Advances of Renewable Energy Powered Desalination

The supply of fresh water is becoming an issue of increasing importance in many areas in the world. In arid areas potable water is very scarce and the lives of people in these areas strongly depend on the amount of available water. Seawater desalination requires large amounts of energy and if this energy is produced by fossil fuels it will harm the environment. Therefore, renewable energy sources coupled to desalination offer an attractive solution. Considerable research is under way to optimise the matching of renewable energy technologies with the corresponding desalination technologies and especially to reduce the energy required per unit volume of fresh water produced. The present paper gives emphasis to the following technologies: 1) RO powered by PV and 2) Solar collectors for powering RO through a Rankine cycle. These systems are reviewed and recent developments are presented. Finally the economics of the systems are analysed and overall figures of the present fresh water cost are given.

Renewable energy (RE) has been identified as an appropriate response to climate change and fossil fuel depletion by many governmental bodies. It has shifted the energy industry towards renewable and sustainable energy systems over the last few decades. This expansion has also increased the demand of specialists for design, installation and maintenance of different RE systems. Most people working in this sector are not well trained or educated enough whereas some of them are not even aware of sustainability. This has shifted towards formulation, model, develop and incorporation of new courses and programmes that would provide sufficient knowledge and skill in the sustainable RE sector. Moreover, the implementation of these new RE courses shouldn’t be limited to engineering level but also focuses on providing basic knowledge to everyone working in this field. Hence, in the present study, two-course structures have been suggested, i.e. general course which would offer basic knowledge and awareness of different RE systems in school level (including primary, elementary, intermediate and secondary) and in the professional programmes (Industrial Training Institute (ITI), diploma, undergraduate, postgraduate and research). Moreover, adequate knowledge would be provided not only in the theoretical field but also in the practical field depending upon the level of programme. Furthermore, undergraduate, postgraduate and research levels students would be provided with a broad knowledge of science, engineering design, planning and implementation of RE systems, while ITI and diploma level would acquire skill development and training in the RE systems.

The building sector has a significant contribution to global warming with direct or indirect emission of greenhouse gases, including CO2, CO, N2O, and CH4. Residential sector building contributes 36% of the total CO2 emission globally. The delocalized energy production and building with more sustainable design and low energy are the features that attract the project developers and architects to Renewable Energy Systems (RES). This chapter presents an attempt for the sustainability assessment of building-integrated renewable energy systems. The chapter identifies different RES used for onsite production of renewable energy for buildings’ energy need and their environmental and socio-economic impacts. Solar, wind, geothermal, and biomass energy are the primary sources for standalone and onsite energy production in building sector. The selection of RES technology highly depends on the availability of the energy source and type of required energy. The fluctuation in availability of renewable energy sources and the diverse nature of the required energy for building makes integrated renewable energy systems more sustainable for buildings energy requirement. LCA is a standard assessment method considered by researchers for the environmental analysis of building-integrated RES, while economic impact assessment is performed by Life Cycle Costing (LCC). All energy systems, including renewable and non-renewable energy systems, have an impact on the environment. Energy is strongly associated with environmental problems ranging from local to global issues. This includes air pollution, carbon emissions, ozone depletion, etc. For industrialized and developing countries, these problems can be more severe if not properly integrated with infrastructure. The technological non-complexity and local applicability make the solar energy preferred choice for buildings’ energy application. Solar energy is used both for the production of electrical and thermal energy. RES resulted in higher environmental sustainability with lower impact as compared to fossil fuels. However, the extent of impact strongly depends on variables like location and source of energy for the replaced energy system. Biomass-based system is the most economical system among the considered building-integrated RES. RES systems provide more job opportunity for the equivalent spent on fossil fuels based system. However, higher installation cost, lack of expertise, high maintenance, and high capital investment are the critical barriers in its application. A case study presenting a renewable energy system for building different energy needs such as heating, cooling, electricity, and hot and cold water production is presented at the end of the chapter.

V-7-100 - Petroclival meningloma. Presigmoid approach

Chapter 15 - Environmental Life Cycle Analysis of Water Desalination Processes

In order to reduce fossil energy consumption at desalination plants, it has become necessary to replace fossil energy with clean energy. Currently, the reverse osmosis systems connected to solar energy is a promising technology for desalination of seawater / brackish water, especially in arid and semi-arid areas that have a large solar deposit and are remote from the public grid. The objective of this work is to show the efficiency of introducing renewable energy in brackish water desalination plants by the effect of comparing the energy consumption for a system without renewable energy source and system powered by the photovoltaic system (solar energy). As well as a program developed on Matlab software environment in order to, optimize the energy consumption of a desalination plant for the proposed plant is about 0.1269 kWh/m3.

Sea water desalination is a developing technology producing potable water with many applications worldwide particularly in arid areas. It is an energy intensive process and its integration with renewable energies can produce low-carbon fresh water. Among several water desalination technologies reverse osmosis is the dominant method, based on semi-permeable membranes, producing high quality clean water. The island of Crete, Greece has moderate water resources while their demand is increasing for several reasons. Unfortunatelly, its supply is adversely affected by climate crisis. One method to increase the supply of potable water in Crete is the desalination of seawater using reverse osmosis. The water desalination plants can be powered by solar and wind energy which are abundant in the island. The integration of seawater desalination with renewable energies results in the production of fresh water with low carbon impacts. A SWOT analysis of using solar and wind electricity to power the water desalination plants in Crete has been implemented. It is indicated that there are several strengths and many opportunities for developing seawater desalination plants powered by green electricity in the island. It is concluded that the use of solar-PV and wind electricity for powering seawater desalination plants in Crete reduces the carbon footpritnt of the produced drinkable water minimizing the impacts to climate change.

This paper investigates the exergy and energy rationality of a near-future, two-step hydrogen production system in the Black Sea on a custom-built hydrogen ship with 100% onboard wind, wave, and solar energy system. In the first step of this concept, hydrogen will be produced from the low-salinity seawater by electrolysis utilizing the onboard renewable energy. Part of the hydrogen produced will be used in the second step, which is the major production step, claiming the H2S gas, which is exceptionally rich in the seawater. The hydrogen and sulfur products will be shipped by hydrogen-powered shuttle ships to the nearby city of Sinop to blend hydrogen with the natural gas (NG) to form a hydrogen city. Thus this project presents a novel coupling of the land-side and the sea-side operations with renewable energy and hydrogen in an exergy-based minimum CO2 emissions responsibilities. This on-board H2S exploration concept for hydrogen and sulfur production is compared with the current NG explorations in the Black Sea and the use of NG on the landside. A detailed comparison of the total carbon footprint shows that NG explorations in the Black Sea will be responsible for direct and indirect-nearly avoidable (due to exergy destructions) CO2 emissions, while the ever-increasing H2S threat faced by all Black Sea countries will remain at an increasing rate. A new exergy-based optimum H2S claim depth calculation and control algorithm for onboard operations have also been developed and designed, which shows that economy-based optimization—if ever exists—will be responsible for nearly avoidable CO2 emissions, while the on-board hydrogen production and utilization on the land side have a minimal environmental footprint. None of the earlier studies available in the literature concerning the exact harmful effects of hydrocarbons address exergy rationality. Renewable energy systems like wind turbines and solar energy systems, along with other renewable and waste energy systems like geothermal and wave energy are mostly treated individually, which are not free from large exergy destructions. Therefore, future energy plans with environmental concerns must be carried out from the source to the very last point of demand sectors. This is the specific attribute of this research. Novelty Statement None of the studies about the exact harmful effects of hydrocarbons involve exergy rationality and the consequences of this ignorance on the environment and overall energy budget and economy. Renewable energy systems like wind turbines and solar energy systems, along with other renewable and waste energy systems like geothermal and wave energy are mostly treated individually, which are not free from exergy destructions. For example, a solar photovoltaic (PV) plant generates power but releases heat back without claiming it. This unclaimed heat represents about 50% of the unit exergy of the available solar energy and leads to exergy destruction that is responsible for nearly avoidable CO2 emissions because destroyed thermal exergy has to be offset by spending additional fuel in another system, which most likely is using fossil fuels in a boiler. The term nearly precedes the word avoidable, because exergy destructions may not be completely avoided. Even solar and wind energy systems have exergy destruction components during their operation. Yet, a solar PV and heat system would be a much better choice from the exergy rationality point of view. Although the ongoing increase in the renewable shares in the energy stock, it is essential to follow where the power is used in the built environment. For example, according to Global Wind Energy Council, within the next 10 years 234 GW, within the next 30 years 1400 GW offshore wind power capacity is expected to be installed. However, these installations will never know where this electricity and how this electricity is used in an energy/exergy balance and rationality when coupled to the landside through national and international grids. Therefore, future energy plans with environmental concerns must be carried out from the source to the very last point of demand sectors. Whether off-shore or land-based, wind turbines just generate electric power without asking where the electricity goes and how rational it is used in the built environment. There is no control over the best way of utilizing this wind energy. Instead, hydrogen production with renewables and utilization in next-generation fuel cells produces power and heat (pending on heat distribution tariffs for the fifth-generation district energy systems and LowEx applications, the temperature is the best fit for LowEx applications). The interrupted and unpredictable characteristics of renewables are offset by hydrogen storage.

A deep learning-based forecasting model for renewable energy scenarios to guide sustainable energy policy: A case study of Korea

The transition from fossil fuels to renewable energy sources is imperative to mitigate climate change and achieve sustainable development goals (SGDs). Hydrogen, as a clean energy carrier, holds great potential for decarbonizing various sectors, yet its production remains predominantly reliant on fossil fuels. This study explores a novel approach to sustainable hydrogen production by integrating offshore wind energy with reverse osmosis (RO) desalination technology. The proposed configuration harnesses offshore wind power to energize both a RO desalination system and water electrolysis unit. Initially, the wind energy powers the RO desalination process, purifying seawater, and then desalinated water is directed to water electrolysis system for generating green hydrogen directly from seawater. The resulting renewable hydrogen holds potential for diverse applications, including marine industries, and can be transported onshore as needed. The RO system is configured to treat 20 kg s−1 of seawater with a salinity of 35 000 ppm, aiming for a high recovery ratio and reduced freshwater salinity. A pressure exchanger (PX) is integrated to recover energy from high‐pressure brine stream and transfer it to the low‐pressure feed water, thus reducing the overall energy consumption of the RO process. The concentrated brine extracted from RO desalination is proposed to be utilized for the production of sodium hydroxide that can further pretreat incoming seawater and enhance the effectiveness of the filtration process by mitigating membrane fouling. This pressure exchanger increases the energy efficiency of the RO system from 63.1% to 64.0% and exergetic efficiency from 13.9% to 18.2% increasing the overall first and second law efficiencies to 37.9% and 33.5%. By leveraging offshore wind power to drive RO desalination systems, this research not only addresses freshwater scarcity but also facilitates green hydrogen generation, contributing to the advancement of renewable energy solutions and fostering environmental sustainability.

Hydrogen farm concept: A Perspective for Turkey

The area of the Western Route Project for South-to-North Water Transfer (WRP) in China, located in the upper reaches of the Yangtze River and the marginal area of the Qinghai-Tibet Plateau, has sufficient water resources that transfers could be considered. However, potential transfers are limited due to a fragile eco-environment. The eco-environmental water demand is the key constraint for determining the available quantity of water that could be transferred in view of the existing water demand for local social and economic development. Considering the effect on the eco-environment, this study investigates the available quantity of transferable water in the WRP for the dual purpose of protecting the local eco-environment and decreasing the crisis of water resources in the western areas by considering the water demand for river channel eco-environment downstream of the dams as the main constraint. In order to estimate the eco-environmental water demand, the low runoff and Tennant methods are studied. According to the results of risk analysis, the proposed schemes for water transfer have high reliability and low risk. The risk will be further reduced if in the future reservoirs are operated jointly.

Solar and wind opportunities for water desalination in the Arab regions

Freshwater shortage in many areas around the world presents a constraint to sustainable development. Desalination of saline water, especially seawater which accounts for more than 97% of the total water quantity on earth, represents a feasible option in many cases. The need for sustainable sources of energy to operate high energy - consumption desalination systems is mandatory. Future, in remote coastal and arid areas, the use of renewable energy for powering desalination plants could be a feasible option in view of several technical, economic and environmental considerations. In this paper, the issue of integration of desalination technologies and renewable energy from specified sources is addressed. The features of Photovoltaic (PV) system combined with reverse osmosis desalination technology, which represents the most commonly applied integration between renewable energy and desalination technology, are analyzed. Further, a case study for conceptual seawater reverse osmosis (SW-RO) desalination plant with 1000 m3/d capacity is presented, based on PV and conventional generators powered with fossil fuel to be installed in a remote coastal area in Egypt, as a typical developing country. The estimated water cost for desalination with PV/ SW-RO system is about $1.21 m3, while ranging between $1.18-1.56 for SW-RO powered with conventional generator powered with fossil fuel. Analysis of the economical, technical and environmental factors depicts the merits of using large scale integrated PV/RO system as an economically feasible water supply with an autonomous power supply.

Over the past decade, energy demand has witnessed a drastic increase, mainly due to huge development in the industry sector and growing populations. This has led to the global utilization of renewable energy resources and technologies to meet this high demand, as fossil fuels are bound to end and are causing harm to the environment. Solar PV (photovoltaic) systems are a renewable energy technology that allows the utilization of solar energy directly from the sun to meet electricity demands. Solar PV has the potential to create a reliable, clean and stable energy systems for the future. This paper discusses the different types and generations of solar PV technologies available, as well as several important applications of solar PV systems, which are “Large-Scale Solar PV”, “Residential Solar PV”, “Green Hydrogen”, “Water Desalination” and “Transportation”. This paper also provides research on the number of solar papers and their applications that relate to the Sustainable Development Goals (SDGs) in the years between 2011 and 2021. A total of 126,513 papers were analyzed. The results show that 72% of these papers are within SDG 7: Affordable and Clean Energy. This shows that there is a lack of research in solar energy regarding the SDGs, especially SDG 1: No Poverty, SDG 4: Quality Education, SDG 5: Gender Equality, SDG 9: Industry, Innovation and Infrastructure, SDG 10: Reduced Inequality and SDG 16: Peace, Justice and Strong Institutions. More research is needed in these fields to create a sustainable world with solar PV technologies.