Habitats destroyed Uncertainty
High net energy High efficiency No CO2 during operations in temperate areas Can provide flood control below dam Provides irrigation water
Flooding land High CO2 emissions from rapid biomass decay in shallow tropical reservoirs Decreases fish harvest below dam Decreases flow of natural fertilizer to land below dam http://www.bing.com/images/search?q=flooding+by+dam&FORM=BIF D&adlt=strict#focal=5249bbf4bd6015e1b41e92abc0251da5&furl=http %3A%2F%2Fwww.hazchek.com%2Fimages%2Fflood2.jpg
Dams are very expensive to build and may not provide sufficiently economical electrical power generation, water supply, or irrigation. http://s0.geograph.org.uk/photos/99/98/999804_f781b8af.jpg
It can cause upstream flooding Lowers levels of water downstream Countries get into wars or disagreements about this http://i.telegraph.co.uk/telegraph/multimedia/archive/00674/china-dam-flooding_674281c.jpg
Conventional: one-way water flow Run-of-River: little, or no, stored water. Weather changes cause fluctuations in power output. Storage: storage to offset seasonal changes…constant supply of electricity. Large dams enough storage for years. Pumped Storage: reuse water. After it is used it flows into reservoir, then some pumped back up and reused.