One-fifth of the continental United States is currently under "extreme or exceptional" drought conditions. Crops across the country have reached a point of no return, withering in the field and leaving no hope for this growing season. And, as water becomes increasingly scarce, the nation's energy supplies could also be threatened.
According to Dr. Michael Webber* at The University of Texas at Austin:
"Our energy system depends on water. About half of the nation’s water withdrawals every day are just for cooling power plants. In addition, the oil and gas industries use tens of millions of gallons a day, injecting water into aging oil fields to improve production, and to free natural gas in shale formations through hydraulic fracturing... All told, we withdraw more water for the energy sector than for agriculture. Unfortunately, this relationship means that water problems become energy problems that are serious enough to warrant high-level attention."
In his recent NY Times Op-ed, Dr. Webber - a recognized expert on the energy-water nexus - explores how the current widespread drought could threaten U.S. energy supplies. He discusses how cities in Texas are already forbidding the use of municipal water for hydraulic fracturing (fracking). And how, in the Midwest, power plants are going head-to-head with farmers for limited water supplies.
In response to Dr. Webber's concerns, one could quickly propose potential technical solutions to these water-for-energy problems. Sea water, for instance, could be used to cool power plants either directly (salt-water cooling systems) or indirectly (through desalination plants). But, these potential solutions come with tradeoffs in energy and also face geographical constraints that will not be easily or cheaply overcome.
So, where do we go from here?
According to Dr. Webber, the nation should look toward:
- Data - the government should "collect, maintain and make available accurate, updated and comprehensive water data, possibly through the United States Geological Survey and the E.I.A."
- Research - "...the government should also invest in water-related research and development (spending has been pitifully low for decades) to seek better air-cooling systems for power plants, waterless techniques for hydraulic fracturing, and biofuels that do not require freshwater irrigation."
- Operation-ready solutions - for example, using reclaimed water for irrigation and cooling requirements at power plants and industrial complexes. Not to mention, expanding the use of dry cooling technologies and encouraging conservation and efficiency throughout the nation's energy systems.
Further, greenhouse gas emissions standards might help. Today's coal-fired power plants use much more water than combined cycle natural gas power plants, which use more water than many renewables including wind and solar power. Limiting greenhouse gas emissions - and, in turn, reducing the use of coal to produce electricity - could result in significant reductions in water use.
But, in the meantime, the fate of these two critical resources - energy and water - remain intertwined.
*Michael E. Webber is an assistant professor of mechanical engineering and the associate director of the Center for International Energy and Environmental Policy at the University of Texas, Austin. He also as a primary advisor for Plugged In authors Melissa C. Lott and David Wogan during their tenure as graduate students at UT Austin from 2007-2010.