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Capacity building strategies and policy for desalination using renewable energies in Algeria
Abstract
The integration of renewable resources in desalination and water purification is becoming increasingly attractive. This is justified by the fact that areas of fresh water shortages have plenty of solar energy and these technologies have low operating and maintenance costs. In this paper, an overview of capacity building strategy and policy for desalination in Algeria is presented. Importance of training and education on renewable energies is also outlined. The contribution of the Middle East Desalination Research Center in capacity building and research and development in desalination in Algeria is also presented.
... According to the Ministry of Water Resources, the main objective of the desalination program is to free water from the reservoirs so that it can be pumped up for irrigation in the High Plains zone, thereby slowing migration from the High Plains to the already crowded coastal plain where 80% of the population live (Mahmoudi et al., 2009). Desalination is thus part of a socio-political program geared to slow the volatile urbanization process. ...
... The desalination program is conducted through a public-private partnership. The vast majority of the newly launched plants are under private build, own, and operate contracts (Mahmoudi et al., 2009). This allows the local governments to overcome the barriers of cost and uncertainty in the diffusion of seawater desalination as the private companies maintain the majority of the responsibility. ...
... Moreover, desalination in Spain conforms to, and supports, the emerging federalist pressure for greater regional sovereignty over water (Lopez-Gunn, 2009), which is backed by a network of economic and environmental actors (Swyngedouw, 2013). In Algeria XL desalination allowed the government to retain more water in the uplands in order to slow the rural exodus to the highly volatile cities along the Mediterranean (Mahmoudi et al., 2009). In Israel XL desalination was embarked upon only when the Treasury came to see it as part of a neo-liberal agenda it espoused to break the monopoly power of the national water company (Feitelson & Rosenthal, 2012). ...
In the wake of rapid population growth coupled with climate change and environmental degradation, countries around the world face increasing uncertainty in their ability to provide ample, safe and sustainable potable water. To meet this uncertainty, seawater desalination has been advanced around the world as a reliable new supply that improves water quality, aquifer restoration, water security and is essentially insensitive to climate change. Not only is the number of facilities increasing, but the size of the facilities is also increasing in order to take advantage of economies of scale. This paper analyzes the emerging trend of extra-large-capacity (XL) seawater desalination facilities by examining the rate of their global diffusion and the variables that influence this rate. These variables are explored quantitatively using logistic regression. In addition, selected country case studies provide insight into the factors that drive the adoption of XL desalination. They indicate that the decision to embark on XL desalination is largely determined by internal political factors. Specifically, XL desalination is advanced when the political costs of alternative water management strategies are high.
... According to the Ministry of Water Resources, the main objective of the desalination program is to free water from the reservoirs so that it can be pumped up for irrigation in the High Plains zone, thereby slowing migration from the High Plains to the already crowded coastal plain where 80% of the population live (Mahmoudi et al., 2009). Desalination is thus part of a socio-political program geared to slow the volatile urbanization process. ...
... The desalination program is conducted through a public-private partnership. The vast majority of the newly launched plants are under private build, own, and operate contracts (Mahmoudi et al., 2009). This allows the local governments to overcome the barriers of cost and uncertainty in the diffusion of seawater desalination as the private companies maintain the majority of the responsibility. ...
... Moreover, desalination in Spain conforms to, and supports, the emerging federalist pressure for greater regional sovereignty over water (Lopez-Gunn, 2009), which is backed by a network of economic and environmental actors (Swyngedouw, 2013). In Algeria XL desalination allowed the government to retain more water in the uplands in order to slow the rural exodus to the highly volatile cities along the Mediterranean (Mahmoudi et al., 2009). In Israel XL desalination was embarked upon only when the Treasury came to see it as part of a neo-liberal agenda it espoused to break the monopoly power of the national water company (Feitelson & Rosenthal, 2012). ...
In the wake of rapid population growth coupled with climate change and environmental degradation, countries
around the world face increasing uncertainty in their ability to provide ample, safe and sustainable potable water. To meet this uncertainty, seawater desalination has been advanced around the world as a reliable new supply that improves water quality, aquifer restoration, water security and is essentially insensitive to climate change. Not only are the number of facilities increasing, but the size of the facilities is also increasing in order to take advantage of economies of scale. This paper analyzes the emerging trend of extra-large-capacity (XL) seawater desalination facilities by examining the rate of their global diffusion and the variables that influence this rate. These variables are explored quantitatively using logistic regression. In addition, selected country case studies provide insight into the factors that drive the adoption of XL desalination. They indicate that the decision to embark on XL desalination is largely determined by internal political factors. Specifically, XL desalination is advanced when the political costs of alternative water management strategies are high.
... Furthermore, selecting the best retrofit options for a given context can vary significantly due to many factors, such as retrofit objectives, building types, climate contexts, technical issues, and stakeholder interests [23]. The benefits of retrofit policies in addressing the above issues are highlighted by literature [24][25][26][27].For example, building assessment and certification policies can assist householders in understanding the energy performance of their homes and the retrofit benefits to their homes. In addition, financial incentives can reduce economic burdens on homeowners and encourage them to start retrofits [28][29][30][31]. ...
... A lack of practitioners with rich retrofit knowledge and skills is a big challenge that hinders the implementation of energy retrofits [67,68]. Training programs and support tools can strengthen practitioners' knowledge and skills associated with energy retrofits and provide convenience for them to initiate retrofitting and avoid troubles [24], [94]- [99]. Targeted training audiences generally involve occupants and professionals. ...
This research conducted a literature review and identification of BC policies and incentives for reducing overall GHG emissions from the existing building sector. Then, this research analyzed worldwide policies and incentives that reduce embodied carbon emissions in the existing building sector. After reviewing the two categories of retrofit policies, the authors identified links and opportunities between existing BC strategies, tools, and incentives, and global embodied emission strategies. Finally, this research compiled key findings from all resources and provided policy recommendations for reducing embodied carbon emissions in retrofits in British Columbia.
... 20% of the land [1]. Moreover, this imbalance is aggravated by migration from the southern remote regions due to shortages of fresh water and energy [2]. To remedy this situation, the Algerian government has launched *Corresponding author. ...
... (2014) [1][2][3][4][5][6][7][8][9][10][11][12] www.deswater.com doi: 10.1080/19443994.2013.875947 ...
A huge geothermal aquifer is located in the northern Algerian Sahara, with
brackish water free from toxic inorganic compounds and organic matter. Therefore, this
water is appropriate for good quality potable water production after partial desalination. This
paper deals with the basic desalination plant design considerations in the context of overall
optimal aquifer exploitation. The main types of criteria for such optimization are economic
and environmental. Implementing the concept of “blending” reservoir water (at appropriate ...
... They can also help reduce reliance on fossil fuels (electricity), which are a major contributor to climate change and which provide energy security [17]. The desalination of brackish water or seawater systems powered by renewable energy sources offers a promising and sustainable solution that resolves water scarcity in many regions of the world [18]. Indeed, solar energy systems coupled with desalination have contributed to sustainable development that can take into account the environment. ...
In recent years, reverse osmosis water desalination has developed rapidly and has become the most competitive and widely used technology in the world. The number of desalination plants is increasing rapidly as freshwater needs increase. Various membrane technologies have been developed and improved, including nanofiltration (NF) and reverse osmosis (RO), whose desalination costs have been relatively reduced. Therefore, this work proposes an experimental study for a small desalination unit based on RO generated by renewable energy, which is mainly suitable for arid regions or desert areas that do not have electricity and water and can be applied for emergency treatment to meet strong freshwater resource needs. In this study, to meet the drinking water demand, a reverse osmosis desalination system is designed and evaluated in order to improve and optimize its operation. This system has a daily capacity of 2 m3. We used brackish groundwater, which has been characterized as reference water, to produce synthetic water for different salinities until seawater. The analysis is based on data obtained from experiments carried out in the standalone RO pilot designed for the production of fresh water. For this purpose, we conducted relevant experiments to examine the influence of applied pressure, salt concentration and temperature on the RO membrane performance. The effects of different factors that affect the energy consumption in the RO desalination process were analyzed, and those with significant influence were explored. The effectiveness of RO desalination coupled with a photovoltaic (PV) energy system is shown. We found the recovery rate for system operation to be 32%. An optimization study is presented for the operation of an autonomous RO desalination system powered by photovoltaic panels. The energy produced by the PV system was used to feed two pumps forthe production of drinking waterwithanRO membrane, under the conditions of the town of Bou-Ismail. As results, a 3 kWp PV system was installed based on the energy demand. The design data have shown that a 3 kWp PV system can power a 1.8 W RO load given the Bou-Ismail climate. Energy consumption in the case study under Bou-Ismail weather conditions were analyzed. The desalination of brackish water at a TDS value of 5 g/L requires an energy of about 1.5 kWh/m3. Using seawater at a TDS value of 35 g/L, this value increases to 5.6 kWh/m3. The results showed that the optimal recovery rate for system operation was determined to be 32% for a feedwater salinity of 35 g/L, and 80% for a feedwater salinity of 1 g/L.
... Furthermore, selecting the best retrofit options for a given context can vary significantly due to many factors, such as retrofit objectives, building types, climate contexts, technical issues, and stakeholder interests [24]. The benefits of retrofit policies in addressing the above issues are highlighted by literature [25][26][27][28].For example, building assessment and certification policies can assist householders in understanding the energy performance of their homes and the retrofit benefits to their homes. In addition, financial incentives can reduce economic burdens on homeowners and encourage them to start retrofits [29][30][31][32]. ...
The existing buildings and building construction sectors together are responsible for over one-third of the total global energy consumption and nearly 40% of total greenhouse gas (GHG) emissions. GHG emissions from the building sector are made up of embodied emissions and operational emissions. Recognizing the importance of reducing energy use and emissions associated with the building sector, governments have introduced policies, standards, and design guidelines to improve building energy performance and reduce GHG emissions associated with operating buildings. However, policy initiatives that reduce embodied emissions of the existing building sector are lacking. This research aims to develop policy strategies to reduce embodied carbon emissions in retrofits. In order to achieve this goal, this research conducted a literature review and identification of policies and financial incentives in British Columbia (BC) for reducing overall GHG emissions from the existing building sector. Then, this research analyzed worldwide policies and incentives that reduce embodied carbon emissions in the existing building sector. After reviewing the two categories of retrofit policies, the author identified links and opportunities between existing BC strategies, tools, and incentives, and global embodied emission strategies. Finally, this research compiled key findings from all resources and provided policy recommendations for reducing embodied carbon emissions in retrofits in BC.
... Renewable energy education: The importance given to renewable energy by the Algerian government is reflected in its plans to establish educational institutes to train professionals in the field of renewable energy and sustainable development [19]. ...
This study examines the objectives behind the Algerian government’s investment in renewable energy—whether the investment decision is for financial or socio-economic feasibility. The study applies the Net Present Value (NPV) method to provide an answer. The findings show that socio-economic feasibility, rather than financial feasibility, is sought from the investment in renewable energy. The latter remains an inappropriate criterion for assessing a project’s success or failure. The findings are helpful for future studies to build on and will likely attract the attention of policymakers in Algeria.
... The nexus of energy and water is critical in creating an environmentally safe society, and also reducing water poverty. There is a growing interest in the MENA region regarding using renewable energy for the desalination process (Mahmoudi et al., 2009). ...
... Supplying drinkable water has become a very challenging task around the globe. It is more pressing in the Middle East and North Africa due to water scarcity [1]. In reality, only 2.53 % of the global water resources are potable out of which merely 0.36 % are easily accessible by mankind [2]. ...
In this study, a rigorous modeling and simulation of a novel multi-stage flash (MSF) configuration consisting of reversing the brine circulation, termed MSF reversal (MSF-RV), is developed. Its performance is theoretically investigated and compared with conventional MSF Once Through (MSF-OT) with and without brine mixing. The MSF-RV concept is suitable for treating geothermal streams and can be driven by low grade thermal energy such as solar and geothermal energy and waste heat for direct seawater desalination. Hence, two options of MSF-RV are proposed, i) driven by a direct hot stream (MSF-RVc), and ii) powered by external heat to treat raw seawater (MSF-RVh). The analysis showed that the temperature distribution throughout the stages plays a significant role in the thermal efficiency and heat transfer area requirements for both configurations. Hence, careful selection of the design parameters is necessary to achieve the best performance. For the same recovery ratio, the MSF-RVc was found superior to MSF-OT in terms of gain output ratio (GOR) and specific energy consumption (SEC) by 52% and 60%, respectively. However, the specific area (sA) requirement of MSF-RVc is higher than that of MSF-OT by 50%. Brine mixing by recycling the rejected brine enhances the recovery ratio, GOR, and SEC for both structures. Conversely, the sA requirement increases with brine mixing but marginally for MSF-RV and remarkably for MSF-OT. Moreover, the design parameters of MSF-RVc such as the coolant inlet temperature, the temperature drop on the coolant side, and the coolant to brine ratio affect the overall performance. However, a trade-off between the thermal efficiency (GOR, SEC) and surface area requirement is still observed.
... Mahmoudi et al. established that it was critical to improve the conversion from solar energy into electrical or thermal energy so that economically viable scale-up strategies could be implemented. As solar equipment reaches mass production status (photovoltaic cells, solar collector, solar thermal plants), the case for adopting renewable-energy-driven desalination will become stronger, especially in remote areas with a high solar irradiance [26]. Ghaffour et al. [21] also noted that the development of software packages for coupling desalination and energy systems could address some limitations of solar desalination. ...
... The majority of the reviewed studies are about sizing PV/wind hybrid systems. Wind/solar energy coupling holds great promise for increasing water supplies in water-scarce regions (Mahmoudi et al. 2009). ...
The use of clean energy, especially solar energy, is “essential” to contribute to Algeria’s efforts to ensure sustainable agriculture in rural areas while reducing fossil energy exploitation. In fact, Algeria has considerable sun potential, due particularly to the Sahara desert, one of the world’s largest solar deposits. This research is based on a qualitative approach using a thematic literature review of scientific documents related to the use of solar energy in agriculture in Southern Algeria. The analysis shows that solar energy can improve farmers’ living conditions in the Saharan regions by ensuring their electricity needs (pumping water for domestic consumption, agricultural irrigation, livestock watering … etc.). The use of this type of energy is a rational solution for the sustainable development of agriculture in the Saharan area.
... Shen et al. presented the contemporary progress of BEE (Bureau of Energy Efficiency) policy mechanisms in seven particular countries and areas by investigating their practices on this policy [98]. The governments play an important role in ensuring environment protection issues and encourage building energy efficiency development by introducing and practising BEE (Bureau of Energy Efficiency) policy [98,100]. In 1997, Denmark becomes the primary country in applying for the requisite building energy efficiency program. ...
Automation, modernization, economic development and global progress depends on
efficient extraction and utilization of energy. Power generation by burning fossil fuels makes various adverse impacts on the environment. Additionally, the worldwide fossil fuel reserve is limited and depleting very fast. Hence, efficient energy usage and savings are crucial to address the environmental issues to ensure sustainable development. Buildings, both commercial and residential, represent a major energy consumption sector. Approximately 40% of the total energy is reportedly consumed in the building sector. Worldwide building energy consumption, performance measuring systems
and best practices, energy-saving techniques and policies are reviewed and summarized in this article. Underfloor air distribution, double-glazed windows, use of highly efficient electric motors and variable speed drives may play a great role in reducing building energy consumption. In the UK, the application of double-glazed windows in commercial buildings can save 39–53% energy. The proper maintenance of a building’s central heating system can save up to 11% energy. The automatic HVAC control system can reduce up to 20% of the building’s total heating load. Proper utilization of a VSD system in motor and building performance optimization by an ANOVA tool also proved instrumental in saving energy. Apart from this, the building codes of different countries also help to improve building performance by reducing energy consumption. This study will help building researchers and policymakers to make a framework for sustainable, green building.
... Seawater desalination has become an essential part of the daily routine in many countries due to the lack of freshwater resources and projected water scarcity caused by the growing population, climate change and industrial developments [1,2]. The global desalination market is now governed by reverse osmosis (RO) which currently occupies over 65% of all desalination technologies [3,4]. ...
Although membrane filtration became a dominant water treatment technology globally, it suffers from membrane fouling which aggravates with time and imposes severe adverse effects on process performance, permeate quality and, eventually, its related costs. In this work, we introduce pulsating CO2 solution backwash with intermittent pressure drops to maximize CO2 bubbles yield and radically enhance membrane cleaning. The novel backwash technique was probed during ultrafiltration (UF) of feed waters containing sodium alginate, a model polysaccharide foulants, sea salts enriched in Ca²⁺, and SiO2. Transmembrane pressures (TMP) observed during the experiments with pulsating CO2 backwash acquired an up/down profile indicating that a considerable portion of TMP was recovered after each backwash cycle, in contrast to insufficient fouling removal and subsequent TMP build-up observed with continuous CO2 and Milli-Q backwashes. Notably, pulsating CO2 backwash alleviated irreversible membrane fouling in highly saline conditions with 30 g/L of sea salts and when it is combined with 1 mg/L of SiO2 (i.e., when conventional membrane backwash was not effective). Furthermore, intense cleaning of the membrane surface and its pores was resembled by a lower fouling resistance in the subsequent UF cycles implying potentially longer operation time with less cleaning frequency and substantial energy savings.
... Furthermore, selecting the best retrofit options for a given context can vary significantly due to many factors, such as retrofit objectives, building types, climate contexts, technical issues, and stakeholder interests [25]. The benefits of retrofit policies in addressing the above issues are highlighted by literature [26][27][28][29].For example, building assessment and certification policies can assist householders in understanding the energy performance of their homes and the retrofit benefits to their homes. In addition, financial incentives can reduce economic burdens on homeowners and encourage them to start retrofits [30][31][32][33]. ...
Energy retrofits are significant in improving the energy efficiency of existing residential buildings (ERB) and mitigating greenhouse gas emissions. While many countries have introduced relevant retrofit policy instruments (RPIs), retrofit rates are still relatively low due to various complications in practical implementation. This study aims to organize the scattered information related to RPIs and their implementation, success, and obstacles across different countries and provide valuable references for retrofit strategy development. This article examined various RPIs for ERB in 11 selected countries. The investigated RPIs were grouped into four categories: direction and command, assessment and disclosure, research and service, and financial incentives. The RPIs implementation approaches in the surveyed countries were summarized and compared. Furthermore, obstacles to the uptake of retrofit schemes were identified. Finally, policy recommendations to overcome the obstacles and improve the penetration of retrofit schemes were proposed. This study can assist policy makers and other stakeholders in gaining a holistic view of RPIs and their implementation in different countries, understanding the barriers to the uptake of retrofit schemes, and developing more efficient RPIs in the future.
... The demand for these vital commodities is exponentially growing due to the rapid increase in population, industrialization and modernization. The situation becomes more severe in developing and arid regions such as the Middle East and North Africa [1]. Other regions may also face water shortages as only 2.53% of the total earth water reserves are drinkable out of which merely 0.36% are accessible to mankind [2]. ...
This work addresses the feasibility of a previously proposed hybrid desalination system comprising multiple effect evaporation (MEE) and membrane distillation (MD) processes. The feasibility study introduced here focuses on the impact of the hybridization of two separate processes on desalination plant economics. The water cost of the hybrid system is found to be 2.05 $/m³, which compares well with previously reported values and is 17% lower than that of standalone MEE system. The sensitivity of the water production cost to the MD feed flow rate indicated the existence of an optimal cost at a single-pass feed flow rate of 900 L/h. In addition, the sensitivity of the water cost with respect to the MD unit cost indicated a 0.0084 $/m³ change in water production cost for every unit change in the MD module cost. A modified structure of the hybrid system that leverages the thermal energy of all MEE effluents has also been suggested. With this system, the overall water recovery ratio can reach as high as 52% and the water cost can further be reduced to 1.84 $/m³.
... As the world's population increases and global industrialization accelerates, fresh and sustainable water supplies are under unprecedented pressure [1][2][3] . Large amounts of pollutants, such as antibiotics, organic dyes, pesticides, and heavy metal ions, are released daily into different types of water bodies, finally polluting raw water. ...
Recently enormous exertions have been dedicated to modify graphitic carbon nitride (g-C3N4)-based photocatalysts via morphological adjustment and compositional control, providing various ways for the advance of high-efficiency catalysts in the field of photocatalytic water purification. This review summarizes the latest developments in photocatalytic removal of contaminants and sterilization in water with g-C3N4-based materials, highlighting the performance and mechanism of multi-component cooperative photocatalysis. We review various strategies for improving the catalytic performance of g-C3N4-based photocatalysts, introducing theoretical calculations to explore the relationships between basic properties and photocatalytic activity. Then the performance and mechanism of photocatalytic water purification with g-C3N4-based materials are discussed. Finally, we put forward the principles and ways for the enhancement and application of g-C3N4-based composites in the future, evaluating their full life-cycle in photocatalytic water purification.
... As for the education sector, the government has recently announced the development of an executive decree on the establishment of an educational institution to train RE and sustainable development professionals [87]. The graduated professionals from this program will support the job needs for the 22 GW RE plan by 2030. ...
Energy demand has been overgrowing in developing countries. Moreover, the fluctuation of fuel prices is a primary concern faced by many countries that highly rely on conventional power generation to meet the load demand. Hence, the need to use alternative resources, such as renewable energy, is crucial in order to mitigate fossil fuel dependency, while ensuring reductions in carbon dioxide emissions. Algeria—being the largest county in Africa—has experienced a rapid growth in energy demand over the past decade due to the significant increase in residential, commercial, and industry sectors. Currently, the hydrocarbon-rich nation is highly dependent on fossil fuels for electricity generation, with renewable energy only having a small contribution to the country’s energy mix. However, the country has massive potential for renewable energy generation, such as solar, wind, biomass, geothermal, and hydropower. Therefore, the government aims to diversify away from fossil fuels and promote renewable energy generation through policies and renewable energy-related programs. The country’s Renewable Energy and Energy Efficiency Development Plan focuses on large scale solar, wind generation as well as geothermal and biomass technologies. This paper provides an update on the current energy position and renewable energy status in Algeria. Moreover, this paper discusses renewable energy (RE) policies and programs that aim to increase the country’s renewable energy generation and its implementation status.
... As for the education sector, the government has recently announced the development of an executive decree on the establishment of an educational institution to train RE and sustainable development professionals [87]. The graduated professionals from this program will support the job needs for the 22 GW RE plan by 2030. ...
Energy demand has been overgrowing in developing countries. Moreover, the fluctuation of fuel prices is a primary concern faced by many countries that highly rely on conventional power generation to meet the load demand. Hence, the need to use alternative resources such as renewable energy is crucial to mitigate fossil fuel dependency alongside the reduction of Carbon Dioxide emission. Algeria’s being the largest county in Africa has rapid growth in energy demand since the past decade due to the significant increase of residential, commercial, and industry sectors. Currently, the hydrocarbon-rich nation highly dependent on fossil fuels for electricity generation, where renewable energy only has a small contribution to the country’s energy mix. However, the country has massive potential for renewable energy generations such as solar, wind, biomass, geothermal, and hydropower. Therefore, the government aims to diversify away from fossil fuel and promoting renewable energy generations through policies and renewable energy-related programs. The country’s Renewable Energy and Energy Efficiency Development Plan focuses on large scale solar, wind generation as well as geothermal and biomass technologies. This paper provides an update on the current energy position and renewable energy status in Algeria. Moreover, this paper discusses RE policies and programs that aim to increase the country’s renewable energy generation and its implementation status.
... In the Mediterranean area various examples of inclusion of desalination techniques into the overall water system can be found [13,14]. ...
... The next region, lying to the south and southwest is the High Plateau; a highland region of level ground together with the mountains and massifs of the Saharan Atlas of the south region. The fourth region, comprising more than 80% of the country's total area, is the great expanse of the Algerian Sahara [2]. ...
Millions of people have no access to a secure source of fresh water. Nevertheless, since many arid regions are coastal areas, Desalination of seawater and brackish water by reverse osmosis is a reasonable alternative. The main objective of the present work is the study of a reverse osmosis plan operation. We have especially worked on the effect of pressure and salinity on the production and quality of the water produced. The performed work is purely experimental and is part within the framework of improving the profitability of an RO device. During this period of experimentation a physicochemical and bacteriological analysis of the permeate was carried out.
... Solar PV-based desalination system is considered one of the strongest options for renewable energy powered desalination but the levelized cost of energy (LCOE) is still high for an off grid or stand-alone renewable energy system. Previous desalination studies outlined in more details the Reverse Osmosis (RO) applications (prospect and challenges) [20][21][22], the integration of renewable energies such as solar and wind for RO desalination systems (system performance and cost analysis) [23][24][25] and the capacity building strategies and policy for desalination using renewable energies [26]. ...
This paper presents results on simulation, optimization and control of hybrid solar based energy system to power a desalination plant. The principal objective is to design a clean energy system to meet the desired electric load of the desalination plant with high renewable fraction, low cost of energy, and low carbon dioxide gas emissions. Hourly simulations and optimization were performed to determine the performance and life cycle cost of the different hybrid power configurations. The results of the baseline or the actual power system from the grid are compared with two new renewable power systems: (1) grid tied solar system: solar PV/grid/inverter power system, and (2) Off grid solar power system: PV/diesel generator/battery/inverter power system. The results show that the solar PV/grid/inverter power system offers the best performance compared to PV/diesel generator/battery/inverter. The total energy from the hybrid grid tied solar system is used to meet the AC load of the desalination plant with almost no excess electricity and power shortage. The proposed hybrid power system for the desalination plant is sustainable, economically viable and environmentally friendly: high renewable fraction (47.3%), low excess power (0.15%), low levelized cost of energy (90$/MWh), and low CO2 gas emissions (264.25kgCO2/MWh).
... Although it has been almost a decade since FITs were first introduced, the country's energy sector is still heavily dependent on hydrocarbon reserves and the solar PV sector is dominated by imports from foreign countries [88]. The main reasons for this underachievement are the dominance and preferential treatment of the oil sector (which is one of the outstanding export commodities), lack of qualified human resources in the renewable energy sector, and insufficiency of government funds for renewable energy projects [57]; (p. 923). ...
Renewable energy will be a crucial ingredient in the transition to a more sustainable future. The renewable energy sector requires a variety of financial support mechanisms in order to further consolidate and expand. Currently, the most prominent renewable energy support mechanisms are feed-in tariffs and renewable energy auctions. Although these mechanisms have been used and analyzed extensively in Western countries and, more recently, economies in transition, they have rarely been examined in the Arab Gulf region. Yet, particularly the Gulf Cooperation Council (GCC) states have undertaken important steps towards renewable energy adoption, which could be greatly facilitated with the use of financial support mechanisms. This paper analyzes the feasibility of feed-in tariffs and renewable energy auctions adoption in GCC. Based on an extensive meta-analysis of the literature on these two mechanisms in both developed and developing countries, the paper identifies a set of conditions necessary for success and evaluates the presence of favorable these conditions in the GCC context. Our findings reveal that while conditions that would ensure political feasibility are largely absent for both types of mechanisms, auctions could be a more successful strategy at the moment.
... The importance of RES for the Algerian energy system is well established in several studies. Mahmoudi et al. [32] analyzed the use of renewable energies for desalination and concluded on the importance of training and education on renewable energies for the country; [57] studied the potential of renewable energy for the development of the country calling already attention to aspects such as security supply, reliability, greater efficiency in energy conversion, transmission and utilization although no formal multicriteria analysis was proposed; [21] presented an overview of interactions between water and energy sectors concluding on the expected energy demand increase for the water sector. More recently [53], proposed a multi-criteria group decision-making to rank different renovation solutions for thermal renovation of masonry buildings in Algeria considering economic, energetic, environmental, architectural, social, and technological issues. ...
Currently, the Algerian energy system relies almost exclusively on fossil resources, but a new paradigm is emerging in the country. The Algeria program on renewable energy and energy efficiency established the ambitious goal of deriving 40% of electricity production from renewable energy sources (RES) by 2030. This study addresses the sustainability objectives of this program using a methodology, which combines an analytic hierarchy process (AHP) and experts’ feedback to evaluate different renewable energy options. The performance of different RES options was assessed against 13 sub-criteria reflecting social, environmental, economic and technical concerns. The results highlighted the importance of social and environmental criteria as the main drivers for the obtained final ranking, with three of these sub-criteria weighting 35% in the decision process. Solar power was shown to be particularly well suited for Algeria, outperforming most of the other renewable options in a large set of highly weighted criteria. Wind power ranked second, followed by biomass, geothermal and lastly by hydropower. Wind and solar power together achieved a total score of more than 0.5 out of 1. From the results, policy implications were drawn and directions for future research were suggested.
... In brackish/sea water desalination process, pre-treatment of the saline feed is a crucial step in designing of the process to avoid membrane fouling and scaling and to reduce its cleaning frequency [13]. Proper pre-treatment is an essential aspect in desalination process via reverse osmosis technology for successful plant operation to ensure treatment performance [14][15][16]. ...
Integration of renewable energy with desalination technologies has emerged as an attractive solution to augment fresh water supply sustainably. Fouling and scaling are still considered as limiting factors in membrane desalination processes. For brackish water treatment, pre-treatment of reverse osmosis (RO) feed water is a key step in designing RO plants avoiding membrane fouling. This study aims to compare at pilot scale the rejection efficiency of RO membranes with multiple pre-treatment options at different water recoveries (30, 35, 40, 45 and 50%) and TDS concentrations (3500, 4000, and 4500mg/L). Synthetic brackish water was prepared and performance evaluation were carried out using brackish water reverse osmosis (BWRO) membranes (Filmtec LC-LE-4040 and Hydranautics CPA5-LD-4040) preceded by 5 and 1μm cartridge filters, 0.02μm ultra-filtration (UF) membrane, and forward osmosis (FO) membrane using 0.25M NaCl and MgCl2 as draw solutions (DS). It was revealed that FO membrane with 0.25M MgCl2 used as a draw solution (DS) and Ultra-filtration (UF) membrane followed by Filmtec membrane gave overall 98% rejection but UF facing high fouling potential due to high applied pressure. Use of 5 and 1μm cartridge filter prior to Filmtec membrane also showed effective results with 95% salt rejection.
... Considerable research has been directed at overcoming the challenges associated with using renewable energy to help meet the growing power needs for water desalination [1][2][3]. Goosen [4,5] argued that while economic development creates new wealth for nations, millions are forced to struggle to make meaning of the darker side of growth that is not environmentally sustainable. With the rapid increases in global population and industrialization, as well as enhanced demands on natural resources such as fresh water supplies, the earth is no longer able to sustain a healthy and balanced ecosystem [6][7][8]. ...
The use of alternative energy sources is essential to meet the growing demand for water desalination. Up till now, the expansion of renewable energy sources to run desalination processes at a larger scale is hampered by technical, economic, regulatory and environmental challenges. While medium-scale renewable energy driven desalination plants have been installed worldwide, many are connected to the electrical grid to assure a continuous energy supply for stable operation. This critical review paper focusses on integrated approaches in using renewable energy such as solar and geothermal technologies for water desalination. Innovative and sustainable desalination processes which are suitable for integrated renewable energy systems are also presented, along with the benefits of these technologies and their limitations. The market potential, environmental concerns, regulatory & socio-economic factors are likewise evaluated as well as the need for accelerated development of renewable energy-driven desalination technologies.
... RO has taken the lead due to its tremendous technology developments in different aspects especially with regard to membranes improvements, reduction in energy consumption and better designs [3,[5][6][7][8][9][10]. Most of the recent large scale desalination plants built in Algeria use RO, including the world's largest seawater reverse osmosis (SWRO) plant with a total production capacity of half million cubic meters per day which is under construction in Maqta, located in the West of Algeria [1,11]. ...
The scarcity of natural freshwater in Algeria is already very sensitive to drought, increased demand for domestic use and for agriculture, industry and tourism sectors. Therefore, water policy is the key challenge to overcome these issues in the second largest African country. Seawater desalination is one of the crucial options for supplying fresh water as over 80% of the Algerian population is concentrated in the Mediterranean coastline. The main commercial desalination processes for desalting seawater are Multi Stage Flash (MSF) and Reverse Osmosis (RO). The objective of this study is to compare the physico-chemical quality of the desalinated water, after post-treatment, produced for drinking purpose by the different desalination processes under study. The product water of the Kahrama MSF plant located at Arzew industrial zone and the Bousefer SWRO plant located in the West of Oran were investigated in this study. The physico-chemical balance revealed that the desalinated water produced by Kahrama plant is of better quality than the one obtained by Bousfer plant. Indeed, the Langelier Saturation Index (LSI) of the first plant is slightly positive with over 77% of the values ranging from 0 to 0.12 while about 23% of the values were negative. This is due to the increase of seawater temperature from 25°C to 33°C during the last months of the study period and the calcium levels which decreased to a minimal value of 50 mg/l. Bousfer desalinated water has a negative LSI with an average value of -4.45 which means that the produced water is highly aggressive and becomes improper for human consumption. These negative values are directly related to the temperature below 25 °C, calcium concentration below 50 mg/l, and pH value of less than 8. Finally, it seems that the post-treatment of Bousfer desalination plant needs improvement to make the remineralization process more effective.
... Therefore, the government must take a leadership in protecting environment and promoting building energy-efficiency. And government usually plays this leading role through introducing and implementing BEE policy measures (Mahmoudi et al., 2009). ...
Policy instrument is the key to drive improving energy-efficiency in building sectors. This paper presents the current development of BEE policy instruments by examining their practices in seven selected countries and regions. These policy instruments are classified into three groups: the mandatory administration instrument, the economic incentive instrument, and the voluntary scheme instrument. The developments of the three types of instruments are analyzed among the selected countries and regions from the perspectives of the number of policy instruments developed, the development trend and the experiences gained in developing these instruments. The study shows that different countries have made good progress in achieving better building energy-efficiency through adopting different type of policy instruments. The research reveals various experiences gained in the process of developing and implementing BEE policy instruments from various countries.
... Meanwhile, the cost of desalination and renewable energy systems are steadily decreasing, while fossil fuel prices are rising and its supplies are depleting. The desalination units powered by renewable energy systems are uniquely suited to provide water and electricity in remote areas where water and electricity infrastructures are currently lacking [42]. The rapid increase in demand for energy is making the world focus on alternative sustainable sources. ...
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.
... Although modern DES plants can operate largely unattended because of automation [76], the construction of new DES plants is associated with the creation of local employment [77]. However, this staff must be qualified, since qualified employees are an essential requisite for a well-established DES industry [78]. Tasks as operation monitoring, analyzing the trends of information, anticipation of problems and maintenance of equipment must be done by trained staff [79]. ...
Membrane desalination does help at procuring an increasing freshwater (FW) global demand. Energy requirements of desalination technologies compromise the environmental sustainability of desalination. The integration of renewable energies with desalination technologies might improve the sustainability of desalinated water over other alternative FW sources.
... For example, while the Sydney SWRO plant has been designed to take its power from the grid, the energy demand of the facility (when operational) 1 is compensated by a newly developed wind farm in an offsite location with 67 turbines producing 132 MW of power. Presently, there are no large desalination plants being driven directly by RE, however, there are a lot of small, stand-alone systems [2,[6][7][8][9]. In the KSA, solar and geothermal energy are of most relevance in terms of local conditions. ...
Globally, the Kingdom of Saudi Arabia (KSA) desalinates the largest capacity of seawater but through energy-intensive thermal processes such as multi-stage flash (MSF) distillation (>10 kW h per m(3) of desalinated water, including electrical and thermal energies). In other regions where fossil energy is more expensive and not subsidized, seawater reverse osmosis (SWRO) is the most common desalination technology but it is still energy-intensive (3-4 kW h_e/m(3)). Both processes therefore lead to the emission of significant amounts of greenhouse gases (GHGs). Moreover, MSF and SWRO technologies are most often used for large desalination facilities serving urban centers with centralized water distribution systems and power grids. While renewable energy (RE) sources could be used to serve centralized systems in urban centers and thus provide an opportunity to make desalination greener, they are mostly used to serve rural communities off of the grid. In the KSA, solar and geothermal energy are of most relevance in terms of local conditions. Our group is focusing on developing new desalination processes, adsorption desalination (AD) and membrane distillation (MD), which can be driven by waste heat, geothermal or solar energy. A demonstration solar-powered AD facility has been constructed and a life cycle assessment showed that a specific energy consumption of <1.5 kW h_e/m(3) is possible. An innovative hybrid-approach has also been explored which would combine solar and geothermal energy using an alternating 12-h cycle to reduce the probability of depleting the heat source within the geothermal reservoir and provide the most effective use of RE without the need for energy storage. This paper highlights the use of RE for desalination in KSA with a focus on our group's contribution in developing innovative low energy-driven desalination technologies.
Water is an essential component of our lives. Conventional seawater desalination, based on fossil fuel energy, is primary in meeting freshwater demands. Thus, solar desalination still emerged as an alternative technology that employs environmentally friendly renewable energy. Here, we aim to design and simulate a novel hybrid solar photovoltaic (PV) system coupled with a single‐slope solar still unit for freshwater production. Various design techniques were utilized to fine‐tune the model towards producing 3‐4.6 kg/m2.day of distillate water, thereby calculating the design aspects such as tank size, energy, and cost. The results revealed that a conventional solar desalination system had 22% lower efficiency than the proposed novel still distillation unit assisted with a solar photovoltaic system (connected to a heating element). The maximum efficiency of 45% has been recorded at the peak solar insolation due to the combination of the solar PV system. According to our design constraints, only a 3 m2 basin area was required to achieve a productivity of Pst =1‐5 kg/day. Design analysis showed that the total capital cost of a conventional still can be significantly reduced from 2600 $/unit to 1500 $/unit with photovoltaic system integration at the specified productivity and optimal solar radiation ~17 MJ/m2.day at peak time (14,00 time). This work paves the way towards maximizing solar energy utilization from photovoltaic integration with solar desalination to achieve high freshwater productivity in single‐basin solar still systems.
Over the last decade because of an outstanding technological advancement concerning desalination particularly in RO systems which gave rise to a significant reduction in the price of desalinated water and ever-increasing water demand, desalination capacity has sharply escalated. Regardless of capital and operating costs, other factors like subsidies or local incentives might cause a significant variation in produced water costs between different areas and facilities. Most of the present cost calculation tools offer limited details and their usages are restricted to certain conditions. Site-specific costs associated with raw materials like transportation and tariffs, the local difference in energy prices, plant retrofit, or treatment are particular conditions that have contributed to higher produced water delivery costs. Hence, the precise estimation of ultimate water cost is extremely challenging as it is highly volatile. As a result, the presence of a highly translucent and special methodology to cost estimation will greatly assist in the selection of a pertinent desalination skill appropriate for each site taking to account all cost-related crucial and affecting factors. The present paper takes into spotlight economic assessment and a thorough exploration of major influential factors which contributed to the total water cost using various desalination methods. Moreover, the authors propose several recommendations to demarcate future research pathways and minimize water final costs. The application of integrated systems using renewable energy sources, and advancements in material and process design besides increasing unit capacity are current developments that caused a drastic decrease in both cost and energy consumption. The emergence of cutting-edge desalination technologies can have a marked effect on the calculation of cost differences in the future.
Water scarcity has become a major issue in many parts of the world. By 2050, most countries will face water scarcity due to population expansion and climate change. Desalination is now widely used to overcome freshwater scarcity in regions where brackish or saltwater is accessible. Thermal-based processes are increasingly used in desalination plants, and Multi-Effect Distillation (MED) is the preferred technology for new construction. There are several advantages to Multi-Effect Distillation (MED) technology over more typical Multistage Flash Technology. The significant energy consumption in such systems necessitates alternate energy sources for driven desalination, which renewable sources can supply. The most common renewable energy sources are wind, geothermal, and solar power. Among the various renewable energy sources, geothermal energy can meet a steady power requirement, such as a cogeneration desalination plant, without the need for power storage. Furthermore, geothermal energy can be used as an indirect or direct source of freshwater generation when integrated with a desalination plant. This review paper will investigate and show the viability of a geothermal power-desalination plant, especially Multi-Effect Distillation (MED) system that can produce high-quality water in large quantities at a reasonable cost.
This study investigates the appropriate conditions for geothermal desalination design using the geothermal energy of abandoned oil wells. In this research, the most appropriate method for using the heat of oil wells abandoned by the desalination process is selected by examining different desalination methods. Four frameworks, including conventional multistage desalination, multistage desalination with secondary preheating, multistage desalination with secondary preheating and external flash box, and multistage desalination with secondary preheating, external flash box, and internal flash box, are used in this research. Due to secondary preheating and rising feeding water temperature, the flash box can be placed in the feeding water path in some stages. Considering the operating temperature of the tenth stage onwards, the use of flash boxes seems reasonable. This study shows that freshwater production could be increased to 592 m³/d using flash boxes in the feeding water route.
The large thermal potentials with geothermal gradient of abandoned wells provide the possibility and opportunity for carbon-neutrality transition of district heating systems, whereas energy harvesting from abandoned geothermal wells is full of challenges, due to the considerable initial investment in economic cost, system performance degradation, and so on. In this chapter, a systematic and comprehensive review on the application techniques of abandoned wells is presented, in terms of advanced thermal/power conversions, renewable integrations for district heating, and strategies for performance enhancement. Discussions on real applications have been conducted and future prospects presented, from perspectives of lifetime system performance, techno-economic feasibility analysis, and potential assessment of abandoned wells for carbon-neutrality transition. The results of this chapter can provide preliminary knowledge and cutting-edge technologies on renewable integrations with abandoned wells, so as to demonstrate techno-economic-environmental potentials of abandoned wells and contributions toward carbon-neutrality transition.
Geothermal energy (GE), as an ideal renewable resource for building cooling/heating with stability and abundance in energy supply, has been widely exploited in developing countries. The common utilization forms of GE mainly include the ground source heat pump (GSHP), underground duct system (UDS), and abandoned wells energy (AWE) system. However, there is still a lack of comprehensive overview of the current developmental status of the GSHP, UDS, and AWE systems for building cooling/heating in developing countries. This chapter will be conducted from the following aspects: (1) The literature review and categories of GE utilization in the developing countries, mainly including the latest literature review on GE development and categories of utilization for building cooling/heating. (2) The common utilization of the GSHP system and its current application and development in the developing countries, mainly including the ground-coupled heat pump (GCHP) system and groundwater heat pump (GWHP) system. (3) The common utilization of the UDS system and its current application and development in the developing countries, mainly including the horizontal UDS system, vertical UDS system, and the corresponding coupled system with phase change energy storage and other advanced technologies. (4) The common utilization of the AWE system and its current application and development in the developing countries, mainly including the abandoned oil and gas wells. (5) The existing issues and in-depth analysis on the practical application of GE for building cooling/heating in the developing countries. This chapter can provide some effective guidelines on the various GE utilization forms for building cooling/heating in developing countries.
Building heating or electricity generation using fossil fuels perilously affect the environment, and therefore, it is imperative to use clean energy to substitute pollution-causing energy resources. Geothermal energy contributes a major share to the global environmentally sustainable energy output. But its application is restricted due to high drilling costs, which can occupy up to half of the total geothermal project liabilities. More than 700 wells are indicated as abandoned in Pakistan. The reuse of abandoned oil and gas wells (AOGWs) for harnessing geothermal energy can not only eliminate prospecting risk and drilling expenditure, but also overcome the pollution. Abandoned wells offer a deal of essential data needed for geologic characterization of the reservoir, such as borehole temperature (BHT), petrophysical and lithostratigraphic logs, and porosity, and permeability. This data along with thermal gradient and geothermal play type is utilized in this study to evaluate geothermal systems and their energy potential. It is reviewed that there is a plentiful potential of geothermal energy trapped in abandoned petroleum fields of Indus Basin. A novel enhanced deep borehole heat exchanger (EDBHE) technology is recommended for heat extraction from hot dry rocks (HDR), which involves filling composite materials (with higher thermal conductivity) into the geothermal reservoir in order to ameliorate the thermal conductivity of the reservoir. Withal, utilization of AOGWs can expunge plug and abandonment-related expenditures and bestow steady energy sources for a long period.
The transition from fossil fuels to sustainable, renewable, green energy requires technological advances and adaptations to meet current and future energy needs. Oil well conversion for geothermal development, for both power generation and direct use, can meet many of these challenges in rural communities. The Williston Basin has the necessary geological setting and production infrastructure, though it lacks localized techno-economic analysis of system potentials. The techno-economic analysis in this proposal can serve as a template, benefitting rural communities of the Williston Basin in the following manner: alleviating energy poverty, supporting energy sovereignty, and providing jobs from the energy transition.
The proposed study site for this pilot project is in Mandaree, North Dakota, a rural town on the Fort Berthold Indian Reservation that needs sustainable energy. There are more than 70 oil and gas wellheads within 3500 m of the town center, most exploiting Bakken shales at a depth greater than 3000 m. Data from previous injection well and wastewater disposal studies indicate that the Inyan Kara formation has a high permeability with a thermostratigraphy derived temperature of greater than 80°C, at a reservoir depth of 1550 m below the surface.
We focus on the direct use of hot water in the Inyan Kara formation. The system configuration uses two abandoned wells designed as a doublet (one injector and one producer), located 1400 m from town with a well spacing of 1250 m. Both wells are vertical, using existing 7″ (17.8 cm) casing with perforations, put in place at the Inyan Kara formation providing geothermal fluid flow at about 40–50 L s− 1. After meeting all in situ heat demand across Mandaree (4.1 MWthermal), the well output should provide more than 1 MWthermal in addition, generating heat for commercial greenhouse operations. This case study further explores the economic potential, technical considerations, and future work necessary to achieve the energetically enabled desires of the community.
With the increasing scarcity of water and unavailability of portable drinking water at many places, in this paper, we present a feasible solution to this problem. The only solution in sight right now is to carry out the desalination of the huge saline water bodies. The conventional methods to do so have resulted in a failure as with the consumption of fossil fuel to run them, which in turn results in global warming. This draws us more towards the usage of renewable energy and its importance in order to obtain portable water from the saline and brackish water. In this study, we present to you a novel hybrid method that uses the geothermal energy and sun energy to produce fresh drinkable desalinated water from the seawater. This proposed system does not require fossil fuel to run, and hence, along with keeping the environment pure, it is a solution to the burning problem of water crisis throughout the world. With the help of engineering and technological skills, we can draft a better future for humanity.
Desalination projects play a vital role in the water supply of coastal regions with scarce water resources. The risks associated with desalination projects are worth investigating, especially for large-scale projects. This paper presents the risk identification and evaluation processes of large-scale desalination projects. Two levels of risk indicators are identified and the first-level risks include water intake and outfall risk, processing risk, financial risk and circumstance risk. With the identified risk indicators, an integrated fuzzy comprehensive evaluation (FCE) and analytic hierarchy process (AHP) method is introduced to conduct quantitative risk evaluations for large-scale desalination projects. Twenty experts in desalination-related fields are invited to vote to determine the weighting vectors for the FCE through the AHP. They also participate in deciding the membership matrixes in the FCE for three practical desalination projects. The evaluation results indicate that the overall risks of all the considered projects are at the “Very low” level. Finally, to diminish the potential risks, several instructions and recommendations are suggested that depend on the evaluation outcomes. It is expected that the current risk evaluation research will make remarkable contributions to the risk management and control of large-scale desalination projects and further promote the development of the desalination industry.
Data on the condition of drinking water supply in the world are provided in this work, as well as resources, shortages and forecasts on fresh water resources in the world are estimated on the basis of the available data. The assessment of water resources and condition of drinking water supply in Uzbekistan is presented and the problem of the Aral Sea is mentioned. As one of the main solutions to the problem of drinking water supply for the region’s population, the desalination of saline waters with the use of renewable energy sources (RES), generally solar energy, is proposed. Current global trends on the development of desalination installations with the use of renewable energy sources and forecasts for further development are analyzed. Taking the international experience and development into account, as well as the specifics of our region, some recommendations on the stimulation and development of use of desalination installations using renewable energy sources to improve the quality of the population’s drinking water supply, especially in remote regions, are offered.
Algeria is located in a semi-arid region, suffering now more than ever from the problem of inadequate water resources. It is also characterized by irregular rainfall. Membrane sea water desalination technology has known in recent years remarkable progress. Reverse osmosis is the most widespread process to increase fresh water production for domestic, agriculture and industrial uses. Currently, renewable energies can provide a sustainable and alternative solution for generating reverse osmosis systems operating at high pressure. The production of fresh and potable water by solar water desalination remains a sustainable strategy and economic option to fill the water deficit in areas that do not have access to safe drinking water and electricity. For this, this principle is developed industrially for the desalination of the sea waters and the purification of the water. The main objective of the present work is the study of a small capacity (100 I/h) reverse osmosis plan intended for desalination and water treatment operation. We have especially worked on the effect of pressure and salinity on the production and quality of the water produced. The performed work is purely experimental and is part within the framework of improving the profitability of an RO device. Initiation of coupling of the reverse osmosis pilot to solar energy in order to reduce energy consumption (4 KW/ 1m3) is being investigated. During this period of experimentation a physicochemical and bacteriological analysis of the water before and after treatment were carried out.
Building energy-efficiency (BEE) is the key to drive the promotion of energy saving in building sector. A large variety of building energy-efficiency policy instrument exist. Some are mandatory, some are soft scheme, and some use economic incentives from country to country. This paper presents the current development of implementing BEE policy instruments by examining the practices of BEE in seven selected countries and regions. In the study, BEE policy instruments are classified into three groups, including mandatory administration control instruments, economic incentive instruments and voluntary scheme instruments. The study shows that different countries have adopted different instruments in their practices for achieving the target of energy-saving and gained various kinds of experiences. It is important to share these experiences gained.
Experiments were conducted with a commercial membrane distillation module, which has an air-gap membrane distillation (AGMD) and spiral-wound configuration. Tests were performed simulating the salinity and temperature of the water using as a case study the Albian aquifer in Algeria. Solar thermal energy from a field of stationary flat-plate solar collectors was supplied to the module. The total productivity of the AGMD system was analyzed for different operational conditions and compared with that from the RO system. The effect of brackish water temperature on the energy consumption was scrutinized, and the energy requirements assessed toward the design of a pilot unit for decentralized autonomous solar desalination. Results showed that for producing a higher volume of distillate, module with less surface area is better. Also, it was found that recovery ratio increases linearly with the temperature difference in both modules. The maximum value was 6% for the highest feed flow rate operated in module 1 with highest surface area. These values are much lower than those obtained with RO processes, which can reach 45%.
This study proposed a process utilizing the wind transmission vacuum pump and freezing system for seawater desalination. The wind drives the vacuum pump pressure to near absolute vacuum stage, and creates evaporation of seawater at low temperature. Then the compressor of the freezing system evaporates water and condenses the vaporized water into ice at low temperature using the circulating system via wind transmission. The most significant feature of this study is the complete application of renewable resources. Although the initial capital cost is high, it will be more economical in the long-term. At 40 min of desalination time, the concentration can be reduced to 58, 54, and 50 g from the original concentration of 333, 666, 999 g of 20 L of seawater, respectively. Therefore the outcome of this study provides a good contribution to understand the technical practice of this process.
Cardona et al. proposed a two-stage RO system. As reported, this two-stage RO system presents about 20% energy saving compared with conventional single-stage RO system when pressure exchanger is excluded from consideration. Since two mixing steps occur in this two-stage RO system, will it still show advantages from the point of the second law of thermodynamics? This paper makes an exergetic discussion on this two-stage RO system and a conventional single-stage RO system. It is found that input pressure exergy accounts for a large proportion of total input exergy in RO systems. Two-stage RO system presents about 42% of rise in input pressure exergy and 33% of rise in total exergy destruction compared with single-stage system. The blending exergy destruction is much smaller than the total exergy loss. Therefore, the key points that improve the exergetic efficiency of this two-stage RO system lie in other ways. Increasing the product flow by heating feed is an effective method. Because of the higher investment, solar collector is not appropriate for application. Solar pond can also provide heat for feed water. Because the salt for the solar pond can be supplied by the brine exiting the first stage in this two-stage RO system, the main investment comes only from the construction of the solar pond. It is possible that within the life range of the solar pond, the increased investment can be offset by the increased product.
In order to promote the development of Green Building Market without bringing heavy financial burden to the government, this paper studies the optimal subsidy problem in Green Building Market from the perspective of policy benefit, in which the government and the end-user are the principals and the developer is their agent. Optimal subsidy principal-agent models under conditions of asymmetric information and complete information are established, and equivalent models are presented to get the optimal solutions. The results show that from the perspective of policy benefits, subsidy policy is influenced by construction costs, transfer paid by the end-user and developer’s preference toward green buildings. Furthermore, comparisons of models under two conditions demonstrate that eliminating asymmetric information can contribute to more green building areas and fewer unit subsidies. Finally, a numerical example is presented to show the effectiveness of the model.
Recent advances in solar-cell technology and membrane-separation technology do promise the economic viability of distributed seawater and brackish-water solar desalting systems in the near future. Reverse osmosis desalting processes driven by photovoltaic solar electricity can have the potential of displacing fossil fuel and curbing the rise of CO2 in the environment. This paper models desalination by spiral-wound RO membrane modules driven by solarto-power photovoltaic converter panels with the purpose of revealing the economic potential of the combination. The paper then investigates the variability of the cost of desalted water with the major efficiency parameters of the desalting process and of the solar-to-power conversion process given water product rate, initial salt content, provisional reject brine salt content, design solar intensity and solar duration. Systems are generated by grouped input parameters of interest to the unit costs of solar power and product water. Runs covering a wide range of system input parameters are made and sample results are presented. The results already show two designs close to competitiveness. As fuel prices rise and/or technology advances, competitiveness becomes more assured. The obvious statement that high-efficiency solar and high efficiency desalting processes are keys to competitive solar desalination within the constraint of cost-effectiveness is confirmed in this study. The study also proposes a dimensionless number for RO membranes that may be useful.
The common methods of desalination salt water for production of fresh water by distillation, reverse osmosis and electrodialysis are intensive energy techniques. However, in remote arid areas, the desalination needs not exceed a few cubic meters per day. This decentralised demand favours local water production by developing other desalination processes, especially those using renewable or recovered energy (solar, geothermal, etc.). Solar desalination process is one of these methods used to resolve the scarcity of fresh water. Several reviews have been published by different authors. Small production systems as solar stills can be used if fresh water demand is low and the land is available at low cost. To supply the population of remote arid lands of South Algeria with drinkable water, solar distillation of brackish waters is recommended. It satisfies some of theses demands. Solar stills are used to produce fresh water from brackish water by directly utilising sunshine. These stills represent the best technical solution to supply remote villages or settlements in South Algeria with fresh water without depending on high-tech and skills. The production capacity indicates a possible daily production of far more than 15 l/m2d. Therefore, the still has a place in the upper range of known comparable products with regards to production output. This depends on the material used and the price of the solar stills and their accessories. The best working temperature solves most problems. Small, modular high-performance stills with features like the possibility of decentralised use, less maintenance and robust construction can help to reduce fresh water scarcity. The recent development of stills based on new concepts and heat recovery has been successful. The technical optimization is still in process today, it aims to improvement of the efficiency of these distillers. In our research work, a plant for brackish water distillation by directly sunshine and heat recovery was constructed and investigated experimentally and theoretically in South Algeria. This study aims the improvement of the performance of this solar distillation plant, conducted under the actual insulation, for brackish underground geothermal water desalination.
A thermodynamic simulation study was performed on the influence of greenhouse-related parameters on a desalination process that combines fresh water production using humidification-dehumidification with the growth of crops in a greenhouse. With the system under study, surface seawater trickles down a porous front wall evaporator through which air is drawn into the greenhouse. The saturated air passes through a condenser, which is cooled using cold deep seawater or cool seawater coming out of the evaporators. Thermodynamic modeling of the seawater greenhouse system in our laboratory has shown that the dimension of the greenhouse had the greatest overall effect on water production and energy consumption. A wide shallow greenhouse, 200 m wide by 50 m deep gave 125 m3.d−1 of fresh water. This was greater than a factor oftwo compared to the worst-case scenario with the same area (50 m wide by 200 m deep), which gave 58 m3.d−1. Low power consumption went hand-in-hand with high efficiency. The wide shallow greenhouse consumed 1.16 kWh.m−3, while the narrow deep structure consumed 5.02 kWh.m−3 . The benefits of the development of the seawater greenhouse for arid regions are discussed.
Advancing renewable energy for desalination in the MENA region
- K Neumann
Neumann K. Advancing renewable energy for desalination in the MENA
region. J Assoc Arab Univ Basic Appl Sci 2007;4:37-8.