The Influence of Photovoltaic Self-Consumption on Water Treatment Energy Costs: The Case of the Region of Valencia

Energy consumption is one of the principal components of the operative costs incurred by providers of water services, both financial and environmental. Fortunately, in recent years solar panel technology has improved substantially, and photovoltaic self-consumption has become a tool that can reduce the costs of water reuse and other water services. Regions with a scarcity of water resources make a considerable use of non-conventional sources, consuming a significant amount of energy, which has a high financial and environmental cost and compromises the sustainability of the water supply. This research analyses the possibility of replacing part of this energy with self-consumption through photovoltaic panels based on data obtained for the Region of Valencia in order to analyse the impact of energy substitution on energy costs. Performing a Cost–Benefit Analysis, self-consumption projects require an electricity market price of between 0.14 and 0.18 EUR/kWh, so in financial terms it is not a particularly attractive alternative. However, the avoided greenhouse gas emissions have a high value, and including them in the calculations, the price needed to be in feasible amounts of 0.04–0.10 EUR/kWh for a small installation and 0.02–0.08 EUR/kWh for a large one. In other words, photovoltaic self-consumption is still today an alternative with financial difficulties, but the associated environmental benefit justifies public intervention as it is a beneficial energy alternative in a context of high greenhouse gas emissions.