No abstract

The supply of freshwater has become a worldwide interest, due to serious water shortages in many countries. Due to rapid increases in the population, poor water management, and limitations of freshwater resources, Egypt is currently below the water scarcity limit. Since Egypt has approximately 3000 km of coastlines on both the Red Sea and the Mediterranean Sea, seawater desalination powered by marine renewable energy could be a sustainable alternative solution, especially for remote coastal cities which are located far from the national water grid. The objective of this research work is to evaluate the feasibility of a floating desalination plant (FDP) concept powered by marine renewable energy for Egypt. A novel design of the FDP concept is developed as an innovative solution to overcome the freshwater shortage of remote coastal cities in Egypt. A mobile floating platform supported by reverse osmosis (RO) membrane powered by marine renewable power technology is proposed. Based on the abundant solar irradiation and sufficient wind density, Ras Ghareb was selected to be the base site location for the proposed FDP concept. According to the collected data from the selected location, a hybrid solar–wind system was designed to power the FDP concept under a maximum power load condition. A numerical tool, the DNV-GL Sesam software package, was used for static stability, hydrodynamic performance, and dynamic response evaluation. Moreover, WAVE software was used to design and simulate the operation of the RO desalination system and calculate the power consumption for the proposed FDP concept. The results show that the proposed mobile FDP concept is highly suitable for being implemented in remote coastal areas in Egypt, without the need for infrastructure or connection to the national grid for both water and power.

Increasing water demand in remote coastal areas in Egypt has shifted attention to the role of floating desalination plants to alleviate water shortages. A novel mobile floating desalination plant is proposed for Ras Ghareb city in Egypt. The compatibility between floater natural periods and the energy excitation range of waves in deployment area can lead to resonance responses. Therefore, understanding the motions behaviour among waves of such floaters at a particular location is important for its safety, performance and operation. The goal of the present study is to investigate the suitability of proposed concept for Egyptian environment conditions by characterising the behaviour of the plant motion responses during its entire deployment conditions. Based on full scale design of the proposed plant, experimental study over a range of wave heights and frequencies was performed in the present study using a 1:100 scale model test. In order to identify the plant natural frequency and damping ratio, free decay and swinging tests were performed for different load conditions. Different wave heights were tested during the experiments in order to investigate the effect of wave height on the heave and pitch responses at plant natural frequencies. The experimental test results were compared with numerical results from frequency domain program HydroD implemented in Sesam DNV GL software package. Results show that heave and pitch motion responses give the closest agreement between the measurements and numerical predictions over the whole range of wave periods except the peak spike. The proposed cylindrical FDP is compared against a conventional ship FPSO concept widely used for offshore freshwater production and it was concluded that new cylindrical FDP shows better motion responses compared to conventional ship FPSO concept in same wave bands in Egypt.