The International Energy Agency concluded that freshwater use is becoming an increasingly crucial issue for energy production around the world in its 2012 World Energy Outlook.
Between steam systems for coal plants, cooling for nuclear plants, fracking for natural gas wells, irrigation for biofuel crops, and myriad other uses, energy production consumed 66 billion cubic meters (BCM) of the world’s fresh water in 2010. That is water removed from its source and lost to evaporation, consumption, or transported out of the water basin — as opposed to water withdrawn, used, and then returned to its source for further availability, which is a far larger amount.
According to figures it shared with National Geographic, IEA anticipates this water consumption will double from 66 BCM now to 135 BCM by 2035 with most of the growth accounted for by coal and biofuels:
If today’s policies remain in place, the IEA calculates that water consumed for energy production would increase from 66 billion cubic meters (bcm) today to 135 bcm annually by 2035.
That’s an amount equal to the residential water use of every person in the United States over three years, or 90 days’ discharge of the Mississippi River. It would be four times the volume of the largest U.S. reservoir, Hoover Dam’s Lake Mead.
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More than half of that drain would be from coal-fired power plants and 30 percent attributable to biofuel production, in IEA’s view. The agency estimates oil and natural gas production together would account for 10 percent of global energy-related water demand in 2035….
The surest way to reduce the water required for electricity generation, IEA’s figures indicate, would be to move to alternative fuels. Renewable energy provides the greatest opportunity: Wind and solar photovoltaic power have such minimal water needs they account for less than one percent of water consumption for energy now and in the future, by IEA’s calculations.
This presents a challenge, since river flows, aquifers, and other sources of fresh water are already being strained by the twin drains of population growth and less reliable rainfall due to climate change. The United Nations is projecting that by 2025, 1.8 billion people will live in regions with severe water scarcity, and two-thirds of the world’s population could be living under water-stressed conditions. Given water’s importance in different forms of energy production, this presents a double hit: Less available fresh water for human consumption, plus strained and costlier energy supplies.
IEA sees water consumption for coal electricity shooting up 84 percent, from 38 to 70 BCM per year by 2035. So-called “dry cooling” systems could address this, but the plants cost more and generate electricity less efficiently. Nor is carbon capture and sequestration technology likely to help.
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While biofuels’ water consumption will be lower than coal’s — 41 BCM in 2035, up from 12 BCM today — its increase of 242 percent will be much larger. Irrigation requires a lot of water, though estimates vary wildly and the industry claims it’s finding ways to cut back. IEA puts it between four and 560 gallons of water needed to produce one gallon of corn ethanol. Other estimates put it as high as 10,000 gallons of water per one gallon of biofuel. And that’s all bound up with the damaging effect biofuel production is having on world food supplies.
There are solutions, such as moving to less water-intensive methods like pump irrigation, but the trade-off is far more electricity use from potentially unsustainable sources. Cellulosic ethanol, made from non-food sources, is another possibility, but IEA estimates it won’t be commercially viable until at least 2025.
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Also, as National Geographic notes, biofuels’ level of water consumption is grossly out of whack with their contributions to world energy supplies: They provide a mere 3 percent of the energy that drives cars, trucks, ships, and aircraft, and IEA projects they’ll increase to just 5 percent by 2035 under current government policies.
As for fracking, IEA’s estimates covered the entire source-to-carrier production process, and under this framework natural gas’ water consumption reach just 2.85 BCM by 2035, or 2 percent of total consumption. Though the concentration of water use at individual fracking projects can still put a strain on water supplies for local commentaries.
By. Jeff Spross
