The effects of including intricacies in the modelling of a small-scale solar-PV reverse osmosis desalination system

With the global demand for freshwater rising alongside the cost of power generation from fossil-based fuels, access to potable water in small (marginalised) or coastal communities can be alleviated using renewable energy sources such as solar or wind. Whilst large-scale renewably powered desalination systems have been the focus of much research, where smaller systems are concerned, there remains ambiguity as to the significance of modelling all system intricacies and the effects of Solar-Photovoltaics (solar-PV) scalability on total water yield.After detailing the methodology used to model such Reverse Osmosis (RO) systems, this paper presents the results of simulations used to investigate a small-scale, stand-alone, solar-PV powered (RO) system, with/without battery storage. Results indicate that system performance is affected differently when including power characteristics of RO devices and also by the temporal resolution used in simulations. The scale of the renewable energy conversion used (solar-PV) appears to be a factor in some cases. Parameters varied in the simulations include RO (unit) power characteristics, saline water concentration/temperature, PV panel power characteristics as well as the dynamic charging and discharging of batteries and the efficiency of power conditioning. Simulations are done using MATLAB and use laboratory-based data to establish device characteristics.

► We model a small-scale, stand-alone, solar-PV powered reverse osmosis system.
► We examine time-resolved power characteristics of system components.
► Also examined is the effect of temporal resolution on system performance.
► Water estimates increase with time-resolved power and lower temporal resolution.
► Effects increase with smaller PV conversion capacity (metre square of panels).