Evaluating the potential for conserving water and energy in the water supply system of Bangkok

Abstract

The need to conjunctively manage water and energy has found widespread acceptance by the scientific community and professionals. However, its implementation on the ground has been limited due to the lack of enough evidence-based studies, proof of concepts, and an actionable agenda. This study aims to plug this gap by conducting a systematic scientific study to evaluate water and energy savings in the water supply system managed by the Metropolitan Waterworks Authority (MWA) of Thailand. A hydraulic model using EPANET 2 was developed for the pilot area within the framework of water-energy nexus, to analyze water and energy consumption, and potential tradeoffs for several alternatives. The study found that decreasing the service pressure will conserve water, while increasing the supply pressure will conserve overall energy uses by the utility and the consumers. Further, the application of hydro turbines can reduce pressure and generate electricity, while Pressure Reducing Valve (PRV) can reduce leakage by 20–25 % in case of high pressure. A supply pressure of 18 m with PRV can reduce the total energy use by 32 % (from 0.6765 to 0.4613 kW h/m3). Study results help water utilities such as MWA in taking tangible decisions to enhance both water and energy security.