Logo: University of Southern California

“The wars of the future will be fought over water"

New professor Kelly Sanders' work unites energy and water systems to conserve both
By: Rosalie Murphy
March 07, 2014 —
Illustration by Katherine Duffy

Kelly Sanders came to Los Angeles because she shouldn’t be able to.
“I’m intrigued by the water situation here,” said Sanders, a new assistant professor in the Sonny Astani Department of Civil and Environmental Engineering. “In 2012, we had four inches of rain. Most of our water is imported from hundreds of miles away. There’s no reason Los Angeles should exist.”
Sanders, the department’s newest member, studies the intersection of water and energy systems. She’s here because southern California has very few local water resources, and therefore, depends extensively on imported water sources located hundreds of miles away. In addition to its high water demand, Southern California has a large electricity demand, and many of the power plants that deliver that power, require water for cooling. Thus, water-scarcity could manifest itself as a vulnerability to power production if we don’t think about these resources holistically. 
Likewise, disruptions in power generation affect the water supply. “Think about Hurricane Katrina,” Sanders said. “When they lost power, they lost the ability to treat and distribute water for drinking. They lost sanitation. In developing countries, there might be access to water, but it can’t be purified and delivered to homes without sufficient energy. If you had infinite clean electricity sources, though, you could desalinate the ocean.”
Right now, Sanders is working on actually quantifying the energy used to purify and transport water. In the simplest possible terms, saving water can save energy, and vice versa.
“She’s already achieved high-level impact,” said Michael Webber, co-director of the Energy Institute at the University of Texas at Austin and Sanders’ Ph.D. advisor. “I’ve heard staffers in the U.S. Senate quoting her numbers, citing her research.”
Sanders’ passion goes beyond quantifying the problem: She wants to solve it.
The first solution she imagines is transporting more electricity and less water. In a drought like the one we’re in now, Southern California could import power from plants in water-rich regions instead of using water here locally to produce its own. Some electricity is lost in transmission, of course, but not nearly as much as is necessary to move heavy water. Plus, the infrastructure – power lines – is already in place.

But what if power plants used less water? Currently, the electricity grid withdraws a whopping 50 percent of all water taken from reservoirs the U.S. Most of it returns to its native reservoir, but not all – 4 percent of all U.S. water withdrawals evaporate when they pass through power plants. Plants that evaporate less water such as solar panels and wind turbines would, of course, conserve more water and provide air quality and climate benefits.
Or, what if we were able to match water quality with water use? Currently our water infrastructure uses “potable water,” which is safe enough to drink, for everything from sinks to toilets to lawn sprinklers. Water for irrigation doesn’t need to be so pure. Finding a way to recycle wastewater without purifying it so completely could save lots of energy – which in turn, we know, saves water.
“Sustainability crosses a lot of traditional departmental boundaries. Water and energy are incredibly interconnected,” Sanders said. “You can’t look at sustainability in a box.”
Sanders’ career itself is interdisciplinary: She completed a B.S. in bioengineering from Penn State, then shifted her focus to mechanical engineering during her master’s degree and, finally, to civil engineering for her Ph.D. from the University of Texas at Austin.
But the boundaries she wants to cross aren’t only within engineering. USC’s policy, business and film schools also drew Sanders to USC Viterbi.
“Engineers can’t solve all our problems,” Sanders said. “There’s also a social part there – we need more innovative ways to get information out. Public knowledge regarding water and energy conservation is not very good.”
That’s why Sanders is already teaching her first class – ENE 505, “Energy and the Environment.” She hopes to connect her students’ technical expertise with the social and political sides of energy and water. Without policy changes, engineering can only do so much.
There’s a special urgency in Sanders’ voice when she closes the conversation, imploring others to understand just how critical her work is.
“The wars of the future will be fought over water.”