VOA标准英语2012--Energy Production Facing Limits of Water Scarcity发电面临用水危机

Energy Production Facing Limits of Water Scarcity¹发电面临用水危机

Nearly all forms of energy production use large amounts of water. Coal, which generates nearly 50 percent of the electricity in the U.S., needs water for mining and transport, and to cool and lubricate equipment.

Water is also used to cool fuel rods at nuclear plants and to generate steam to power turbines. The biofuel industry needs water for irrigation, fermentation and the production of ethanol and biodiesel fuels.

Alexander Ochs, director of climate and energy at the Worldwatch Institute, says that adds up to a lot of water.

“Per megawatt hour, coal uses 500 to 1000 gallons of water for the production of just one megawatt hour of electricity," said Ochs. "If we look at all the plants combined in the U.S., all the thermo-electric plants [powered by steam] in the US in 2008 alone, they drew 60 billion to 170 billion gallons of water, per year.”

Without water, most types of energy could not be produced. Even renewable energy, like geothermal and solar, use water to cool equipment and to clean the collector panels.

Those requirements have led California, Massachusetts and several Midwestern states to halt the operations of some power plants.

“Places like the Midwest where water is a very scarce resource already today, a number of power plants have actually been halted, and this is actually true for across the United States," said Ochs.

David Brown directs programs for the National Oceanic and Atmospheric² Administration across the southern United States. NOAA collects data on climate patterns. Brown says the drought in the American southwest, the worst in a century, is prompting changes in the energy industry.

"Energy companies are also being forced to be more efficient in the way they use water, whether it is for electricity production in a coal factory or in the mining of natural resources through the fracking [hydraulic fracturing to extract natural gas] process," said Brown. "These companies are also realizing that water resources are strained and will continue to be strained as the climate continues to warm,”

The NOAA expert says water systems in the American Southwest will be under even greater stress over the next several decades.

The agriculture industry is the prime user of water in the United States, closely followed by energy production.

Experts say competition for water resources - from a growing population, and from the agriculture and energy industries - will require difficult decisions, eventually, by local and national governments.

1 scarcity   

n.缺乏，不足，萧条

参考例句：

• The scarcity of skilled workers is worrying the government.熟练工人的缺乏困扰着政府。
• The scarcity of fruit was caused by the drought.水果供不应求是由于干旱造成的。

2 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。