Environmentally friendly hybrid solutions to improve the energy and hydraulic efficiency in water supply systems

Electricity is needed to extract, treat and convey water. Water service providers recognize that electricity costs constitute one of the biggest operational costs of Water Supply Systems (WSS). The practice of water supply requires new energy management strategies and solutions which need to improve WSS energy and hydraulic efficiency and to be innovative, cost-effective and environmentally friendly.Three management practices and solutions for WSS are presented and analyzed in this paper. The first solution proposes the installation of a water turbine in gravity pipes for pressure control and for electricity production. The second solution is the optimization of pump operational schedules according to electricity tariffs and water demand patterns. The third solution focuses on the coupling of a renewable energy source capturing device (a wind turbine) to a water supply pumping station in a hybrid configuration. The studied water system, typical for Water District Metering Areas (DMAs), represents a conventional WSS, which consists of pump and gravity branches.The main findings suggest that water turbines can be used to take advantage of the excess and otherwise unutilized available hydraulic energy in piping systems and to convert it into electricity. The optimization of WSS pump operational schedules and the renewable hybrid electricity producing solution can both minimize operational costs and electricity consumption for water pumping. The use of a wind turbine results in electricity production from a renewable energy source, which minimizes the reliance on electricity produced from fossil fuels. The result is minimized CO2 emissions depending on the emissions factor of the electricity transmission grid and the generated electricity can be used locally or fed to the national electricity transmission grid.

► Three management practices for Water Supply Systems (WSS) are presented.
► Water turbines take excess hydraulic energy and convert it into electricity.
► Pump optimization and renewable sources minimize the costs of running WSS.
► Wind turbines for electricity production minimize CO2 emissions and energy reliance.