Search

Worldwide, the emerging trend of hybrid renewable energy sources integration in modern power systems is increasing due to privileged prices and clean electricity supply. However, the optimal planning of rural hybrid systems is a challenging and complex task, especially when different alternatives and sustainability aspects are considered. This paper develops an integrated decision-making approach for the optimal planning of a 100% renewable energy supply system comprising solar, wind, hydro, and biomass sources in a rural area located in Pakistan. An hourly-based design optimization analysis of twelve on/off-grid electrification alternatives is performed. The optimization model simultaneously addresses five sustainability criteria related to economy, reliability, ecology, society, and topography aspects. Furthermore, a novel hybrid decision-making model has developed to identify the unique best configuration with on-grid and off-grid options. The proposed model combines fuzzy analytic hierarchy process, multi-objective optimization based on ratio analysis technique for order of preference by similarity to an ideal solution, and evaluation based on distance from average solution methods. The results reveal that the solar-hydro-biomass battery with a life cycle cost of 10.9 M$ is the top-ranking off-grid system. When the hybrid system is connected to the grid, the solar-hydro-battery has found the most appropriate design with a life cycle cost of 12.96 M$. Both scenarios have a negligible capacity shortage of 0.09%. Ecologically, the optimal off-grid system produces only 408.37 kg/yr of CO 2 due to the significant energy share of solar and hydro sources (99.3%). The optimal on-grid system produced the minimum CO 2 with 29,177.89 kg/yr compared to other alternatives. Also, employing the optimal on/off-grid designs require land area and jobs of 96.6 m2, 14 jobs, and 118 m2, 15 jobs, respectively. Overall, the developed approach with the presented case study offers a valuable benchmark and guidelines for investors and stakeholders to create realistic investment plans for the energy industry looking to push efficient inducements to encourage the high dissemination of renewables. [Display omitted] • 100% renewable energy system is established for on/off grid rural electrification. • Twelve distinctive solar/wind/hydro/biomass-based hybrid energy alternatives are optimized. • An integrated fuzzy-AHP/TOPSIS/EDAS/MOORA decision-making model is proposed. • Cost, reliability, emission, social, and topographical criteria are simultaneously considered. • Results prove the long-term sustainability of 100% renewable in rural Pakistan. [ABSTRACT FROM AUTHOR]

• An overview for infrared thermography (IRTG) detection of PVs is introduced. • Classification of IRTG techniques, detected faults are discussed in detail. • The manuscript provides a good guide for selecting a proper IRTG system for PV plants. Globally, solar photovoltaic (PV) plants have been in continuous increase, attracting researchers and governments' interest, and PV markets witness high competition. That requires advanced research and development of reliability and efficiency optimization, fault detection and diagnosis, and maintenance of various components, particularly PV modules. Along with that, many works and technical investigations have been conducted via many detection methods based on either indoor or outdoor tests. Specifically, the temperature is a common indicator of any structure components' health as faulty and damaged components, and corroded electrical connections can lead to abnormal temperature distribution. Hence, such faults can be detected through imaging and analyzing temperature distribution patterns localizing the faulty part. For so, Infrared Thermography (IRTG) has become a widely-utilized condition monitoring (CM) technique; through which real-time temperature can be measured. It is regarded as reliable, accurate, and economical method due to the advent of IR cameras. IRTG features for being safe and non-destructive testing technique (NDTT); and hence it has been effectively used in detecting PV plants either in small or large scales. This survey manuscript presents a general view about IRTG and focuses on its utilization in condition monitoring of PV plants merging the state-of-the-art researchers' efforts in this field. In addition, some common patterns of detected faults and their analyses are also illustrated. [ABSTRACT FROM AUTHOR]

• A systematic framework for the optimal design of hybrid energy systems is proposed. • The developed approach is applied to agriculture and irrigation area in Sudan. • Effect of uncertainty parameters on system design and cost is examined. • Solar-wind-diesel-battery-converter system is a cost-effective and reliable solution. • Renewable resources and interest rate have high influences on investment decision. Today, particular attention is being globally paid towards clean and sustainable energy system. The rapid development in renewable energy technologies, growth of energy markets, and adopted financial strategies and policies have the key role in achieving this target. This paper provides a comprehensive feasibility analysis of a gird-isolated hybrid renewable energy system for electrification of agriculture and irrigation area in Dongola, Sudan. A systematic and integrative framework combined with techno-economic optimization analysis for adequate planning and design of hybrid renewable energy system is proposed. Different hybridization cases of a solar photovoltaic, wind turbine, diesel generator, battery storage, and converter technologies, together with a diesel generator-based energy system as base case are modeled, evaluated and compared considering the stochastic behavior of renewable energy resources with a main target to find the most feasible and reliable solution with least system cost and realistic environmental impacts. This followed by a sensitivity analysis to reveal the effects of uncertainty in system parameters on the designed system and its economic performance. The obtained results indicate that solar-wind-diesel-battery-converter hybrid system is of optimal performance and superiority over the studied cases to serve the load demand of the investigated area. The system not only gets the minimum values of the total net present cost (24.16 M$) and levelized cost of energy (0.387 $/kWh), but also effectively achieves a positive return on investment of 39.94% and around 95% reduction in both carbon emissions and fuel consumption compared to the base case. Meanwhile, the result of sensitivity analysis demonstrates the high dependability of system cost on the volatility of solar radiation and wind speed as well as the changes in the rate of interest with the prospect of ignoring the effect of variation of diesel fuel price in the future investment decision. Finally, the output of this study is projected to raising the potentiality awareness of renewable energy in Sudan and providing a valuable reference about the optimal planning and utilization of hybrid renewable energy system in energy sector. [ABSTRACT FROM AUTHOR]

• Model for the design and control of an off-grid 100% renewable system is proposed. • Nine alternatives of solar/wind/different storages are modelled and optimized. • Evaluation criteria are cost, emission, and load voltage/frequency constancy. • Solar/wind/lead-acid battery shows the most economic and reliable alternative. • Lead-acid battery/supercapacitor is more efficient than battery only. The continuous rise of global electricity demand and significant dependency on fossil fuel-based centralised power plants are the main indicators of increasing greenhouse gas emissions, thus negatively affecting climate change and human health and increasing the earth temperatures. This alarming situation has demanded the transition to 100 % renewable energy to decarbonise energy use. However, the fluctuating weather resources, and high investment cost are the major challenges with renewable energy implementation. In this context, the combined integration of multiple sources with energy storage in a so-called hybrid renewable energy system was developed as a durable remedy for the previous issues. This paper proposes a joint and conceptual approach for techno-economic design and dynamic rule-based power control of an off-grid solar/wind hybrid renewable energy system integrated with a hybrid energy storage system that comprises a lithium-ion battery, lead-acid battery, and a supercapacitor. Such concurrent integration of 100 % renewable energy systems and hybrid energy storage systems is lacking in the existing literature. First, with the aid of HOMER software, the feasibility and optimisation analysis of nine different configurations was performed in 1 min resolution to find the optimal component sizes. Second, MATLAB/Simulink models were assembled for the winning design based on a dynamic rule-based strategy to investigate and analyse the system's dynamic response, power equilibrium, DC-bus voltage supervision and load voltage/frequency control against instantaneous and dynamic changes in the load or renewable energy resources. The proposed approach was promoted and validated on an actual case study for isolated residential community electrification in Saudi Arabia, in which a multi-tier framework was adopted to accurately simulate the stochastic energy consumption of the community's households. From the design results, the hybrid renewable energy system, which integrates solar, wind, lead-acid batteries, and converter with optimal capacities of 55 kW, 18 kW, 325 kWh and 42 kW converter, respectively, is the most cost-effective alternative with the minimum net present and energy costs of $232,423.3 and $0.3458/kWh, respectively. The system has the least unmet load with 13.5 kWh/years (0.02 %), thus ensuring maximum reliability and customer satisfaction. Meanwhile, the developed control strategy efficiently improved the dynamic response, the DC-bus voltage stability, and the load voltage/frequency during different climatological and load interruptions. Further, the use of lead-acid batteries and supercapacitors has effectively diminished the maximum overshoot of the DC-bus and load voltages by 50 % during all disturbances. In addition, the integration of supercapacitors proficiently saved 2.3–6 kW during wind speed change and 2–9 kW during simultaneous changes in the radiation and load. Overall, the presented method, together with the reported results, provides an improved understanding and highlights the extent to which the successful integration of hybrid renewable energy system and hybrid energy storage system can be used to develop reliable and sustainable energy access for off-grid areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • A GIS-based MCDM model for the site selection of solar and wind energies in Kenya is proposed. • A decision-making sizing model for sustainable energy access is developed for rural electrification. • 19.28 and 35, 18.9% of Kenyan's land has the potential for installation of solar, wind, and hybrid solar/wind. • Hybrid solar-wind-diesel mini-grid is the first ranked alternative for supplying the representative rural village. • The designed system has the best energy, economy, and ecology performances compared to grid extension and diesel systems. The use of hybrid renewable energy system (HRES) holds great promise for sustainable electrification and support countries reaching their energy access goals. The site selection and design of HRES are strategic stages towards ensuring an affordable, sustainable, and well-performing project. However, both are multidimensional and intricate issues that involve multiple conflicting assessment criteria and alternatives, which are not yet investigated comprehensively and simultaneously in many of the existing literature. In this context, the paper aims to develop a systematic and conceptual decision-making framework for site suitability and optimal design of HRESs, with an application on a regional scale in Kenya, Sub-Saharan Africa. The suggested framework is applied through three consecutive phases. First, a geographical information system (GIS) is combined with Best Worst Method (BWM) decision-making approach to spatially investigate and analyze the potential sites of solar, wind, and hybrid solar/wind systems. Within the spatial investigation, 9 different climatology, environment, location, and orography criteria are considered. Second, energy-economy-ecology (E3) design optimization is conducted to determine the list of feasible alternatives among grid-extension, autonomous HRES, and stand-alone diesel genset electrification schemes for powering a representative remote rural village in Kenya. Third, a post-optimality multi-criteria decision-making (MCDM) analysis is applied to decide and assess the optimal energy access design against 12 key sustainability indicators. In the third phase, the BWM is employed to define the weights of each indicator. Then, the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) and the VIšekriterijumsko KOmpromisno Rangiranje (VIKOR) decision making approaches are used for the final ranking of feasible alternatives. The obtained site suitability maps of Kenya show that 0.91% (5322 km2) and 1.5% (8828.4 km2) of the land is highly suitable, 10.25% (59687 km2) and 33.04% (192360 km2) is suitable, and 80.5% (470313 km2) and 65% (378407 km2) is permanently unsuitable for establishing solar and wind systems, respectively. Also, E3-MCDM results indicate that the development of solar/wind/diesel/battery HRES is the best sustainable solution to supply the studied region as compared to other feasible alternatives. The system does not only guarantee a reliable operation with an unmet load of 552 kWh/yr, but it also has the lowest net present and energy costs at 2.6 M$ and 0.28 $/kWh, respectively, meanwhile avoiding annual CO 2 of 804 tons compared with diesel system. [ABSTRACT FROM AUTHOR]

This paper investigates the potential and feasibility of an integrating hybrid renewable power generation system with a large-scale reverse osmosis desalination plant to provide electricity, heat, and water for the New Capital International Airport, Egypt. The proposed energy system contains photovoltaic panels, wind turbine, combined heat-power microturbine generator, diesel generator, batteries, converter, thermal load controller, and a boiler. A comprehensive energy-economic-environmental optimization analysis was performed to optimize energy systems in which 16-feasible solutions were evaluated and compared. The results revealed that the optimal system has the least net present and energy costs by 1.54 M$ and 0.089 $/kWh, respectively, and needs only 1.12 years to recover the invested money. Moreover, the proposed system produces emissions of 59.5% less than the base-case. The optimal system has a negligible unmet load ratio since it has a negligible loss of power supply possibility of 0.0993%. The thermal load controller has a significant impact on reducing the net present cost, cost of energy, emissions, and needed batteries by 52%, 56.4%, 36.5%, and 90%, respectively compared to the base-case. The obtained results are expected to attract large investments in clean energy and water desalination because of the government's challenges in such fields. • Energy-economic-environmental optimization is performed for an airport in the new capital of Egypt. • Prominence is set to provide the airport with the daily need for electricity, heat, and water. • The effect of renewables, TLC, and batteries on the optimal system performance is discussed. • The cost of energy of the optimal system is reached to 0.08 $/kWh with a payback period of 1.2 years. • The proposed system generates 59.5% of CO 2 emission less than the traditional diesel. [ABSTRACT FROM AUTHOR]

• Solar-wind-diesel hybrid system is proposed for a large-scale reverse osmosis desalination plant. • A 3E fuzzy decision-making optimization model is developed for ten distinct energy systems. • Performance of flow batteries and pumped hydro storage technologies are investigated and compared. • Hybrid system with battery option results in better energy, economic, and ecological benefits. • Sensitivity analysis on storage cost show more savings in NPC and COE with pumped hydro than the battery. This paper aims to propose a conceptual design model for sustainable hybrid renewable stand-alone energy system (HRSES) to meet the electricity demand of a large-scale reverse osmosis desalination plant in Baltim, Egypt. The model investigates the feasibility of different HRSES alternatives and develop a fuzzy-based multicriteria decision-making model for meticulously selecting the optimal energy solution. Both zinc-bromine flow battery and turbine-pumped hydro energy storage technologies are integrated independently with wind, solar, and diesel power sources. Firstly, the proposed model uses HOMER software to execute an energy-economic-ecological optimization analysis for studying the practicability and components sizing of nine HRSES alternatives. Second, an integration between Fuzzy-AHP and Fuzzy-VIKOR decision-making methods is executed to choose the best design considering ten performance criteria. In the second stage, the fuzzy environment is engaged to expedite decision-makers to express their ratings in linguistic terms and to achieve more sensible and accurate results. Among ten feasible alternatives, the results reveal that the optimal system consists of 5 × 20-kW wind turbines, 328-kW photovoltaic array, 100-kW diesel generator, 112 batteries and 235-kW converter. This system has the best economic performance among all alternatives with least NPC, COE, and payback-period of $1,048,046, 0.101$/kWh and 1.1 yr, respectively. Besides, it has a treasured share of renewable of 95.55%; hence, it produces a realistic CO 2 of 25,426.46 kg/year. Lastly, the sensitivity analysis illuminates that the future load growth and low-interest rate hurt upcoming investments while the projected reduction in the cost of energy storages has an encouraging influence on financing decisions. [ABSTRACT FROM AUTHOR]

• A multi-objective optimization model for the optimal design of HMGESs is proposed. • The optimization model includes energy, economic and environmental aspects in the assessment. • SPV/WDG/DslG/Battery is the most economic, sustainable, and ecologically favorable option. • A power management strategy is applied efficiently on the optimized system to safeguard system power quality. Currently, the global gives a unique awareness of sustainable development by exploiting renewables to provide the people with affordable and clean energy and preserve the climate. This paper proposes a methodical and explicit framework of four phases, to design an autonomous hybrid renewable energy system in a community area in Egypt: preliminarily assessment, design optimization analysis, findings evaluation, and power-quality assessment. In the first three phases which performed by HOMER Pro® software, five hybridization scenarios are evaluated and compared regarding their life-cycle cost, carbon outflows, and reliability to distinguish the extraordinary scenario to supply the addressed community area. Contrary to the majority of studies that suffice only the first three phases, the fourth phase is proposed to perform a power-quality valuation based on a power management strategy (PMS). The results reveal that the optimal configuration consists of a photovoltaic generator, wind-driven generator, diesel-genset, battery-bank, and a power converter with the minimum net present cost of 351,223 $ and energy cost of 0.2262 $/kWh among all configurations. The optimal system has a negligible capacity shortage of 0.0955% and produces the least amount of emitted gases by 50.43 tones/year due to the high renewable fraction (57%). Moreover, the optimal proposed system can recover the invested money after only 3.4 years. The proposed PMS profitably harmonized the system's energy exchange, kept sufficient reserve energy at all times, and maintained the system stability under various meteorological and load disturbances. This can be verified from the superior stabilization of the dc-bus, load voltage and frequency during the examined disturbances. [ABSTRACT FROM AUTHOR]

• A comprehensive review of the recent nano-based PV cooling systems is conducted. • Separate nano-enhanced PCMs, separate nanofluid-based, and hybrid PV cooling units are discussed. • Governing equations of materials' properties and PV performance are derived. • Detailed systems' description and major results are illustrated. • Research trend is analyzed via VOSviewer software based on Scopus database, and Future prospects are suggested. The environmental pollution and growing energy demand necessitate the development of power generation using renewable energy systems, especially solar photovoltaic (PV) panels. Despite being an eco-friendly and durable power generation technology, PVs demerit for low conversion efficiency (15–20%). In other meaning, a very low amount of the incident irradiance is converted into electricity, whereas the major is absorbed as heat, uplifting the PVs' surface temperature and declining their efficiency and reliability. Therefore, it is crucial to find a proper cooling technique for upgrading PVs' performance. Recently, along with the nanotechnology development, nano-based PV cooling units have been proposed and investigated as the inclusion of nanoparticles enhances the thermal properties of base materials. Herein, in this paper, the conducted efforts to improve the PVs' performance using nano-based cooing systems were reviewed and discussed. The surveyed PVs' cooling methodologies were classified into separate and hybrid systems: nano-enhanced PCMs, nanofluid-based, and hybrid nano-based cooling units. All relevant equations of materials' properties and PV performance were presented. In addition, the research trend of this field was analyzed by conducting a comprehensive bibliometric analysis using VOSviewer software and based on the Scopus database in the period (2006–2020). Besides, comprehensive discussions of proposed and designed systems were conducted, and major findings were summarized. Based on the literature, using hybrid nano-based cooling systems, the surface temperature reduction can reach 16 °C with enhancement in electrical efficiency up to 50% compared to conventional uncooled PV panels. Furthermore, some future work suggestions were given. [ABSTRACT FROM AUTHOR]

• Experimental investigation on copper basin and graphite nanofluid was performed. • The influence of weather and operational parameters was examined. • A new prediction method using a modified version of RVFL network was proposed. • Firefly Algorithm was applied to optimize parameters selection of the RVFL. This study introduces a modified random vector functional link (RVFL) as an alternative prediction method for the thermal performance of a developed pyramid solar still (DPSS), which consists of a copper basin integrated with graphite nanofluids. Experimental work is performed to investigate the performance enhancement of the DPSS. The real experimental data are recorded and utilized to build the proposed prediction models based on artificial neural network (ANN). Four ANN prediction models are presented, evaluated and compared to strength the prediction of the thermal performance of the DPSS. Different six statistical criteria are used to determine the optimal prediction model to be implemented in the prediction of the hourly freshwater (HF) and instantaneous energy efficiency (IEE) of the DPSS. From the experimental investigation, the use of proposed DPSS has total freshwater productivity of 5.26 L/m2. The performed comparative study shows that the proposed RVFL approach tunned by firefly algorithm (FA), called FA-RVFL, is of optimal performance to be the best model among the investigated prediction models. The proposed FA-RVFL model is characterized by a determination coefficient of 0.981 and 0.999 and regression values of 0.996 and 0.999, respectively for the total data sets of HF and IEE. The present study shows the efficiency of proposed DPSS to enhance the freshwater capacity. Besides, it proves that FA-RVFL can be used as an effective tool to predict the thermal performance of the solar stills compared to the other models with no need for further experiments, thus saving financial expenses, effort, and time. [ABSTRACT FROM AUTHOR]

• Large-scale reverse osmosis desalination powered by hybrid renewable energy source. • The optimal off-grid power system was photovoltaics/wind/diesel/battery/convertor. • The emitted carbon dioxide of the optimal system outperformed diesel system by 81.5%. • Energy storage systems are required to meet the energy demand during night times. Seawater desalination is a viable source of potable water, particularly for the coastal and remote areas. However, their sustainability is limited by the intensive energy demand of the present methods. Renewable energy is an inexhaustible source of energy, accompanied by cost reduction benefits and clean power generations. Seawater desalination powered with renewable energy sources is being attractive, mainly if the utility-grid is absent. This paper aims to design a renewable energy system, to meet the electrical load demand of large-scale reverse osmosis desalination plant (1500 m3/d), and to find the optimal sizing and techno-economic and environmental feasibility assessment of several off-grid power systems. Two off-grid scenarios with different combinations of hybrid power systems were proposed and compared with the base-case of diesel. The first scenario consists of a photovoltaic, wind turbine, diesel, and generator, while the second scenario is equipped with battery storage devices. A total of eleven hybrid renewable energy systems were modelled, analyzed, and compared with the aid of HOMER Pro software to identify the best performance and the optimal plan configuration. The optimization results show that the proposed photovoltaic/wind/diesel/battery/convertor system outperformed the other alternatives and exhibited reduction potential of 60.7%, 73.7%, 62% and 81.5% lower than the existing diesel with regards to the net present cost, renewable fraction, cost of energy, and carbon dioxide emission, respectively. The optimum case consists of 451 kW solar panels, 25 wind turbines, 250 kW diesel power, battery storage of 352 string, and 358 kW system converter. The results obtained by the optimal plan with low cost and environmental protection aspects would provide a new sight for real field applications of large scales reverse osmosis applications. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) panels, being an eco-friendly technology, have become a crucial source of electricity, satisfying the increasing energy demand and substituting the related shortage occurring in the conventional energy sources. Despite absorbing about 80% of incident radiation, PV cells have low conversion efficiency; hence, a minor portion of the absorbed radiation is gained as electrical power, and the majority is converted into heat increasing the panel temperature. Undesirably, the higher panel temperature, the lower conversion performance, and lesser reliability over the long term occur. Hence, many cooling systems have been designed and investigated, aiming to effectively avoid the excessive temperature rise. This paper aims to review and merge the recent cooling methods investigations on PV, categorizing them according to heat transfer modes: convective cooling (hydro and aero-based cooling with or without extended surfaces), conductive cooling (phase change materials), and radiative cooling. Each category and corresponding works are discussed in detail, and main resulted enhancements, with respect to uncooled PV panels, are presented. In addition, applications of hybrid photovoltaic-thermal systems are clarified with indicating main improvements in their electrical, thermal, and overall efficiencies. It expected that the presented work can provide a new comprehensive taxonomy for cooling techniques applied to photovoltaics. • A deep survey on the state-of-the-art aspects of PV cooling is presented. • A new comprehensive taxonomy for cooling methodologies including nanofluid-based PVT are proposed. • Enhancements of thermo-electric performance of PVT systems are discussed. • Improved convective cooling via extended surfaces is surveyed. • Radiative cooling performance of PV modules, and corresponding applications are reviewed. [ABSTRACT FROM AUTHOR]

Today, clean water availability is quite hard especially for people living in remote areas and coastal ones. Even for those who find underground water, they need to treat it before using. Solar still is a very useful method to be used in desalination and purifying water as it uses solar energy which is available around the globe with no cost and is eco-friendly. Many types of solar stills are invented to increase its daily productivity (stepped solar stills, inclined solar stills, pyramid solar still, wick, etc.). In this regard, this paper represents a mini-review of a new type of solar still named tubular solar still (TSS), its working method, thermal analysis, performance and method of enhancement. The remarkable improvement is attributed to the use of nanotechnology (ZnO nano-rod shape) by which the productivity and efficiency are increased by 30% and 38% respectively. Moreover, some futuristic developments on TSS are included in this review. [ABSTRACT FROM AUTHOR]

• A novel hybrid stochastic-IGDT model is developed for HEM problems in nZEBs. • Real energy price and vehicle-to-home capability are properly modelled. • Unpredictable behavior of the electric vehicle is formulated via IGDT. • A bi-objective structure is presented to jointly optimize the energy consumption and cost using lexicographic optimization. • The problem is kept linear being solvable by standard solvers. Residential sector is being promoted to evolve towards nearly-Zero Energy Buildings (nZEBs), which draw a yearly net energy consumption near zero. This target can be attained through on-site renewable generation, achieving high efficiency in consumption. In this context, Home Energy Management (HEM) systems become an indispensable tool for obtaining optimally coordinating smart appliances, renewable generation, and on-site storage facilities. Due to the high unpredictability of renewable generation and some emerging appliances like electric vehicles, these tools must be able to deal with different uncertainties properly. At the same time, a variety of objectives are jointly considered. The existing approaches commonly fail to deal jointly with these two premises. This paper aims to fill this gap by developing a novel solution for HEM systems in nZEBs. The proposed procedure uses lexicographic optimization to find a compromise solution among objectives. At the same time, the variety of uncertainties caused by unpredictable weather, demand, energy pricing, and electric vehicle behavior is adequately modeled using a hybrid stochastic-Information Gap Decision Theory (IGDT) approach. The mathematical modeling is sufficiently comprehensive (comprising various energy sources and vehicle-to-home capability) and tractable due to its integer-linear structure. A case study on a benchmark nearly zero energy home is considered to validate the developed approach, which its results reveal its effectiveness in terms of minimizing various objective functions while the degree of robustness is preserved and the whole procedure is efficient yet. [ABSTRACT FROM AUTHOR]

Solar-driven desalination methods, particularly solar stills (SS), and their improvements have been widely paid attention. Along with that, the current work aimed to evaluate the augmented evaporation/condensation performance of a modified double slope solar still (MDSSS) compared to conventional solar still (CSS). For evaporation enhancement, three alternative combinations were applied in the still basin, which consisted of nanoparticles/fluid (carbon black/water), heat localization (wick), and sensible storage (gravel) materials. In other meaning, three cases were experimented; namely: MDSSS-I with gravel immersed in carbon black (CB) nanofluid, MDSSS-II with gravel atop thermal insulation and covered with black wick, and MDSSS-III with dispersed CB nanoparticles on the top of the second case combination. These modifications were suggested to enlarge the wet area subjected to solar radiation, increase thermal conductivity, and localize the heat on the water surface. On the other hand, for condensation improvement, passive water-based glass cooling technique was integrated with all cases to degrade the glass cover temperature. Besides the experimental investigation, thermo-economic assessment analysis of the system was performed via estimating energy and exergy efficiencies, and production cost. The results proved the aimed enhancements for all cases and the best performance was achieved from the MDSSS-III. In this case, the yield, average energy efficiency, and average exergy efficiency were improved by 68, 50.6, and 146.3%, respectively, compared to CSS. In addition, MDSSS-III attained highest cost saving by 30.7% compared to CSS as the cost per liter of freshwater productivity was 0.0147 $/L, and 0.0212 $/L, respectively. Hence, integrating such locally-available materials with DSSS may open a new sight for further enhancement and increase the opportunities for establishing large-scale practical plants. • Modified double slope solar still (MDSSS) were experimented compared to conventional one (CSS). • Alternative combinations were proposed from three materials: gravel, wick, and carbon black nanoparticles. • The MDSSS-III achieved best performance with enhanced average energy efficiency 50%. • The MDSSS-III achieved highest saving in freshwater price by 30.7%. [ABSTRACT FROM AUTHOR]

Ongoing to the modern societies and global economic developments, the water is recognized as one of the main concerns of humankind, particularly with the continuous decrease of the freshwater supply. Solar energy, which is abundant and available in many areas, can solve the problem of long-term energy and freshwater reduction in the whole world. Researchers do their best to solve this problem in different ways. Currently, many studies have used solar energy to improve the efficiency of evaporation, solar desalination, and wastewater treatment since it is the basis for freshwater. One of the new ways applied to achieve this is named "hydrogel", which has various structures. Hydrogel, as a novel light-absorbing material, is an effective technique to enhance photothermal solar efficiency conversion by decreasing the heat loss in the heat transfer process due to the heat localization on the air-water interface. Moreover, hydrogel has many pores structures with excellent water transport from the bottom to the water-air interface. Hydrogels are floatable, durable, anti-fouling, and suitable recycling materials, which are energetically favorable for harvesting and amplifying the steam generation. Furthermore, over the past three years, they have revolutionized solar water vaporization with an evaporation efficiency of 95% and the evaporation rate of 4 kg/(m2. hr), which cannot be achieved by other materials. • A deep survey on the state-of-the-art aspects of hydrogel technology of solar steam generation is presented. • Recent developments of water desalination, wastewater remediation, and industrial sewage using hydrogel are discussed. • A new taxonomy of preparation and concretization methods of the hydrogels is proposed. • Performance comparison between hydrogel-based systems and other conventional ones are analyzed. • Future-prospects of hydrogel technologies and its applications are introduced. [ABSTRACT FROM AUTHOR]

In this study, efforts were made to enhance the performance of inclined wick solar still (IWSS) by integrating different basin metals and a novel wick-metal chips pad. Three different metal materials (aluminum, copper, and steel) were used as basin and their metal chips were sandwiched in a novel wick-metal pad. Experiments were carried out to figure out the influence of different basin metal materials and their metal chips filled in a wick pad on the thermal performance of IWSS. The enhanced solar still was compared with conventional inclined wick solar still (CIWSS). Results revealed that using aluminum and copper basins led to increase the productivity by 34.23% and 54.26%, respectively, compared with CIWSS. The use of metal chips sandwiched between two layers of wicks (wick-metal chips pad) caused an increase in the daily production by about 27.76%, 41.54, and 65.3% for steel, aluminum, and copper, respectively. This implies that the basin materials and the novel wick pads with metal chips, which acted as evaporation surface and heat storage medium, played a vital role in enhancing productivity. Also, the maximum thermal efficiency was 60.98% for the modified IWSS with copper basin and a novel wick-copper chips pad. While, the maximum thermal efficiency for the CIWSS with steel basin was 37%. To understand the temperature distribution through different layers of desalination surfaces, a numerical simulation was carried out under real weather conditions using the finite element software; COMSOL Multiphysics. Results showed that, there was a good agreement between experimental work and numerical investigation. Image 10485 • The proposed inclined wick solar still has thermal efficiency of 61%. • Different combinations of basin metals and novel wick-metal chips pads were studied. • Aluminum and copper basins lead to increase the productivity by 34% and 54%. • Experimental results have been successfully verified by numerical simulation. [ABSTRACT FROM AUTHOR]