A water-energy balance application with adaptations to a brazilian water supply system

According to the Alliance to Save Energy, between 2 % and 3 % of the total electric energy consumed in the world is used for water pumping in supply systems, with the consumption reduction potential through energy efficiency and conservation measures being estimated at 25 %. In Brazil, the water supply sector corresponds to 2.6 % of the total energy consumed in the country, with pumping systems being responsible for over 90 % of the total energy consumption. It is extremely common to find supersized facilities with pump motor sets operating outside their ideal points, with it being a common practice to perform flow and pressure control through the installation of valves. The use of reducing valves inserts unnecessary pressure drops into the hydraulic system, increasing energy consumption. The objective of this work is to present an energy balance of a study sector of the Autonomous Water and Sewage Service (AWSS) of a municipality in the south of Minas Gerais, Brazil, aiming to elucidate the electric energy consumption of the system and where the reduction in such consumption may occur. For this, we measured data such as the efficiency of the pump motor sets, calculated performance indicators and water loss indices, and applied the energy balance adapted. This work presents an application of a water-energy balance with adaptations to a Brazilian water supply system, under the perspective of the energy efficiency in lift station pump motor sets.