Benchmarking techno-economic efficiency of bioresources management in the water industry: a synthetic index-based approach

Abstract

The transition towards a circular economy in the water industry has increased the strategic importance of bio- resources management, particularly in relation to renewable energy generation and sewage sludge treatment within wastewater services. Despite this relevance, techno-economic performance in bioresources activities has not been systematically assessed. To address this gap, this study introduces the Techno-Economic Bioresource Index (TEBI), a novel benchmarking indicator based on a non-radial Data Envelopment Analysis approach. The framework is applied to a sample of 50 observations operating in England and Wales. The results reveal sub- stantial heterogeneity in performance, with TEBI values ranging from 0.124 to 1.000 and an average score of 0.76, indicating an average improvement potential of approximately 24%. Inefficiencies are found to be variable- specific rather than systemic, with energy utilization, energy export, and untreated sludge emerging as the main sources of inefficiency for several utilities. No relationship is observed between techno-economic efficiency and utility size. A super-efficiency analysis further discriminates among efficient utilities, enabling the identification of robust benchmarks. The findings demonstrate that efficient bioresources management can play a key role in supporting the transition towards a circular water industry, and that TEBI provides a transparent and operational tool to support regulatory benchmarking and evidence-based decision-making.