Impact Assessment of Household Demand Saving Technologies on System Water and Energy Use

Climate change, population growth, migration, urbanisation, and ageing infrastructure will all impose significant strains on the urban water services in Europe, and cities across Europe will experience increasingly frequent shortfalls in supply/demand balance. It is widely accepted that the mitigation of these and other emerging challenges should be sensitive to increasing energy prices, the environment, and the desire for low carbon intensity solutions. This paper presents the development of a new methodology for assessing the impact of household water savings from different water demand management interventions based on their water-related energy use and cost, as well as their impact on the supply/demand balance. The methodology has been applied to the water distribution system of a European city to demonstrate its application using different water demand management interventions for different types of water savings. Sensitivity analysis for different population growth rates that are representative of the different growth rates across the EU was carried out. The results show different degrees of water, energy, and cost savings can be achieved depending on the type (s) and proportion of household micro-component appliances and fittings considered. In all the intervention strategies considered, there are important trade-offs to be made between the different performance indicators as not all interventions will result in water savings and/or reductions in water-related energy use and costs or have a positive impact on supply/demand balance.