Various enhancements to solar stills aim to increase their output of fresh water. This research experimentally compared the efficiency of two solar stills (SS) in terms of producing fresh water. The conventional solar still (CSS) was compared to the Coconut leaf sheath single slope solar still. Natural fibres were used to fill the basin, increasing the surface area in contact with the sun and, by extension, the rate of evaporation. Utilize its capillary effect while simultaneously putting it to use as a heat sink (thermal storage material). We calculated the exergy and thermal energy efficiency of both systems and the associated costs. Daily accumulative freshwater productivity was found to be 5170.8 gm/m² when employing natural fibre, a 45.8 % improvement over the usual method. Solar stills made from natural fibres were discovered to have daily thermal energy efficiencies of 46.8 % and exergy efficiencies of 5 %, while CSS systems achieved 33.8 and 3.2 %, respectively. When compared to a standard solar still, which costs ₹9.68 every litre of water produced, a solar still made with natural fibre reduces that cost to just ₹6.64 per litre.

Different shaped floating wick (FW) material in the basin improved the efficacy of a single slope solar still (SS). Thermocol is used to support a basin in which cotton wicks are suspended. The three forms of modified solar stills (MSS) are analyzed, each with a unique absorber geometry. Absorber surfaces in the MSS-RCT (Rectangular teeth), MSS-ITT (Isosceles Triangular teeth), and MSS-HCT (Half-circular teeth) configurations are made up of FW layers. These improved designs are far more efficient and effective than the Conventional solar still (CSS). All MSS absorber surfaces produce more potable water than the CSS experiment does for the bulk of the workday. The MSS-HCT process achieved a maximum daily yield that was on par with that of the other modified stills and a 68 % increase in daily yield compared to the CSS process.

Solar energy (SE) is non-polluting and sustainable. However, the strength of the sun’s rays shifts as the seasons change, the weather shifts, and the day and night cycles. It is possible to store energy as heat, which can then be used for a variety of applications in the future. The primary objective of this research was to extend the time that high water temperature (HWT) was maintained by using phase change materials (PCM) to reduce energy consumption. To test the efficacy of an FPSWHS using 18 % (63 kg) of PCM condensed paraffin wax of type RT42, an experimental rig was constructed. To further expand PCM surface area and speed up charging and discharging, 18 aluminium cylinders were employed. Given the varying weather patterns in the India, this research was also useful in settling on a suitable PCM for SWHS. At 60°C input temperature of water (Tin) and 0.11 kg.s-1 flow rate of mass in water (mw), including RT42 into a water-PCM storage tank reduced power consumption by as much as 5.75 kWh, for a total system energy consumption of 31.4 kWh. The results showed a 27 % drop in daily average carbon footprint and a 27 % increase in overall system efficiency.

The primary objective of this study is to determine the Coir fibres (CF) utilization in solar stills (SS) to boost the quantity of freshwater production. By placing dry CF fibres in the absorber basin, researchers were able to accelerate the rate at which water evaporated from the SS. Under various CF densities, the freshwater production of the absorber basin was measured (8, 11, 14, 18, 20, 23, and 26). The outcomes demonstrated that yield was raised by 27.23 percent after 18-fiber SSCF was added to the absorber basin. There were 14.27 percent, 19.40 percent, 24.57 percent, 25.00 percent, 16.28 percent, and 6.23 percent yield improvements for solar stills with 8, 11, 14, 18, 20, 23, and 26 fibres in the absorber basin, respectively, as compared to a CSS. The results demonstrate that compared to CSS, the cost to produce one litre of freshwater with SSCF is reduced by 23.1%. The return of investment for SSCF is much more immediate than it is for CSS. An estimated ₹242 was needed to produce 1 litre of freshwater using CSS, while an estimated ₹199 was needed to produce 1 litre of freshwater using SSCF. The payback time for SS was only 6.23 months, which was significantly less than that of solar panels. CF are preferable to other materials for use in the solar still due to their lower cost and higher energy efficiency.

In recent years, developments of hybrid polymer composites by adding the natural and synthetic resources as reinforcement materials are significantly increased to enhance the required properties of the composites. In this research work, effects of Nano alumina particles and water hyacinth particles addition into the HDPE polymer matrix for its tensile properties were studied through experimentation. Fine Nano alumina particles are used as filler and the well water hyacinth particles are used as reinforcement materials. Hybrid composite specimens were prepared by varying the weight percentage of filler and reinforcement materials and keeping the HDPE’s weight percentage as constant. Hybrid composite boards were fabricated by using hydraulic type injection moulding machine. Hybrid polymer composite specimens for tension test is cut away from the hybrid composite boards as per the ASTM standards with the help of water jet machining process. Experimental results reveal that the limited addition of fine Nano alumina and water hyacinth particles into the HDPE polymer matrix improves the tensile properties of the hybrid composites significantly when compare to the pure HDPE polymer composite.