Year around study of tubular solar still with green almond shells biowaste as energy storage material: energy, economic, and environmental analysis.

Solar-based desalination is one of the prominent contributors to overcoming the water scarcity problems in desert areas and a major alternative to fossil fuel-based desalination methods. The present study focuses on utilizing green almond shells (green almond shells) as energy storage materials in tubular solar still (TSS) to enhance water productivity, energy efficiency, and economic and environmental analyses. Further, this study discusses the yearly water output, annual energy efficiency, and economic and environmental analyses. Two different TSS were utilized which consists of conventional TSS (CTSS) without any storage materials and modified TSS with the inclusion of green almond shells (MTSS) in the climatic conditions of Chennai, India. The yearly distilled water output from the CTSS and MTSS was evaluated as 512 and 691.2 kg/m2, respectively. The yearly distilled water output from the MTSS is 26% higher when compared to the CTSS. Furthermore, the maximum monthly energy efficiency of the CTSS and MTSS was 14.4 and 19.44%, respectively. The annual energy efficiency of the CTSS and MTSS is 12.6 and 17.02%, respectively. The economic analysis of the system is also carried out, and the findings show that better economic feasibility is achieved in MTSS considering the INR 5 (Indian Rupees) cost of water. The payback period for MTSS was 12 months, while for CTSS it is calculated to be 20 months. Furthermore, CO2 emission and mitigation have also been evaluated, and the results indicate that the utilization of porous material has increased the emission for MTSS, while CO2 mitigation has been significantly higher as compared to the CTSS system.

Performance analysis of snail shell biomaterials in solar still for clean water production: nature-inspired innovation for sustainability.

In this current investigation, the experimental performance of a solar still basin was significantly enhanced by incorporating snail shell biomaterials. The outcomes of the snail shell-augmented solar still basin (SSSS) are compared with those of a conventional solar still (CSS). The utilization of snail shells proved to facilitate the reduction of saline water and enhance its temperature, thereby improving the productivity of the SSSS. Cumulatively, the SSSS productivity was improved by 4.3% over CSS. Furthermore, the SSSS outperformed in energy and exergy efficiency of CSS by 4.5 and 3.5%, respectively. Economically, the cost per liter of distillate (CPL) for the CSS was 3.4% higher than SSSS. Moreover, the SSSS showed a shorter estimated payback period (PBP) of 141 days which was 6 days less than CSS. Considering the environmental impact, the observed CO2 emissions from the SSSS were approximately 14.6% higher than CSS over its 10-year lifespan. Notably, the SSSS exhibited a substantial increase in the estimated carbon credit earned (CCE) compared to the CSS. Ultimately, the research underscores the efficacy of incorporating snail shells into solar still basins as a commendable approach to organic waste management, offering economic benefits without compromising environmental considerations.

Potable water production through a low-cost single chamber solar still in north India.

The main aim of this study is to evaluate the performance of a single slope solar still and to assess the effect of nanofluid on its performance. A single basin single slope solar still was designed and fabricated at the Department of Chemical Engineering, IET Lucknow. Its performance was assessed in terms of the yield of potable water. The effect of various climatic parameters was also studied. Al2O3 nanofluid was used to enhance the yield of the solar still. In the presence of nanofluid, the total yield of the solar still improved by 16.6%. Its economic feasibility was analyzed and reported. The portability of the small size of solar stills, its better economics, easy fabrication, and good performance make them very useful for industrial as well as household purposes.

Distillate yield improvement techniques for solar still coupled with evacuated tube collector: a review.

Many effective solutions to the problem of freshwater scarcity have been offered by the research community across the globe. Evacuated tube collector (ETC)-aided solar thermal desalination devices have succeeded magnificently in providing drinking water to the general public, especially in solar-rich isolated locations. Furthermore, heat transfer fluid ETC solar water desalination units are a much smarter, novel, and cost-effective solution that does not needed additional power and is well-suited to remote locations with a greater rate of self-sustainability. The efficiency of ETC-assisted solar distillation equipment as well as the essential analytical parameters related to the device and heat transfer fluid are thoroughly examined in this study. Literatures published in the last three decades are keenly reviewed and reported. The key finding reveals that solar still integrated with ETC can produce 3.5 to 4 l of freshwater per m2 area with depth varying from 0.01 to 0.03 m. It is discovered that the ETC-assisted solar still has a mean energy efficiency that is around 33% greater than the traditional solar still. When it comes to exergy efficiency, the ETC solar still outperforms conventional stills by 4%. Novel methods adopted for boosting the effectiveness of a solar still combined with ETC are reported for further research.

Performance enhancement of the solar still using textiles and polyurethane rollers.

The acquisition of clean drinking water in regions with limited power sources has been a challenge of paramount concern. Solar stills have emerged as a popular and sustainable option for obtaining clean water in such regions. This process involves employing solar radiation to heat up water, which is then condensed to obtain potable water. The present study introduces a solar still system that is both cost-effective and energy-efficient, while simultaneously ensuring sustainability. Fabric-coated polyurethane rollers with capillary action enhance evaporation area, leading to notable performance improvements. Water vapour condensed on the cooling chamber's inclined aluminium plate and collected in the distillate chamber within the solar still. The thermal, energetic, and economic performance and productivity of the proposed model were evaluated. The fabricated solar still boasted maximum instantaneous system efficiency and exergy efficiency of approximately 62.16% and 7.67%, respectively. This system's cost-effectiveness and performance improvements are particularly noteworthy. The daily average distillate productivity of the proposed still was estimated at 1.14 L/m2, resulting in an annual production rate of 416.54 L/year. The estimated cost of producing 1 L of distillate was 0.023 $.

Sustainable freshwater production using novel cascade solar still with phase change material, serpentine water path, and copper fins.

Heat losses in solar stills are high, which has led to a decrease in their thermal efficiency. Also, the production of these devices is limited to the presence of the sun, and their production stops during cloudy hours or at night. To solve these problems, in this experimental study, two cascade solar stills are examined under relatively similar conditions for sustainable freshwater production. One of these solar stills is modified with the phase change material and copper fins, and another one is a conventional cascade solar still without using the phase change material and copper fins. Paraffin was selected as a heat storage material to increase the time of desalination of water by the solar still. In addition, the copper fins are used to increase the conduction heat transfer in phase change material and provide better melting and solidification processes. To prolong the water path along the steps, the serpentine water path was considered. The results showed that at sunset hours, desalination efficiency with phase changing material and fins was increased. At 5 pm, the efficiency of the modified device was increased by 29% (on average) as compared to the conventional solar still without using phase changing material and fins. The rate of water production in conventional solar still in midday was higher compared to the modified solar still. However, in the sunset and night hours, the modified solar still has a higher production rate due to heat released from the thermal storage system.

Analysis for optimized prerequisites of modified solar stills.

This research portrayed the analysis of performance enhancement through a relative optimization approach of novel solar still models based on energetic-exergetic performances and energy matrices with environs-economic breakthroughs and is an extension of the existing research done by Singh & Samsher, and Singh & Gautam in the year 2022. The existing solar distiller models haven't shown relative influence on the performance of variable number of vacuum tubes, fully/partially illuminated and with/without the augmentation of parabolic concentrators among different schemes of solar still models. The present research bridges the above gaps to identify the analytical observations for the optimized results for the novel arrangement of the solar distillers compared to others. The dual slope solar still (DSS) with parabolic solar receiver (PSR) and evacuated annual tubes (EATC) found superior among other schemes and the DSS-EATC-PSR arrangement is advanced and enhanced with basin mass temperature (11.4 %) in observance with 30° inclined glaze cover and vacuum tubes altogether. A natural circulated thermo siphon shows increment (28.1 % & 0.1 %) to DSS-EATC-PSR relative to SSS with EATC & PSR, respectively. Further, the daily overall efficiencies (energy and exergy) have a marginal decrement of 8.4 % and 4.7 %, respectively, than the single-face solar still scheme (SSS). The daily yielding improvement is 4.6 % than the SSS scheme with nominal promotional cost (0.07 $/l) at a noticeable production cost. The CO2 mitigates, and environmental revenue is better than the SSS scheme by 5.9 % & 14.6 %. The concern price of the DSS coordination is lower by 6.6 %, and the productivity of the systems was found to be more than 100 % which assures the viability of the projected scheme.

Improved Thermal Performance and Distillate of Conventional Solar Still via Copper Plate, Phase Change Material and CuO Nanoparticles.

BACKGROUND: The world is currently facing a growing concern regarding freshwater scarcity, which has arisen as a result of a complex interplay of various factors. Renewable energy-powered water desalination is a feasible solution to address freshwater scarcity. METHODS: This study presents a comprehensive investigation of the performance of a conventional solar still (CSS) and its modified versions, such as a still with copper plates, a still with PCM and a still with PCM and 3 wt% CuO nanoparticles blend. The experiments were carried out concurrently under identical circumstances for the CSS and the proposed stills. Prior to usage, the CuO nanoparticles and their blend with PCM were characterized through various analyses. RESULTS: The investigation showcased the copper plate attached solar still with 3 wt% CuO nanoparticles blended with PCM significantly improved the distillate production, achieving approximately 6.85 kg/m2/day. This represents an increment of approximately 23.42% compared to the still with copper plate and PCM and 69.14% related to the CSS. CONCLUSION: Moreover, the solar still with 3 wt% CuO nanoparticles blended with PCM demonstrated a thermal efficiency of 74.23% and an exergy efficiency of 9.75%. The production cost of distillate for all four stills remained at $0.03 per kg. These findings highlight the effectiveness of the proposed copper plate attached solar still with 3 wt% CuO nanoparticles blended with PCM as a viable method for producing potable water.

Modifying performance of solar still, by using slices absorber plate and new design of glass cover, experimental and numerical study.

By utilizing novel techniques on the absorber plates as well as the glass cover, this effort attempts to increase the distilled water productivity of a modified pyramid solar still. Under the climatic conditions of Iraq, the use of basin absorber plates with slices along its length, and a W-shaped glass cover was investigated experimentally and numerically. In this work, two comparable solar stills with basin absorber plates of 1 m2 have been planned and built using regional resources. Two absorber plates made of stainless steel were produced, first one was solid and the second was sliced. Two covers made of glass were produced one has a pyramid-shaped glass cover and the other a W-shape. According to experimental and numerical findings, forming slices and changing the glass cover resulted in a 20 % increase in the amount of distilled water. when compared to a pyramid glass cover and a standard sort of absorber plate.

An effective solar assisted semi-cylindrical saline water desalination system with direct atomizer and energy storage materials for domestic use: an experimental investigation.

Solar still is the easiest method to purifying the saline water for domestic usage, but this method needs much improvement for better performance since it has lower productivity. In this paper, an experimental investigation is completed to analyse the semi cylindrical solar productivity still. The semi-cylindrical still is incorporated with direct atomizer and scrap used as an energy storage medium. Experiments are carried out during March 2020 in Kovilpatti, the southern part of India, with a depth of 2 and 4 cm saline water. Comparative performance analysis is made for conventional semi-cylindrical still, semi-cylindrical still with an atomizer, and semi-cylindrical still with atomizer and storage materials. The experimental study shows that the productivity of still increases while decreasing the water depth. Compared with 2-cm and 4-cm depth, solar still with 2-cm depth gives promising distillate productivity. The solar productivity still having 4-cm depth of water without atomizer gives only 2670 ml; on the other side, 2-cm water depth without atomizer gives 3100-ml productivity. The maximum productivity of solar still is found on a semi-cylindrical solar still combined with atomizer and energy storage medium having 2-cm water depth. Results revealed a higher freshwater production rate of 3610 ml found while incorporating atomizer and energy storage with the solar still. The system efficiency improved up to 35.20% compared to conventional semi-cylindrical still with 4 cm of saline water depth.

Design and process parametric investigations on acrylic-based single slope solar still to enhance daily energy efficiency and productivity of water: an application to desalination and dye removal.

Solar-driven water desalination is growing quickly, typically using other renewable energy sources. However, its efficiency is heavily reliant on design and process parameters. The aim of this study is to experimentally investigate the impact of various design and process parameters on the performance of single slope solar still. Thus, a homemade solar still has been fabricated using acrylic sheet with a basin area of 0.25 × 0.25 m2 to carry out the experiments in Vellore, India (latitude 12.9692° N and longitude 79.1559° E). Additionally, this solar still setup is investigated using different absorbing plates (copper plate and copper plate with black coating), various glass cover angles (15°, 30° and 45°) and changing the wind speed (3 m/s, 3.5 m/s and 4 m/s) with help of electric fan. Daily energy efficiency and productivity of water are compared for the same basin area with different design and process parameters. From the results, daily energy efficiency and water productivity are improved with the increase of glass cover angle and wind speed. It is found that the best combination is copper plate with black coating, glass cover angle of 45° and wind speed of 4 m/s. This exhibits 34.09% in daily energy efficiency and 2640 ml/m2 in productivity of water. After the desalination process, the primary ions (Na+, K+, Mg2+, and Ca2+) of seawater are significantly reduced and satisfy the requirement of WHO standards. Subsequentially, dye removal is effectively achieved in the proposed solar still.

A detailed review on various aspects of inverted solar still desalination systems proposed for clean water production.

Rapid degradation of quality and quantity of the available limited fresh water reserves has forced nations around the globe to search for alternate fresh water sources. This has led to the development of various desalination technologies to generate potable water from abundantly available sea and brackish water. Desalination sector has undergone various upgradations to meet the rising fresh water demand in a sustainable way. One such upgradation is the utilization of solar energy as an energy source. High cost and associated environmental impacts with large-scale desalination systems have shifted the focus of researchers towards research and development of various small-scale efficient solar stills for cheap potable water production in rural, remote, arid, and coastal locations. In this review article, various configurations of a non-conventional solar still, namely inverted solar still, have been reviewed extensively by highlighting its classifications, design aspects, working principle, features, and economics. Moreover, the role of inverted solar still's evaporating and condensing surface characteristics and thermal properties on its distillate productivity has also been discussed. Inverted absorber multi-basin solar still and inverted multi-effect diffusion solar still configurations are highly productive. Economics of inverted solar still is better than other conventional solar still configurations and conventional reverse osmosis plant of few m3/day capacity. This review article will facilitate researchers to select appropriate inverted solar still configuration for further performance improvement and commercialization. The scope for future research works on inverted solar still has also been listed.

Feasibility assessment of a stepped solar still integrated with hexagram fin: an experimental and numerical approach toward sustainability.

Effective utilization and conservation of freshwater is a global concern due to the rapid population growth and industrial usage. To address this challenge, various approaches have been developed and implemented to convert brackish water into freshwater and meet the global water demand. This study introduces hexagram-shaped aluminum fins attached to a powder-coated basin to improve the freshwater production rate of stepped solar still. The experiment involved testing the modified stepped solar still (MSSS) equipped with hexagram fins and the conventional stepped solar still (CSSS) without hexagram fins during summer days at the Sathyamangalam location (11.49° N, 77.27° E). A mathematical model was used to analyze the performance of the solar stills, and the simulation results were validated by comparing CSSS and MSSS in terms of their freshwater production. The results indicate that the productivity of CSSS increased by 40% using hexagram fins, and the MSSS with hexagram fins produced a maximum of 4.45 l/m2 of fresh water daily. The annual performance of MSSS and CSSS in the experimental location reveals a 12.6% reduction in the payback period of the solar still due to the presence of fins. The study recommends using fins in solar stills in hot climates for efficient and cost-effective water desalination applications to achieve sustainable development objectives while reducing carbon emissions.

Efficient solar desalination for clean water production from different wastewaters.

Solar energy is one of the sustainable sources for many fruitful applications. Desalination of wastewater by solar power is a priority research focus and has attracted many researchers and scientists world-wide. However, handling industrial and other wastewater is typically a challenging task for effective treatment and re-use. The presence of contaminants in the effluent is hazardous to the environment and human health. In the present work, an attempt has been made to investigate different wastewaters including (i) garbage wastewater, (ii) waste vegetable water, (iii) landfill leachate, and (iv) pharmaceutical effluent fed into a solar distiller evaporated under natural solar illumination. Herein, different waste waters' pH, chemical oxygen demand (COD), ammoniacal-nitrogen (NH3-N), arsenic (As), Barium (Ba), Cobalt (CO), Chromium (Cr), Iron (Fe), Mercury (Hg), Potassium (K), Manganese (Mn), Magnesium (Mg), Sodium (Na), Nickel (Ni), Phosphate (P), and Zinc (Zn) were investigated by the inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The concentration of NH3-N in the garbage wastewater, vegetables wastewater, landfill leachate, and pharmaceutical effluent were 157 mg/L, 142 mg/L, 161 mg/L, and 164 mg/L, respectively. The evaporated water output of garbage, waste-vegetable water, landfill leachate, and pharmaceutical effluents are 1.7 L/m2.day, 1.8 L/m2.day, 1.9 L/m2.day, and 1.65 L/m2.day, respectively. Finally, the test result reveals that the water quality is greatly improved after consecutive evaporation process by the solar distiller. This is one way to deal with the wastewater through a sustainable process for a better future.

Performance evaluation of solar still using evacuated tube collector with and without nanoparticles.

Solar-thermal distillation is recognized as a low-cost, long-term technique of producing high-quality fresh water in the lack of energy and clean water infrastructure. Improvements to distillation have lately been developed by the application of three main phases depending on the transition of sunlight into heat energy, the generation of thermal vapor, and the condensation of vapor into water. The effectiveness of collected distillation water from evacuated tube collectors on nanoparticles was examined along with basic fluids including water and copper oxide, aluminum oxide, and zinc oxide. Additionally, an investigation of the relationship between specific heat and thermal conductivity, as well as between actual and theoretical heat generation, was conducted. For 11 h of operation, 2275 ml of distilled water was collected using evacuated tube collectors without nanoparticles. The efficiency of the nanoparticles compared to water was more than 17.4% CuO, 15.7% Al2O3, and 14.5% ZnO improved and an increase in overall efficiency of 66.6%. As a result of the experiment, the greatest actual heat generation, expressed in kilowatt-hour, exceeds the theoretical value.

Exergo-enviro-economic and yearly productivity analyses of conical passive solar still for sustainable solar distillation.

This paper focuses on exergo-enviro-economic and yearly productivity analyses for conical passive solar still having the potential to fulfil the sustainable development goal of the United Nations. A new approach for thermal modelling of conical passive solar still has been carried out with experimental validation in the present work, wherein different weather conditions have been considered for the analysis of the proposed system. The carried out work has been done for each month of the year. In further methodology, the computational code in MATLAB has been used for the computation of hourly freshwater production, exergy, and energy followed by the estimation of their annual values. Thereafter, exergo-enviro-economic parameters, yearly productivity, payback period, and freshwater cost have been estimated, and the obtained results have been compared with the earlier published research. Concludingly, the exergo-economic parameter, enviro-economic parameter, and yearly productivity for the proposed system have been found higher by 44.25%, 25.68%, and 44.07%, respectively, than the conventional solar still. The comparative freshwater cost is 13.56% less than the conventional solar still for 0.025 m water depth. Additionally, the payback period for the proposed system will remain at 2.75 years, which is 13.82% less in comparison to the conventional solar still considering a 2% interest rate.

Comparative study on conventional and phase change material (PCM) based solar desalination still using low-pressure water as a heat storage medium.

Over the years, solar desalination is a renewable energy-driven method to produce freshwater from saline/ brackish water. Since solar radiation is available only in the daytime, many studies have been undertaken to store solar energy using phase change material (PCM). The aim of this study is to compare the two solar stills (still I as a conventional solar still and still II as a PCM-integrated solar still). In still II, using low-pressure water as thermal energy storage, PCM in a copper tube with a 1 liter capacity has been additionally installed than still I. Five trials have been conducted to compare the performance and yield between stills I and II, with various factors during the experiment. Remarkably, three distinct vacuum pressures - 712 mmHg (for trials 1, 2, and 3), - 690 mmHg (for trial 4), and - 660 mmHg (for trial 5) were used for the investigation to compare the performance of PCM-based solar still with conventional solar still among five trials. Finally, at a vacuum of -712 mmHg and 175 ml of water poured inside the low-pressure system, the distillate yield obtained from still II is 9.375% higher than the yield of still I.

Experimental analysis of enhanced solar still operating with induced turbulence.

This work experimentally investigates the performance of solar still with induced turbulence (SWIT) which operates with a novel approach for improved productivity. A metal wire net has been submerged in basin water of still and direct current vibration micro motor has been used to develop small intensity vibrations in wire net. These vibrations serve to induce turbulence in basin water and also break the thermal boundary layer between still surface and water to enhance the evaporation. The energy-exergy-economic-environment analysis of SWIT has been performed and compared with conventional solar still (CS) of identical size. The overall heat transfer coefficient of SWIT is found to be 66% more in comparison of CS. The SWIT provided 53% increase in yield and it is 55% more thermally efficient than CS. The average exergy efficiency of the SWIT is found to be 76% higher than that of CS. The cost of water from SWIT is 0.028 $ with a payback period of 0.74 years and the carbon credit gained by SWIT is found to be 105 $. The productivity of SWIT has also been compared for intervals of 5, 10, and 15 min between the induced turbulence to find suitable interval duration.

Water depth effect on energy, exergy losses, and exergy efficiency of solar still with wick materials: an experimental research.

This study analyzes the energy and exergy destruction of a solar still with black painted wick materials (SS with BPWM) at different salt water depths (Wd) of 1, 2, and 3 cm. The coefficients of heat transfer for evaporative, convective, and radiant heat transfer have been calculated for a basin, water, and glass. The thermal efficiency and exergy losses caused by basin material, basin water, and glass material were also determined. An SS with BPWM at Wd of 1, 2, and 3 cm has produced a maximum yield of 0.4, 0.55, and 0.38 kg per hour, respectively. An SS with BPWM at Wd of 1, 2, and 3 cm has produced a daily yield of 1.95, 2.34, and 1.81 kg, respectively. From the SS with BPWM at Wd of 1, 2, and 3 cm, respectively, daily yields of 1.95, 2.34, and 1.81 kg were obtained. The highest exergy loss of the glass material, basin material, and basin water for the SS with BPWM at 1 cm Wd was 728.7, 133.4, and 123.8 W/m2, respectively. The SS with BPWM's thermal and exergy efficiency are 41.1 and 3.1% at 1 cm Wd, 43.3 and 3.9% at 2 cm Wd, and 38.2 and 2.9% at 3 cm Wd, respectively. The results show that compared to the exergy loss of basin water in SS with BPWM at 1 and 3 cm Wd, the basin water exergy loss of SS with BPWM at 2 cm Wd is minimal.

Performance studies of a solar thermal-electric hybrid desalination system: 4E (energy-exergy-economics-enviroeconomics) analysis.

In this work, a hybrid desalination system uses solar thermal-electric clean energy to maximize production and consistency through optimum temperature management to deliver clean water for good health. It is an effort in the direction of aligning with few of UN's sustainable developmental goals. BIPV system-powered thermoelectric modules boost evaporation and condensation rates in a unique bio-inspired butterfly roof design-based twin wedge solar still (TWSS). A microcontroller-based temperature control unit (TCU) regulates and maintains the hybrid system to provide practically constant higher yields. To understand system performance, 3 days of testing has been carried out. Average yield, energy efficiency, exergy efficiency, cost per liter of freshwater, and payback period of hybrid TWSS (hTWSS) and passive TWSS over 15 years are 8.64 l/m2/day, 61.93, 9.05, and 0.116 $/l in 44 months, and 1.3 l/m2/day, 23.06, 1.26, 0.068 $/l in 20 months. The hTWSS mitigated 5.1 tons and TWSS 59.6 tons of CO2. This hybrid technology utilizes clean energy to deliver clean water and electricity in green energy buildings with a small footprint. As a futuristic work, AI and machine learning are suggested to be used to enhance and commercialize this solar still desalination method.