Water and energy have always been linked. Large-scale hydroelectric plants at reservoirs such as Shasta Dam may be the most obvious connection, but today the focus is turning to less visible links such as the amount of energy needed to pump, treat and deliver water to Californians.
Climate change is making the water-energy connection even more important as local agencies continue to find ways to reduce fossil fuel emissions.
It takes a significant amount of energy to treat and deliver water to homes and businesses. Once that water is delivered, consumers use even more energy to heat, cool and pressurize it for various daily activities.
The California Energy Commission estimates that water-related energy consumption and demand account for up to 19% of all electricity used in California, with much of that use occurring in the residential and industrial sector.
Reducing water use translates directly into energy savings. The state’s roadmap for reducing greenhouse gas emissions, formally known as the AB 32 Scoping Plan, includes a section on water that calls for significant investments in water conservation, system-wide water efficiency projects and water recycling.
Local water agencies are implementing a number of programs to reduce their energy use or at least the impacts their operations are having on the environment. Some of their responses include using solar panels, anaerobic digesters, hydropower, conservation, high-efficiency vehicles and performing high energy operations to off-peak times.
Sonoma County Water Agency, for example, recently committed to delivering “carbon-free” water to its customers by 2015. Carbon-free water means that all agency utility power will be replaced by renewable energy sources resulting in zero net greenhouse gas emissions from water supply operations. The agency plans to achieve this goal by using solar, biogas, hydropower and conservation.
The agency recently installed two new solar power systems totaling more than 1.5 megawatts, equivalent to the energy needed to power 1,500 homes. The systems will help save $250,000 a year in utility costs and reduce carbon emissions by 37.5 million pounds. Last year, the solar panels provided about one-third of the Sonoma Valley County Sanitation District’s power needs.
At the Inland Empire Utilities Agency in Chino, where 300,000 dairy cows are packed into a 50 square-mile area, cow manure is being converted into usable energy using anaerobic digesters. Bacteria in the digesters break down the organic waste into “biogas,” a renewable energy that is used to generate electricity and operate the agency’s groundwater desalter. The leftover waste product is turned into a high quality organic fertilizer used by schools, gardeners and golf courses.