Hydropower: Electricity From Moving Water

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Hydropower Electricity From Moving Water

• By Lauren Murphy
• and Candice Burgan

http//www.lasvegastourism.com/tours/hoover_dam.gi
f
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Main goal

• To provide an adequate and efficient natural
  source of energy without the burning of fossil
  fuels.
• To harness the energy of moving water
• To provide a cheap source of energy

http//www.danville-va.gov/upload/images/Utilities
/Pinnacles20Hydro.JPG
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Layout of a Dam
http//ga.water.usgs.gov/edu/hyhowworks.html
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How it works

• Build a dam on a large river that has a large
  drop in elevation
• The dam stores lots of water behind it in the
  reservoir
• Near the bottom of the dam wall there is the
  water intake
• Gravity causes it to fall through the penstock
  inside the dam
• At the end of the penstock there is a turbine
  propeller, which is turned by the moving water

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How it works contd.

• The shaft from the turbine goes up into the
  generator, which produces the power
• Power lines are connected to the generator that
  carry electricity
• The water continues past the propeller through
  the tailrace into the river past the dam

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Hydroelectric generator
A hydraulic turbine converts the energy of
flowing water into mechanical energy. A
hydroelectric generator converts this mechanical
energy into electricity.
http//ga.water.usgs.gov/edu/hyhowworks.html
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Hydroelectric Power 9.8
http//www.eia.doe.gov/cneaf/electricity/epa/epa_s
um.html
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Top Generating Countries
http//www.eia.doe.gov/cneaf/electricity/epa/epa_s
um.html
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Expense of Power Production
http//www.eia.doe.gov/cneaf/electricity/epa/epa_s
um.html
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Purpose of Dams
http//www.eia.doe.gov/cneaf/electricity/epa/epa_s
um.html
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Provides 97.9 of all Electricity by Renewable
Resources
http//www.eia.doe.gov/cneaf/electricity/epa/epa_s
um.html
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Advantages

•  - Fuel is not burned so there is minimal
  pollution -Water to run the power plant is
  provided free by
• nature -  It's renewable - rainfall
  renews the water in the reservoir, so the fuel is
  almost always there
• No waste products
• Moderate to high net energy
• High efficiency (80)
• Low cost electricity
• Long life span
• Provides flood control below dam
• Provides year-round water for irrigation and crop
  land
• Useful for fishing and recreation due to
  reservoir

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Disadvantages/Environmental problems

• High construction costs
• High environmental impacts
• High CO2 emissions from biomass decay in shallow
  reservoirs
• Floods natural areas
• Converts land habitat to lake habitat
• Danger of collapse
• Uproots people
• Decreases fish harvest below dam
• Decreases flow of natural fertilizer to land
  below dam
• Large water loss due to evaporation

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Collapsing of dams

• Many dams arent maintained properly
• Lack of concern about risk and problems
• This causes mass-flooding and even loss of life
• Internal erosion

http//www.hatchenergy.com/Innovations/Spring2006/
guest_dam.html
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Problems with hydropower

• Takes up a lot of space
• Costs are extremely high
• Good land areas for construction have already
  been taken
• Consumes a lot of time for planning and
  construction
• The life expectancy of dams are only around 50
  years
• Even at this age these dams are considered to be
  at a high risk for failing

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Rate of construction
http//ga.water.usgs.gov/edu/wuhy.html
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Make a difference

• Hydroelectricity eliminates the flue gas
  emissions from fossil fuels, including pollutants
  such as sulfur dioxide, nitric oxide, carbon
  monoxide, dust, and mercury in the coal.
• Doesnt contribute to global warming!

http//www.solcomhouse.com/Global_Warming.gif
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Technological obstacles

• Building strong and efficient dams to withstand
  the passage of time
• Find efficient ways to minimize environmental
  impacts

http//www.srh.noaa.gov/tlh/cpm/woodruff_dam_pic.j
pg
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Political/Economic obstacles

• High production/building costs
• Creating total revenue to build
• Value tradeoffs
• Market prices
• Water use allocations cause controversy
• Mass displacement of people
• Large investments in energy sources (large scale
  dams)

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Three Gorges Dam

• Largest dam in the world

http//www.theage.com.au/ffximage/2006/06/23/knDAM
_wideweb__470x309,0.jpg
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Bibliography

• http//ga.water.usgs.gov/edu/hyhowworks.html
• http//ga.water.usgs.gov/edu/wuhy.html
• http//www.eia.doe.gov/cneaf/electricity/epa/epa_s
  um.html
• http//www.lasvegastourism.com/tours/hoover_dam.gi
  f
• http//oilbeseeingyou.blogspot.com/2007/07/post-pe
  ak-dam-maintenance-or-lack.html
• http//www.theage.com.au/ffximage/2006/06/23/knDAM
  _wideweb__470x309,0.jpg
• http//www.srh.noaa.gov/tlh/cpm/woodruff_dam_pic.j
  pg
• http//www.hatchenergy.com/Innovations/Spring2006/
  guest_dam.html
• http//www.danville-va.gov/upload/images/Utilities
  /Pinnacles20Hydro.JPG