Assessment of Alternatives for Energy Efficiency Improvement Using A Hydraulic Simulation Model 

Rodrigo Ulises Santos-Tellez1 , José Manuel Rodríguez-Varela1 , Juan Maldonado Silvestre1 , and Marco Antonio Jiménez García2 

1. Urban Hydraulics Department, Mexican Institute of Water Technology, México 

2. Commission for Drinking Water and Sewerage, Quintana Roo, Mexico 

Abstract: Many water utilities that provide water, drainage and sanitation services in Mexico encounter several problems performing these duties. They face insufficient funds, frequent changes of administrative and qualified technical personnel, as well as distribution-network aging. This situation, along with high water losses in transmission pipelines and distribution networks, illegal service connections, and intermittent water supply have led to a large portion of the water utilities having to deal with a low willingness from the users to pay for the service provided. Pumping and water treatment make up most of the high electricity costs generated from the provision of water supply services. 

  This paper presents the results of an energy efficiency study, using a hydraulic simulation model as a starting point in which various energy-consumption optimization scenarios were considered. Priority was placed on existing infrastructure use, the assessment of alternatives for pumping equipment operation, the addition of complimentary equipment with its corresponding capital and running costs as well as its repercussions on the service provided to end-users and finally their impact on the total running costs for the water utility. To carry out an adequate interpretation of the hydraulic model, it was necessary to perform a detailed analysis of existing pumping equipment, primarily its electromechanical parameters in such a way that upon integrating them into the model, the proposed alternatives carry the certainty of success. 

  In general form, the analyzed sources of supply produce an average of 437 L/s, with an energy consumption of 920 kW/h. Based on the hydraulic simulation, it is possible to take 5 pumping sites out of operation from the Pump Stations G.O. 1 and 2 which implies a reduction of 121.7 kW/h and as such, considering the rate at the moment of this study which is $1.025 kW/h, yields an annual savings of $55,000.00 USD, representing a 24% decrease in the total energy consumed by the distribution network. 

Key words: energy saving, water utilities, water pumping and treatment