Developing intelligent, cost saving pump controls for wastewater networks through integration with the electricity spot market

Abstract

The provision of stable and reliable wastewater services at an appropriate cost is a significant issue for public utilities (Rathnayake, et al., 2012). Energy costs often constitute the largest part of expenditure for nearly all water utilities worldwide and can consume up to 65 per cent of a water utility’s annual operating budget (Martinez, et al., 2007). One of the greatest potential areas for energy cost-savings is the scheduling of daily pump operations (Boulos, et al., 2001). In general, sewer networks are divided into two types, gravity and forced by pumps networks (Ermolin, 1999). Ideally, efficient sewer systems are designed to drain sewage by gravity of the topology where the sewer flows from the high point to the low point (Ostojin, 2011). However, pump stations are often required subject to topology, ground conditions, location of wastewater treatment plants and other factors (Chen, et al., 2001). Majority of sewer networks and pump stations operate based on the common high/low sewage levelsand not taking into account energy costs associated with pumping (Vanrolleghen, et al., 2005).The intelligent and smart control of the utility’s assets can offer electrical energy and cost saving opportunities when coupled with the ability to purchase electricity from the spot market. The purpose of this project is to develop a pump control method to test the feasibility of operating a wastewater system on the spot electricity market with the goal of cost reduction. Therefore, Infoworks ICM has been used to assess the performance of pump control method. This paper describes both the improvement of evaluation methods for the proposed smart controller and the rate of cost savings.