October 13, 2010

Will There Be Enough Water To Power The Future?

There are two active and two abandoned coal mines in southwest Virginia’s Dumps Creek watershed that bring the competition between energy and water into sharp focus.

Hundreds of thousands of gallons of water are used daily to cool and lubricate mining machinery, wash haul roads and truck wheels to reign in airborne particulates, and to suppress underground dust that otherwise could ignite.

For the uninitiated, the mining and processing of Dump Creek’s coal are just the first stages of an economically essential and ecologically damaging accord between energy production and water that is steadily attracting more notice from scientists and policymakers.

It’s not just that mining and burning coal could not occur without using vast amounts of water. Neither can every other source of energy except wind and solar photovoltaics. In the era of climate change and swift population growth, the competition for water at every stage of the energy production process is growing more fierce, more complex, and much more difficult to resolve.

Here are the three basics of why.

First, the demand for energy in the U.S. by 2050 will be 40 percent higher than it is today, forecasts the Energy Information Administration, a research unit of the federal Department of Energy.

Second, climate change is steadily reducing snowmelt and rainfall that feeds lakes and rivers, says the National Oceanic and Atmospheric Administration.

Third, the U.S. uses 200 billion gallons of water a day, half of all water withdrawals, to cool electric generating stations, says the U.S. Geological Survey (USGS).

Resolving the problem, say engineers and scientists, will take much keener energy and water conservation programs. It also will take new practices and technology. Using seawater or treated wastewater for cooling, for instance, is a practical alternative to fresh water.

Many more new tools will be needed because producing energy takes vast amounts of water and the trend is troublesome at best. The tar sands of northern Alberta, Canada, for instance are already the largest single source of petroleum imports to the U.S., according to the Energy Department, and contain enough oil to supply the country for decades. But mining and refining tar sands petroleum takes at least four barrels of water for every barrel of oil produced, or four times as much water as it takes to develop and refine a barrel of oil from conventional sources.

Similarly new supplies of natural gas, which burns much more cleanly than oil or coal, are being tapped in the two-mile deep shale formations of the Northeast, Texas, the Rocky Mountain states, and Michigan. But tapping those hydrocarbon reserves involves fracturing the rock using 2 million to 6 million gallons of water pumped into each well under high pressure. Much of the shale gas development, moreover, is occurring in water-scarce regions of Colorado and Wyoming.

Still, none of the country’s energy sectors face more trouble with water than the coal and utility industries. The typical 500-megawatt coal-fired utility burns 250 tons of coal per hour, and uses 12 million gallons of water an hour — 300 million gallons a day — for cooling, according to researchers at Sandia National Laboratories.

To produce and burn the 1 billion tons of coal America uses each year, the mining and utility industries withdraw 55 trillion to 75 trillion gallons of water annually, according to the USGS. That’s roughly equal to the torrent of water that pours over Niagara Falls in five months.

Coal industry executives insist they are ready to install more efficient water-conserving cooling systems. A small number of utilities, led by Duke Energy, also are testing a favored fix for climate change, a way to snare all the climate-changing carbon from coal-fired combustion and store it deep underground – so-called “carbon capture and sequestration” or CCS.

But there’s a big problem. Scientists with Sandia National Laboratories say CCS will increase water use by up to 40 percent. In other words, without significant advances in technology, the path to a low-carbon economy that includes coal will put enormous new pressure on America’s declining supply of fresh water.

“Carbon capture may reduce greenhouse gases going to the air,” said Jeff C. Wright, Director of the Office of Energy Projects at the Federal Energy Regulatory Commission, during a federal conference on energy and water in April. “But it will increase the amount of water needed in thermoelectric plants, coal plants especially.”

What’s happening with the competition between energy and water in your region? Let us know.

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