Potential Energy, Economic, and Environmental Impacts of Hydro Power Pressure Reduction on the Water-Energy-Food Nexus

The installation of hydropower pressure reduction (HPPR) technology in water supply networks (WSN) has recently been encouraged to limit water losses through leakage. Traditionally, pressure reducing valves (PRVs) were positioned at strategic nodes in a water network and were operated continuously to dissipate excess energy and minimize pipe failure. The alternative adoption of low-cost and highly reliable HPPR technology - Pump As Turbine (PAT) - can recover energy to improve the sustainable management of water networks and increase the energy, economic, and environmental benefits derived from the provision of water resources. To encourage the exploitation of HPPR, indicators and metrics were developed and applied for a case study (olive crop production with an irrigation network in Andalusia, Spain). The case study incorporated (1) a number of WSN scenarios based on water supply conditions, location of the HPPR within the network, and pipe age; (2) the expected performance of the PAT in the market; and (3) the expected optimal performance of an HPPR design based on a variable operation strategy (VOS). Independent life cycle indicators and nexus metrics were created to enhance the evaluation of the performance of HPPR technology as part of the water-energy-food nexus. In this case study, the new metrics expressed the impact of HPPR technology on the water-energy food nexus in terms of climate change and in the context of olive production in an irrigation network. The methodology for assessing combined energy, economic, and environmental metrics (3EM) can be used to account for the value of HPPR deployment in any WSN. These metrics can inform local decision makers and national policy makers, by providing relative and/or absolute evidence on the environmental impacts of HPPR technology in the water sector.