Life-cycle energy analysis of performance- versus age-based pipe replacement schedules

摘要

Although many North American water utilities are upgrading their systems through both regular maintenance programs and additional pipe replacement, rarely does this process take whole-of-life considerations into account. This article details the development of a life-cycle energy analysis (LCEA) that accounts for energy associated with reducing leakage through pipe replacement and describes its implementation at a large system. Energy used in pumping was compared with embodied energy tied to pipe replacement in a baseline scenario and three replacement plans. Results indicated that the annual operational energy savings of 4.9 × 10~6 to 6.4 × 10~6 kW·h achieved by 2020 comes at a cost. The embodied energy invested in replacing pipe stock for ductile-iron pipes with diameters of 6 to 16 in. would be 0.88 x 106 to 2.05 × 10~6 kW·h/mi, a significant expense that results in an initial energy payback period of 17.6 years for the most aggressive replacement plan.