Dr. Sharon deMonsabert, P.E. Associate Professor, Urban Systems Engineering George Mason University Fairfax, VA 22030-4444 Phone: 703-993-1747 Fax: 703-993-1706 Barry L. Liner Consultant - Management Practice Water Research Center (WRc inc.) 7700 Leesburg Pike, Suite 400 Falls Church, VA 22043 Phone: 703-918-9573 Fax: 703-749-7962
Orlando, Florida January 6, 1996
ACKNOWLEDGMENTS: The authors would like to thank Mark Ginsberg, Director of the Federal Energy Management Program (FEMP) for the funding and support of this research; Katherine Mayo of the National Renewable Energy Laboratory (NREL), without whom this project would not have been successful, for her overall guidance; and Rick Albani, Director of Technical Services, Vista Consulting Group (703-827-9752), for his help in providing information about water and wastewater utility operations.
WATERGY: A Water and Energy Conservation Model for Federal Facilities Dr. Sharon deMonsabert, P.E. Barry L. Liner
PURPOSE Federal facility managers have more information on energy systems than they do on water usage and conservation practices. Through financial assistance and education, FEMP hopes to give these managers a clearer determination of the impact water use has on energy consumption. Although many software tools exist for the evaluation of energy conservation measures alone, WATERGY will analyze the potential of water savings, and associated energy savings associated with water conservation, at Federal facilities. This paper serves as an overview of the water-energy relationship assumptions which were used in the development of WATERGY. INTRODUCTION Water conservation can be defined as any action that reduces water use of loss in which the resources used to generate the savings have a lesser value than the resources saved. These resources include fuel oil, natural gas, coal and other energy resources in addition to water. For example, boilers and cooling systems may consume large quantities of both water and energy in commercial buildings. Similarly, domestic hot water typically represents the second largest (behind only heating and cooling) energy usage in residential facilities.1 Reducing hot water consumption through the use of low flow shower heads, as well as efficient washers and dishwashers, will result in a reduced energy demand. The Energy Policy Act of 19922 directs Federal agencies to implement all energy and water conservation projects with payback periods of less than 10 years to the maximum extent possible. Executive Order 12902, Energy Efficiency and Water Conservation at Federal Facilities3, requires that U.S. Government agencies perform survey to "identify those facilities with the highest priority projects based on cost effectiveness." A June 1993 Energy and Environmental Institute study approximates Federal expenditures for water resources between $0.5 billion
and $1.0 billion annually4. The Federal Energy Management Program (FEMP) is required to consider water as well as energy, and includes the SAVEnergy program, which conducts Federal facility energy and water surveys and prioritizes proposed water and energy conservation projects, a water component.5 As mentioned above, this paper is meant as a general overview of the relationship between water and energy conservation and cursory attempt to provide some guidelines to generate a ballpark estimate of how much water and related energy can be saved at a given facility. EXISTING INFORMATION The difficulty surrounding the quantification of the relationship between water and energy conservation is primarily due to the lack of coordinated studies. A substantial amount of work has been done on both water and conservation and energy conservation, and many realize that there exists a relationship between them. Yet few efforts have attempted to quantify the synergy between the two fields. In...