Renewable EnergyRenewable Energy

HydropowerHydropower

What happensWhat happens

Falling water (kinetic energy) is Falling water (kinetic energy) is capturedcaptured

Converted to mechanicalConverted to mechanical Mechanical Mechanical electrical by generator electrical by generator Electrical transfer and conversion toElectrical transfer and conversion to

mechanicalmechanical HeatHeat Light etc.Light etc.

Sizes- Micros to GiantsSizes- Micros to Giantshttp://www.wvic.com/hydro-http://www.wvic.com/hydro-

works.htmworks.htm

Parts: Dam/ReservoirParts: Dam/Reservoir

Impounds waterImpounds water Creates ReservoirCreates Reservoir Provides flood Provides flood

control, irrigation, control, irrigation, recreation, wildlife recreation, wildlife habitat, aestheticshabitat, aesthetics

TurbineTurbine

Spins because of Spins because of flowing water.flowing water.

Converts kinetic to Converts kinetic to mechanicalmechanical

(impeller pictured)(impeller pictured)

Like toy motorsLike toy motors

See note at bottomSee note at bottom

http://www.wvic.com/how-gen-works.http://www.wvic.com/how-gen-works.htmhtm

How much electricity can be How much electricity can be produced?produced?

Depends on how Depends on how much water is much water is falling and how far. falling and how far. (HEAD)(HEAD)

How much power is How much power is produced?produced?

PowerPower = (Height of Dam) x (River Flow) x = (Height of Dam) x (River Flow) x (Efficiency) / 11.8(Efficiency) / 11.8

Power-Power-The electric power in kilowatts The electric power in kilowatts (one kilowatt equals 1,000 watts).(one kilowatt equals 1,000 watts).

Height of Dam-Height of Dam-The distance the water The distance the water falls measured in feet.falls measured in feet.

River Flow-River Flow-The amount of water flowing The amount of water flowing in the river measured in cubic feet per in the river measured in cubic feet per second.second.

Efficiency- Efficiency- How well the turbine and How well the turbine and generator convert the power of falling water generator convert the power of falling water into electric power. For older, poorly into electric power. For older, poorly maintained hydro plants this might be 60% maintained hydro plants this might be 60% (0.60) while for newer, well operated plants (0.60) while for newer, well operated plants this might be as high as 90% (0.90).this might be as high as 90% (0.90).11.8 11.8

Converts units of feet and seconds into Converts units of feet and seconds into kilowatts. For the dam in our area, lets say kilowatts. For the dam in our area, lets say we buy a turbine and generator with an we buy a turbine and generator with an efficiency of 80%.efficiency of 80%.

Then the power for our dam will be:Then the power for our dam will be: PowerPower = (10 feet) x (500 cubic feet = (10 feet) x (500 cubic feet

per second) x (0.80) / 11.8 per second) x (0.80) / 11.8 = 339 = 339 kilowattskilowatts

Since electric energy is normally Since electric energy is normally measured in kilowatt-hours, we measured in kilowatt-hours, we multiply the power from our dam by multiply the power from our dam by the number of hours in a year.the number of hours in a year.

Electric EnergyElectric Energy = (339 kilowatts) x = (339 kilowatts) x (24 hours per day) x (365 days per (24 hours per day) x (365 days per year) = year) = 2,969,000 kilowatt hours.2,969,000 kilowatt hours.

The average annual residential energy use The average annual residential energy use in the U.S. is about 3,000 kilowatt-hours in the U.S. is about 3,000 kilowatt-hours for each person. So we can figure out how for each person. So we can figure out how many people our dam could serve by many people our dam could serve by dividing the annual energy production by dividing the annual energy production by 3,000.3,000.

People ServedPeople Served = 2,969,000 kilowatts- = 2,969,000 kilowatts-hours / 3,000 kilowatt-hours per person) = hours / 3,000 kilowatt-hours per person) = 990 people.990 people.

How much of our power is from How much of our power is from hydro?hydro?

http://www.bluefish.org/http://www.bluefish.org/idpowr01.htmidpowr01.htm

WebsitesWebsites

http://www.idahopower.com/http://www.idahopower.com/energycenter/electricitybasics/energycenter/electricitybasics/default.htmdefault.htm

This material is based upon work This material is based upon work supported by the National Science supported by the National Science Foundation under award DUE-Foundation under award DUE-04344050434405