1
 The Relationship between Greenhouse Gases and
Hydroelectric Power

• Colleen Smith
• CHE379
• Fall 2007

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Hydroelectric Power Generation
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Environmental Concerns of the 20th Century
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Environmental Concerns of the 21st Century
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Formation and Release of Biogas

• Anaerobic Digestion
• Hydrolysis
• Bacteria splits protein
• Acidification
• Requires/depletes Oxygen
• Methanogenesis
• Biogas formed

• Percolates upward out of reservoir surface
• As the Methane rises it is oxidized into CO2
• Rapid Release of methane at turbines
• Pressure drop causes______

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Affect of Biogas on the Environment

• Assume greenhouse gases, such as methane and
  carbon dioxide, cause global climate change

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Affect of Global Warming on Precipitation
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Affect of Global Warming on Snowpack

• Decreased snowpack means that more precipitation
  is turning directly into runoff and adding to
  streamflow in the winter months
• High flows in winter leave less snow to melt and
  provide water in the summer

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Affect of Global Warming on Snowmelt

• Average time of Snowmelt is in
• Warmer weather causes earlier snowmelt
• Snowmelt time directly affects streamflow
  throughout the year

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Affect of Snowmelt on Streamflow

• Increased March streamflow

• Decreased June streamflow

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Affect of these changes on the Grand Coulee Dam

• General Hydroelectric Dam constraints
• Prevent downstream flooding
• Provide water during dry months
• Generate electricity when releasing water
• Increased precipitation, less snowpack, and
  earlier snowmelt increases chance of flooding
• Less snowpack and earlier snowmelt decreases
  water availability during the summer
• Hydroelectric power generation is dependent upon
  flood hazard and water allocation needs

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Modeling the Grand Coulee Dam

• HEC-HMS
• The 24hr 2yr and 100yr storm
• In 2000 and 2050
• Turbine generators and spillway

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Affect on The Grand Coulee Dam

• In all cases, water flowed over the spillway
• The greatest effect was seen in the 2yr storm
  event
• Without additional downstream dams, there would
  be disastrous flooding
• More additional water means greater potential for
  hydroelectric generation
• If more turbines were installed

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Conclusions

• Dams produce GHGs
• CH4 and CO2
• There is still debate regarding the scale and
  extent of the emissions
• On a case by case basis
• There are small scale measures that could help
• Vegetation Removal
• Underwater logging
• Capture of CH4
• Ignore methane problems
• Do nothing

• Global Warming affects the climate
• Increased Precipitation
• Decreased Snowmelt
• Earlier Snowmelt
• Earlier streamflow
• Possible flooding
• Could be harnessed with increased hydroelectric
  generation
• More turbines

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Questions?