A new study estimates that, by the time the last fossil-fuel based power plant retires around 2065, the retired plants could make available about 2.6 billion cubic meters (687 billion gallons) of water per year.
Scientists measured the potential water savings by combining the nationwide retirement ages of fossil fuel-based powerplants with water use rates and hydrologic modeling. The savings is equivalent to enough water to fill over 4.3 trillion 20-ounce water bottles annually.
The new results will be presented at the American Geophysical Union’s (AGU’s) annual Fall Meeting on Tuesday, Dec. 13 at 3:55 p.m. CST, at the McCormick Place Convention Center in Chicago, Ill. and online everywhere.
While transitioning from fossil fuels to renewable energy has a primary goal of reducing carbon emissions, in the case of retiring fossil fuel power plants, there are significant water benefits, too.
Many fossil fuel-based power plants use water to cool their systems and scrub pollutants like sulfur dioxide from combustion exhaust. Electricity production currently accounts for approximately 40 percent of the United States’ water withdrawals.
“Climate policy is water policy,” says Emily Grubert, a civil engineer at the University of Notre Dame who co-authored the new research. “The decarbonization of the energy industry can have significant implications on water systems.”
About two-thirds of the water use reduction could occur as soon as 2035, the target date for total energy sector decarbonization set by the Biden administration. The authors conservatively estimate the last existing fossil fuel-fired power plant will retire in 2065 if they run for about as long as similar plants have in the past, and if they are not slated to be replaced.
“This isn’t something that will happen decades from now. It’s in a shorter-term timeframe,” says Landon Marston, a civil engineer at Virginia Tech who will be presenting the research.
Water rights sometimes stay with the site, so net water availability depends on what replaces the fossil fuel-based power plant. When a power plant shuts down — either from policy changes or degradation — the water right isn’t necessarily released back to rivers, surface storage, or groundwater. If a more water-intensive use like a nuclear power plant replaces a coal plant, for example, no water may be freed up. But, if it’s replaced with something less water-intensive, the benefits can ripple downstream — literally. In many river basins, the models estimate that streamflow could increase by more than 50 percent by 2050.
“When that power plant goes offline, that water can be made available to downstream folks,” Marston says. “We show that some of these water availability benefits can propagate hundreds of miles downstream, where they can help not only with environmental flows, but also with [human] water needs.”
This effect is especially poignant in the western U.S., which faces worsening droughts. Some urban areas, especially like those in southern Colorado where water availability is a concern, have already been buying up water rights as power plants are decommissioned.
