RT info:eu-repo/semantics/article
T1 Carbon efficiency analysis in the provision of drinking water: Estimation of optimal greenhouse gas emissions
A1 Maziotis, Alexandros
A1 Sala Garrido, Ramón
A1 Mocholi Arce, Manuel
A1 Molinos Senante, María
K1 Carbon
K1 Water services
K1 Efficiency analysis trees (EAT)
K1 Environmental variables
K1 Greenhouse gas emissions
K1 3308 Ingeniería y Tecnología del Medio Ambiente
AB Assessing carbon efficiency (CE) in the provision of drinking water services is essential to achieve a net-zerogreenhouse gas (GHG) urban water cycle. Previous studies evaluating the CE of water companies are veryscarce and employed parametric and non-parametric. Both methodological approaches present limitations suchas overfitting issues or require assumptions about the production technology which could lead to less reliableefficiency scores. To overcome these limitations, in this study, and for the first time, we estimated CE of Englishand Welsh water companies using the Efficiency Analysis Trees (EAT) approach. This technique brings togethermachine learning and non-linear programming techniques to estimate production frontier and efficiency scores.It also allowed us to quantify the optimal level of GHG emissions in the provision of water services and estimatepotential GHG savings. Bootstrap truncated regression methods were employed to quantify the impact ofoperating characteristics on CE of water companies. The optimal level of GHG emissions was estimated to bebetween 0.062 and 133.03 tons of CO2 equivalent (CO2eq) per year and per connected property. The average CEwas at the level of 0.632. This means that GHG emissions could reduce by 36.8% to maintain the same level ofwater services. Equivalently, this corresponds to a reduction of 488,321 tons of CO2eq per year. Water onlycompanies exhibited a better performance than water and sewerage companies with an average CE of 0.785 and0.540, respectively. The performance of the English and Welsh water companies decreased over time. In 2011 theaverage CE was 0.772 whereas it went down to 0.534 in 2020. It was also estimated that on average watercompanies could reduce 0.034 tons of CO2eq per cubic meter of drinking water supplied and 16.16 tons of CO2eq/connected property per year. The regression results showed that topography and water treatment complexity hada significant impact on CE. The conclusions of this study are relevant for policy makers to define policies towarda low-carbon urban water cycle.
PB Elsevier
SN 0959-6526
YR 2023
FD 2023
LK https://uvadoc.uva.es/handle/10324/58522
UL https://uvadoc.uva.es/handle/10324/58522
LA eng
NO Journal of Cleaner Production, 2023, vol. 392, p. 136304.
NO Producción Científica
DS UVaDOC
RD 25-dic-2024