Water and Energy

It is often a surprise to learn how much energy is embedded in the water we consume. Although it is more apparent when we are using heated water for showers, washing our hands, or doing the laundry, even cold water comes to our tap having been pumped and treated at great energy cost to the local water utility. A large amount of energy is used to pump, convey, treat, and deliver water, and much more energy is consumed to heat water at the consumer level. Energy is also required to collect, treat, and discharge wastewater.

The same is true on the energy side of the equation. When we turn on the lights, watch television, listen to the stereo, grab a cold beer from the refrigerator, or use a hair dryer, the amount of water used to create the electricity we are consuming is usually not top of mind. Large quantities of water are embedded in the energy we use, since water is used in the production of energy, primarily for cooling purposes.

When water or energy resources are managed, it is often with a siloed focus on each and not on the deep connection that exists between water and energy. This is often called the “water-energy nexus.”

How Much Energy is Embedded in Local Water Use?

Extensive research on this topic has been done in California, but the question remains largely unanswered for the rest of the United States and Canada. The amount of energy embedded in drinking water and wastewater likely varies greatly from region to region due to different water pumping and treatment requirements, and national averages are not very helpful. Each water utility will need to calculate these values for their own systems.

How Much Water is Embedded in Energy?

A considerable amount of water is withdrawn and used for cooling in the production of energy. The United States Geological Survey's Estimated Water Use in the United States in 2015 report estimated that 41 percent of total freshwater withdrawals in the nation were for thermoelectric power generation.

The AWE/ACEEE Water and Energy Collaboration

Over the past decade the Alliance for Water Efficiency and the American Council for an Energy-Efficient Economy (ACEEE) have partnered on a number of water and energy related projects, thanks to grant funding from the Turner Foundation.

Water and Energy in California

California moves more water than any other region in North America, and in doing so embeds a great deal of energy in its water. The California State Water Project (which delivers water to two-thirds of California’s population in northern and southern California) is the nation's largest state-built water conveyance and power development system.

What Can Water Utilities Do?

Water utilities can recognize the water/energy connection and create water management strategies that factor both water and energy into the planning process. Water providers can use the Alliance for Water Efficiency’s Water Conservation Tracking Tool, which contains a greenhouse gas module to estimate energy savings and reductions in greenhouse gas emissions resulting from water saved through efficiency programs and plumbing codes.

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