A Case based approach to benchmark the energy and water consumption of supermarkets in Sri Lanka

Abstract

Buildings are responsible for about 40% of global energy consumption, 42% of global CO2 emissions and about 30% of global fresh water consumption. Therefore, the importance of energy and water consumption benchmarking in buildings has become a major objective for governments and relevant authorities. Since energy and water consumption patterns depend upon various factors such as climate conditions, personal habits, hygiene practices and economic factors, it is most suitable to develop local benchmarks for countries/regions instead of using global benchmarks to compare the performance of the buildings. The main intention of this research is to analyse the major research gaps in energy and water benchmarking in Sri Lankan buildings, and to develop water and energy benchmarks to bridge those gaps. Energy consumption benchmarks in Sri Lankan context are available for commercial sector, hospitality industry, apparel industry and tea processing industry, which are established by Sri Lanka Sustainable Energy Authority (SLSEA). However, energy benchmarks are not available in local context for retail (supermarkets), educational, healthcare and residential building sectors. Moreover, it is identified that, water consumption benchmarking is a major research gap in Sri Lanka, as the water consumption benchmarks have been developed only for hospitality sector. The focus of this study is to establish the energy and water benchmarks for retail sector (supermarkets) in Sri Lanka. During the study, electricity consumption data from 2008 to 2020, and water consumption data from 2018 to 2020 were collected from 101 supermarkets across the country. Annual electricity consumption, annual electricity cost and annual water consumption of these 101 supermarkets were analysed against the sales floor areas and total floor areas of the relevant supermarkets. According to the analysis, electricity consumption benchmarks for Sri Lankan supermarkets was estimated as 780 kWh/year/m2 per sales floor area and 465 kWh/year/m2 per total floor area. Moreover, the water consumption benchmarks was estimated for the Sri Lankan supermarkets as 247 L/year/ m2 per sales floor area and 137 L/year/ m2 per total floor area.