Study helps consumers identify the most water and energy efficient appliances
By Corrie Goldman, Siebel Energy Institute
The cost benefits of energy efficient appliances and water efficient fixtures are pretty well understood by most Americans. Switch to an energy efficient refrigerator and your electricity bill should go down. Install a low-flow toilet and your water bill should go down.
But a new study supported by the Siebel Energy Institute reveals why consumers need to consider combined water and energy use when deciding which household appliances to upgrade for increased efficiency.
Conducted by a team of scientists at the University of Illinois at Urbana-Champaign (UIUC), the research shows how water efficiency measures support energy savings and vice versa. For example, a clothes washer uses both water and electricity, but it also takes energy to get clean water to the washer and to sanitize the wastewater it produces. Likewise, water is used to produce energy, such as in cooling power plants and the fossil fuel extraction process. A consumer would need to take all of those factors into account to get a full picture of the cost of running that machine.
The researchers made some surprising discoveries by quantifying the connection between water and energy at the residential level. Cost abatement curves produced with data about appliances illustrate how you would save more money by replacing a furnace than a clothes dryer, or by upgrading to new windows instead of getting a new refrigerator.
The project, entitled “Characterizing the Performance and Cost-Effectiveness of Energy and Water Efficiency Measures in Buildings,” was led by Ashlynn Stillwell, an Assistant Professor in Civil and Environmental Engineering at UIUC, and included students Chris Chini, Kelsey Schreiber, and Zachary Barker.
The study surveyed purchase, installation, and maintenance costs, as well as direct and indirect energy and water consumption and life expectancy of items from the U.S. EPA’s ENERGY STAR and WaterSense programs.
A paper on the research was published in the August 8, 2016 edition of Environmental Science & Technology.
Stillwell said study results can be used as a decision-making tool for consumers to help them better understand which appliances and fixtures will make the most difference in water and energy use in the home.
Stillwell and Chini spoke with the Siebel Energy Institute about the project.
Q: This study takes a holistic approach to examining each appliance and fixture; looking at energy and water consumption in tandem. In your opinion, what’s most valuable about analyzing the energy-water nexus?
The most valuable reason to evaluate the energy-water nexus is that we get a fuller picture of the water and energy sectors together. As we strive toward a sustainable and resilient future, we can no longer consider only singular components of the system (e.g., drinking water) without considering a broader systems perspective: How much energy does it take to get water to my home, and then how much energy does it take to treat the water when it leaves my home? Without considering the interplay between these two vital resources, we leave out an important piece of the sustainability puzzle.
Q: Previous analyses have examined energy and water efficiency at the household scale. What’s unique about this research?
In this research, we take examining of energy and water efficiency a step further beyond in-home consumption and consider indirect resource consumption also. The indirect resource consumption for energy and water in the home takes place at the utility level. By incorporating these indirect consumptions, we create a tool that can be used for both residential consumers AND utilities.
Q: The study used publicly available data about energy and water usage in American homes. What were some of the challenges you encountered when collecting or using the data?
One of the biggest challenges in collecting data is the availability of indirect consumption statistics. For example, while there is a national database of energy consumption through the Energy Information Administration, there is no such database for water resources or energy-for-water. This challenge was significant for creating local applications of our research and data were obtained through open records requests or previous publications.
Read the rest of the interview on the Siebel Energy Institute website here.
Corrie Goldman directs communications and events for the Siebel Energy Institute, a nonprofit organization that funds cooperative research grants in data analytics and machine learning to accelerate advancements in energy science.
(Top image credit: Danilin / iStock)