A Conceptual Paper on the Design and Analysis of Solar Stills with Evacuated Glass Tube Augmentation

Abstract

Background: Water scarcity is a critical global issue. Solar desalination using solar stills is a sustainable solution, but efficiency is low. Evacuated glass tube collectors (EGTCs) can enhance performance.

Objectives: This review analyses advancements in EGTC-integrated solar stills, evaluating performance, design challenges, and economic/environmental implications.

Method: A systematic review of literature (2010-2024) from ScienceDirect, Springer, and Google Scholar using keywords like "solar desalination" and "solar stills." Included peer-reviewed studies on solar desalination, agrivoltaics, and photovoltaics. Excluded irrelevant or pre-2010 studies. Compared performance, design, and economics of conventional vs. EGTC-augmented stills using tables and synthesis.

Findings: EGTCs improve thermal efficiency (up to 60%) and yield (up to 7 L/m²/day) over conventional stills (25-35%, 2-3 L/m²/day). PCMs and reflectors further enhance this (up to 75%, 10 L/m²/day). Bottlenecks include thermal coupling, condensation, and costs. Emerging research includes smart heat management, nanomaterials, hybridization, CFD modelling, and agrivoltaics. A roadmap with short-term (interface improvement, standardized testing) and long-term (commercial prototypes, IoT, zero-energy plants) goals is proposed.

Significance: This review offers an updated, comprehensive analysis using a performance-bottleneck-resolution approach, integrating design and strategic directions, unlike narrower previous reviews. It highlights cross-sector opportunities and provides a future research roadmap.