Sunday, November 22, 2009

ONGOING COVERAGE: WSU REPORTING PROJECT: WARMING

Hydropower experts evaluate warming scenarios

Mike Brambley
Special to The Spokesman-Review
December 13, 2008

For decades, the waters of the Columbia River system have powered the Pacific Northwest.

Hydropower dams are able to harness these waters to provide more than half of the region’s electricity today.

But if scientists’ predictions are correct, that could change with the onset of climate change.

“The biggest challenge in a predominately hydropower electricity supply is that fuel is free, but it falls from the sky,” said John Harrison, spokesman for the Northwest Power and Conservation Council, an intergovernmental organization responsible for planning the region’s energy future. “We never know from one year to the next how much will fall or where.”

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While the Northwest power system is structured around the strengths of clean and renewable hydropower, climate change has already begun to alter the environment and water resources of the Columbia River system.

Power analysts predict that future climate change will decrease the region’s hydropower production, drive up electricity bills and cost the power industry hundreds of millions of dollars in lost profit.

Today, hydropower provides more than 50 percent of the region’s energy. But by 2040, hydropower production could drop by 2,000 average megawatts, or twice the amount of electricity needed to power Seattle, according to the council.“This is not a doom-and-gloom scenario,” Harrison said. “It’s just a shift away from hydropower, potentially, to other forms of generation – and to demand reduction through conservation – to meet future demand for power.”

Climate change is expected to diminish water resources in the Columbia River system, resulting in less water for the Northwest hydropower system, according to the power council.

While warmer temperatures will bring more rain in the winter, scientists predicted there will be less snow for the summer’s hydropower production.

“Snow is essentially a natural reservoir for storing water until later in the summer,” said Michael Barber, director of the WSU Water Research Centercq. “We could see less hydropower during critical summer periods.”

Snowpack in the Northwest has been declining for the past 50 years, causing earlier snow runoff annually, according to a recent article on the hydrology of the western United States.

“These already noticeable effects of climate change appear to be causing less water flows through rivers during the later months of the summer,” wrote Barbara Goss Levi in a 2008 Physics Today article about trends in the hydrology of the western United States.

Reduced river flows could cause problems for electric companies when demand increases in warmer summers, Harrison said.

As climate change raises temperatures, more households are expected to increase the use of air conditioning, creating a stronger demand for energy resources during this season, according to the council.

New water storage programs could benefit a troubled hydropower system, Harrison said. But such proposals are fraught with controversy.

“There have been proposals for new storage reservoirs, but building a new, large reservoir would involve flooding a place where people probably live at the moment, and that combined with the enormous cost make it seem unlikely,” he said.

Reservoir operations are managed according to various laws regarding flood control and endangered species protection, Harrison said.Changing the existing water storage rules will be necessary if climate change adversely affects hydropower, he said.

“If there is an irresolvable conflict of water for fish versus water for power, the hydrosystem wins, just as it did during the drought of 2001,” Harrison said. “By law, to preserve public health and safety, the lights stay on.”

Wind turbines stand along the rolling hills and highways throughout the Pacific Northwest, symbolizing the potential for renewable energy to benefit the region.

“The wind power industry will be increasingly important in the Northwest in the coming decades, but the power supply will continue to be dominated by hydropower,” Harrison said.

Wind power is expected to increase to about 9 percent of the region’s total power supply over the next 15 to 20 years, he said. Although wind power continues to grow, it currently represents only 5 percent of the Northwest’s total power generation.

New energy solutions will be necessary in the future to compensate for losses to hydropower.

The implementation of alternative power sources, like wind, solar, natural gas, and clean-coal technology, as well as conservation, will make up for lost hydropower, Harrison said.

Avista Utilities, an energy company located in Spokane, receives more than half of its energy resources from hydropower, generating electricity from eight hydropower dams on two rivers -- the Clark Fork River in Montana and the Spokane River in Washington and Idaho.

“There are probably no comparable alternatives to hydro,” said Hugh Imhof, manager of media and information for Avista. “It is clean and efficient, does not produce greenhouse gases and it is renewable.”

Due to hydropower, the Northwest’s production of carbon dioxide – a key greenhouse gas -- is about half that of other western states, according to a study by the Northwest Power and Conservation Council.

With a reduced hydropower system, even if wind and other alternative energy resources are implemented, the region’s carbon dioxide production may increase 20 percent over current levels by 2024, according to the NPCC.

If climate change depleted river resources, Avista would probably expand its investments in natural gas and wind, Imhof said.

Wind is a variable resource, only producing energy when the wind blows, he said. At this time, storing that energy is less practical.

“New resources are expensive to build,” Imhof said. “Currently wind power costs about three times the price of hydro. Solar is even more expensive and so far, not economically viable in the Northwest on a utility scale.”

The costs of modifying energy resources to compensate for the loss of hydropower would probably have to come out of consumers’ pockets when they pay their electric bills, Harrison said.

Avista’s electric rates would most likely increase as climate change impacts hydropower, Imhof said.

A portion of each electric bill is used to maintain the dams and construct new power plants, Harrison said. Another portion is used to mitigate the impacts of dams on fish and wildlife.

Avista is currently using state-of-the-art technology to replace turbines on a number of its dams to make them more efficient, Imhof said. With the same amount of water, the new turbines can produce roughly 10 percent more electricity.