Blocked by concrete or killed by climate?


In the context of climate change, our energy appetite has shoved us into a corner. We've gotten used to a diet of cheap, energy-packed fossil fuels, and it will probably be impossible to find an alternative that doesn't bring along its own set of environmental impacts: Solar arrays will damage deserts, wind farms decimate birds and bats, and where the heck will we site the transmission lines? 

And now the Idaho Statesman is describing another twist to the general dilemma: when it comes to killing salmon, hydro power dams and climate change are in fierce competition. Right now, dams may be decimating smolts by the millions, but wait a few decades and warmer water temperatures may stop southerly salmon populations -- and those that spawn in the summer -- dead in their tracks.

In light of those facts, the article poses the question: do we demolish dams or not? After all, argues the Statesman reporter, if we remove dams, fossil-fuel powerplants might replace them. Some salmon populations will benefit from unimpeded spawning runs, but will the added carbon emission result in a larger threat to the species as a whole? Which is more dangerous: millions of tons of greenhouse gases distributed in the atmosphere, or all those tons of concrete sitting in a river?

As the Statesman article puts it:

This means the hydroelectric dams that provide more than half of the electricity in (the Pacific Northwest) -- without emitting carbon dioxide -- are more valuable than ever.

That presents an ethical challenge to the environmentalists, Indian tribes and commercial and sport fishermen who have fought for years to reduce the impacts of dams on the fish. The dams are no longer just economic drivers in the region. They could be -- at least for the short term -- critical tools for reversing the most dramatic peril of our time.

It's a dilemma that hydropower interests have readily accepted:

"We are no longer in the time when these are economic versus environmental arguments," said Steve Wright, administrator of the Bonneville Power Administration, which markets the power from the dams and uses some of the proceeds to pay for fish recovery. "Increasingly these are environmental versus environmental arguments.

Though, if we're being asked to choose between big hydro dams or carbon emissions, we may be facing a false choice -- however much BPA might like to argue that dams actually protect salmon. As one voice in the Statesman article does point out, efficiency measures and other sources of renewable energy could mean that the hydroelectric turbines (in particular, four on the lower Snake River) won't necessarily be replaced with fossil fuels.

There are always trade-offs
Ed Quillen
Ed Quillen
May 05, 2009 02:08 PM

    We seem to forget that no technology is perfect and that there are always trade-offs.

    Wind-generated electricity is wonderful, except there are people who are annoyed by the presence of nearby wind turbines, and beyond that, dead bats and birds have a way of accumulating under the blades. Large-scale solar generation is clean, renewable energy, but those transmission lines can turn into a NIMBY issue along the corridor. Compact fluorescent lamps save electricity but contain toxic mercury. Cloth shopping bags cut down on plastic litter, but may come from sweatshops in China. Name just about any "green" way, and you can find somebody who has a problem with it.

    The first time I had to think of this came about 25 years ago. I had written a story for a national magazine (Country Journal) about a rancher in Custer County, Colo. He had designed and built his own small hydro-electric plant on tiny Hennepin Creek, which flowed fast down the steep east side of the Sangre de Cristo mountains.

    He did it because the local electric co-op wanted thousands of dollars to extend service to his remote ranch house. He figured he could do it better and cheaper on his own.

    The rancher diverted most of the creek water for about 450 feet. It ran down some irrigation pipe parallel to the creek bed, and entered a small shed. There he had a pelton-wheel turbine and a generator. The water returned to the creek, and he had enough clean electricity to heat and light his house. It was also more reliable than the local co-op's power, whose lines were vulnerable to lightning and wire-downing windstorms.

    His system sounded like a pretty good deal, but the magazine got a letter, which it forwarded to me, from someone who wondered why I hadn't addressed the fate of the fish on account of the diminished flows in a stretch of Hennepin Creek.

    I checked with the rancher, and with the state wildlife department. Both said the creek was too steep to have ever supported any significant fish population.

    So all was well enough on the fish front, but it does illustrate that even a tiny effort at a self-sufficient and sustainable electrical system comes with potential trade-offs. We have to make decisions, and it's safe to predict that not everyone will be pleased, no matter what we do.