Energy efficiency in a water supply system: Energy consumption and CO2 emission

This paper presents important fundaments associated to the water/energy consumption and enhances the importance of renewable energy sources. A model of multi-criterion optimization for energy efficiency based on water and environment management policy, the preservation of the water resources, the control of water pressure and energy consumption, through a hybrid energy solution is developed and applied to a water supply system. The methodology developed includes three solutions: (i) water turbine installation in pipes where there is a need to control the pressure by pressure reducing valves, (ii) the optimization of pumping operations according to the electricity tariff and the water demand and (iii) the addition of a renewable energy source, a wind turbine, to supply energy to the pump-station and to sell the remaining to the national grid. The use of an integrated solution (water/energy) shows to be a valuable input to benefit from available hydro energy in WSS to produce clean power and the use of wind source allows reducing the energy consumption in pump-stations, which is still mostly based on fossil fuels with high levels of CO2 emissions.