Feasibility study of photovoltaic powered reverse osmosis and pumping plant configurations

The present study has as main goal to make a technical and financial feasibility study of a photovoltaic powered reverse osmosis (PV-RO) and pumping system developed at the Renewable Energies Laboratory, Federal University of Ceará, in Fortaleza, Brazil, with the aim to supply drinking water for human consumption at low cost from brackish water in semi-arid areas. The research intends to determine parameters like drinking water production, specific energy consumption and specific costs, as well as the optimal system size regarding financial viability. The used configurations allow comparing two strategies: with and without batteries. The research was conducted with different levels of brackish water salinity, to identify a viability limit. The technical and financial analysis show that the unit produces satisfactory and competitive results, comparing with different plants in the world, concluding that, assuming a 2748 mg/l brackish water well, the configuration that brings the best cost/benefit is the no battery plant using 3 PV panels, which provides a daily production of 175 l of drinking water at 324.60 mg/l, with a specific consumption of 3.12 kWh/m³ and presenting a competitive specific cost of 10.32 US$/m³.