Traumatized Salmon

I was going to write about something else today, but I read an article in the NY Times today titled "As Wind Power Grows, a Push to Tear Down Dams" The article discusses a push by environmentalists to destroy 4 hydroelectric dams on the Snake river in Oregon. They claim that the dams interfere with salmon migration and are traumatizing the salmon. They also said that the dams aren't necessary since many windmills have been built and can be backed up by building natural gas plants.

I decided to go work the numbers on that for a bit. I checked and the 4 dams have a total capacity of 3 GigaWatts. This means the dams have a capacity of 26.3 Terawatts-Hours a year. Dams never run at full capacity, but at a typical 42% capacity factor, these dams would produce 11 TWH.

Oregon has 2 Gigawatts of Windmills. Windmills in the United States run at about 24% of capacity. That means that these windmills should produce about 4.2 TWH or about 38% of what the dams produce. The really big difference is that the dams can turn the power up or down as needed. Windmills can't.

Now consider; these dams don't produce carbon dioxide. If you leave these dams alone and go shut down a coal plant instead that would reduce carbon dioxide production by 11.6 Megatons per year. If you do like the envionmentalists are saying and built natural gas plants instead, you would indeed avoid a lot of pollution that a coal plant produces, but you would still be producing 7.3 Megatons of carbon dioxide a year.

As far as I can see, it doesn't make sense to shut down any hydroelectric dams until we have shut down every coal, natural gas and fuel oil electric plant in the United States.

References:

New York Times Story
http://www.nytimes.com/2009/06/12/business/energy-environment/12bonneville.html

Alternate Link
http://www.ocala.com/article/20090612/ZNYT01/906123002?Title=As-Wind-Power-Grows-a-Push-to-Tear-Down-Dams

Wikipedia Article on Windpower
http://en.wikipedia.org/wiki/Wind_power#Annual_generation

Wikipedia Article on Hyroelectricity
http://en.wikipedia.org/wiki/Hydroelectricity

Wikipedia Article on Snake River
http://en.wikipedia.org/wiki/Snake_River

Carbon Dioxide Emissions from the Generation of Electric Power in the United States
http://www.eia.doe.gov/cneaf/electricity/page/co2_report/co2emiss.pdf