Water scarcity makes some types of energy less appealing
By Jeff Thomas
Water and energy have been inexorably linked in human history at least back to ancient Babylonia, where windmills helped power irrigation as early as 1700 BC. Since then, that relationship has become one of the great axioms of the industrial age – that is, it takes great volumes of water to extract and convert energy resources, and often great energy resources to move and treat water.
And in a world in which such resources are under increased pressure, the interconnection between the two – known as the water-energy nexus to some—may never have been more pronounced. That is particularly true in the arid West, where rapidly increasing populations are expected to more than double the need for more power by 2030, which will compete with agriculture and growing municipal use for freshwater supplies.
“I think it’s really surprising people about the interconnection,” said Tom Iseman, the water program director for the Western Governor’s Association. “For a long time WECC (the Western Electric Coordinating Council) has dealt with water supply and power generation scenarios, but this is the first time we have worked on it from a regional perspective.”
The numbers can be a little staggering. For instance, the Virginia Water Resources Research Center estimates it takes 60 liters of water to keep a single, 60-watt light bulb lit for 12 hours. Conversely, about 80 percent of the cost for supplying municipal water supply is the power cost for treatment and distribution, according to the Nuclear Energy Institute.
The fact that proposed power plants are finding it difficult to get through water issues in places such as New Mexico and Arizona perhaps isn’t startling, but in the last decade the issue is also cropping up in wetter areas of the Rocky Mountain West. Two power plants have been denied permits because of water impact issues in Idaho and the Corette plant in Billings was denied water supply from the Yellowstone River during critical low-flow months.
“I have talked to a lot of power companies, like Excel, which tell me that they have surplus water rights, but even they are looking at the upcoming constraints from a water perspective (up to and including global warming),” said Stacy Tellinghuisen a Resource Analyst for Western Resource Advocates in Boulder, Colo.
This hasn’t escaped the attention of the U.S. Department of Energy, environmental advocates, water resource organizations and the electrical supply organizations of our nation. The DOE has a national program examining issues surrounding the water-energy nexus. WECC, which oversees the grid and electrical reliability over much of the western U.S. and parts of Mexico and Canada, has contracted with the agency’s Sandia Lab in New Mexico for a state-by-state examination of where and what future power plants could be located to best serve transmission needs amid decreasing water availability.
The nexus necessarily deals with a large range of environmental issues including clean water and air, carbon emissions, aquatic natural resources, water and power conservation and renewable energy. But for some people, that complexity makes this nexus the Norman McClean poster child of environmental issues—that is: “Eventually, all things merge into one, and a river runs through it.”
And that’s the primary reason it is the No. 1 issue for Tellinghuisen.
“I love rivers,” Tellinghuisen said bluntly. “And I think most water managers recognize that we are now in a zero-sum game. There is no more water available, so it’s simply a shift to a new user from an old user.
“The fact that it’s a zero sum game makes it even more pressing, but there are solutions that have multiple benefits.”
One solution that has little benefit is business as usual, in which traditional coal-fired generating plants consume large amounts of water account for the most of the energy consumed in most western states.
Your run-of-the-mill 500 megawatt coal-fired plant, which could serve a city of about 140,000 people, consumes about 3,500 gallons a minute of water in creating electricity, cooling and air treatment, said Mike Hightower, who oversees research and evaluation of innovative environmental and energy technologies for the DOE’s Sandia Lab in New Mexico.
“That’s about 5 million gallons a day – the same water consumption as a town of about 50,000,” said Hightower, adding that this figure doesn’t take into account the water consumed or polluted in extracting and cleaning coal before it is shipped to the power plant, not to mention the carbon load that burning coal puts in our atmosphere.
Other thermal generating plants -– which create steam to move turbines and water to cool the steam—don’t get a free pass either. A thermonuclear plant employing the closed-loop cooling technology common to the West consumes slightly more water than a coal plant. That’s about 23 gallons of water per day per household, or an additional 30 percent of what that typical U.S. home consumes in water, according to the Nuclear Energy Institute.
But natural gas-fueled power plants consume even slightly more water in steam-powered plants, Western Resource Advocates (WRA) reported, though other natural gas technologies can significantly reduce water consumption. And the generation of natural gas is not without its own additional water and environmental concerns.
Hydrofracking, where water and chemicals are pumped into wells to free the natural gas through extended fractures in the rock, is now an established norm in the West. That process can consume 3 million to 6 million gallons of water per well, and generates concerns that the injected toxic chemicals may also contaminate ground and surface waters.
The Rocky Mountain West already uses a great deal of water in energy exploitation, WRA reported, as much as 500 million gallons a day for oil and gas recovery. Oil shale recovery has advanced quite a bit in reducing water consumption since the idea was actively advanced in western Colorado in the late 1970s, but will also come with a price.
“Oil shale is looking at consuming about three gallons of water for every gallon of fuel produced,” Hightower said. “The projections are for about 1.5 million barrels (of oil) per day, which is about 200 million gallons of water a day. That is about the same as the water consumption for Denver metropolitan area.”
In the West, almost all power plants have closed-loop systems for cooling (think cooling towers) rather than once-through systems, which require most water to be withdrawn but don’t actually consume as much water.
Few of our rivers could in fact tolerate the warming influence of a once-through system, but there are evolving technologies allowing for dry cooling. The downside? These systems reduce the effectiveness of the power plants and are not very useful in higher temperatures and that’s precisely where power needs are growing fastest in the West – for cooling in the summer months.
“The issues are great in the West, but we are also in a good position to make changes,” Hightower said. “The renewable side of the equation is very high in the West.”
But through the prism of the nexus, even renewable energy has a different focus experts said. In a cursory glance of some of the renewable options:
For years, energy policy has had little or nothing to do with water policy, or the reverse for that matter, experts said. But according to Iseman, that will likely change as policy makers in the West are quickly coming aware of the nexus.
“I think there going to be some great opportunities to put some better strategies together,” he said.
Essays in the Range blog are not written by High Country News. The authors are solely responsible for the content.Originally posted at NewWest.net