Analysis of reverse osmosis plants coupled with battery-less solar photovoltaic source: comparative cases

This article attempts to simulate and compare the technical and economic performances of a battery-less solar-powered Brackish Water Reverse Osmosis (BWRO) system in accordance with actual climatic circumstances of 4 regions in Iran. In fact, the main focus is to demonstrate a possible alternative to the conventional renewable energy sources that utilize battery as a cost-intensive and component. The basic system is powered by solar PV panels. The chosen technique for connecting the RO unit with solar panels is utilizing an elevated tank for brackish water and a pump assisted by a variable frequency drive (VFD) at the same time. This system is simulated and assessed for four different regions in Iran as the case study. The results are shown based on three different numbers of PV panels that provide electricity to the system (20, 30 and 40 panels). The assessments include both technical and economic analyses. According to the technical assessment, two of the regions (Zabol and Kerman) are more favorable to utilize this system. The annual water production in these regions is 25950 and 25600 m3, respectively. Also, it is shown that the unused energy ratio increases when the number of panels increases. Economic analysis shows that Tabriz and Rasht have less feasibility due to their higher levelized cost of water ($1.25 and $1.28 per cubic meter, respectively). Moreover, it is revealed that with a higher water price, all regions can yield acceptable payback periods which are lower than 3 years.