Hydroelectric Power

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Hydroelectric Power

• Overview
• Indirect solar power rainfall at elevation
• Largest form of renewable energy in world over
  90 of renewable electricity
• Hydro not renewable energy?
• Virtually 100 of hydro power is for electricity
  generation
• 16 of global electricity supply in 2002

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Energy from Biomass
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Hydroelectric Power

• Overview
• Indirect solar power rainfall at elevation
• Largest form of renewable energy in world over
  90 of renewables
• Hydro not renewable energy?
• Virtually 100 of hydro power is for electricity
  generation
• 16 of global electricity supply in 2002

4
Hydroelectric Power

• History
• First hydro power for pumping water and milling
  grain (similar to wind energy) mechanical power
• Waterwheel power used for shaft work papermills,
  textiles mills, etc.
• Rittenhouse papermill, Germantown, PA 1690

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Hydroelectric Power

• Waterwheels

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Hydroelectric Power

• History
• First known use of hydro for electricity 1881
  in UK -
• waterwheel power on river River Wey
• Very fast growth into 20th century public power
  and power grid established
• Recognized that hydro was tremendous resource for
  electricity generation
• Key to growth availability of hydraulic turbine
• Fourneyron (UK) outward flow turbine
• 80 efficiency
• Francis (USA) inward flow turbine

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Hydroelectric Power

• Fourneyron turbine

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Hydroelectric Power

• Francis turbine

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Hydroelectric Power

• Hydro Power Fundamentals
• Based on potential energy (pe) due to elevation
  and effect of gravity
• For hydro power, need source of flowing water
• pe (mass water)(height)(gravity) MgH
• (kg)(m/sec2)(m) (kgm)(m) (Newton)(m) 1
  Joule
• sec2
• Power must be a function of volume flow of water
  (Q)
• Q m3/sec
• Power (P) Energy per unit time
• P (?)(Q)(g)(H) (kg/m3)(m3/sec)(m/sec2)(m)
• N-m/sec Joules/sec watts

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Hydroelectric Power

• Hydro Power Fundamentals
• For water where ? 1000 kg/m3 ,
• P (1000)(Q)(H)
• Efficiency (?) electrical output lt 100
• mechanical input
• Efficiency 75 95 for hydroelectric
  turbines
• Effective Power using water (?)(1000)(Q)(H) W
• Power in kW (?)(10)(Q)(H)

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Hydroelectric Power

• Hydro Power Fundamentals
• Available Head usable height of water in
  reservoir
• Related to pressure energy of stored water
  (?)(g)(H)
• Presure Force per unit area, i.e. lb/in2 psi
  
• (?)(g)(H) (kg/m3) (m/sec2)(m) N/m2
• Turbine types and efficiencies vary with head

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Hydroelectric Power

1. Hydro Power Fundamentals

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Hydroelectric Power

• Hydro Power Fundamentals
• High Head dam high usable potential energy
• Does not necessarily need high water flowrates
  (Q) for sufficient power generation
• High pressures at outflow requires high
  construction costs
• Low Head dam low usable potential energy
• Must have high water flowrates for reasonable
  power generation
• Difference between tidal barrage and low head
  dam
• variable water head in tidal barrage
• Causes periodic power spikes as opposed to
  continuous power generation