Methodology for Improving Pump Operation Efficiency

A methodology to optimize the operation of water supply pumps is developed for use in minimizing pump operation costs. The developed methodology is directly applicable to complete water distribution systems or isolated pressure zones with a single dominant storage facility and multiple pump stations. The optimal pump operation methodology involves two basic phases: the development of an optimal tank trajectory, and the development of an optimal pump operating policy to achieve the optimal trajectory. The optimal trajectory is determined using dynamic programming while the associated pump policy is determined using an explicit enumeration scheme. In order to test the applicability of the developed methodology it was applied to the third high pressure zone of the Washington D.C. water system. To examine the impact of a variable electric rate schedule and a variable system demand schedule on the resulting optimal pump policy, the methodology was applied to four different representative days. Annual energy usage cost savings of approximately 6.7% were projected.