Climate change challenges power plant operations

View Photo Gallery — Dealing with drought at the Hoover Dam: Water managers across the country are scrambling for ways to produce the same amount of power from the hydroelectric grid with less water, including from behemoths such as the Hoover Dam.

By Juliet Eilperin, Published: September 9

BOULDER CITY, NEV. — Drought and rising temperatures are forcing water managers across the country to scramble for ways to produce the same amount of power from the hydroelectric grid with less water, including from behemoths such as the Hoover Dam.

Hydropower is not the only part of the nation’s energy system that appears increasingly vulnerable to the impact of climate change, as low water levels affect coal-fired and nuclear power plants’ operations and impede the passage of coal barges along the Mississippi River.

“We’re trying to manage a changing climate, its impact on water supplies and our ability to generate power, all at once,” said Michael L. Connor, commissioner of the Bureau of Reclamation, the Interior Department’s water-management agency. Producing electricity accounts for at least 40 percent of water use in the United States.

Warmer and drier summers mean less water is available to cool nuclear and fossil-fuel power plants. The Millstone nuclear plant in Waterford, Conn., had to shut down one of its reactors in mid-August because the water it drew from the Long Island Sound was too warm to cool critical equipment outside the core. A twin-unit nuclear plant in Braidwood, Ill., needed to get special permission to continue operating this summer because the temperature in its cooling-water pond rose to 102 degrees, four degrees above its normal limit; another Midwestern plant stopped operating temporarily because its water-intake pipes ended up on dry ground from the prolonged drought.

Scott Burnell, a spokesman for the Nuclear Regulatory Commission, said the safety of America’s nuclear plants “is not in jeopardy,” because the sources of water cooling the core are self-contained and might have to shut down in some instances if water is either too warm or unavailable.

“If water levels dropped to the point where you can’t draw water into the condenser, you’d have to shut down the plant,” he said.The commission’s new chairman, Allison Macfarlane, has asked her staff to look at “a broad array of natural events that could affect nuclear plant operations” in the future, such as climate change, Burnell added.

For more than three-quarters of a century, the Hoover Dam has represented an engineering triumph, harnessing the power of the mighty Colorado River to generate electricity for customers in not just nearby Las Vegas but as far away as Southern California and Mexico.

But the bleached volcanic rock ringing Black Canyon above Lake Mead, the reservoir created by the dam, speaks to the limits of human engineering. Higher temperatures and less snowpack have reduced the river’s flow and left the reservoir 103 feet below elevation for its full targeted storage capacity, which it last came close to reaching in 1999.

In the Colorado River’s 100-year recorded history, 1999 through 2010 ranks as the second-driest 12-year period, yielding an average of 16 percent less energy.

Scientists have just begun to study some key questions, such as the rate of evaporation off dams’ storage facilities. Predicting river flows — which can flood one year and dry up the next — is even harder.

COMMENT:

cyberchem, of course the falling levels of Lake Mead are just a very small part of the evidence of human-causd climate change, which include TONS of evidence from ice core samples, the melting glaciers, Greenland and the polar caps and ice sheets, as well as global temperatures and rising CO2 levels all corelating from studies and analysis. But they are a part of the evidence. In the past there were local 1 to 3 year fluctuations in levels due to local weather conditions, and these were due to natural variations before climate change and global warming started showing noticeable changes.

But in the last 13 years or so there has been a definite trend towards more or less CONTINUAL falling levels at Hoover Dam, not ever seen before, and these falling levels closely corelate with rising global temperatures and CO2 levels at the same time. In fact, if you graph the opposite trace of the dam levels with the rising gobal temperatures and CO2 levels with time, they would show a striking similarity in the way they line up. The same trend has been seen on the Great Lakes, which normally fluctuate up and down at random, but have been dropping at a similar time trend as the other factors, along with the decade-long drought in the West above the Colorado basin. There are defintie trends here, not random fluctuations.