Energy, Water In "Catch-22"

By John Fleck
Albuquerque Journal

Thursday 20 March 2008

Humanity's demands for energy and water supplies are on a collision course, new research suggests.

It takes water to make energy - to cool power plants or process the fuels that power our cars. And it takes energy to get new water - to pump it to where it is needed, or to purify it for human use.

"You're kind of in a Catch-22," Sandia National Laboratories researcher Mike Hightower said in a recent interview.

In a far-reaching analysis published today in the British scientific journal Nature, Hightower and Sandia colleague Suzanne Pierce argue that water and energy development need to be coordinated or we will not have enough of both to meet humanity's growing needs.

The problem is particularly noticeable in water-scarce New Mexico.

Two big coal-fired electric power plants in northwestern New Mexico consume as much water as 150,000 typical Albuquerque households. A third plant proposed for the Four Corners area would add another 60,000 households' worth of water consumption.

A portion of that electricity is shipped to California - almost as though we were exporting our water, Hightower noted in an interview.

"If we have a drought in New Mexico, what happens to California's power?" Hightower asked.

The question is not so far-fetched.

Because of a loss of power plant cooling water, France lost 15 percent of its supply of electricity from nuclear power plants and 20 percent of the power it normally receives from hydroelectric dams during a drought in 2003, according to Hightower and Pierce.

Fears of similar problems arose during last year's drought in Australia. This year, drought in the southeastern U.S. threatened the cooling water for 24 nuclear power plants. Without enough cooling water, the plants would have to cut their power output.

Hightower is one of the leaders of a group of researchers at Sandia, Los Alamos National Laboratory and the National Energy Technology laboratories who have been studying energy-water connections. The work grew out of a study of the security of U.S. long-term energy supplies.

The issue is not limited to generating electricity.

Oil shale, one alternative to traditional oil for making gasoline and other liquid fuels, requires 2 to 5 gallons of water to make a gallon of oil-equivalent fuel, according to Hightower and his colleagues.

Biofuels - irrigating corn or soybeans to process into ethanol or biodiesel - can take as much as a thousand times as much water as ordinary oil refining, according to the researchers.

Even if we are willing to use that much water to irrigate crops to make fuel, Hightower questions what would happen when there is a drought.

"If you have a drought," he asked, "can you afford to have your biofuels go away?"

The problem also works in reverse, with high energy costs for creating new water supplies.

Desalination - the purification of seawater or brackish groundwater - takes massive amounts of electricity. Several desalination projects are under consideration in New Mexico, including in Sandoval County northwest of Albuquerque, and in Alamogordo.

Desalination takes five times as much energy as conventional water supplies, according to Hightower - 10 times the energy in the case of seawater.

All of this is coming as global energy demand is rising - an expected 50 percent in the next two decades, according to Hightower and Pierce. Over roughly the same period, according to Hightower, demand for irrigation water globally will rise 20 percent and urban water demand will rise 40 percent.

"We're seeing huge parts of the world, including parts of the United States, that are going to be water-scarce," Hightower said.

Options for dealing with the issue, according to Hightower and Pierce, include using low- or no-water energy sources like solar and wind power. There also are new approaches to cooling power plants that do not require water, and brackish water or seawater can be used for cooling.

On the water side, purifying sewage so the water can be used again is a lower-energy alternative to desalination, Hightower pointed out.

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