Feasibility study of brackish water desalination in the Egyptian deserts and rural regions using PV systems

Nowadays, shortage of the water resources is a global issue. Water desalination is a solution that can be used to solve the water shortage problem. Several methods have been proposed for water desalination and are categorized to membrane and non-membrane procedures. The most popular membrane processes are electrodialysis (ED) and reverse osmosis (RO); in contrast, the most popular non- membrane processes are capacitive deionization (CDI) and distillation. All water desalination procedures need energy supplies. The solar and Photovoltaic (PV) energy is potentially a desirable green energy supply for water desalination especially for non-residential areas where the grid is not available. In areas such as deserts and offshore stations, the PV solar energy is a practical and cost effective solution for water desalination systems. Where the grid connection is available, the PV and solar desalination systems produce fewer emissions. The PV energy needs to be processed through power electronic power conditioning systems. This paper proposes the application of PV power and solar energy to supply the water desalination systems.

In this work the performance evaluation of directly driven Reverse Osmosis (RO) water desalination system by Photovoltaic (PV) arrays is investigated by a novice method. Reverse Osmosis water desalination system needs continuous supply of energy and on the other hand energy from the PV is intermittent in nature. The energy consumption of RO plant is strong function of clean water (permeate) flow rate and system pressure and they needs to be tuned to match the maximum power provided by the PV arrays. In this work a novice method to tune the RO system parameters by manipulating the position of the valve at the brine side of the RO system is proposed. A simple perturb and observe algorithm is used for automatic control of the valve position. The performance of the proposed battery less system is compared with a conventional system using PV, charge controller and battery. The proposed directly driven battery-less system provides more water per day than battery operated system.

Water is one of the earth's most abundant resources, covering about three-quarters of the planet's surface. Yet, there is an acute shortage of potable water in many countries, especially in Africa and the Middle East region. The reason for this apparent contradiction is, of course, that ∼97.5% of the earth's water is salt water in the oceans and only 2.5% is fresh water in ground water, lakes and rivers and this supplies most human and animal needs. Tackling the water scarcity problem must involve better and more economic ways of desalinating seawater. This article presents a comprehensive review of water desalination systems, whether operated by conventional energy or renewable energy, to convert saline water into fresh water. These systems comprise the thermal phase change and membrane processes, in addition to some alternative processes. Thermal processes include the multistage flash, multiple effects boiling and vapour compression, cogeneration and solar distillation, while the membrane processes include reverse osmosis, electrodialysis and membrane distillation. It also covers the integration into desalination systems of potential renewable energy resources, including solar energy, wind and geothermal energy. Such systems are increasingly attractive in the Middle East and Africa, areas suffering from shortages of fresh water but where solar energy is plentiful and where operational and maintenance costs are low. The advantages and disadvantages, including the economic and environmental aspects, of these desalination systems are presented.

Design, simulation and economic analysis of a stand-alone reverse osmosis desalination unit powered by wind turbines and photovoltaics

Although current water desalination technologies are mature enough and advanced, the shortage of freshwater is still considered as one of the most pressing global issues. Therefore, there is a strong incentive to explore and investigate new potential methods with low energy consumption. It is well-known that polymer hydrogel network has the ability to absorb water via swelling. In the case of polyelectrolyte hydrogels, the charges localized on the polymer chains, which mainly drive the swelling pressure inside the hydrogel, can also separate added salt via charge-based selectivity (Donnan exclusion). When combining this material with a temperature-sensitive polymer, the heat generated by solar energy can trigger the desorption process via conformational change of polymer chains. Hence, hydrogels designed from both materials, polyelectrolyte and thermo-responsive polymer can reduce the salinity of water, such as brackish water by means of reversible thermally-induced absorption and desorption desalination processes. In addition, the desorption process can also be achieved based solely on a polyelectrolyte hydrogel system by altering the ionization of charges within the hydrogel via pH. In this thesis, hydrogel-based water desalination process were developed using acrylic acid (AAc)/sodium acrylate (SA)-based polyelectrolytes as the charge-based separation function, alone or with a combination of N-isopropylacrylamide (NIPAAm) as thermo-responsive comonomer. In the latter case, a series of chemically cross-linked polymeric hydrogels were synthesized via either free radical-initiated copolymerization or reversible addition-fragmentation chain transfer (RAFT) polymerization, thus realizing different macromolecular architecture. According to the nature of hydrogels, the reversible sorption/desorption state were triggered by either chemical stimulus (pH), or physical stimulus (heat) as the thermo-responsive polymer introduced into the hydrogels. In detail, the effect of hydrogel composition as well as the influence of the macromolecular architecture on the swelling/deswelling behavior for the synthesized hydrogels were studied. For this, their properties including their responses to external stimuli were investigated, and their ability to desalinate brackish water as well as the effciency of such desalination process were evaluated. Generally, the results demonstrated correlations between macromolecular architecture of the network structure and their performance in the proposed desalination process, such as salt rejection and desalination capacity. Moreover, the potential of the best performance materials for applications was also discussed.

It is a scientific production whose theme is that of photovoltaic energy in a residential property in the municipality of Porto Velho. Photovoltaic solar energy is the electrical energy produced from heat and sunlight. The greater the solar radiation on the solar plates, the greater the amount of electrical energy produced. Solar energy is considered an alternative, renewable, clean and sustainable source of energy. Solar energy has been used in homes, businesses, industries, in rural areas and in the generation of electric energy through solar plants, being a great option for savings in the electricity bill, in addition to being an alternative, renewable and clean energy. There are 3 types of solar energy: solar photovoltaic energy, solar thermal energy and heliothermic energy. Each acts in a different way. The growth of photovoltaic technology in Brazil and in the world has become increasingly accentuated. This is due to the decrease in equipment costs and the increase in the population’s information about alternative energy sources. However, like any type of technology, photovoltaic systems have advantages and disadvantages. Photovoltaic Solar Energy: Advantages and Disadvantages – The purpose of this text is to clarify the main ones and to resolve any doubts regarding the generation of energy through the sun. The objective is to demonstrate the advantages of this type of energy in a residential property in Porto Velho. The methodology used was that of systematic literature review.

Modeling and optimization of hybrid wind–solar-powered reverse osmosis water desalination system in Saudi Arabia

Handling the variability and uncertainty associated with integrating large capacities of renewable energy sources (RES) into the power grid is a challenge that is increasingly influencing the power systems operation. At the same time, the growing need for desalinated water in arid areas increases the importance of suitable energy sources for sustainable operation of water desalination plants. However, as power and water system operators have traditionally operated their systems in isolation, there is a lack of understanding of the interdependence and interactions between these two systems. This paper addresses this gap by proposing a risk-based two-stage stochastic co-optimization framework that coordinates the operation of a renewable-rich power system with the operation of grid-connected reverse-osmosis water desalination plants (RO-WDP) to minimize their combined operational costs while increasing the utilization of RES. From the power system operation standpoint, the RO-WDPs are considered as controllable demand, and the proposed model integrates the energy flexibility of RO-WDPs in the day-ahead power system operation. The proposed model considers the operational constraints of both power and water desalination systems, thus co-optimizing their operation without compromising the reliable supply of power and water to end-users, while taking into account the uncertainty of the demands and RES. Simulation results demonstrate the benefits of the proposed coordination on enhancing the power system efficiency, facilitating RES integration, and minimizing the combined operational costs of both systems while minimizing their operating risk using conditional value at risk.

A small-scale brackish water reverse-osmosis desalination system used in northern Saudi Arabia: A case study

Desalination of brackish water by using reverse osmosis (RO) system powered by solar PV has not been tried and examined in Palestine until now. This paper proposes rural village Al Maleh for erection and testing of the first PV-powered RO system. Al Maleh is highly qualified for testing of such systems since it has a lot of mineral hot water springs of about 3400 ppm salinity. Based on the climate conditions in Al Maleh, the paper presents the design of the PV-powered RO water desalination system. The obtained design results can be used for an economic feasibility study of this technology [Mahmoud, M. Techno-economic feasibility of PV-powered water desalination in Palestine. Special Case: Al Maleh Village (to be published).]. The performance of the designed system is investigated by software simulation. The obtained results show that a daily production of 1 m3 from the brackish water in Al Maleh would require about 820 peak watt of PV generator.

A Review on Solar Water Distillation Using Sensible and Latent Heat

The shortage of freshwater is becoming a major threat to sustainable environmental development. Water desalination techniques provide solutions for freshwater requirements. Solar energy is considered as a plentiful and effortlessly available renewable energy. Desalination with solar energy is a suitable technique to convert brackish water into fresh water and that has received greater attention. The traditional desalination processes require a substantial quantity of energy, and with an extensive investigation of different methods of desalination, frameworks have experimented in the most recent couple of decades. The different types of desalination techniques using solar energy with exergy analysis are studied and presented in this review paper. The exergy performance cost affecting factors and the economic feasibility of several desalination plants such as solar stills, humidification and dehumidification, multi-effect distillation, reverse osmosis, and multi-stage flash desalination techniques are studied and reported in this paper. The present study revealed that the desalination of water using solar energy as an efficient as well as a cost-effective method as compared desalination of water with other energy sources.

Chapter 9 - Solar water desalination system

Optimization strategy for a small-scale reverse osmosis water desalination system based on solar energy

Sea water contains 35 g/L of salt, while the maximum concentration for water intended for human consumption is 400 mg/L (fresh water). Freshwater is an essential component in our daily life; but its availability is on the decline due to population growth and climate change. To meet the demand for fresh water in regions where reserves are insufficient, several countries have adopted seawater desalination. Several physical methods allow the production of fresh water from seawater, one of them being distillation and reverse osmosis, and there is great potential to use renewable energy sources such as solar photovoltaics. In order to model the phenomenon of reverse osmosis solar-based desalination, the author presents generalities of deslination technologies in the first part of this paper. The second part is devoted to the presentation of different water desalination systems combined to renewable energy, and their benefits and drawbacks from different perspectives. In the third part, the author describes the model of a PV water desalination system using Matlab Simulink software. Based on the simulation results, the author concludes this paper with the prospects of the presented work.