Boutros Boutros-Ghali, former United Nations secretary-general, has said that the next global conflict will erupt not over oil, but over water. Each year, more than 2 million people die from diseases associated with a lack of safe drinking water. A 2003 U.N. report estimated that, by 2050, as many as 7 billion people could suffer from severe water shortages.

In the United States, thermo-electric power plants are the third-largest consumer of water, after agriculture and industry. These plants, fired by fossil fuels, produce 53 percent of the power in this country and, according to a study by the Virginia Tech Water Resources Research Center, consume 136 billion gallons of fresh water every day. Power plants use water to scrub pollutants, cool and clean machinery, and produce steam to power turbine generators.

Dr. Tamim Younos, director of the Virginia Tech study, says water has been taken for granted in the national energy puzzle “because water has been cheap, plentiful and easily extracted. In many areas across the country, that’s no longer the case.”

Most people in this country grew up during a time when, as Younos says, “you flipped a switch, and the lights came on. You turned a faucet, and water came out. Most people viewed them as separate and distinct items.”

The study found that it takes 20 gallons of water to produce 1 million BTUs from hydro-electric power, 1,100 gallons for the same energy output from fossil-fueled thermo-electric plants, and 2,400 gallons for a nuclear plant. In 2005, U.S. energy consumption came to 100 quadrillion BTUs.

Michael Hightower and Suzanne Pierce, water and power experts at Sandia National Laboratories in Los Alamos, N.M., believe the only way to deal with the issue is to integrate water, energy and natural resources planning and “not do things that are good for only one aspect and bad for others,” Hightower says. “For example, in California, most power plants are coastal. If the coastal commission puts in place a moratorium on new plants, that protects the marine environment, but it forces the plants into an area where they have to rely on fresh water.”

Technologies for power production and new energy sources continue to evolve. For example, many plants are now relying on “dry cooling,” which greatly cuts water consumption, Hightower says. “Many plants are using cooling systems that function just like radiators. You can do that in areas of the country where they have lower air temperatures during key times. And some new plants are hybrids, using dry cooling during the winter and water during the summer.”

Ethanol and biodiesel products are often viewed as solutions to America’s energy-independence challenges, but most biofuels “are grown where they have rain-fed crops, so they don’t have to irrigate,” Hightower says. “My concern is that, as biofuels become more in demand, their growth will move out of the Midwestern areas into parts of the country where they need to irrigate.”

In chronically water-short Australia, a multinational corporation has begun looking at farming algae for biofuel, an approach that has caught the interest of the U.S. departments of Energy and Defense.

“The thing about algae is that you get a high oil yield per acre,” Pierce says. “Algae are compatible with a wide range of water quality, and it’s not a land-based, irrigated crop, so it doesn’t compete with food crops for land or water resources.”

“We’re in a transition period right now,” says Lorraine White, a specialist with the California Energy Commission. “We’re not going to go from a petroleum economy to a solar economy overnight, so we need to protect ourselves with a diversified portfolio of energy sources.

“As a society, we have to accept the need to invest in the future,” she says. “Or else that future will be much more expensive and much less easy to measure and manage.”

Lance Frazer is a California freelance writer, specializing in science, health, nature and environmental issues.