Reverse Osmosis
Large-scale reverse osmosis (RO) plants with productions of the order of several cubic meters per day are extensively used throughout the world for water desalination. These systems, using electricity for running the high-pressure pumps, are among the ones with the lowest cost per cubic meter of water produced. Nevertheless, in some cases, for instance small rural sites or during catastrophes where drinkable water is not available, small RO systems running on photovoltaic (PV) systems could also be used to obtain drinkable water for life support.
Water desalination systems using renewable energies as a power source are still not common due to the high initial investment cost since the desalination processes are very energy intensive. In this study, the possibility of using Photovoltaics (PV) as a power source to run a Reverse Osmosis desalination system has been investigated. Reverse Osmosis has been chosen because it is the cheapest desalination technology and also it is commercially available in a range of sizes.
A reverse osmosis (RO) plant with an average daily drinking water production of 0.8–3 m3/d was installed by the Aachen University of Applied Sciences and the Energy and Water Research Centre of the Canary Islands Technological Institute (CIEA–ITC) at the test fields of the Spanish institute in Pozo Izquierdo (Gran Canaria Island). The plant is supplied by a stand-alone 4.8 kWp photovoltaic (PV) system with an additional battery storage of 60 kWh.