RT info:eu-repo/semantics/article T1 Assessing energy efficiency and its dynamic changes in the water sector integrating heterogeneity and carbon emissions A1 Maziotis, Alexandros A1 Sala Garrido, Ramón A1 Molinos Senante, María K1 Energy efficiency K1 Energy productivity change K1 Benchmarking K1 Heterogeneity K1 Stochastic frontier analysis K1 Water services AB Enhancing the energy performance of water utilities is a critical step towards achieving a net-zero carbon industry. Traditional energy performance assessments in the water industry often overlook heterogeneity among water companies and fail to account for changes in energy efficiency (EE) over time. To address these shortcomings, this research employs Stochastic Frontier Analysis (SFA) techniques to assess energy performance of two types of water companies such as Water and Sewerage Companies (WaSCs) and Water-only Companies (WoCs) within a single energy frontier model. Empirical analysis of water companies in England and Wales reveals an average EE score of 0.940 over the 2010–2020 period, suggesting a 6% energy-saving potential. English and Welsh water industry exhibited an overall 0.3% annual improvement in energy productivity change (EPC). This improvement was primarily attributed to efficiency changes (average 1.005), which offset the negative shift in technology change (average 0.998), while the scale effect remained negligible (average 1.000). WaSCs experienced a slight increase in EPC, with an average value of 1.018, indicating an improvement in energy productivity. In contrast, WoCs exhibited a decrease in EPC, with an average value of 0.989, suggesting a decline in energy productivity. These disparities were due to opposite shifts in the efficient production frontier; WaSCs had a positive shift (average 1.012), while WoCs had a negative shift (average 0.984). The study also highlights the impact of regulatory policies on energy performance. The 2009 price review involved modest improvements (average EPC = 1.013), while the 2014 price review yielded unfavorable results (average EPC = 0.993), emphasizing the need for long-term policies to facilitate sector-wide transformation towards carbon neutrality. PB Elsevier SN 0959-6526 YR 2024 FD 2024 LK https://uvadoc.uva.es/handle/10324/73627 UL https://uvadoc.uva.es/handle/10324/73627 LA eng NO Journal of Cleaner Production, noviembre 2024, vol. 480, 144137 NO Producción Científica DS UVaDOC RD 05-feb-2025