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Historical Growth of Hydroelectric power:
Hydropower is a natural renewable energy source as it makes use
of The
Hydrological Cycle:
Hydropower production is sensitive to secular evolution of weather; seasonal snowpacks, etc, etc. Long term droughts (10 years or so) seem to occur frequently in the West
About 30% of the hydropotential in the US has been tapped
to date
Why is Hydro so attractive?
average price
in the PNW is around 4 cents per KWH
this is 3 times less than
the national average!
which reflects costs of mining, transport and distribution.
Energy density in stored elevated water is high:
720 watts x 24 hours/day x 30 days/month = 518 Kwh/month.
Power generating capacity is directly proportional to the height the water falls. For a fall of say only 3 m, 30 times less electricity would be generated (e.g. 17 Kwh/month) - but this is just for a miniscule flow rate of 1 kg/sec.
Capacities of some large dams:
Grand Coulee 1942 6500 MW John Day 1969 2200 MW Niagara (NY) 1961 2000 MW The Dalles 1957 1800 MW Chief Joseph 1956 1500 MW McNary 1954 1400 MW Hoover 1936 1345 MW Glen Canyon 1964 950 MW Three Gorges 2000 18000 Mw
Pacific Northwest has 58 hydroelectric dams 63% of total
electricity generated. Most of the rest comes from coal fired steam plants
(e.g. Centralia Washington).
Note, the Trojan Nuclear Power Plant was relatively easy to shut down because replacement power was immediately available.
Again the main advantages of Hydro are a) its renewable and b) there is a lot of energy available:
Some Real Disadvantages:
Hydroelectric Power - The Risks:
Note that reservoirs offer expanded habitat for geese, pelicans, eagles, osprey. They also help with flood control thus minimizing soil erosion in the watershed.
Adverse effects of dams on salmon:
Solutions:
this has proven successful for trout in Oregon
How will potential lost power be compenstated for?
Internet Resources: