This month, for the first time in more than a century, many Colorado residents will be able to legally collect rainwater that falls on their own property. That’s an example of the complex regulations that govern water access and control in the drought-ridden states in the U.S.
And while states are battling over water rights for agriculture, the energy industry is facing a growing water problem of its own.
Electric power plants withdraw about 190 billion gallons of a day making them the largest user of freshwater in the United States. And while the industry returns all but a small percent of this water to its source, getting access to the needed volumes of water is becoming more costly and more challenging.
And even more water will be needed in coming years as electricity demands grow and carbon capture solutions (which are heavily dependent on water processes) are deployed. Unfortunately, the timing could not be worse as many parts of the country are experiencing droughts.
Adding to the problem for utilities is the fact that water requirements are now being used by various groups to constrain operations at existing plants or block plans for new plants. For example, writing in his blog in March, EnergyBiz Editor-in-Chief Marty Rosenberg cited a Wall Street Journal reported that noted “mounting concerns about water [were beginning] to shape local energy decisions.” The Journal article pointed to examples where companies were re-evaluating new coal power plants plans or putting projects on hold.
Problems across the Board
Water issues cut across all forms of traditional energy production and generation including oil, gas, coal, and nuclear.
(It should be noted that many alternative fuels also have water problems. Biofuels such as ethanol and biodiesel consume enormous amounts of water for irrigation to produce the crops the fuels are based on.)
The energy industry has had several major efforts over the years that explored the water/energy relationship including the DOE funded ZeroNet program, National Energy Technology Laboratory projects under the “Innovative Water Management Techniques and Concepts for Coal-Fired Electric Utility Boilers” program, and the Sandia National Laboratories Energy-Water Nexus program.
Most of the current DOE work falls under four broad categories including investigations into non-traditional sources of process and cooling water, innovative water reuse and recovery, advanced cooling technology, and advanced water treatment and detection technology.
One demonstration of adopting new water management approaches can be seen at the Pacific Gas and Electric Company's Gateway Generating Station. The 530 megawatt, natural gas station employs a dry cooling technology that uses 97 less water and produces 96 percent less discharge than a conventional water cooling system. Essentially, rather than relying on the commonly used once-through cooling approach that draws water, uses it once, and returns it to the source, the plant re-circulates water in a closed system. This reduces evaporation and draws significantly less water (intake is cut from 40,000 gallons a minute to 1.6 gallons).
Approaching the problem from another angle, this year DOE Office of Fossil Energy and Clemson University researchers demonstrated that manmade wetlands can be used to economically treat non-traditional waters sources, which can then be used (or reused) in power plants. The project, managed by the National Energy Technology Laboratory, worked with ash basin water, cooling water, and flue gas desulfurization water. The constructed wetland treatment systems, which cost 10 to 50 percent less than conventional treatment systems, were able to return the water to acceptable criteria for reuse or discharge under the National Pollution Discharge Elimination System and Clean Water Act.
Even if the drought lifts and these technologies are widely adopted, there are more problems ahead. According to an April report compiled by the National Energy Technology Laboratory, when the highly anticipated carbon capture and compression solutions are deployed, a coal plant’s water consumption will increase by 90 percent.
