Interest in solar stills as straightforward, affordable, and sustainable methods has increased due to the world's freshwater crisis and the shortcomings of traditional desalination technology. Nevertheless, their significant thermal losses and low productivity continue to be major obstacles to widespread use. From thermodynamic, material, and sustainability viewpoints, this review offers a creative assessment of absorber augmentation techniques, including selective coatings, geometric changes, phase change materials (PCMs), Nano fluids, and hybrid systems. This study presents an integrated comparison methodology that links absorber-level alterations to system-level outcomes, such as thermal/exergy efficiency, Leveled Cost of Water (LCOW), and environmental effect. From the analysis it can be concluded that geometry modifications and selective coatings provide the most sustainable benefits and cost (10-35 %), in addition using PCM enables 20 to 40 % nighttime productivity and Nano fluids enhance heat transfer by 45 %. Solar hybrid / PCM thermal systems achieve the greatest advantages with 60 %, but necessitate higher control costs and complexity. This article's primary and novel contribution is its comprehensive evaluation, which combines insights from thermodynamics, sustainability, and smart control to establish an organized research pathway for next-generation absorber designs. This article concludes by outlining important research gaps and suggesting potential solutions, including modular absorption systems, ecofriendly materials, and predictive control driven by artificial intelligence (AI). This work offers researchers and engineers precise, data-driven recommendations to enhance solar distillation systems toward dependable, intelligent, and sustainable freshwater production.

The growing demand for sustainable energy, clean water, and green fuels has increased interest in integrated renewable-energy systems, which can produce multiple valuable outputs from a single energy source. In this paper, a laboratory-scale geothermal-based multi-generation system was designed, developed, and experimentally investigated for the production of electricity, HHO gas, and desalinated freshwater. The proposed system is composed of a geothermal steam generator, a steam turbine coupled with a DC generator, an alkaline water electrolyzer, and a waste-heat-assisted solar still combined by a thermal cascading configuration. The steam turbine for electricity generation was driven by the superheated steam generated from the geothermal heat source. In order to improve the performance of the solar desalination unit, the electricity generated was then used to produce HHO using an alkaline electrolyzer, and the low-pressure turbine exhaust steam was recovered in a submerged heat exchanger. In addition, a three-dimensional Computational Fluid Dynamics (CFD) simulation was performed using ANSYS Fluent to study the fluid flow and heat transfer behavior and to validate the experimental results. The experimental results showed the stable operation of the integrated system with an average electrical power output of about 31 W, which is enough to run the electrolyzer continuously. The maximum efficiency in the four-cell alkaline electrolyzer was about 79%, and the time of HHO production was decreased compared to the two-cell. The recovered turbine exhaust heat improved desalination performance significantly with increased freshwater productivity to 8.6 L day-1. Water quality analysis indicated a significant reduction of total dissolved solids (TDS) to about 76 ppm, indicating the production of high-quality fresh water. The maximum deviation between numerical and experimental results was approximately 6%. The results demonstrate the technical feasibility of integrating geothermal power generation, HHO production, and desalination on a single platform.

This study investigates whether increasing the number of phase change material (PCM) layers in a passive single-slope solar still continuously improves freshwater productivity, or whether an optimum thermal-storage configuration exists due to the trade-off between heat-transfer resistance and latent heat storage. A conventional solar still (CSS) was experimentally compared with a modified solar still (MSS) integrating wire-mesh capillary thin-film evaporation, internal reflectors, and one-, two-, and three-layer PCM thermal storage under stable outdoor conditions in Egypt. The thermal response, evaporation–condensation phenomena, productivity, energy performance and techno-economic feasibility were evaluated by measuring the solar radiation and the temperatures of the water, vapor space, glass-cover, PCM, and the temperature of the basin, and the distillate yield. The two-layer PCM configuration was the best performer during the day when the results obtained were 2124 mL (an improvement of approximately 65% over the CSS configuration, which generated 1284 mL). The two-layer MSS had a latent heat release that resulted in 1020 mL, while the CSS had 294 mL, which is a 247% improvement. The three-layer PCM configuration gave the maximum night time yield of 1440 mL, however this was due to the higher storage thickness, which also caused a higher conductive resistance, which slowed down the heating during the day. The two-layer MSS case had the best balance of practical performance, with an estimated LCOW of $0.0121/L and a payback period of 1.8 years, while the three-layer case had the lowest LCOW of $0.0116/L, but a higher material complexity. The results show that solar-still improvement is not linearly proportional with the amount of PCM, but rather it is the balance between evaporation-surface enhancement, internal radiation redistribution, heat-transfer resistance and night-time heat discharge that play a role in achieving optimum performance. The proposed configuration provides a simple passive route for improving decentralized solar desalination, while longer-term testing under variable climatic conditions is recommended for broader validation.

The use of reverse osmosis (RO) membranes for desalination has gained popularity in generating drinking water from seawater sources. This study assesses the performance of a single-module feed-forward reverse osmosis (RO) system, representing the membrane module as a tubular module with feed flow on the tube side. A superstructure for the single-module feed-forward RO system forms the basis for a comprehensive mathematical model of the RO system. Mass, materials, and energy balances are meticulously applied to all system components. The study also explores external factors’ influence, such as feed parameters, utility costs, and product costs, on RO system performance and optimal design. It delves into parameters affecting unit performance, including feed characteristics and operational conditions. Additionally, the impact of feed specifications and operating conditions on concentration polarization within each module is investigated. The obtained results showed that the total permeate from the unit decreases with higher salt concentration on the membrane wall as the feed concentration increases, while the unit cost remains constant. In addition, the rise in feed flow rate and feed temperature led to a decrease in wall concentration. Finally, a substantial 20

This research conducts a comprehensive experimental study of a solar distillation configuration enhanced with phase change material and internal electric fans, in a single-slope solar stills. Despite their operational simplicity, conventional single-slope solar stills are fundamentally limited by low distillate yields due to significant thermal losses and the formation of a stagnant vapor boundary layer that impedes efficient mass transfer. An experimental arrangement was constructed and tested at Faculty of Engineering, Sinai University, Egypt, and analyzed using 11-E framework, which encompasses assessments of energetic, exergetic, economic, environmental, and sustainability aspects. Four operating scenarios were examined: (i) conventional solar still (CSS), (ii) Enhanced solar still with fans only (ESSF), (iii) Enhanced solar still with paraffin wax only (ESSP), and (iv) Enhanced solar still with both paraffin wax and fans (ESSPF). The results indicated that integrating PCM beneath the absorber plate extended operation into post-sunset hours by providing latent heat storage. At the same time, fans improved internal convection, accelerated vapor transport, and enhanced condensation. The combined configuration (ESSPF) yielded the highest performance, with a supreme daily freshwater productivity of 5.26 f 0.01 kg/ m2, representing an 87.90 f 0.01% increase compared with the conventional one. Energy and exergy productivity rates for ESSPF reached 49 f 0.05% and 2.0 f 0.05%, respectively, while the water production cost decreased to 0.00772 $/L, resulting in a reduced payback period of 5.25 months. An environmental analysis confirmed a substantial decrease in CO2 emissions resulting from a decrease in dependence on traditional fuel-based water production. Furthermore, sustainability and improvement potential indices indicated that the enhanced stills provide a more viable long-term solution. Overall, the integration of paraffin wax and internal fans provides a cost-effective, reliable, and scalable modification to conventional solar stills, supporting global strategies for sustainable and environmentally friendly water desalination.

The transition to sustainable energy sources is essential for reducing greenhouse gas emissions while ensuring long-term energy security. Green hydrogen, produced through water electrolysis powered by renewable energy systems such as photovoltaic (PV) technology, is considered one of the most promising alternatives to fossil fuels. Egypt possesses excellent solar resources that can be leveraged to establish large-scale green hydrogen infrastructure. This study investigates the potential for hydrogen production in Egypt using solar-driven electrolyzers and machine learning (ML)-based forecasting models. Hourly meteorological data—including global horizontal irradiance (GHI), temperature, wind speed, and atmospheric pressure—were collected from the Egyptian Meteorological Authority, NASA Power database, and other sources. Preprocessing involved normalization and dimension reduction using Principal Component Analysis (PCA). Two ML algorithms, Long Short-Term Memory (LSTM) neural networks and Facebook Prophet, were implemented to forecast solar power generation which was subsequently converted to hourly hydrogen production forecasts. Four regions, representing diverse climatic zones—Bir El Abd, Cairo, Abu Minqar, and Aswan—were selected for evaluation. Model performance was assessed using statistical indicators such as the coefficient of determination (R2), mean absolute error (MAE), mean squared error (MSE), and root mean square error (RMSE). Results demonstrated that LSTM consistently outperformed Prophet in all regions, achieving R2 values exceeding 0.95 in Cairo and Aswan. Forecasts indicated hydrogen production potentials above 41,000 kg km⁻2 month⁻1 in these regions, confirming their viability for large-scale deployment. Overall, the proposed data-driven framework supports strategic decision-making for future green hydrogen investment in Egypt, providing a scalable and accurate method for forecasting solar-based hydrogen production in regions with high-irradiance profiles.

One of the world’s most urgent problems is still freshwater scarcity, especially in arid and semi-arid areas where traditional desalination methods are constrained by high energy consumption, operating costs, and environmental issues. The breakthroughs, performance enhancements, and sustainability issues in solar still desalination systems are all thoroughly reviewed in this paper. The goal of the current review is to measure the present technological progress for developing the freshwater production while maintaining the viability from an economic and environmental viewpoint. The effects of the numerous improvement methods on the yield, the efficiency, and the cost are surveyed. These strategies include using the nanofluid techniques, phase change materials techniques, wick layers techniques, hybrid photovoltaic/thermal (PV/T) systems, and thermal management techniques. The multi-effect and hybrid systems can increase the freshwater output up to three times and can enhance the energy efficiency and the long-term dependability, according to the comparative studies which be done with the conventional single basin stills. Despite those improvement methods, issues including material degradation, scalability, and high capital expenditures still pose significant obstacles to wider implementation. Overcoming these limitations requires several approaches that combine cutting-edge materials, computer modeling, and the integration of renewable energy sources. The study concluded that the solar distiller systems are an inexpensive, decentralized, and sustainable way for producing fresh water when their benefits are maximized through the hybrid and smart design. These results provide the researchers and the engineers with a roadmap for creating next-generation solar-powered desalination arrangements that help in enhancing global water security and advance the Sustainable Development Goals.

Chemical Looping Combustion (CLC) offers an efficient pathway for carbon capture by inherently concentrating CO2 without energy-intensive separation steps. This study experimentally investigates the combustion of Liquefied Petroleum Gas (LPG) in a dual-reactor CLC system using a 50 g bed of iron-based oxygen carrier (150 mu m). Tests were conducted at fuel flow rates of 2, 4, and 5 kg center dot h-1 under a constant air supply of 16.17 m3 center dot h-1. The oxygen carrier substantially enhanced combustion, elevating the fuel reactor temperature from a baseline of 780 degrees C (air-only) to 905 degrees C, 918 degrees C, and 932 degrees C, respectively an average thermal enhancement of 18.6 %. CLC operation also increased the maximum CO2 concentration to 72-74 vol% (dry basis) from 43-47 vol% in conventional mode, while CO emissions were reduced by 38-52 %. The system reached thermal stability 40 % faster (2.1 min) with the carrier, indicating accelerated kinetics via lattice oxygen transfer. These results confirm that LPG, despite its complex hydrocarbon nature, can achieve over 70 % CO2 capture potential in CLC when paired with an iron-based oxygen carrier, demonstrating significant promise for retrofitting existing LPG infrastructure for low-carbon, high-efficiency combustion.

This study experimentally evaluated waste cooking oil (WCO) biodiesel–diesel blends in an unmodified single-cylinder direct injection diesel engine operated at 1500 rpm under no load and 1–5 kW load conditions. Diesel and B10–B50 were compared in terms of brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), and CO, HC, CO2, and NOx concentrations. Across 1–5 kW, diesel produced a mean BSFC of 310 g kW−1 h−1, while B20 showed the lowest value among the biodiesel blends at 320 g kW−1 h−1. Mean BTE decreased from 29.0

Alkaline water electrolysis is a pivotal technology for sustainable hydrogen generation. While the individual effects of operational parameters are well-documented, a significant research gap exists in understanding the synergistic interaction between electrolyte chemistry and electrolyzer structural design. This study addresses this gap by presenting a holistic experimental investigation into the coupled effects of electrolyte type (NaOH, KOH), concentration (5-20 %), and electrode plate count (4, 6, 8) on hydrogen production rate, thermal stability, and system efficiency. Three distinct electrolyzer prototypes-varying in material, complexity, and cost were constructed and tested under identical conditions with a 12 V, 30 A DC supply. The results demonstrate that higher electrolyte concentrations (15-20 %) significantly enhance ionic conductivity and hydrogen yield, with KOH exhibiting marginally superior performance due to its higher conductivity. Crucially, the number of electrode plates non-linearly impacts performance; while increasing plates generally improves hydrogen production and thermal management, an optimal configuration of 6 plates was identified, beyond which factors like bubble resistance and uneven current distribution diminish returns. Model 3, with its optimized polyethylene design and 8-plate setup, achieved the highest efficiency and operational stability but at a higher fabrication cost. The novel finding of this work is the identification of a critical trade-off: systems with low concentrations (5 %) exhibit rapid temperature rise despite theoretical conductivity advantages, highlighting a previously underexplored thermal sensitivity. This study provides actionable insights into the integrated optimization of electrolyte properties and reactor geometry, offering a practical framework for designing cost-effective, efficient, and durable alkaline water electrolyzers for scalable hydrogen production.

Solar stills provide a sustainable solution to freshwater scarcity by utilizing solar energy to purify water, making them an environmentally friendly option in the context of climate change. This study presents an experimental investigation into the performance of a solar still enhanced with phase change materials (paraffin wax), Peltier modules, and electric heaters powered by a photovoltaic system. Two identical single-slope solar stills were constructed using the same materials and dimensions: one as a conventional solar still (CSS) and the other as a modified solar still (MSS). Key parameters, including temperatures, solar radiation, and water productivity, were measured and recorded hourly at Faculty of Engineering, Suez Canal University. Energy, exergy, and economic evaluations of both systems were conducted at water depths of 1, 2, and 3 cm. The results showed that the conventional and modified solar stills produced 3.58 and 8.30 l/m2 & sdot;day, respectively, indicating a 131.8 % increase in productivity for the modified still. In addition, the modified still also demonstrated higher energy efficiency, achieving 70 % compared to 47 % for the conventional one at a 1 cm water depth. At 3 cm, energy efficiency declined to 50 % for the modified solar still and 30 % for the conventional one. The average exergy efficiency of the MSS reached 5.8 %, compared to 3.5 % for the CSS at a 1 cm depth. The maximum thermal efficiency recorded was approximately 73.5 % for the MSS and 32.45 % for the CSS. Economically, the MSS produced 2975 L annually, compared to 1225 L for the CSS, resulting in a lower cost per liter of $0.008 versus $0.009. These findings demonstrate that integrating Peltier modules and phase change materials significantly enhances solar still performance, offering a cost-effective and sustainable solution for freshwater production.

Pyrolysis is a promising thermochemical process for converting organic waste into valuable products syngas, biooil, and biochar under oxygen-free conditions. Syngas, a combustible mixture rich in hydrogen (H2), carbon monoxide (CO), and methane (CH4), offers significant potential as a renewable energy carrier. This study investigates the catalytic effects of zeolite on syngas production from three distinct waste feedstocks: polyethylene (PE), olive pomace, and water hyacinth, using a fixed-bed pyrolysis reactor (600 degrees C, 3 h residence time, N2 atmosphere). Experiments were conducted with zeolite concentrations of 10 %, 20 %, and 30 % (by weight) to assess its role in enhancing gas yield and quality. Results demonstrate that zeolite significantly improves syngas production by promoting cracking and deoxygenation reactions, leading to higher yields of H2 and CO (key syngas components), reduced CO2 and tar formation (undesirable byproducts), and feedstock-dependent performance, with polyethylene achieving the highest syngas yield (68 % at 30 % zeolite), followed by olive pomace (62 %) and water hyacinth (54 %). The study highlights zeolite's effectiveness in optimizing waste-to-energy conversion, offering a sustainable solution for managing agricultural, plastic, and aquatic waste. These findings advance the development of efficient, scalable pyrolysis technologies and contribute to cleaner waste valorization strategies.

This study experimentally investigates the performance enhancement of a pyramid solar still (PSS) through the integration of optical lenses, paraffin wax as a phase change material (PCM), and a thermoelectric coolers (TECs). These modifications were applied to concentrate solar radiation and store/release heat, thereby extending the operating hours of the solar still. Experimental tests were conducted at Suez Canal University, Ismailia, Egypt, under the weather conditions observed during consecutive days in August 2024. Five experimental case studies were explored: (i) PSS without any modifications, (ii) PSS with paraffin wax as PCM, (iii) PSS with paraffin wax and TECs, (iv) PSS with paraffin wax and optical lenses, and (v) PSS with paraffin wax, TECs, and optical lenses. The study included multiple performance analyses, such as embodiment evaluation, exergy destruction across various components, cost analysis, and payback period estimation. The recorded accumulated daily productivities for cases (i) through (v) were 3255 ml/m2, 3848 ml/m2, 4324 ml/m2, 4915 ml/m2, and 5652 ml/m2, respectively. Corresponding average daily thermal efficiencies were 32.9 %, 45.4%, 52.4%, 62.9 %, and 68.7%, respectively. Over a projected 30-year lifespan, the energy production factor (EPF) increased from 31.6 % in case (i) to 41.1 % in case (v), while the life cycle conversion efficiency (LCCE) rose from 29.2 % to 34.2 %. An exergy destruction analysis for case (v) showed the highest exergy loss in the basin and the lowest in the paraffin wax. The average exergy efficiency improved from 2.81 % in case (i) to 11.32 % in case (v). Additionally, the cost per liter of freshwater dropped from $0.01189 in case (i) to $0.0078 in case (v), assuming a 2 % interest rate and a 30-year system life. The corresponding payback periods, at a water selling price of $0.06/l, were 1.07 years for case (i) and 0.70 years for case (v). Finally, COQ emissions reductions and carbon credit assessments demonstrated the enhanced environmental sustainability of the modified system.

One of the superior, realistic traditions to moderate water shortage is the utilization of a solar distiller, but one of its drawbacks is its low productivity and efficiency. Consequently, this study designed a double-slope solar system (DSS) incorporating recyclable waste metal as heat storage materials. Metal trash is produced from metalworking procedures in factories and workshops and is readily available, disposed of, or repurposed. These metals have high thermal conductivity, which keeps a portion of the absorbed solar energy through high solar intensity before discharging it throughout cloudy periods. Aluminum, copper, and stainless steel metal wastes are used in different concentrations in solar distiller basins. The weather conditions of Suez City, Egypt, were used to perform the trials. Compared to the traditional distiller of 4360 mL/m(2) per day, the results showed that incorporating metal waste yielded a maximum yield of 7527 mL/day m(2). The solar still yield is enhanced by about 72.6%, 50.1%, and 39.5% using aluminum, copper, and stainless steel recyclable waste metal, respectively. Also, using recyclable waste metal as sensible heat storage materials in the solar distiller basin increases the thermal energy efficiency from 26.4 to 45.73%. In addition, the exergy efficiency improved by 128%, and the price of one liter of fresh water was reduced by 44%. The modified solar still also reduces CO2 emissions by 30.24 tons.

The scarcity of freshwater drives the development of efficient, cost-effective small-scale desalination devices that are suitable for off-grid power solutions. This research formulates and evaluates an integrated humidification-dehumidification (HDH) desalination system powered by photovoltaic energy and supplemented by a heat pump cycle. This study experimentally demonstrates the hybrid architecture in outdoor conditions, measuring the influence of airflow and spray rate on water yield, thermodynamic performance, and cost, surpassing previous laboratory-only or single-subsystem investigations. We constructed a full-scale prototype and conducted operations in Ismailia, Egypt (July 2022, 07:00-22:00), adjusting the air mass flow from 252 to 504 kg center dot h- 1 and the humidifier spray rate from 1 to 2 L center dot min- 1. We documented environmental and process variables and calculated distilled-water productivity, gained-output ratio (GOR), and levelized water cost. The system attained a maximum productivity of 17.64 L center dot h- 1 at an air flow of 504 kg center dot h- 1, with a peak gas-to-oil ratio (GOR) of 2.98 and a daily distillate of 141.1 L. Within the identical operational parameters, the projected water cost was $0.034 per liter. The productivity of distilled water rose approximately linearly with air flow within the examined range. The results indicate that a photovoltaic-powered, heat-pump-assisted humidificationdehumidification system can yield significant freshwater production at a low unit cost in arid regions, offering a viable solution for decentralized, sustainable water supply. The originality of this work is the outdoor experimental demonstration and parametric evaluation of an integrated PV-heat-pump-assisted HDH desalination system, including a transparent cost assessment under real weather.

This study presents an innovative solar desalination system that integrates wick-assisted evaporation with latent heat recovery to significantly enhance thermal performance and reduce water production costs. Experimental investigations were conducted during the summer season in Kafr Elsheikh city (31 degrees 6 ' N, 30 degrees 56 ' E), Egypt, aiming to improve the thermal efficiency of solar stills through effective utilization of rejected heat. The system features a 2 m2 solar evaporation collector combined with a compact flash evaporation chamber for latent heat recovery. Thermal enhancement was achieved by spraying saline water over a heated rod, thereby increasing evaporation rates and maximizing the reuse of latent heat. This study systematically evaluated the effects of varying saline water filling ratios and the incorporation of wick materials on thermal efficiency, freshwater productivity, and production cost. Results demonstrated that the absorber surface temperature averaged 82.6 degrees C, with a filling ratio of 77 % yielding the highest thermal efficiency and freshwater productivity, reaching 18.45 kg/m2/day under an average solar radiation of 940 W/m2, at a production cost of 0.0099 $/l. However, exceeding this filling ratio led to a decline in thermal performance. Moreover, an Artificial Neural Network (ANN) model accurately predicted the system's thermal behavior and productivity, maintaining an error margin within 10 %. Overall, the hybrid approach combining wick-enhanced evaporation with latent heat recovery offers a cost-effective, energyefficient solution for small-scale and domestic desalination applications, outperforming traditional solar still designs in both thermal performance and economic viability.

In recent years, the urgency for harnessing solar energy for water desalination has grown significantly, driven by the escalating costs and the increasing scarcity of clean water sources. Numerous research efforts were dedicated to enhance the productivity of solar still, including the thermal energy storage materials, solar concentrators, nanofluid, and more. The main objective of this research is to improve the solar still performance by using wastes of workshops and factories so, their actual cost can be assumed to be zero. The experimental setup placed at faculty of Engineering Suez Canal University. Two solar still were included: one representing the conventional and the second one is modified with internal reflectors and woven wire mesh. The performance of the stills was assessed under identical climate conditions, considering water depths of 1, 2, 3 and 4 cm using both fresh and saline water with Total dissolved Solids of 18,562 and 35643 ppm. The obtained results indicated that the incorporation of internal reflectors and woven wire mesh led to a notable percentage increase in daily thermal efficiency and accumulative productivity ranged from 42.49 % to 45.04 % and from 43.0 % to 46.8 % respectively. The economic analysis demonstrated that the cost per liter for conventional and modified solar still was about 0.0018 and 0.0011$ per liter per m2 respectively. This study's findings suggested that the integration of internal reflectors and woven wire mesh into solar stills to obtain high productivity potable water with low cost. These results align with and reinforce previous publications in this field, highlighting the potential of this approach for addressing the pressing challenges of affordable and efficient water desalination.

This research introduces design and layout of a shell-and-tube heat exchanger (STHX) capable of producing electrical energy through a thermoelectric generator (TEG). The STHX is used simultaneously to enhance the efficiency of a desalinating-water unit through pre-warming of the sea water at 25 degrees C using waste heat from thermal power plants at 300 degrees C. Simulation using ANSYS FLUENT with realizable k-epsilon model is first considered to predict the thermo-hydraulic performance of STHX with considerable accuracy comparing with the well-known Bell-Delaware method. For fresh/salty cold water, the results indicate that the values of the outlet temperature of both water and air are increasing with increasing capacity ratio, while heat transfer rate, number of transfer unit (NTU), and heat exchanger effectiveness decrease. The results recommend the use of STHX with high water flow rate to obtain high heat transfer rate and effectiveness. Increasing the salinity (S) of salty water at the same mass flow rate causes increase of the outlet water temperature, heat transfer rate, NTU, and effectiveness but the air outlet temperature decreases, and the rate of change becomes high with the salinity value. The pumping power needed increases for both air and fresh/salty water with increasing mass flow rate, while it decreases with increasing the salinity of salty water. In the second part, TEG has been implemented in the STHX and simulated. The maximum efficiency of TEG is found to be about 5.5% at temperature difference of 375 K, and this means that the major deficiency of TEG is its lower efficiency. The voltage, the current, and the power increase with decreasing increment under the same temperature difference. The Joule heat produced in the TEG legs might change as the electrical current changes quickly. The enhanced Joule heat at a higher electrical current raises the temperature of cooling water.

Different researches were performed by using thermal storage materials, solar concentrators, reflectors, and other technologies to increase the productivity of solar stills. The main objective of the present study is to enhance the basin solar still productivity by using ecomaterials from the wastes of workshops and factories. So, this study presents an experimental investigation of basin solar still performance using steel wool pads, internal reflectors, and woven wire mesh. The experimental setup was performed at Suez Canal University, Ismailia City, Egypt. Two solar stills were included: one represents the conventional design (CSS), and the second one is the modified with steel wool pads, internal reflectors, and woven wire mesh (MSS). Both solar stills were evaluated under identical climate conditions, considering water depths of 1, 2, 3, and 4 cm, and the required parameters were measured and tabulated during the working days. The results indicated that incorporating these modifications led to a notable increase in accumulative productivity and daily thermal efficiency with minimum cost per liter. The MSS enhanced the daily yield and thermal efficiency by 22.1