January-February 2012

From: Federally Facilitated

Save Water—Save Energy, or, Save Energy—Save Water

The water/energy nexus is a growing area of opportunity for energy efficiency companies. In 2010, Johnson Controls published “Savings Multiplied: Conserving Water and Energy to Maximize Efficiency and Reduce Emissions” a white paper that addresses water and energy savings technologies and practices, along with various case studies. One of the studies presents Johnson’s efforts at its Glendale, WI, headquarters, where water efficiency methods on the five building campus include a 30,000-gallon cistern to capture rainwater from all new roof surfaces; a graywater system to flush toilets, reducing potable water for bathroom fixtures by 77%; high-efficiency plumbing fixtures; permeable pavers that allow rain and snowmelt to filter through parking lots and move via groundwater to a retention pond; and green roofs to reduce runoff.

Water and energy are hot topics for the American Council for an Energy Efficient Economy (ACEEE), according Eric Mackres, the Council’s senior analyst and local policy lead.

“The water efficiency and energy efficiency communities are aware of each other but haven’t worked directly together to try to solve problems, and there’s a lot of opportunity,” says Mackres. Much of that opportunity is presented in a publication coauthored by Mackres, Addressing the Energy-Water Nexus: A Blueprint for Action and Policy Agenda. Mackres notes that the ACEEE’s efforts included participants working in professional capacities and nonprofits, government agencies and other research labs and organizations, and firms and manufacturers.

“Government buildings offer an opportunity, and there’s a lot of different ways of thinking about water usage and energy usage,” notes Mackres. “You can effectively target water and energy consumption in buildings, and one of those examples would be government buildings and public buildings. If you can reduce demand for water, you don’t have to worry about the treatment plant as much, because your need for new equipment and capacity decreases. In some cases up to 20% to 25% of a local government’s energy costs can be just water treatment and distribution.”