When you open that faucet, it’s more than water that’s flowing.
A few years back, number crunchers at the California Energy Commission tried to add up how much electrical power (and other forms of energy) goes into using water in California. The bottom line number they came up with: 19%. That is, nearly a fifth of all the power generated in California — as well as huge quantities of natural gas and diesel fuel consumed in the state — goes into water-related uses. You might call that report, entitled California’s Water-Energy Relationship, as The Great Wake-Up Call. The idea that so much power could go into this one vital activity—moving and treating and using water—is both stunning and captivating. And it has spurred both state agencies and water and power utilities into action.
The California Public Utilities Commission, responsible for overseeing the activities of the state’s big investor-owned electric utilities on one hand and numerous small water providers on the other, responded to the 19% number by authorizing a series of pilot projects to assess how to cut the amount of power used in connection with water. Since the CPUC is supposed to make sure that utility investments are cost-effective and don’t burden ratepayers with excessive charges, the focus of most of the pilots was on areas where utilities could get the most bang for the buck. Mostly, that turns out to be water conservation.
The logic for that is pretty straightforward: Water is heavy (62.4 pounds per cubic foot) and tends to resist moving uphill. It takes a lot of energy to move water, but also to treat it, and then treat it again after we use it. If you use less water, you move and treat less water, and you use less energy. The pilot projects ranged from installing high-efficiency toilets and low-flow shower heads in a jail to high-tech systems to manage landscape irrigation, to new methods of closely regulating pumping operations to minimize power consumption.
Rami Kahlon, who directs the CPUC’s Water Division, says the pilot projects did show water savings but were less successful in showing reduced energy consumption. “We were hoping it would be easier to quantify how much energy is in water,” he says. “We were hoping that we could operate pumps and motors more efficiently and gain huge energy savings. That just didn’t occur. But the effort was worthwhile because it gave us ideas of where we need to put our focus.”
In fact, the effort has led the CPUC to dive deeper into the water-energy nexus. One preliminary finding: The California Energy Commission’s oft-quoted 19% “power for water” number is likely an underestimate (among other findings, the CPUC says a lot more power is needed for pumping groundwater than previously known). And in a decision adopted last month, the commission recognized the water-energy nexus as an area for big potential power savings and invited utilities to submit new project proposals.