Performance Enhancement of an Inverted Pyramid Solar Still Using Pebble Stones, Coir Fiber, and Sugarcane Bagasse

¹ Departmentof Mechanical Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai-600124.
² *Institute of Agricultural Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India-602 105.
³ Department of Mechanical EngineeringRathinam Technical Campus, Coimbatore - 641021.
⁴ Department of Mechanical EngineeringMeenakshi College Of Engineering Chennai- 600078

^* Corresponding Author Email:This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 16 April 2026

Abstract

This work is first systematic assessment of combined thermal performance of different natural materials incorporated in geometry-optimized inverted pyramid made of aluminum. A comprehensive framework, which incorporates energy, exergy, and environmental parameters is used to assess the study. It also presents a new solar still design that utilizes such materials. Interrelations between the incorporation of the pebble stones with the coir fiber and sugarcane bagasse on heat transfer relationship, behavior of the evaporation, and efficiency of the entire system have never been studied previously, particularly in an optimized basin shape. In order to develop a viable and economical desalination system, the present idea combines both the geometrical solar intensification and material-enhanced thermal betterment. The experiment results proved the integrated arrangement to be the most effective one of all the scenarios taken into consideration: To regulate the temperature, pebble stones were used as thermal storage, coir fiber stimulated evaporation of thin-film using capillaries and sugarcane bagasse with its porous structure, facilitated even distribution of water in addition to restricting the thermal losses. The inverted pyramid structure enhanced thermal use by minimizing convection heat losses and enhancing solar energy concentration. The optimal construction produced 32.9% better than the reference still given a similar operating protocol and attained a peak yield of 3.16 kg/day of distillate per m². The increase in efficiency was identified as 36.3% with a rise in efficiency to 26.6 to 41.8% in terms of heat transfer in embodied energy respectively. This result offers viability to the logic that a sustainable and effective solution to distributed solar desalination is the addition of multifunctional natural materials on an ideal basin.