Friday, February 16, 2007

"Dam'd" If You Do... "Dam'd If You Don't!

In the latest example of why the renewable energy mandate is going to be so hard to meet, the Sacramento Bee has a story about Arnold's new $4.5 billion dam project. The idea was to create more hyrdroelectric power, which will cut down on greenhouse gas emissions, right? Wrong.

Apparently dams are actually greenhouse gas emission factories. When you pour all that cement to build a dam? Emissions. When the water pools into a reservoir? Decaying organic material causes emissions.

And, according to the Bee, it's not just a front-loaded problem:

"Emissions continue throughout the dam's life as more organic matter washes in from upstream, and when water is released to make electricity, causing a pressure drop that frees gases locked within the stored water."


The Bee also notes:

"Only one study has been done so far in California, led by researchers at the University of Quebec in Montreal. Published in 2004 in the journal Global Biogeochemical Cycles, it looked at Shasta Lake, Lake Oroville and New Melones Reservoir.

It estimated that Shasta Lake released 224 tons per day of carbon dioxide, both through diffusion from the surface and during power generation. That's equal to about 14,500 average automobiles, each driven 40 miles a day. Lake Oroville emissions equaled about 3,400 cars."


I'm sure the hydro guys will have plenty to say about all of this.

'Clean' energy dams may be dirty after all [Sacramento Bee]