For decades, Americans worried about running out of energy to keep their cars revving and their homes heated, but with technologies making oil, natural gas and other fossil fuels more plentiful, the danger now is that the world might run out of the water needed to produce power.
Top energy analysts are finding that power generation and oil and gas development — particularly from shale bedrock — are threatened in areas of water scarcity because increasingly critical extraction techniques are heavy users of water.
The danger, reports say, lies in the U.S. Southeast and West, as well as in the deserts of the Middle East and China, home to some of the most promising fields for fuel extraction worldwide.
Outside of farming, no other industry uses as much water as energy. Worldwide, the energy industry typically consumes 15 percent of the water withdrawn from rivers, lakes and reservoirs. In the U.S., the share is even higher: Electric power alone accounts for 40 percent of all water use, increasingly putting it on par with drinking water and other essential uses by households and businesses.
As the planet’s population grows to 7 billion and beyond, and people increasingly migrate to dry, sunny climates such as the American West that have limited supplies of water, clashes between human and commercial needs for water are expected to grow.
“When we flip on a light, we rarely think about water. But electricity generation is the biggest user of water in the United States,” said Sandy Postel, director of the Global Water Policy Project.
Huge quantities of water are needed to drive the turbines that generate power and to cool nuclear power plants. The amount of water needed to produce oil and gasoline is growing rapidly as companies tap into harder-to-reach sources buried deep in the bedrock using water-intensive techniques such as hydraulic fracturing. This technique, commonly called fracking, shatters rock by forcing water and chemicals into it at high pressure.
Even oil wells in Saudi Arabia, Iraq and other Middle Eastern nations that have been producing billions of gallons of fuel for decades increasingly require water-intensive techniques such as fracking and water injection to keep the fuel flowing. As a result, every gallon of gasoline consumed on the highways today requires at least 13 gallons of water to make, Ms. Postel said.
Reports from the U.S. Department of Energy and the International Energy Agency have documented some spot energy shortages in the U.S. and abroad that were caused by water constraints. Analysts predict the trend will only increase.
• In 2012, a delayed monsoon in India reduced hydropower output at the same time electricity demand was running high, contributing to two days of blackouts that affected an estimated 660 million people.
• Lack of water available for injection for some of Iraq’s biggest oil fields in the south is keeping hundreds of thousands of oil barrels off international markets each day.
• An extreme drought in September 2010 cut the Hoover Dam’s power-generating capacity by 23 percent, while low snowpack in the Sierra Nevada mountains last year cut California’s hydroelectric power by 8 percent.
• Extreme drought in the fall of 2011 led the city of Grand Prairie, Texas, to ban the use of municipal water for hydraulic fracturing in order to save the dwindling drinking water supply.
• In 2007, 2010 and 2011, the Tennessee Valley Authority had to reduce power output from its Browns Ferry Nuclear Plant in Alabama because the temperature of the river into which the plant discharges was high enough to raise ecological risks.
• In 2009, an energy company in Nevada had to abandon plans to build a coal-fired power plant because not enough water was available.
Shortages in the South
Although water shortages in the American West have been anticipated for years, the report found that the areas most likely to experience power outages caused by water stress were the Southeastern states of Florida, Georgia, Alabama, North Carolina and South Carolina. In those states, periodic droughts cause low river flows and high water temperatures, either of which can force utilities to cut back on power generation.
“Water is increasingly becoming a limiting factor on U.S. energy production,” said Melissa Whited, an economist at the Civil Society Institute. Because power plants consume so much water, they increasingly are “at the heart of controversies” in communities plagued by power shortages, she said.
China is even more strapped for water to generate electricity. More than 70 percent of China’s coal-fired power plants are in areas prone to water shortages, and the Asian giant has plans to double power generation in desert regions in the west and north where water is also scarce.
China “is likely to face significant water constraints and conflicting water interests between population and industry” in coming years, said Paul Reig, an analyst with the World Resources Institute. China’s power companies will have to develop techniques such as air cooling and wastewater recycling if they hope to stay in business, he said.
One ray of hope in desert regions like western China and the U.S. is the increasing viability of solar and wind power, which use little water. The International Energy Agency predicts that water constraints will force the U.S., China and India to rely increasingly on such technologies for power generation.
Water and shale drilling
In the U.S., the mandate to include about 10 percent of corn-based ethanol in each gallon of gas also has indirectly stepped up energy demands on water supplies in the Midwest, which grows much of the corn, a particularly water-thirsty crop.
Perhaps the most far-reaching problem stemming from water scarcity lies in Texas and other areas of the arid West where large fields of shale oil and gas have been discovered. Extraction of oil and gas from shale requires vast quantities of water — as much each year as is used by a city of 5 million people, the Environmental Protection Agency calculates.
But such ample water resources are not available in West Texas, where a drought has left some reservoirs nearly empty. That has posed a threat to developing the Wolfcamp shale wells and other sizable shale formations there.
Energy analysts are optimistic, however, that the innovative U.S. energy firms that pioneered shale extraction will find ways to get around the water constraints through recycling and other techniques.
In a promising development, Apache Corp. and a few other shale specialists have reported success at using brackish water for fracking their shale wells. Brackish water is more plentiful in the regional aquifers.
Apache also says it is treating and recycling its fracking water to eliminate the need for fresh water, in a process that is cheaper than disposing of the water entirely. The development has been heralded as a breakthrough in the fracking industry.
The efforts of fracking pioneers in the U.S. are being watched around the world. A report by the energy consulting firm Wood Mackenzie found that more than half of all shale resources worldwide are in areas where water is scarce, and the problem particularly plagues China, which has the world’s largest known reserves of shale gas.
“If shale gas production is really to take off globally,” the water scarcity problem must be resolved, said Tara Schmidt, a Wood Mackenzie analyst.