Dynamic Simulation and Control of Reverse Osmosis Water Desalination Plant Integrated Within Photovoltaic System

With the significant increase of water demand, fossil- fuel cost and associated environmental impacts, the renewable energy sources driven desalination technology has become promising and attractive solution. Integrating photovoltaic (PV) and reverse osmosis (RO) technologies is considered a sustainable and cost-effective solution for brackish or seawater desalination. PV systems and membrane desalination units are available and well developed for commercial applications, and their prices decrease from year to year. RO and PV units are also available in modular configuration that can easily be built to supply water. The main challenges for further penetration PV-RO systems are associated with the fluctuating nature of the solar power resources and the decrease of the efficiency of PV module operating at high temperature. A reverses osmosis (RO) ideally operates at steady state design load, but it is required to operate on at different base load and off-design load conditions due to the fluctuations of supply and demand and increased penetration of renewable energy sources. Flexible operation of RO system is essential factor for reliable grid stability as well as for economics. Experimentation and dynamic simulation of behavior of PV-RO system offers effective tools for optimizing RO performance and control structures. The aim of this study is to assess the feasibility and effectiveness of using PV solar for seawater desalination through experimental and theoretical investigations. A PVRO unit will be designed and manufactured locally at KFUPM to evaluate the performance of the unit operating under real climate conditions (Dhahran city). A mathematical model for the PV cell for estimating the I-V characteristic curves of photovoltaic panel with respect to changes on environmental parameters (temperature and irradiance) will be developed. Based on dynamic equations for the salt concentration, and specific energy, dynamic simulation of RO will be carried out and calibrated. These theoretical and experimental studies will be used to optimise the RO performance, assess its capabilities and limitations and propose the appropriate control structures. A good control design is necessary to maintain water-production costs at acceptable level and elevate the plant availability. The main deliverables of this study will include a pilot, a reference scientific and technical knowledge base on the performance characteristics of PV-RO systems. Furthermore, a conceptual design and site-specific guideline for implantation of the proposed solar desalination application will be undertaken. Thus, this proposed PV-RO project will contribute to the growth of renewable energy to KSA national energy mix and ensure sustainable use of water resources.