Search

Energy management plan is utilized as an optimum strategy by using solar and wind energies, as a new preliminary implementation. The aim of the study is to create an optimum strategy through an optimization of an energy management system. The study implemented an onsite model, two numerical approaches, and an optimization analysis on a Mediterranean port. Two approaches have been used: solar energy is applied experimentally and numerically, and then wind energy is simulated. An optimization analysis integrated the two approaches together to control their operation. The results showed the installed solar panels provided sufficient generated power for the buildings. Also, the simulated wind arrays showed good behavior with increased power coefficient for the wind turbines, for future implementation. These results were validated using the DesignBuilder software and showed accurate values regarding the experiment for solar panels and CFD simulation. Eventually, a Pareto optimality analysis is applied between the solar and wind energies to reveal an energy management plan. Renewable energy offered energy to support the consumption of the port's buildings., (© 2023. The Author(s).)

Green hydrogen is a clean and renewable energy source that has the potential to play a major role in decarbonizing the global economy. Green hydrogen has become a promising decarbonization strategy for several industries, including transportation and manufacturing. The widespread use of green hydrogen technology still confronts several obstacles, such as high costs, a lack of infrastructure, and regulatory restrictions. The paper commences by examining the potential of green hydrogen production in MENA countries with a specific emphasis on Egypt as best practice example. It proceeds to identify the key drivers that will shape future scenarios of green hydrogen and outlines the best and worst-case scenarios for green hydrogen in MENA region by 2050. Through scenario analysis, the paper presents potential pathways for green hydrogen deployment in Egypt and the wider MENA countries, highlighting key drivers and potential barriers. According to the findings, Egypt emerges as pivotal player in driving the deployment of green hydrogen within the MENA region. The MENA region, rich in solar and wind resources and strategically located, emerges as a potent hub for green hydrogen production. Egypt, in particular, is at the forefront of this initiative, aiming to become a key exporter in the global hydrogen economy by leveraging its renewable resources, strategic projects, and conducive investment environment. The study employs a multifaceted methodology, integrating PEST analysis and identifying key drivers like renewable targets and technological advancements to assess green hydrogen’s potential in the MENA region, focusing on Egypt. It constructs best- and worst-case scenarios by 2050, utilizing these drivers to evaluate the implications of various influencing factors. In the best-case scenario, by 2050, Egypt aspires to be a pivotal player in the global green hydrogen economy, aiming for up to 8% market share. Through strategic investments, policy enhancements, and global partnerships, Egypt plans to become a major exporter, particularly to the European Union, aligning with global decarbonization goals. Comprehensive strategies are expected to drive economic prosperity, potentially increasing Egypt's GDP by $10-18 billion by 2025. Collaborations with global entities have fostered a robust infrastructure, enabling an integrated ecosystem for green hydrogen innovation and production. [ABSTRACT FROM AUTHOR]

Rural electrification represents a great worry for developing nations. Isolated microgrids establishment is the brightest solution for this problem. Optimization strategies for mathematical simulation and modelling are accomplished in this research to size an isolated residential microgrid in Egypt consists of wind generators (WG), photovoltaic (PV), battery energy storage system (BESS) and Biomass generator. This paper's novelty relies on the techno-economic performance comparison of three sizing strategies of isolated microgrid based on renewable sources, considering the sources' uncertainty. Also, the environmental and economic effects of using rice straw in biomass gasification are introduced to handle the problem of dark clouds from its open-air burning. Three categories with nine combinations of renewable energy sources (RES) are introduced in this paper to select the ideal option. Multi-objective genetic algorithm (MOGA) optimized the systems under both deterministic and stochastic conditions, taking into consideration the uncertainties of solar radiation and wind speed using Monte-Carlo techniques. The obtained results are compared with the results of epsilon multiobjective genetic algorithm ("-MOGA). Simulation outcomes show that PV with BESS is the most economical option for microgrid sizing with a total system cost of $ 4.04 million. Besides, Scenario 6's hybrid system provides an appropriate ecological-reliable configuration, especially when considering sources' uncertainties. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Journal of Agricultural Sciences (SJAS) is the property of Beni Suef University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The energy strategy was updated in Egypt until 2035 in cooperation with the European Union. This strategy dealt with a study of all the potentials and scenarios of the energy in Egypt, where the generation mix includes nuclear power and renewable energy in addition to the traditional energy from gas and oil with a focus on renewable energy uses to reach about 42% from the generation mix. This paper includes a framework strategy to provide an optimal yearly mix from generation sources that gives minimum cost with an acceptable range from the emitted pollution and satisfying the forecasted load. The paper objective is achieved by calculating the overall generation mix in parallel with the fair sharing from each available source that gives minimum cost against the emitted pollution. The particle swarm optimization (PSO) scheme is used to implement the proposed strategy and subjected to the generation capability limit of each type of generation from solar, wind, nuclear and conventional (thermal and hydro) as given by the government. The effectiveness of this scheme is verified by comparing the results with the Egyptian network data and with conventional optimization methodology. The scheme structure was built using MATLAB library. According to the results, it has been proved that the designed scheme used with the help of the PSO can robustly and efficiently generate great economic benefits. The study concludes the importance of the framework strategy to achieve a reliable and sustainable future energy supply. [ABSTRACT FROM AUTHOR]

Recently, renewable energy resources (RESs) have been utilized to supply electricity to remote areas, instead of the conventional methods of electrical energy production. In this paper, the optimal design of a standalone hybrid RES comprising photovoltaic (PV), wind turbine (WT), and biomass sources as well as an energy storage system, such as a hydro-pumped storage system, is studied. The problem of the optimal sizing of the generating units in the proposed energy system is formulated as an optimization problem and the algorithms heap-based optimizer (HBO), grey wolf optimizer (GWO), and particle swarm optimization (PSO) are applied to achieve the optimal sizing of each component of the proposed grid-independent hybrid system. The optimization problem is formulated depending on the real-time meteorological data of the Ataka region on the Red Sea in Egypt. The main goal of the optimization process is to minimize the cost of energy (COE) and the loss of power supply probability (LPSP), while satisfying the constraints of system operation. The results clarify that the HBO algorithm succeeded in obtaining the best design for the selected RE system with the minimum COE of 0.2750 USD/kWh and a net present cost (NPC) of USD 8,055,051. So, the HBO algorithm has the most promising performance over the GWO algorithm in addressing this optimization problem. [ABSTRACT FROM AUTHOR]

The need for renewable energy sources is recently necessitated by attaining sustainability and climate change mitigation. Accordingly, the use of renewable energy sources has been growing rapidly during the last two decades. Yet, the potentials of renewable energy sources are generally influenced by several climatic factors that either determine the source of energy such as wind speed in the case of wind power or affect the performance of system such as the reduction in solar PV power production due to temperature increase. This highlights the need for assessing climate change impacts on renewable energy sources in the future to ensure their reliability and sustainability. This paper is intended to assess impacts of climate change on wind and solar potential energy in Egypt by the year 2065 under RCP 8.5 scenario. For this purpose, a GIS-based methodology of three main steps was applied. The results revealed that solar energy potential in Egypt is expected to be relatively less vulnerable to climate change compared to wind energy. In this respect, it was found that while wind energy potential was estimated to range ± 12%. By the year 2065 under RCP 8.5 scenario, PV module power is expected to decrease by about 1.3% on average. Such assessment can assist in developing more sustainable and flexible renewable energy policy in Egypt. [ABSTRACT FROM AUTHOR]

In this paper, the present status of energy storage implementation and research in Arab countries (ACs) is investigated. The different technologies of energy storage are reviewed then projects and capacities of installed or planned energy storage systems in the ACs are summarized based on published literature. In ACs, the installed and planned capacity of pumped hydro storage is 4365 MW, while for battery storage it is 5597 MW. No compressed energy storage projects are installed or planned in the near future. Green hydrogen as a fuel is planned in Egypt, Algeria, and Morocco. Renewable energy as a main employer of energy storage is predicted for the next 30 years; similarly, energy storage capacity is forecasted for the next 30 years. To enhance energy storage implementation it is recommended to include energy storage in all new commercial renewable energy projects. In addition to creating a regulatory framework that encourages the development of energy storage schemes. To advance research in the energy storage, modeling and simulation of energy storage systems in residential, commercial, and industrial sectors are recommended. In addition, cold energy storage for cooling and air‐conditioning using phase change material to be investigated. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Sciences is the property of Faculty of Engineering - Assiut University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper investigates the impact of geopolitical risks on renewable energy generation in MENAT oil-importing countries, namely, Egypt, Tunisia, and Turkey over the period 1990–2020 using the autoregressive distributed lag (ARDL) model. The main findings emphasize that geopolitical risks play a crucial role in inducing renewable energy development in MENAT oil-importing countries in the short and long run. Financial development appears to positively and significantly affect renewable energy generation in the three countries. Furthermore, the speeds of adjustment towards the long-run equilibrium are 36.78%, 66.03%, and 17.81% annually in Egypt, Tunisia, and Turkey, respectively. In today's volatile and turbulent world, dramatically rising geopolitical risks make the transition to renewable energy an inevitable reality. Consequently, it is incumbent upon policymakers and relevant authorities in MENAT oil-importing countries to preemptively redirect their efforts and strategies to conform to the demands of the inevitable transition to renewable energy sources and boost energy self-reliance. [ABSTRACT FROM AUTHOR]

Seaports are considered one of the sources involved in the deterioration of the maritime environment due to the excessive amount of exhaust gases emitted from their activities. The majority of seaports depend on the national electric grid as a source of power for the domestic and ships' electric demands. This paper discusses the possibility of shifting ports from relying on the national grid electricity to green power-based ports. Offshore wind turbines and fuel cell units appear as two typical promising clean energy sources for ports. As a case study, the paper investigates the prospect of converting Alexandria Port in Egypt to be an eco-friendly port with the study of technical, logistic, and financial requirements. The results show that the fuel cell, followed by a combined system of wind turbines and fuel cells, is the best choice regarding electricity production unit cost by 0.101 and 0.107 $/kWh, respectively. Furthermore, using fuel cells and offshore wind turbine as a green power concept will achieve a reduction in emissions' quantity of CO 2 , NOx, and CO emissions by 80,441, 20,814, and 133,025 ton per year, respectively. Finally, the paper highlights the role that renewable energy can play when supplying Alexandria Port with green energy to lift the burden on the government in supporting the electricity, with a possibility of achieving a profit from 3.85 to 22.31% of the annual electricity cost compared with the international prices.

Emerging economies are mostly plague by a massive consumption of non-renewable energy amidst an ever inceasing urbanization rate with little or no attention to the quality of the environmental. As such, this paper investigates the relationship between renewable energy, urbanization, economic growth, trade openness, and ecological footprint in CIVETS countries, namely, Colombia, Indonesia, Vietnam, Egypt, Turkey, and South Africa. The study employs augmented mean group estimator, panel cointegration, and causality tests. The findings reveal that renewable energy improves environmental quality, and trade is not particularly harmful to the environment. However, non-renewable energy consumption and urbanization are the chief contributors to environmental degradation in the CIVETS countries. Economic expansion mitigates environmental deterioration in Colombia, South Africa, and Turkey, but contributes to pollution in Egypt, Indonesia, and Vietnam. Finally, the causality test suggests that urbanization drives environmental degradation. Policy directions are discussed. [ABSTRACT FROM AUTHOR]

The annual share of water in Egypt has decreased to approximately 500 m3 per capita, while the annual water scarcity level is 1000 m3 per capita, which indicates that Egyptians are at a high risk of living. A domestic desalination unit based on solar energy was designed, built, and tested to solve this problem in remote areas that do not have access to fresh water or electricity but have access to salty water. The desalination unit has a new design that depends on boiling salty water using photovoltaic solar cells and then condensing the water vapor through a heat exchanger to obtain freshwater. This new design has not been implemented before and can compete with the solar stills used for domestic applications. The output of the developed unit was compared to those of passive and active solar stills that have been developed and built. The new desalination design produced almost the same amount of daily fresh water, 4 Liter/day, compared to the other solar stills (2–4.75 Liter/day), but the cost per unit volume of the new design, 31 $/m3, is less by 30% compared to the best performing solar still, 44.55 $/m3, which produces only 2 Liter/day. The price of the distilled water produced by the new design was 75% lower than the market price at the time of conducting the experiments. Converting a Solar still from a passive system, that is, operating only during sunlight, to an active system operating day and night improves the water productivity rate. However, this is not feasible because of the added accessories that increase the initial cost, consequently increasing the cost of desalination. [ABSTRACT FROM AUTHOR]

Desalination process is an essential demand to overcome the lack of drinking water in remote areas in Egypt. Hybrid energy system drives desalination techniques to provide potable water for islands and coastal zones where there is no electrical grid. This paper analyzes the technical configuration, sizing and economic optimization of off-grid hybrid energy system powered reverse osmosis plant. The hybrid system consists of wind turbines, photovoltaic panels, converters, storage batteries, and a diesel generator. The objective of this study is to satisfy the electrical energy demand of the reverse osmosis (RO) plant with a freshwater capacity of 100 m3/day for use at Nakhl, North Sinai, Egypt. This simulation studied eleven different configurations of energy sources to select the optimal case at the proposed location. Homer package is used to select the cost-effective, sustainable and socially accepted system. The simulation is based on calculating the net present cost (NPC), excess system electricity, cost of energy (COE) and carbon dioxide emissions (CO 2). Through the study, the optimal configuration consists of 160 kW photo-voltaic (PV) panels, 19 strings of lead-acid batteries and a 50 kW diesel generator system. The optimal case achieves the lowest cost of energy ($0.107/kWh) and net present cost ($502,662). • Eleven scenarios are studied to drive a reverse osmosis desalination plant. • Net present cost, cost of energy and gas emissions are calculated. • Homer Pro software simulated more than 300 solutions. • The hybrid of PV/diesel/battery system (case 6) is the optimal design. • The system reduces the emissions of carbon dioxide gas by 94%. [ABSTRACT FROM AUTHOR]

This study contributes to the growing but still limited body of literature on the impact of economic policy uncertainty, renewable energy usage, and economic growth on environmental degradation in Egypt. Using the autoregressive distributed lag (ARDL) bound test, we examine the existence of cointegration relationships in Egypt over the period 1990–2018. Our results indicate that economic policy uncertainty is positively associated with environmental degradation in both the short and long run. Additionally, we find that economic growth exacerbates environmental degradation in both the short and long term. Finally, renewable energy consumption has a significant negative effect on environmental degradation in the long run. Therefore, ensuring economic policy stability is crucial for maintaining environmental quality. To this end, Egyptian policymakers should prioritize low-carbon research and development techniques, as well as the adoption of renewable energy sources to mitigate environmental degradation. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the relationship between tourism and renewable energy. In the study, the economies of Egypt, Kenya, and Ethiopia, which are in the African continent and lead renewable energy in this continent, were analyzed with the Granger causality test. As a result of the causality analysis, a positive and significant relationship was found between the number of tourists coming to the country in Egypt and the renewable energy consumption of this country. In addition, it has been concluded that Egypt's earnings from the tourism sector also affect the renewable energy of this country. In terms of Kenya, although there is no significant relationship in terms of renewable energy, a significant relationship was found between the income obtained from the tourism sector of the country and the number of tourists. In terms of Ethiopia, no causal relationship has been determined. In the absence of a meaningful relationship between renewable energy and tourism, it can be stated that the tourists who come to the country do not care about environmental pollution in terms of energy. In other words, the inclusion of renewable energy in investments in the tourism sector in these countries will not affect the number of tourists. [ABSTRACT FROM AUTHOR]

The Abu Gharadig Basin is regarded as one of the most essential in Egypt, serving as the country's second most important reservoir for hydrocarbon production. Our present study is focused on the investigation of geothermal resources in the Abu Gharadig Basin. Using airborne magnetic and gravity surveys, as well as temperature well records, we can identify possible geothermal sources in this region. Power spectral analysis was used on the airborne magnetic measurements to compute the Curie Point Depths (CPDs) and display the temperature gradients and heat flows regime in the study area, while on the gravity data, 3-D density inversion was used to identify the basement surface. Real data from bottom-hole temperature (BHT) logs and geological data (structural and stratigraphic data from prior studies) were used to cross-validate the geophysical maps and to ascertain the stratigraphy and structural setting beneath the study location. The depth of the basement rock, according to the studies, ranges from 4.5 to 7 km, and the CPDs run from 17 to 22 km. Furthermore, the estimated temperature gradients vary from 25 to 34 degrees Celsius per kilometer, whereas the heat flows vary from 52 to 86 mW/m2. Generally, there is a correlation between shallow curie depths, uplifts on basement rocks, and sites of high heat flow, indicating that basement rocks are primarily accountable for the geothermal potential of the basin. [ABSTRACT FROM AUTHOR]

Slowing and reversing climate change and keeping energy prices at affordable levels are the main important achievements of the use of renewable energy. About 210% increase in energy consumption from 1990 to 2018, reduction in fossil fuel reserves, and high capacity of renewable energy in Arab countries encourage them to increase the use of renewable and sustainable energy sources as a key way to supply the energy in future and have a sustainable economy. There is no a comprehensive review study to focus on the capacity and strategies of renewable energy in Arab countries at the transnational level until 2030. To fill this gap, this article investigates the current and future capacities and strategies of renewable energy production by 22 Arab countries, which are the center of fossil energy production in the world, until 2030. Indeed, it provides a roadmap for advancement towards energy production from renewable sources in these countries. It is observed that Egypt and Morocco with an installed capacity of 5980 and 3447 MW, respectively, had the highest installed renewable energy capacity among the Arab countries in 2020. The results also showed that most ambitious goal is related to Djibouti, where it is targeted to supply 100% of energy from renewable resource by 2035. Finally, it should be mentioned that most Arab countries focus on solar and wind energy, and very little attention is paid to geothermal, biomass, and hydroelectric energy. [ABSTRACT FROM AUTHOR]

• The electrical power generation role for sustainable development and facing the environmental problems of CO 2 emissions increase from electric power generation and burning rice straw. • Multi-objective optimal sizing approach of a real new constructed area on the northern coast of Egypt using renewable energy sources. • The environmental and economic effects of rice straw recycling through using it as biomass fuel for electricity generation in rural areas and cities surrounded by rural areas, either in isolated or grid-connected microgrids. • Comparison between different sizing strategies according to the availability of power conversion sources. • The effect of time of use demand response on system sizing. • The impact of the participation percentage increase in DR programs on the renewable energy share and the net present cost. Many countries encourage the establishment of microgrids to support the spread of renewable energy sources, as it is the best option for dealing with electricity problems and air pollution. In this study, four sizing scenarios of a residential microgrid in a northern Egyptian city surrounded by rural areas are introduced as an interpretative example to explore the optimal scheduling strategy. This paper's novelty originated from the techno-economic and ecological performance comparison of different sizing strategies for a residential load based on renewable sources, considering load shifting algorithms and using rice straw as biomass fuel instead of its open-field burning. The proposed optimization algorithm illustrates that the PV/WG/Biomass/two-ways-grid-connection microgrid is the best investable-reliable sizing option with a minimum net present cost of about ($ 0.7073 m i l l i o n), which is reduced by ($ 0.1664 m i l l i o n) when 30% demand response participation is applied. Also, the PV/WG/Biomass system has the most significant environmental impact with a C O 2 emissions reduction of around (3.465 * 10 8 kg). [ABSTRACT FROM AUTHOR]

This work presents the review of locomotives and the future of railway automotive power in Africa. Locomotives down time on account of inadequate spare parts still remains a challenge in African. It is thus, imperative to review the locomotives in African, to establish the current capabilities as well as provide recommendations to bridge the gaps and its extrapolated trends in future. Firstly, the comparison factors were track length, electrified rails, number of locomotives and yearly passengers on each of Egypt, Ghana, Kenya, Nigeria, South Africa and Zambia rails. Secondly, the focus was on engine parameters from literatures and maintenance logbooks of locomotives. From available data, it was found that South Africa and Egypt have more advanced rail system than the rest four selected countries. It was also found that additive manufacturing, 3D printing, ductile cast iron and die-forging can be used to produce the engine body for diesel engine using steel and aluminum alloys while aluminum silicon and tin doped with copper are good for reciprocation mechanisms. And finally, increased reliability of locomotives can be guided by an engine selection matrix, while use of renewable and energy hybridization are needed to meet the expansion of railroads in Africa. [ABSTRACT FROM AUTHOR]

The paper proposes four hybrid storage options: battery-supercapacitor, battery-flywheel, battery-pumped hydro storage, and battery-fuel cell. A probabilistic approach based on the artificial neural network is implemented to cover the weather uncertainty. The developed options and the approach are combined with comprehensive eco-techno-economic optimization study. Multi-objective optimization scenarios are investigated to reduce either/both total cost or/and greenhouse gas (GHG) emissions considering Utopia point approach. Two new hybrid particle swarm optimization - grasshopper optimization algorithm (PSO-GOA) methods are developed: GOA updated PSO and GOA initialized PSO algorithms. The effectiveness of the developed optimizers and the Utopia point approach are validated. Sensitivity analysis is performed to demonstrate the variable parameters that majorly influence the investment costs and GHG emissions. Through numerical simulations via Matlab™, PV modules rating power, number of wind turbines, and the load demand are the key factors that impact the eco-techno-economic at Qusair city, Egypt. Through the Utopia point solution, supercapacitor integrated battery demonstrates enhancements by 42.48% and 12.92% in the GHG and levelized cost of energy (LCOE) compared to the economic and environmental solutions. The salvage market fosters the hybrid flywheel and pump hydro storage integrated battery options by reducing the LCOE by 44% and 51%, respectively. [ABSTRACT FROM AUTHOR]

Performances of solar dryers for the drying of medicinal and aromatic plants (MAP) in Africa were reviewed. Policy formulation indicators, including the economic and the environmental impact analysis that was lacking in almost all research, were presented in this study. Three countries, Nigeria, Egypt and Algeria, were used as case studies. Key indicators analyzed were the amount of money saved and CO2 reduction based on 10% to 100% rate of utilization and cost of a kWh of energy in each country. Results showed that as the rate of usage increased from 10% to 100% for drying Lemongrass in Egypt, the amount of money saved increased from $102.5 – $1025/year. While, in the same country at the same drying condition and mass, it increased from $123.5 – $1235.44/year for drying Oregano. Drying of Chilli in the coastal area of Nigeria saved more money than drying of Basil in Egypt under the same rate of usage. About 40702.38–407023.8 kg of CO2 per year can be reduced in the drying of Grape in Egypt, while 2308.5–23085 kg of CO2 can be reduced for drying of Chilli in Nigeria. [ABSTRACT FROM AUTHOR]

Clean and renewable energy sources are the preferable power system generations for the overall world. This research aims to present a very highly integrated, economic, professional, and simple construction, clean and natural resources usage of the renewable hybrid generation system. This research performs analysis, systematic representation, evaluation, and design of the hybrid proposed system—pico-hydraulic from home usage water and photovoltaic (PV)—to generate an optimal renewable generation system using a new professional control system. Applying this proposed technique in Egypt shows that the hybrid system successfully overcame Egypt's energy crisis. Renewable energy will rise to 8.782% by increasing 7.323% (14,408.83 GWh/Y). Besides, this system increases the power supply reliability; it gives an additional emergency supply and reduces the exhausts from other generation stations (e.g., CO2). The saving from this hybrid system is very effective for; the residential sector (subscribes), which will be ranged from 9599.298 million E£/10Ys up to 86,393.68 million E£/10Ys that equals 5399.6 million $, government to use this extra generation energy to reduce the maximum loads from various stations. A practical model has been presented with results to verify the high efficiency of the proposed system that illustrates the effective performance of the used hybrid system. [ABSTRACT FROM AUTHOR]

In this research, a technoeconomic comparison of energy efficiency options for energy districts located in different climatic areas (Naples, Italy and Fayoum, Egypt) is presented. A dynamic simulation model based on TRNSYS is developed to evaluate the different energy efficiency options, which includes different buildings of conceived districts. The TRNSYS model is integrated with the plug-in Google SketchUp TRNSYS3d to estimate the thermal load of the buildings and the temporal variation. The model considers the unsteady state energy balance and includes all the features of the building's envelope. For the considered climatic zones and for the different energy efficiency measures, primary energy savings, pay back periods and reduced CO2 emissions are evaluated. The proposed energy efficiency options include a district heating system for hot water supply, air-to-air conventional heat pumps for both cooling and space heating of the buildings and the integration of photovoltaic and solar thermal systems. The energy actions are compared to baseline scenarios, where the hot water and space heating demand is satisfied by conventional natural gas boilers, the cooling demand is met by conventional air-to-air vapor compression heat pumps and the electric energy demand is satisfied by the power grid. The simulation results provide valuable guidance for selecting the optimal designs and system configurations, as well as suggest guidelines to policymakers to define decarbonization targets in different scenarios. The scenario of Fayoum offers a savings of 67% in primary energy, but the associated payback period extends to 23 years due to the lower cost of energy in comparison to Naples. [ABSTRACT FROM AUTHOR]

Solar-powered desalination is a sustainable solution for countries experiencing water scarcity. Several studies have presented different solutions to provide cleaner production in desalination systems. Parabolic trough collector (PTC) is one of these solutions that has proven to be superior among solar concentrators. Furthermore, a number of studies have investigated the use of PTC for distillation of saline water in response to water scarcity. In this study, a modified PTC model was developed, in which the heat exchanger was replaced by a condensation tube to reduce the energy consumption, and a black layer was introduced to the surface of the receiver to enhance its absorptance. As a reference case, the system productivity according to average solar intensities in Zagazig, located at 30°34′N 31°30′E in the North East of Egypt, is estimated. The results indicated that the maximum production rate that can be attained is 1.72 kg/h. Then, the structure of the system is evaluated with the aid of Computational Fluid Dynamics (CFD) modelling, in order to enhance its productivity. Many materials are examined and the results recognised copper as the most suitable material amongst marine grade metals (i.e., aluminium, galvanised steel and stainless steel) to construct the receiver tube. This is due to its superior thermal performance, satisfactory corrosion resistance, and acceptable cost. Afterwards, the selected receiver tube was employed to identify the optimal Concentration Ratio (CR). Consequently, a CR of 90.56 was determined to be the optimum value for Zagazig and regions with similar solar radiation. As a result, the system's productivity was enhanced drastically, as it was estimated that a maximum production rate of 6.93 kg/h can be achieved. [ABSTRACT FROM AUTHOR]