Performance Enhancement of Solar Stills
Access to safely managed drinking water services has become a serious issue for 2.2 billion people worldwide. As is known, traditional stilling designs suffer from low quality and production. Therefore, solar stills offer an eco-friendly solution. This review study provides the first comprehensive cross-comparison of enhancement technologies for solar stills developed between 2020 and 2025. This work rigorously analyzes 121 peer-reviewed articles, comparing 11 different enhancement methods based on technical performance, economic viability, and practical implementation challenges, unlike previous reviews focusing on limited improvements. An innovative combined deductive–inductive taxonomy was developed and validated, providing a rationale-based technology selection framework. Results show productivity improvements ranging from 4.2% to 748%, with costs between $0.0014 and $0.29/L. Low-cost technologies (thermal storage, fins, stepped designs: $0.005–0.035/L) are ideal for resource-limited settings, offering payback periods under 2 years. Moderate-cost options ($0.018–0.060/L), including phase change materials and pyramidal designs, show promise for community-scale applications, though they face short- to medium-term economic barriers. Enhancements are categorized using a four-stage technology readiness scale: deployment-ready, community-scale ready, pilot-scale, and research stage. Key research gaps include insufficient long-term performance data and unsystematic evaluation of hybrid enhancement approaches. This study uniquely provides a systematic, evidence-based framework integrating technical performance with economic feasibility and practical viability, enabling informed decision-making for expanding safe drinking water access through solar desalination technology
- Peer Review Report
- 10.1017/wat.2026.10016.pr12
- Jan 8, 2026
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Peer Review Report
- 10.1017/wat.2026.10016.pr8
- Dec 8, 2025
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Peer Review Report
- 10.1017/wat.2026.10016.pr6
- Nov 24, 2025
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Peer Review Report
- 10.1017/wat.2026.10016.pr20
- Feb 18, 2026
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Peer Review Report
- 10.1017/wat.2026.10016.pr15
- Jan 27, 2026
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Peer Review Report
- 10.1017/wat.2026.10016.pr13
- Jan 18, 2026
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Peer Review Report
- 10.1017/wat.2026.10016.pr7
- Dec 3, 2025
Ensuring easy access to clean and safe drinking water using low-cost technology is essential to mitigate the rising water scarcity in emerging economies. Commercial large-scale desalination technologies need significant investment, making them unsuitable for off-grid and small-scale applications. However, this operation can be carried out using a low-cost desalination technology based on renewable energy, known as the solar still. In this research work, a modified basin solar still (basin solar still + internal mirrors + 8 kg gravel + black ink (400 ppm per litre)) was developed and experimentally tested in Visakhapatnam (17.68°N, 83.22°E), India, to determine its appropriateness for sustainable seawater desalination. It produced 14% to 23% more desalinated water than a conventional basin solar still. In addition, its thermal efficiency was between 41% and 42%, which was significantly greater than other basin solar stills reported in literature. In addition, high-quality desalinated water was generated at a cost that was around three times less than the drinking water offered at Indian Railways kiosks. Moreover, the ability to mitigate significant CO2 emissions while also addressing water scarcity demonstrated that the modified basin solar still continues to contribute effectively to the United Nations Sustainable Development Goal 6 (Clean Water and Sanitation).
- Research Article
26
- 10.1016/j.tsep.2024.102647
- May 22, 2024
- Thermal Science and Engineering Progress
Synergetic integration of machining metal scrap for enhanced evaporation in solar stills: A sustainable novel solution for potable water production
- Research Article
40
- 10.1016/j.solener.2024.113077
- Nov 9, 2024
- Solar Energy
Stepped solar Stills: A comprehensive review of Design, Performance, and optimization strategies for sustainable water desalination
- Research Article
1
- 10.69739/jmsbc.v2i2.857
- Aug 17, 2025
- Journal of Medical Science, Biology, and Chemistry
The worldwide scarcity of potable water has increased significantly due to population expansion and the pollution of accessible water sources from anthropogenic activities. Solar stills are essential for supplying potable water via solar-powered distillation. Alterations, including phase change materials (PCM), nano fluids, and reflectors, markedly enhance heat retention and evaporation rates, leading to increased distillate production. Also, the efficacy of distillate production is significantly affected by design specifications, materials, and operational conditions. This paper delineates the passive and active designs, classifications of solar stills, single - effect and multi - effect kinds, and various improvements made to these types to augment yield, including heat storage, fins, reflectors, and collector types. Also, photovoltaic-thermal stills are encompassed in this review.
- Research Article
12
- 10.53894/ijirss.v4i2.63
- Mar 30, 2021
- International Journal of Innovative Research and Scientific Studies
Production of required thermal energy to heat residential buildings is a considerable issue in energy studies. Kabul city is a city in which the coal-fired central heating systems for providing the mentioned energy is in expansion process. And, coal as feeding source of these systems with generation of carbon dioxide (CO2) is the main cause of greenhouse gases (GHGs) emissions in winter. Fortunately, Kabul city has maximum solar radiation in summer warm season which can be used for fulfilling of this demand in winter cold season. The method which can perform this task is the central heating by seasonal sensible heat storage of solar thermal energy. But, the economic and environmental feasibility and viability of this method is a discussable issue. In this study, the central heating by seasonal sensible heat storage of solar thermal energy and its economic and environmental feasibility and viability is studied. It is tried that this system is compared in a logical method with current coal-fired systems. The economic feasibility study is accomplished by comparison of initial or capital cost and annual operation and maintenance cost with the usage of existing data and thermodynamic analytic methods. The environmental viability study is accomplished by comparison of annual emissions of CO2 with the usage of online emissions calculator. Unfortunately, it is found that seasonal sensible heat storage of solar thermal energy is not an economically feasible method for central heating due to its high initial cost and cannot be used in an economically beneficial manner for central heating. But fortunately, it is an environmentally viable method and environmentally friendly way due to its no and/or zero CO2 emissions. To sum up, it is suggested that, this method should be used for district heating which can make this system economically feasible.
- Research Article
- 10.1002/ep.70264
- Mar 24, 2026
- Environmental Progress & Sustainable Energy
Solar stills offer a sustainable solution to water scarcity, especially in arid and remote regions. Among various configurations, pyramid‐shaped solar stills exhibit superior performance over traditional basin‐type designs, attributable to their augmented condensing surfaces and multifaceted orientations that optimize solar irradiance capture. This study aims to experimentally enhance the performance of a pyramid solar still by integrating naturally sourced gravel and volcanic pebbles as sensible thermal energy storage media. Experimental trials were conducted under the hyper‐arid climatic conditions of Ghardaïa, Algeria. The primary objective was to quantify the improvements in freshwater productivity and thermal efficiency achieved using these economical, regionally abundant, and low‐cost materials. The volcanic pebble configuration yielded the paramount outcomes, with a distillate production that was 75% higher than that of the conventional pyramid solar still. Under direct natural irradiation the pyramid solar still equipped with volcanic pebbles, reached 30.79°C for the natural gravel configuration still. The thermal efficiency of the volcanic pebble‐based pyramidal solar still reached 90%, markedly surpassing the natural pebbles system's efficiency of 62%. This superior performance is attributed to the mineral‐rich architecture of the volcanic pebbles, which improves solar energy absorption and thermal heat retention. Furthermore, the pyramidal solar still design proved cost‐effective, with a cost per liter of 0.0285 USD/L for the pyramid solar still with pebble integrated variant and 0.0494 USD/L for the conventional pyramid solar still.
- Research Article
16
- 10.1016/j.csite.2024.104847
- Jul 17, 2024
- Case Studies in Thermal Engineering
A case study on single basin solar still augmented with wax filled metallic cylinders
- Research Article
2
- 10.36479/jhe.v4i2.52
- Sep 30, 2016
- Journal of Humanitarian Engineering
The lack of safe and clean drinking water sources is one of the problems faced in most rural communities in Zambia. Water in these communities is mostly obtained from shallow wells and rivers. However, this water might be potentially contaminated with harmful substances such as pathogenic bacteria and therefore, unsafe for drinking. Solar water distillation represents an important alternative to palliate problems of fresh water shortages. Solar water stills can be used to eliminate harmful substances from contaminated water by treating it using free solar energy before it can be consumed. Therefore, there is a need to improve solar still performance to produce a greater quantity of safe drinking water. One possible method to improve performance is through adding reflectors to solar stills. Reflectors improve performance by increasing the quantity of distillate by about 22.3 % at a water depth of 15 mm and about 2 9% at a water depth of 10 mm when compared to the distillate produced from a still without reflectors. The water produced using solar stills with reflectors was tested and adhered to World Health Organization (WHO) drinking water standards. This implies that solar distillation with reflectors could be adopted at a larger scale to produce safer drinking water at a reduced cost.
- Research Article
15
- 10.1080/21622515.2021.1921056
- Jan 1, 2021
- Environmental Technology Reviews
The main focus of this review is to investigate the potential of small-scale solar desalination as a viable freshwater source by comparing the performance of different types of modification on solar stills. The design factors that could provide impacts to the parameters affecting the performance in terms of distillate production have been considered. The design factors include mostly the different mechanisms of solar stills, concentration of solar power,sand thermal storage. The impacted parameters of each type of solar stills are one of the highlights of this review. The cost of production has also been explored. The purpose of this review is to enable future researchers in identifying the appropriate features to be used for designing a solar desalination system in water and energy-stressed rural regions. The minimum cost per liter of water production reported was 0.0085 USD and the maximum production reported from modified passive solar still was reported to be 11.65 L/m2/day with a spherical absorber. Minor addition of active elements like a small pump to the still with Fresnel absorber reported producing 12.47 L/m2 day. For performance enhancement of passive solar stills in water and energy scarce regions, it is suggested to add Phase change material (PCM) with heat conductive particles and solar irradiation concentration through absorbers/reflectors or Fresnel lenses. HIGHLIGHTS Renewable energy based desalination methods are preferable over energy-intensive methods. For water and energy scarce regions, independent small scale passive solar stills can be a viable option. Parameters affecting the performance of a solar still include uncontrollable climatic parameters and manipulative parameters. Highly productive passive solar stills can be designed by controlling the manipulative parameters like evaporation area of the basin, tilt angle and temperature of condensation surface, thermal gain of the feedwater by thermal storage, heat transfer using fins/conductive material in the basin. The recent trends to improve passive solar stills’ efficiency with cost effectiveness include usage of sunlight concentrators through refraction, addition of conductive nano particles with thermal storage and multi-staging.