A feasibility study of solar-powered reverse osmosis processes

The use of solar-powered reverse osmosis desalination systems is a sustainable and environmentally friendly solution in the desalination industry. However, there are some substantial technical and economic challenges due to the intermittency and fluctuation of solar energy. Recent technological improvement and feed-in tariff policies enable these systems to be competitive with conventional grid-connected reverse osmosis systems. In this paper, a feasibility study of the integration of solar panels with the grid to power small-scale reverse osmosis systems (namely up to 2000 m3/day) is conducted in Iran, as a country with a low price of electricity. For this purpose, a city located on the northern coast of the Persian Gulf, which deals with water shortage but has high solar radiation, is selected as a case study. Five different scenarios are considered, and the impacts of the use of energy recovery devices, energy storage systems and membrane characteristics have been studied. Finally, a detailed cash flow analysis is provided for each scenario. In the end, we show the economic viability of solar-powered reverse osmosis plants when their unused or surplus solar electricity is exported to the grid. •Impacts of energy recovery devices, batteries and permeability have been evaluated•The scenario where all the PV power is exported to the grid has the highest NPV•Using energy recovery devices is not economically viable in each scenario•For discount rates higher than 23%, there is no room for PV-RO desalination plants•The worst scenario is the one that uses batteries