Within the context of the water-energy nexus in drinking water provision, it is crucial to evaluate temporal shifts in energy efficiency. Utilizing the Stochastic Nonparametric Envelopment of Data (StoNED) approach, this research estimates longitudinal variations in the energy efficiency of drinking water services integrating multiple environmental variables. The analysis, conducted in England and Wales from 2008 to 2020, indicates that the source and quality of raw water, as well as population density, influenced the energy performance of water utilities. Quantitative findings evidenced marked disparity in energy efficiency among different companies, with an average efficiency of 0.617 and a range from 0.437 to 0.944. The dynamic assessment indicates an average annual enhancement of 1.1% in the sector, predominantly propelled by technical advancements (0.9%) rather than by improvements in efficiency (0.2%). This study emphasizes the critical need for bespoke policies and incentives to boost energy efficiency and support sustainable urban water management.

在饮用水供应中的水-能关系的背景下，评估能源效率的时间变化至关重要。利用随机非参数数据包络 （StoNED） 方法，本研究估计了整合多个环境变量的饮用水服务能源效率的纵向变化。这项于 2008 年至 2020 年在英格兰和威尔士进行的分析表明，原水的来源和质量以及人口密度会影响水务公司的能源绩效。定量研究结果显示，不同公司的能源效率存在显著差异，平均效率为 0.617，范围为 0.437 至 0.944。动态评估表明，该行业平均每年增长 1.1%，主要是由技术进步 （0.9%） 而不是效率提高 （0.2%） 推动的。本研究强调了对定制政策和激励措施的迫切需求，以提高能源效率并支持可持续的城市水资源管理。