The Water Energy Nexus: The Connection Between Water Use and Energy

By Marla Esser, USGBC-Missouri
Gateway Chapter Education Committee

I am sure every parent has said it more than they can possibly remember… “Don’t waste the water!” It is an important habit to instill in children. But not wasting water has other implications that even we adults need to be more aware of. Water has a lot more connection to our lives- and our energy bills- than most of us realize.

In the U.S., the average family of 4 will use over 400 gallons of water each day. 70% of that water is used indoors mainly for drinking, cooking, cleaning and hygiene. Leaks are a big part too and account for more than 13% of the water used indoors, according to the EPA’s WaterSense program. And while you probably know that turning off the faucet while you brush your teeth or limiting shower time saves water, what you might not know is those actions also conserve energy.

Connecting Water and Energy –
Save water by saving energy. Save energy by saving water. The interdependency between energy and water is an often unknown fact. It makes sense when you think about it –electricity or other fuels are used to clean, move, and heat water from its source to our sinks. And water is used to cool and clean – key activities in making electricity and making most of the “stuff” we use. For example, a 60-watt incandescent light bulb uses between 3,000 gallons and 6,000 gallons of water to power up 12 hours a day over the course of a year, according to a study by researchers at Virginia Polytechnic Institute and State University.

Pretty much everything we use in our daily lives has an energy and water “cost.” We just don’t think about it since things aren’t labeled with how much energy and water are used in their creation. They should be!
Water and energy are intertwined throughout the five stages in the water cycle, as shared on the EPA web site.

Extracting and conveying water: Extracting water from rivers and streams or pumping it from aquifers, and then conveying it over hills and into storage facilities is a highly energy intensive process.

Treating water: Water treatment facilities use energy to pump and process water.

Distributing water: Energy is needed to transport water.

Using water: End users consume energy to treat water with softeners or filters, to circulate and pressurize water with circulation pumps and irrigation systems, and to heat and cool water.

Collecting and treating wastewater: Energy is used to pump wastewater to the treatment plant, and to aerate and filter it at the plant.

The US alone uses 520 billion kilowatt hours (kWh) of electricity to move, treat, and heat its water. This equates to 13% of the entire electricity use in the US, according to The Guardian.

To learn more, join us at The Water Energy Nexus, as we examine the interrationship between water and energy usage by following a drop of water from water provider through end user into waste treatment facility and discussing all the energy that is consumed along the way.

This USGBC Missouri Gateway program will be held on Tuesday October 13, 2015 at 5:30pm at Alberici, 8800 Page Ave. St. Louis, MO 63114. Visit www.usgbc-mogateway.org/calendar to learn more and register.