Climate change threatens coal and nuclear-fired electricity

Published by MAC on 2012-06-12
Source: PlanetArk

Acid rain isn't a thing of the past

Nuclear, Coal Power Face Climate Change Risk: Study

By David Fogarty

PlanetArk

5 June 2012

Singapore - Warmer water and reduced river flows will cause more power disruptions for nuclear and coal-fired power plants in the United States and Europe in future, scientists say, and lead to a rethink on how best to cool power stations in a hotter world.

In a study published on Monday, a team of European and U.S. scientists focused on projections of rising temperatures and lower river levels in summer and how these impacts would affect power plants dependent on river water for cooling.

The authors predict that coal and nuclear power generating capacity between 2031 and 2060 will decrease by between 4 and 16 percent in the United States and a 6 to 19 percent decline in Europe due to lack of cooling water.

The likelihood of extreme drops in power generation, either complete or almost-total shutdowns, was projected to almost triple.

"This study suggests that our reliance on thermal cooling is something that we're going to have to revisit," co-author Dennis Lettenmaier, a professor of civil and environmental engineering at the University of Washington in Seattle, said in a statement.

Thermoelectric power plants supply more than 90 percent of electricity in the United States and account for 40 percent of the nation's freshwater usage, says the study published in the journal Nature Climate Change.

In Europe, such plants supply three-quarters of the electricity and account for about half of the freshwater use.

Coal, nuclear and gas plants turn large amounts of water into steam to spin a turbine. They also rely on water at consistent temperatures to cool the turbines and any spike in river water temperatures can affect a plant's operation.

Disruptions to power supplies were already occurring, the authors noted.

During warm, dry summers in 2003, 2006 and 2009 several power plants in Europe cut production because of restricted availability of cooling water, driving up power prices.

A similar event in 2007-2008 in the United States caused several power plants to reduce production, or shut down for several days because of a lack of water for cooling and environmental restrictions on warm water discharges back into rivers, the study said.

In the past few months, large parts of the United States have suffered record heat, with March being the warmest on record for the contiguous 48 states, according to the National Oceanic and Atmospheric Administration.

The study projects the most significant U.S. impacts at power plants inland along major rivers in the Southeast.

"Considering the increase in future electricity demand, there is a strong need for improved climate adaptation strategies in the thermoelectric power sector to assure future energy security," the authors say in the study.

They also point to U.S. and European laws enshrining strict environmental standards for the volume of water withdrawn by plants and the temperature of the water discharged.

Adaptation strategies include placing new plants near the sea or building more gas-fired power plants, which are more efficient and use less water.

(Editing by Ed Davies)

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Conservation Groups Challenge EPA's Acid Rain Standards

Environmental News Service (ENS)

4 June 2012

WASHINGTON, DC, - Three conservation organizations today filed legal action challenging the U.S. Environmental Protection Agency's failure to update air quality standards for acid rain.

The petition for review was filed in the federal Court of Appeals for the District of Columbia Circuit by the Clean Air Council, Center for Biological Diversity and National Parks Conservation Association, represented by the nonprofit law firm Earthjustice.

Today's action has a long history.

The Clean Air Act requires the EPA to set so-called "secondary" air quality standards limiting ambient concentrations of air pollutants that affect "public welfare," which includes ecosystems and natural resources.

The Center for Biological Diversity and other groups sued the agency in 2005 over its failure to review the secondary standard for sulfur and nitrogen compounds that react with the water molecules in the atmosphere to produce acid rain. The standard was first established in 1971 and has not been updated.

That litigation led to the EPA's current review of the standard, in which the agency admitted that existing standards are inadequate to protect sensitive ecosystems and fish species from the effects of acid rain.

The groups argue that the EPA "chose to leave these inadequate standards in place," and that the agency has rejected efforts by EPA scientific experts to write a new, more protective standard.

"EPA's scientists identified the problem and provided a formula for action, but EPA dropped the ball," said Charles McPhedran, attorney with Earthjustice, which is representing the three groups. "EPA's inaction hurts our streams, and will not stand."

Coal-burning power plants, factories, and motor vehicles emit sulfur and nitrogen compounds into the air. The gases can be carried hundreds of miles in the atmosphere before they are converted to acids and deposited. In the past, factories had shorter smokestacks that polluted the air locally. Today's taller stacks cause the pollutants to be carried farther afield.

When these sulfur and nitrogen compounds bond with snow and rain, it falls on forests, rivers and lakes, creating an acidifying effect harmful to trees and to fish and other aquatic life.

"Acid rain isn't a thing of the past, but an ongoing and very real threat to forest ecosystems and wild fisheries across the country," said Kevin Bundy, a senior attorney with the Center for Biological Diversity. "EPA is ignoring the hard work of its own scientific experts and instead relying on outdated air quality standards that it knows are not protective enough."

Although many places across the country are at risk from acid rain, the eastern United States, including the Adirondacks, the Green and White mountains, and the Appalachians, as well as the upper Midwest, are among the most sensitive areas.

In the Adirondacks, the groups point out, lakes with more acidic water support only half the species of fish that might otherwise live there. Reduced growth rates in trout and salmon also have been attributed to acid stress.

"Instead of following the law and doing what is necessary to protect our natural resources, EPA has chosen to sit on the sidelines. Meanwhile, acid rain continues to poison our waters and threaten our forests," said Joe Minott of the Clean Air Council, based in Philadelphia.

The high elevation forests of the Appalachian Mountains from Maine to Georgia damaged by acid rain include areas such as the Shenandoah and Great Smoky Mountain national parks.

"Our national parks are unique and fragile places that were set aside to preserve the natural heritage of our nation," said Mark Wenzler, vice president for clean air and climate programs at the National Parks Conservation Association. "The EPA's failure to protect national parks from acid rain risks leaving wildlife and ecosystems permanently impaired."

The level of sulfur dioxide in the air has diminished over the past two decades. The EPA's Acid Rain Program was established under the 1990 Clean Air Act Amendments and requires emission reductions of sulfur dioxide, SO2, and nitrogen oxides by the electric power industry.

The program sets a permanent cap on the total amount of SO2 that can be emitted by electric generating units, and includes provisions for trading and banking emission allowances. The program was phased in, with the final SO2 cap set at 8.95 million tons in 2010, a level of about one-half of the emissions from the power sector in 1980.p