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CH EN 1002 – Sustainable Energy

Conventional Energy Technology:Hydroelectric

October 5, 2007

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Reminders

Homework #4• Due Today

Project assignment coming Friday…

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Hydroelectric Power

715,000 (715 GW) production worldwide20% of world electricityU.S. Production: 79 GW• Can reasonably expand by 30 to 70 GW

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Major Hydropower Countries

0.4928120Norway0.4245157Russia0.4279290USA

0.5669350Brazil0.5969350Canada0.37129417China

LoadFactor

InstalledCapacity

(GW)

AnnualProduction

(TWh)Country

Total World Capacity: 715 GW

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Hydropower Technology

Large-scale hydropower• Dams hold back water and create a "head"

(height difference) of water – potential energy• Water flows through turbines ("propellers")

causing them to spin• Shaft connects turbine and electrical

generator used to make electricity• Turbines can be "spun down" or turned off

when power is not needed

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Hydroelectric Turbine + Generator

Source: Wikipedia.Com

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Hydroelectric Dam

Source: Wikipedia.Com

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Pumped-Storage power

Operates "in reverse" during low demand periods75-80% recovery of pumping energy upon discharge

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Small-Scale ("mini") Hydro

Uses existing water flow, no damsDifferent classifications• Small hydro: less than 25 MW• Mini hydro: less than 1 MW• Micro hydro: less than 0.1 MW

Local production and usageGlobal small-scalehydro production:66 GWChina small-scalehydro: 39 GW

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Micro Hydro

Micro Hydroelectric generation in NW Vietnam village. Set-up involves bamboo and wooden sluices channelling water into oil drums fitted with hand-carved bamboo turbines. Electricity generation was via motorbike alternators. Interestingly, high-tension power lines ran through the middle of the village, but clearly were not used by the villagers. Source: Wikipedia.Com

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Notable HydroelectricPower Plants

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Cragside, Rothbury, England

World's first hydroelectric power plantInstalled 1870Used a Siemens dynamo generatorInitially used for machines (elevator, laundry equipment)Cragside manor first house lit by electric lighting• Arc lamp 1878• Joseph Swan's incandescent

lamps 1880

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Fox River, Appleton, Wisconsin

First hydroelectric plant in U.S.World's first commercial hydro power plantBuilt 1882Supplied power for lighting two paper mills and one house

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Robert Moses Niagara Power Plant

Constructed 18952,500 Megawatts todayDiverts water from above Niagara Falls to reservoir in parallel with river• More than half of water diverted• Majority of water diverted at night• Uses pumped-storage technique

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James Bay Hydro Project, Canada

Constructed in 1970s in northeastern QuebecMultiple dams provide 16,000 MW of powerFlooded total of 3,800 square milesFlooded 10% of the huting and fishing grounds of the indiginous Cree of ChisasibiInitial increase in mercury levels in fish by a factor of 4 to 5• Decomposition of organic material under water;

mercury in this material results primarily from coal-fired power plants in northeastern U.S.

• Subsequent slow decrease in mercury levels

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Grand Coulee Dam

Eastern Washington state, Columbia RiverLargest hydroelectric plant in U.S.Built 19421 mile long, 550 feet high6.8 GW generating capacity

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Hoover (Boulder) Dam

On Colorado River, Nevada-ArizonaBuilt 1931-19361250 feet long, 726 feet high2 GW (2,000 MW) power output

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Three Gorges Dam, China

Construction complete 20097700 feet long, 616 feet high, 400 feet wide at bottomReservoir 370 miles long22,500 MW (22.5 GW) generating capacity

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Stairs Hydroelectric Plant

Big Cottonwood CanyonBegan operation 1896Still in use today1.2 Megawatts

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Consequences of Hydro

Damage fish habitat, loss of populationSilt buildupGreenhouse gasesPopulation displacementRisk of accident

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Dam built in 1950s• Designed to withstand "1 in 1000 year flood"

August 1975• "1 in 2000 year flood" occurred• 15 inches of rain in 1 hour• 40 inches of rain in 1 day

Dam burst• 79,000 m3/s outflow• 16 billion tons water released• Wave 6 miles wide, 20 feet high

Consequences• 145,000 dead• 6 million buildings collaped

1975 Banqiao Flood, China

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Pros? Cons?

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The End