Integrated Energy and Water Conservation Modeling

Abstract

Under the Energy Policy Act of 1992, the Federal Energy Management Program (FEMP) is required to provide federal facility managers with a clear determination of the impact of water conservation practices on energy consumption. This paper introduces the WATERGY model, which is a spreadsheet model to analyze total energy savings associated with water conservation efforts. The contribution of this effort is the development of a synergistic model based on engineering algorithms as opposed to lumped parameter estimates. The model explicitly details the relationships between direct and indirect water and energy savings. Irrigation, plumbing fixture, appliance, and boiler blowdown savings comprise the direct water component of the model. Reduction in leakage and unaccounted-for water in the distribution system are calculated as indirect water savings. Direct energy savings are calculated for hot water production. Indirect energy savings associated with distribution and collection, electric line losses, and unaccounted-for gas are determined by the model. Data sources, algorithms, and engineering assumptions used in the development of the model are detailed. The model capabilities are demonstrated for a hypothetical federal facility.