WENATCHEE, WASH. — The Rocky Reach Dam has straddled the wide, slow Columbia River since the 1950s. It generates enough electricity to supply homes and industries across Washington and Oregon.
But the dam in recent years hasn't produced as much power as it might: Its massive turbines act as deadly blender blades to young salmon, and engineers often have had to let the river flow over the spillway to halt the slaughter, wasting the water's energy potential.
The ability of the nation's aging hydroelectric dams to produce energy free of the curse of greenhouse gas emissions and Middle Eastern politics has suddenly made them financially attractive -- thanks to the new economics of climate change. Armed with the possibility of powerful new cap-and-trade financial bonuses, the National Hydropower Assn. has set a goal of doubling the nation's hydropower capacity by 2025.
Expanding hydropower is fraught with controversy, much of it stemming from the industry's history of turning wild rivers into industrialized reservoirs struggling to support their remaining fish. The emerging boom in hydroelectric power pits two competing ecological perils against each other: widespread fish extinctions and a warming planet.
The issue has been particularly contentious in the Pacific Northwest, where some are calling for actually breaching dams on the Snake River in an effort to bring back the declining salmon and steelhead.
"Hydropower does have pretty significant and serious impacts on rivers. We know that. The industry knows that," said John Seebach, director of the Hydropower Reform Initiative launched by the conservation group American Rivers. "It also provides some pretty significant benefits in terms of power production. So it's a tricky balance to get those benefits while trying to minimize those impacts."
Across the country, there are about 82,600 dams, but only about 3% of them are used to generate electricity. Hydropower produces about 6% of the nation's electricity, and nearly 75% of all renewable electric power.
The increasing mandates for power utilities to expand their portfolios of renewable energy are prompting dam operators to take a second look at thousands of dams now used for flood control, irrigation, navigation, recreation and industrial water supply that might also be used to generate electricity without further harm to fish.
"Most of the bang for the buck is at existing dams and reservoirs without hydropower facilities, and hydropower facilities that need to be upgraded for additional capacity," said Norman Bishop, vice president of MWH Americas Inc., which designed the dam improvements in Chelan County, Wash., home to the Rocky Reach facility.
The U.S. Department of Energy estimated that there are up to 30,000 megawatts of potential energy at 5,677 undeveloped sites across the nation, more than half of which already have dams.
Newly added to the equation is the emerging market for so-called carbon credits. The credits are part of a strategy to place "caps" on damaging greenhouse gas emissions while allowing companies that can't meet the restriction to buy credits from ones that achieve significant savings. The cap would be gradually lowered to reduce overall emission levels.
Hydroelectric power is a prime candidate to sell credits because it is largely emission-free. The credits typically would be granted only for new or additional power.
The market for the credits is tiny now, but legislation is moving forward that would create caps and a national market that could ultimately reach $120 billion a year.
Even without a national cap-and-trade law, markets such as the Chicago Climate Exchange now allow companies to voluntarily limit their carbon emissions and lower their carbon footprint by purchasing credits, traded on the market like stock.
This added incentive has made building or upgrading hydroelectric facilities a more alluring prospect.
The small rural Chelan County Public Utility District last year became the first hydropower facility in the U.S. to begin trading carbon credits on the Chicago Climate Exchange.
The money the district has made from selling credits -- about $1.6 million so far -- is going back to Chelan County and its customers for new investments in carbon-free electricity. The district has invested heavily in making sure its new electricity results have no net harm to salmon -- a key requirement for trading on the Chicago exchange.
But the possibility of more hydroelectric construction around the world has set off alarm bells among some groups of environmentalists.
"Rivers in the U.S. have been seriously impacted by dam construction," the conservation group International Rivers said in urging California authorities to disqualify hydropower projects producing more than 10 megawatts of power from receiving carbon credits.