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The growing concern about environmental damage and the inability to meet the demand for more versatile, environmentally friendly materials has sparked increasing interest in polymer composites derived from renewable and biodegradable plant-based materials, mainly from forests. These composites are mostly referred to as "green" and they can be widely employed in many industrial applications. Green composites are less harmful to the environment and could be potential substitutes for petroleum-based polymeric materials. It is helpful to limit usage of fossil oil assets by developing biopolymer matrices such as cellulose-reinforced biocomposites using renewable assets such as plant oils, carbohydrates, and proteins. This paper focuses on green composites processing utilizing a variety of naturally available resources, sustainable materials which are not detrimental to the environment, new scientific signs of progress in achieving green sustainable development, as well as nanotechnology and its environmental consequences. Additionally, the environmental impacts of different composite materials are examined in this paper, along with their production from eco-friendly materials. Moreover, the manufacturing aspects of green composites and some concerns related to their production are also discussed. The merits of green composite materials and valid reasons why they are a valuable substitute for the traditionally used composite materials are also covered.

The lack of drinkable, safe water is one problem that governments around the world are dealing with. There are many methods for desalinating saltwater, such as solar distillers, which can be used in remote places without access to traditional energy sources to produce distilled water. In this manuscript, two solar stills [conventional solar still (CSS) and CSS with high thermal conductivity material (HTCM)] were researched at the "School of Mechanical Engineering, B.S. Abdur Rahman Crescent Institute of Science and Technology, Vandalur, Chennai, India," under the same climatic condition. The HTCM (silicon carbide) works as a sensible heat energy storage material, which was placed at the basin of the CSS. The silicon carbide used in the present research is used to enhance the freshwater production during lower solar intensity period and furthermore after evening time. It has been found that the maximum fresh water production from the CSS is 1.5 kg/m

The main focus of the work is to determine the performance efficiency of water-%CuO nanofluids and water at varied flow rate of 0.035 lit/sec, 0.045 lit/sec, and 0.065 lit/sec in an evacuated tube collector integrated with an heat exchanger. A heat exchanger made of copper tube connected to a horizontal pipe for collection of heat from a vertical tube, and a vertical copper tube for collection of heat from an evacuated tube collector for solar radiation were used in the investigation. Water showed no absorption, a low thermal capacity when it was not suitable for high thermal application for improvement in performance, the base fluid with colloidal dispersion of %vol CuO nanofluids in the force convection mode. The evacuated tube collector produced the highest efficiency of water -0.3% vol CuO nanofluids at flow rate 0.035 lit/sec compared to 0.1% and 0.2% vol of CuO nanofluids at flow rate of 0.045, 0.065 lit/sec and water. A comparison to the water CuO nanofluids with the highest effective concentration showed a greater increase in thermal efficiency.The performance of theworking fluid performances was examined for parameters like exit temperature, specific heat, thermal conductivity, energy productivity, and efficiency utilizing.

Demand for renewable energy sources has increased significantly during the past 15-20 years. Due to this demand, one positive scenario has occurred as there has been a decrease in the use of fossil fuels. Among various usages of the fuels, a significant amount of energy is being used in heating and cooling for commercial, domestic houses, etc. Traditional air conditioning systems use a lot of energy and are particularly inefficient in tropical countries. Earth-air heat exchanger (EAHE) systems can help to reduce the air conditioning demand while also promoting the development of renewable energy. This paper focuses on a review of previous research on this notion for system installation done by earlier researchers. Researchers working on efficient heating and cooling for human comfort will benefit from this review article. The researchers working on EAHE for heating and cooling will benefit from this review paper because it will give them the basic knowledge they need to begin their experimental work.

The drying of food products is an essential step in the preservation of crops and agricultural by-products that serve as raw materials for numerous end applications. Solar drying with phase change materials (PCMs) is an efficient low-energy consumption process in the post-reaping stage, reducing food deterioration. A customized solar dryer setup was assembled using Cudappah (black) stones as the base of the drying chamber to facilitate the absorption of solar energy on its surface. The organic paraffin wax, with a melting point of 60 ℃, was used as PCM in the solar dryer. The novelty of the study is the application of a PCM in a solar dryer to improve the effectiveness of drying and decrease the absolute drying period and the microbial content in the dried coconut. The study compared the drying characteristics between open sun drying and solar drying without and with PCM (100 and 200 g). The fabricated setup was utilised for drying coconut using a PCM-based solar drying method. The coconut was dried from an initial moisture content of 55.5% to a final moisture content of about 9%. The prototype dryer model minimized the use of the workforce, avoided improper drying, and decreased the absolute drying time. A total plate count (TPC) test was conducted to characterize the microbial content in the dried coconut. The microbial count decreased with the use of 200-g PCM as the use of PCM retained the heat for a longer time in the chamber. The drying time of coconut decreased by about 28 and 52 h on using 100 and 200 g of PCM, respectively, compared to open sun drying. The sensory characteristics like colour, taste, flavour, quality, and texture of the solar-dried coconut sample were superior to the sun-dried coconut sample.

The objective of the current study is to investigate the performance of the inclined solar panel basin still (ISPBS) incorporated with a spiral tube collector (STC) for various mass flow rates of water (mf). The maximum potable water yield of 8.1, 6.9, and 6.1 kg is obtained for different mass flow rates of 1.8, 3.2, and 4.7 kg/h in each instance. Also, for mf of 1.8, 3.2, and 4.7 kg per hour, the daily average energy and exergy efficiency of the ISPBS is recorded to be 47.9, 39.3, and 31.02 % and 9.8, 7.9, and 5.6 %, in each instance. The average electrical, thermal, and exergy efficiency of the PV panel is noted to be 6.5, 7.1, and 7.5 %; 15.67, 17.1, and 18.04 %; and 20.03, 22.21, and 23.36 % for mf of 1.8, 3.2, and 4.7 kg/h in each instance. The rise in mf causes a drop in the fresh water production yield; thermal, exergy, and overall thermal effectiveness; and an enhancement in the power production of the panel, electrical, thermal, exergy, and overall exergy efficiency of the system. Also, the cost of yield production is noted to be low-cost in AISS at minimum mf of 1.8 kg per hour (0.019 $/l) when compared to the other two mf of 3.2 and 4.7 kg per hour (0.022 and 0.025 $/l).

This paper aimed to improve the thermal performance of the stepped solar still. So, the effects of using different types of basin liners (corrugated and curved basin liners), jute cloth wick, CuO/paraffin wax, and vapor suction on the stepped solar still performance were investigated. The CuO/paraffin wax was placed into a groove parallel to the basin steps’ liner. Also, the stepped distiller was integrated with an external condensation unit. The experimental results revealed that using the corrugated and curved liners increased the productivity of the modified stepped solar still (MSSS) by 42% and 33%, respectively. In addition, using the corrugated liner with wick, corrugated liner with wick and CuO/paraffin wax, corrugated liner with wick, CuO/paraffin wax, and vapor suction improved the freshwater productivity of the distiller by 95%, 127%, and 170%, respectively. At the last studied case (MSSS with corrugated liner, wick, CuO/paraffin wax, and vapor suction), the daily freshwater productivities of the MSSS and conventional still (CSS) were 7000 and 2600 mL/m2·day, respectively. Also, the thermal efficiency of MSSS was calculated as 59% which was obtained at the last studied case. And the efficiency of the CSS was 35%. Besides, the distilled water cost of CSS and MSSS with corrugated liner with wick, CuO/paraffin wax, and vapor suction was 0.023 and 0.014 $/L, respectively.

People around the world are facing water scarcity, and the demand for freshwater is continuously increasing. The purification of water is the only way to satisfy the need for water. Purification can be done in many ways by purifying seawater or by storing rainwater and letting it to the ground. Different types of solar still are there, which are used to increase the output of water produced. Among others, inclined solar still (ISS) is an outstanding solution as it has a wide exterior area of water, having less depth of water to complement the regular potable water production, even the effectiveness of the inclined solar still. A lot of research had been done by increasing the surface area of water. The day to day collection of water from the ISS was found to be 1–8 kg m− 2. In this review, an analysis was made on the current status of different ISS designs to make advance modifications and research to improve the productivity of the ISS to satisfy the increasing demand for potable water. From this investigation, it is identified that active ISS and hybrid ISS are the most effective as compared to other ISS techniques.

In this experimental work, the effect of cotton bags filled with phosphate on solar distillery performance has been investigated. In this study, 25 phosphate bags are evenly distributed (5 × 5) with a length equal to 50 cm in a wooden box called the modified solar still (MSS). This system was compared with the conventional solar still (CSS) in the same climatic conditions. Phosphate bags are placed vertically to increase the energy storage capacity, and the water’s surface area since the capillaries inside the phosphate bags play an important role in increasing the energy storage capacity. Experiments were conducted at El Oued University in Algeria during April and May 2020, with 1 cm and 2 cm of saltwater depth. The cumulative yield of 5.27 and 4.87 kg was produced from the MSS at 1 cm and 2 cm of saltwater, respectively, while the cumulative yield of the CSS was 3.8 kg. The MSS’s overall efficiency at 1 cm and 2 cm of saltwater was enhanced by 28 and 22.5%, respectively compared with the CSS. The presence of calcium and copper in phosphate stores the heat energy during morning and afternoon, and stored heat energy was released during evening. Finally, it can be concluded that increasing phosphate bags significantly enhances the productivity in solar distillation, increasing efficiency and productivity.

The drying of food products is an essential step in the preservation ofcrops and agricultural by-products that serve as raw materials for numerous end applications. Solar drying with Phase Change Material (PCM) is an efficient low-energy consumption processin the post-reapingstage, reducing food deterioration. A customized solar dryer setup was assembled usingCudappah (black) stones as the baseof the drying chamber to facilitate the absorption of solar energy on its surface. Theorganic paraffin wax, with a melting point of 60℃,was used as PCM in the solar dryer. The novelty of the study is the application of a PCMin asolar dryer to improve the effectiveness of drying and decrease the absolute drying period and the microbial content in the dried food products. The study compared the drying characteristics between open sun drying, solar dryingwithout and with PCM (100 and 200 grams). The fabricated setup was utilised for drying coconut using a PCM-based solar drying method.The coconut was dried from an initial moisture content of 55.5% to a final moisture content of about 9%. The prototype dryer modelminimized the use ofthe workforce,avoided improper drying,and decreased the absolute drying time. A Total Plate Count (TPC) test was conducted to characterize the microbial content in the dried coconut.The microbial count decreased with the use of 200 g PCM as the use of PCM retained the heat for a longer time in the chamber. The drying time of the coconut was decreased by about 28 and 52 hours by installing of about 100 and 200g of PCM respectively. The drying time of the coconut decreased with an increase in the amount of PCM in the solar dryer. The sensory characteristics like colour, taste, flavour, quality, and texture of the solar-dried coconut sample were superiorto the sun-dried coconut sample.

Various scientists are looking for effective and easy solutions for augmentation of yield from the Hemispherical Solar Still (HSS). In this study, aluminium foil-sheet was used to reflect the intensity hence augments the evaporation rate and daily yield. Experimentations were conducted on two SS: the first SS is HSS; the second SS is HSS with reflective aluminium foil-sheet walls (HSS-RAFW). The highest distilled water production from the HSS, HSS-RAFW are 3.36 and 4.1 kg/m2, respectively. Compared to the HSS, the yield of distilled water was augmented by 22.21% when using the HSS- RAFW. The daily energy and exergy efficiency (EnE and ExE) of the HSS is 26.27 and 1.04%, respectively and daily EnE and ExE of the HSS-RAFW is 32.75 and 1.71%, respectively.

The availability of drinkable water, along with food and air, is a fundamental human necessity. Because of the presence of higher amounts of salt and pollution, direct use of water from sources such as lakes, sea, rivers, and subsurface water reservoirs is not normally suggested. Solar is still a basic technology that can use solar energy to transform accessible waste or brackish water into drinkable water. Exergy analysis is a strong inferential technique for evaluating the performance of thermal systems. Exergy is becoming more popular as a predictive tool for analysis, and there is a rising interest in using it. In this paper, performance analysis on the aspect of energy and exergy from the proposed solar still (PSS) (conventional solar still with the photovoltaic modules-AC heater) was analyzed on three different water depths (W

Various scientists are looking for effective and easy solutions for the augmentation of yield from the hemispherical solar still (HSS). In this study, aluminum foil sheet was used to reflect the intensity, hence augmenting the evaporation rate and daily yield. Experimentations were conducted on two SS: the first SS is HSS; the second SS is HSS with reflective aluminum foil sheet walls (HSS-RAFW). The highest distilled water production from the HSS and HSS-RAFW is 3.36 and 4.1 kg/m

The world is facing a severe shortage of freshwater, and so we are in urge to fetch new technologies to resolve water scarcity. To desalinate saline water, the single-sloped solar still (SSSS) has proven to be a viable option with much affordability. This research work concentrates on the usage of nanomaterial on the absorbent layer to improve the thermal conductivity of the basin area and thus the distillate produced per hour. The micro-coated and nano-Fe2O3 particles were employed and analyzed. The experiment proved that the implementation of this idea had a better productivity rate. The nanoparticles and microparticles were added at weight proportions of 10%. The experiment was conducted on two consecutive days. On the first day, the saline water was maintained at 0.5 cm depth, while on the next day, the saline water level was maintained at 1 cm. The cumulative yield for micro absorbent layer solar still (MALSS) was 3.23 kg/m2 and nanoabsorbent layer solar still (NALSS) was 4.39 kg/m2.

A detailed exergy analysis of a conventional and copper finned acrylic solar still has been presented in this manuscript. The evaporative, convective, and radiative heat transfer coefficient of water-glass has been calculated. Also energy efficiency, exergy destruction of basin, water, and glass has been determined. Conventional acrylic solar still with fins produced maximum hourly output of 1.24 kg and it produced daily output of 5.08 kg. The conventional acrylic solar still without fins produced maximum hourly output of 0.94 kg and it produced daily output of 3.75 kg. The maximum exergy destruction of the basin, water, and glass for the conventional acrylic solar still with fins are 655.206, 83.35, and 90.48 W/m2, respectively, and conventional acrylic solar still without fins are 616.28, 122.34, and 48.64 W/m2, respectively. The energy and exergy effectiveness of the conventional acrylic solar still with fins are 32 and 2.81%, respectively, and without fins are 24.93 and 1.69%, respectively. The study reveals that exergy destruction of water in the case of still with fins is minimum as related to the exergy destruction of water in the case of still without fins.

The use of solar energy will help to reduce the cost of fossil fuels .The present work is based on the study of a solar dryer with thermal storage using the working medium of water and waste engine oil at a flow rate of 0.035, 0.045 and 0.065 lit / sec. Heat was collected from a parabolic trough collector (PTC) and stored into thermal energy storage (TES) device. The TES consisted of rectangular boxes for stored heat containing Stearic acid phase change materials (PCM) with 0.3vol% of Al2O3 nanofluids. The parabolic trough reflected solar radiation focused on the receiver and the collected heat was stored in the storage medium after it was forced into circulation and transferred to the solar dryer. The dryer used the energy output in the storage tank at varying water and waste oil medium flow rates and discussed heat output of the drying crops of groundnut, ginger and turmeric were showed the flow rate of 0.035, 0.045 and 0.065 lit/ sec with water and waste engine oil medium. Finally, based on the findings of the tests, this research may be useful in agriculture, especially in the drying of vegetables.

The objective of the current study is to investigate the performance of the Inclined Solar Panel Basin Still (ISPBS) incorporated with a Spiral Tube Collector (STC) for various mass flow rates of water (mf). The maximum potable water yield of 8.1, 6.9 and 6.1 kg is obtained for different mass flow rates of 1.8, 3.2 and 4.7 kg/hr in each instance. Also, for mf values of 1.8, 3.2 and 4.7 kg per hour, the daily average energy and exergy efficiency of the ISPBS is recorded to be 47.9, 39.3 and 31.02 % and 9.8, 7.9 and 5.6 % in each instance. The average electrical, energy and exergy efficiency of the PV panel is noted to be 6.5, 7.1 and 7.5 %, 15.67, 17.1 and 18.04 % and 20.03, 22.21 and 23.36 % for mf values of 1.8, 3.2 and 4.7 kg/hr in each instance. The rise in mf causes a drop in the fresh water production yield, thermal, exergy and overall thermal effectiveness and an enhancement in the power production of the panel, electrical, thermal, exergy and overall exergy efficiency of the system.

The objective of the current study is to investigate the performance of the inclined solar panel basin still (ISPBS) incorporated with a spiral tube collector (STC) for various mass flow rates of water (m

This paper aimed to improve the thermal performance of the stepped solar still. So, the effects of using different types of basin liners (corrugated and curved basin liners), jute cloth wick, CuO/paraffin wax, and vapor suction on the stepped solar still performance were investigated. The CuO/paraffin wax was placed into a groove parallel to the basin steps' liner. Also, the stepped distiller was integrated with an external condensation unit. The experimental results revealed that using the corrugated and curved liners increased the productivity of the modified stepped solar still (MSSS) by 42% and 33%, respectively. In addition, using the corrugated liner with wick, corrugated liner with wick and CuO/paraffin wax, corrugated liner with wick, CuO/paraffin wax, and vapor suction improved the freshwater productivity of the distiller by 95%, 127%, and 170%, respectively. At the last studied case (MSSS with corrugated liner, wick, CuO/paraffin wax, and vapor suction), the daily freshwater productivities of the MSSS and conventional still (CSS) were 7000 and 2600 mL/m

The innovation of novel absorbing materials using composite materials and nanotechnology is of new trends for many researches. Here, the present study is concerning to enhance the distilled water productivity of a proposed solar still (PSS) using novel absorbing materials. The absorbing material is composed of chitosan (obtained from waste shrimp shells), ethylene diamine tetraacetic acid (EDTA), and Chrysopogon zizaniodes (Vetiver). The combination of these materials is coined as CHEDZ, and it acts as a super absorbent polymer that is coated on the stepped solar still. Evaporation rate increases due to this absorbent, which further increases the yield of the still. In this present study, the PSS is compared with the conventional solar still (CSS) for the use of assessing the yield of freshwater in the same atmospheric circumstance. The experimental setup was performed through the period from December to February 2020 in the Indian climatic condition. The freshwater productivity was improved to 3.05 L/day while the yield of the CSS is 2.47 L/day. The increase in efficiency obtained from a PSS is 39.71% more than the productivity attained from the CSS. The energy efficiency of the PSS is 18.34% and the exergy efficiency is 0.45%.

In this work, a new attempt was made to study the behavior of the conventional solar still (CSS) by adding a black-painted copper plate and phosphate pellets. Therefore, the performance of the three solar stills has been studied and compared. The first is the CSS, and the second is the modified solar still (MSS). The MSS performance was tested using black-coated copper plate (measuring 49 × 49 cm and 0.2 cm thick) with and without phosphate pellets and compared to the CSS in the similar climatic conditions. The results showed that the combination of black coated copper plate and the inclusion of phosphate pellets improved the evaporation rate and daily productivity. During the experiments, yields using black coated copper plate without and with phosphate pellets were 14.96% and 29.53% greater than the CSS. The effectiveness of the CSS, MSS with copper metal plate (MSS-CP), and MSS with copper metal plate with phosphate pellets (MSS-CP and PP) are around 30.23, 35.3, and 41.44%, respectively.

The efficiency of the photovoltaic (PV) cell reduces with an increase in solar irradiation. The reduction in the efficiency of the photovoltaic (PV) cell can be attributed to the increase in cell temperature. A novel design of a thermal absorber fabricated by a flat spiral tube is used to remove heat and decrease the cell temperature, thus forming the photovoltaic thermal system (PVTS). Water and titanium oxide (TiO

This manuscript presented the annual yield, energy and economic analysis of the Tubular Solar Stills (TSS). Three different TSS such as conventional TSS (CTSS), modified TSS with Phase Change Material (MTSS-PCM) and modified TSS with nano-enhanced PCM (MTSS-NPCM). The annual yield output from the CTSS, MTSS-PCM and MTSS-PNCM were 1100.8, 1536 and 2020.4 kg, respectively. The annual yield from the MTSS-PCM and MTSS-NPCM are 28.33 and 45.57% higher when compared to the CTSS. Also, the monthly energy efficiency of the CTSS, MTSS-PCM and MTSS-PNCM were 27.11, 37.83 and 49.81%, respectively. As the performance of the MTSS-NPCM was enhanced, the cost of freshwater yield obtained was also low in contrast to the other two types of stills. At a selling price of Rs 5 for the freshwater, the CTSS needed a payback period of 7.6 months, while the MTSS-PCM and MTSS-NPCM needed 6.6 and 5.3 months, respectively.

The fruits and vegetable waste has become the highest compared with the production rate. These types of wastes had reached up to 70% by 2019-2020 as estimated by Food and Agriculture Organization (FAO). Improvisation of the performance of still using fibre insulation (Artocarpus heterophyllus rags and Azadirachta indica gum (AHRAIG)) has been carried out in this study. Potable water demand in arid areas is a vast problem where fresh water is very expensive. The proposed solar still (PSS) retains the basin temperature and raises the rate of evaporation. Rags are latex-like filament extracted from the waste of the jackfruit peels and an adhesive agent from Azadirachta indica tree. A comparison is made among still without insulation (SWI), still with polystyrene insulation (SPI) and still with fibre insulation (SFI) in producing the fresh water under same ambient conditions. The experiments result a promising yield of 9.3% rate of rise of potable water produced using AHRAIG insulation related to conventional still. The energy efficiency is premeditated as 26.45%, while the exergy efficiency is 4.07%. The production of the potable water reached 2.58 L/m2 for still with polystyrene insulation, 3.26 L/m2 for fibre insulation and 1.93 L/m2 for still without insulation, respectively.

The semi-transparent photovoltaic (STPV) module is an emerging technology to harness the solar energy in the building. Nowadays, buildings are turning from energy consumers to energy producers due to the integration of the STPV module on the building envelopes and facades. In this research, the STPV module was integrated on the rooftop window of the experimental room at Kovilpatti (9°10′0″ N, 77°52′0″ E), Tamil Nadu, India. The performance of the STPV modules varies with respect to the geographical location, incident solar radiation, and surface temperature of the module. The surface temperature of the STPV module was regulated by the introduction of the mixture of graphene oxide and sodium sulphate decahydrate (Na2SO4·10H2O). The various concentration of the graphene oxide was mixed together with the Na2SO4·10H2O to enhance the thermal conductivity. The thermal conductivity of the mixture 0.3 concentration was found to be optimum from the analysis. The instantaneous peak temperature of the semi-transparent photovoltaic phase change material (STPV-PCM) module was reduced to 9 °C during summer compared to the reference STPV. At the same time, the energy conversion efficiency was increased by up to 9.4% compared to the conventional STPV module. Due to the incorporation of the graphene oxide and Na2SO4·10H2O, the daily output power production of the STPV module was improved by 12.16%.

In this experimental work, the effect of cotton bags filled with phosphate on solar distillery performance has been investigated. In this study, 25 phosphate bags are evenly distributed (5 × 5) with a length equal to 50 cm in a wooden box called the modified solar still (MSS). This system was compared with the conventional solar still (CSS) in the same climatic conditions. Phosphate bags are placed vertically to increase the energy storage capacity, and the water's surface area since the capillaries inside the phosphate bags play an important role in increasing the energy storage capacity. Experiments were conducted at El Oued University in Algeria during April and May 2020, with 1 cm and 2 cm of saltwater depth. The cumulative yield of 5.27 and 4.87 kg was produced from the MSS at 1 cm and 2 cm of saltwater, respectively, while the cumulative yield of the CSS was 3.8 kg. The MSS's overall efficiency at 1 cm and 2 cm of saltwater was enhanced by 28 and 22.5%, respectively compared with the CSS. The presence of calcium and copper in phosphate stores the heat energy during morning and afternoon, and stored heat energy was released during evening. Finally, it can be concluded that increasing phosphate bags significantly enhances the productivity in solar distillation, increasing efficiency and productivity.

This manuscript communicates the use of cement-coated red bricks for augmenting the production of distilled water using a traditional single slope solar still by low cost energy storage. The exposure area of water is increased in modified solar still (MSS) by keeping the cement-coated red bricks in the absorber. Using the energy storage material in the absorber, the water temperature was higher in the case of MSS at 20 kg water mass which was the minimum mass used during the experiment in the basin. From the results, it was also found that there is an improvement of about 34% in the temperature of water which acts as the driving force for evaporation of water inside the closed chamber. Furthermore, with increase in water temperature the productivity was enhanced by 45% as compared to the CSS. Comparison of different solar still on productivity was also analysed, and it is seen that the yield is higher in the present study by 38.8% than double slope-double basin solar still with different energy storage. The daily yield from CSS for water depth of 20, 30, 40 and 50 was found as 3.2, 2.8, 2.7 and 2.6 kg, whereas the modified solar still produced 6.3, 6, 5. 8 and 5.6 kg, respectively. Due to the reduced daily yield at higher water masses, the cost per litre of water produced from both conventional and modified solar still is higher.

This context is about enhancing the freshwater production of a single slope solar desalination still (SSSDS) using water film cooling over the glass cover and using hybrid natural fibre composite (HNFC) insulation. In contrast to the conventional insulations, we proposed the HNFC insulation; this composite was made of natural fibre Pharsalus vulgaris (6 %) and nano-silica (1 %) with unsaturated polyester resin. In this study, conventional SSSDS and proposed SSSDS with enhanced evaporation and condensation have been designed. The same was built with native materials. A conventional and proposed type SSSDS was subjected to the same experimental condition. The experimental result showed that using water film cooling over glass cover and HNFC insulation at 0.5 cm depth caused a 35% increase in the amount of distilled water when compared with the conventional type SSSDS with polystyrene-Styrofoam (thermocol) insulation. Water film cooling over glass cover and HNFC insulation at 1 cm depth caused a 21% increase in the amount of distilled water when compared with the conventional type SSSDS with thermocol insulation. The conventional type solar desalination still with thermocol insulation at 0.5 and 1 cm depth yields are 1.665 and 1.171 l/m2/day, respectively, and the proposed solar desalination still with water film cooling over glass cover and HNFC insulation at 0.5 and 1 cm depth yields are 2.253 and 1.420 l/m2/day, respectively.

In this work, a new attempt was made to study the behavior of the conventional solar still (CSS) by adding a black-painted copper plate and phosphate pellets. Therefore, the performance of the three solar stills has been studied and compared. The first is the CSS, and the second is the modified solar still (MSS). The MSS performance was tested using black-coated copper plate (measuring 49 × 49 cm and 0.2 cm thick) with and without phosphate pellets and compared to the CSS in the similar climatic conditions. The results showed that the combination of black coated copper plate and the inclusion of phosphate pellets improved the evaporation rate and daily productivity. During the experiments, yields using black coated copper plate without and with phosphate pellets were 14.96% and 29.53% greater than the CSS. The effectiveness of the CSS, MSS with copper metal plate (MSS-CP), and MSS with copper metal plate with phosphate pellets (MSS-CP and PP) are around 30.23, 35.3, and 41.44%, respectively.