Solar Desalination Research Articles

Hybrid solar photovoltaic conversion and water desalination via quad-band fano-resonant optical coatings and superwicking cooling

Hybrid Photovoltaic/Thermal (HPT) systems simultaneously convert solar energy into electrical power and thermal energy. These systems are attractive as they enable the thermal management of PV cells to maintain optimal operating temperatures and maximize the overall solar energy conversion. Despite their advantages, HPT systems have been limited to storing solar energy in the form of heat or simple water/space heating, thus restricting the broader application scope of HPT systems, particularly in regions with abundant solar energy. Here, we introduce a device that expands the scope of HPT applications by realizing a hybrid PV/ water desalination system, achieved through the integration of a Fano-resonant optical coating (FROC) onto a silicon substrate, which is turned superwicking via femtosecond laser surface patterning. This configuration allows a single-junction amorphous silicon solar cell to operate under higher solar concentrations with much less heat conversion, achieving a temperature reduction of 101 °C and an efficiency improvement of 335.7% compared to a standalone photovoltaic system under the solar concentration of 5. At the same time, the interfacial water desalination achieves a 2 kgm−2h−1 high evaporation rate. Over a 12-hour cycle, our HPT system showed a consistent performance, demonstrating a combined solar conversion efficiency of 79.6%. The demonstrated superwicking-FROC will pave the way for widespread adoption of HPT systems particularly in sunny coastal regions.

Double-network agar/sodium alginate hydrogel-based photothermal evaporator with layered structure for solar desalination

Double-network agar/sodium alginate hydrogel-based photothermal evaporator with layered structure for solar desalination

Bandgap Engineering on UiO-66 Metal-Organic Framework Derivatives for Solar-Driven Seawater Desalination.

The growing scarcity of freshwater, driven by climate change and pollution, necessitates the development of efficient and sustainable desalination technologies. Solar-powered interfacial water evaporation has emerged as a promising solution; however, its practical implementation is hindered bythe limited availability of efficient and stable photothermal materials. Herein, a bandgap engineering strategy via linker modification to enhance the photothermal conversion capability of metal-organic frameworks (MOFs) is reported toward efficient solar-driven desalination. By systematically introducing functional groups with varying electron-donating and electron-withdrawing abilities, the energy bandgap of UiO-66-X (X = ─F, ─H, ─OH, ─NH2, ─(NH2)2) is finely tuned. Density functional theory (DFT) calculationsand femtosecond transient absorption (fs-TA) spectroscopy reveal that stronger electron-donating functional groups narrow the bandgap of the MOFs, thereby improving their photothermal conversion efficiency. The optimized UiO-66-(NH2)2 material reaches a peak surface temperature of 58.7°C when exposed to simulated sunlight at ≈1 kW·m-2 with a photothermal conversion efficiency of 86.50% and an evaporation rate of 2.34 kg·m-2·h-1 with an evaporation efficiency of 97.40%. This study presents a novel approach for fine-tuning the bandgap in photothermal materials, offering a pathway toward advanced solar desalination technologies to address the global water scarcity crisis.

Comparison of Contact and Non-Contact in Single-Slope Solar Desalination Systems: Experimental Insights and Machine Learning Predictions

Solar desalination systems turn saltwater water into freshwater, which helps to overcome water scarcity. In this study, the effects of direct (contact) and indirect (non-contact) interactions with water in solar desalination were evaluated. The emphasis was on changing water depths to better understand the performance variances. Contact systems have a direct interface between thermal absorption materials and water, whereas non-contact systems avoid material–water contact to increase longevity. The experiments at two elevated water depths (3 cm and 4 cm) were conducted in a single-slope solar desalination system. The productivity of both touch and non-contact systems was investigated in June, August, and October 2024 to gather sufficient data for the training and testing of various machine learning models used to predict the distillate. Surprisingly, the non-contact structure system produced 15% and 8% more distillate than the contact system at 3 and 4 cm water depths, respectively. This insightful result will aid in building efficient and sustainable solar desalination technologies. The comparative study gives information on the trade-off between contact and non-contact techniques, with implications for future advances in solar-powered desalination technology. Among all the machine learning techniques, random forest regression achieved the highest coefficient determination (R2 train of 0.89 and R2 test of 0.95 for the non-contact structure system and R2 of train 0.85 and R2 test of 0.98 for the contact structure system). Machine learning techniques improve solar desalination by allowing for predictive insights and efficient maintenance, ultimately leading to sustainable water production.

An Experimental Investigation on the Performance of a Double Slope Single-Stage Solar Still tested in Cape Town, South Africa

Desalination systems have emerged as an alternative solution to the global water crisis, with many countries using them to alleviate freshwater scarcity. Various types of desalination systems exist, including solar desalination, which is the focus of this study. This research aimed to design, construct, and test a Double Slope Single-Stage Solar Still (DSSSSS) under real environmental conditions in Cape Town, South Africa. The system incorporated an Evacuated Tube Solar Collector (ETSC) to enhance its performance. The DSSSSS was tested during day and night. The experiment took place in October and November 2023, during the spring season in South Africa. The water depth was maintained at 50 mm using a float valve, and a 220 V water circulation pump ensured continuous seawater flow between the basin and the ETSC. The system was tested for 12 days, the highest production obtained per day was 513 ml on a day when the maximum outdoor temperature was 30 oC. The minimum distillate produced was 140 ml on a day that had a maximum temperature of 22 oC and that was one of the coldest days during the testing period. A total of 2142 ml of distillate was produced during daytime and 1679 ml at night, amounting to 3821 ml over the testing period. Salinity and conductivity tests were conducted on both the raw seawater and the distillate to compare water quality before and after the purification process.

Highly Stretchable, Robust, and Floatable Broadband Light Absorber of Carbon Nanotubes–Ecoflex Composite on 3D Mogul‐Pattern for Photothermal Conversion

Addressing the need for efficient and durable photothermal materials, this study presents a novel composite material composed of carbon nanotubes (CNTs) embedded in an Ecoflex matrix with a 3D mogul pattern. This material enhances photothermal effects and is engineered for highly stretchable, durable, and floatable broadband light absorption. Combining CNT‐based inherent light absorption and the 3D mogul pattern with micro‐cavities effectively captures a broad spectrum of light from ultraviolet (UV) to near‐infrared (NIR) of (250–1500) nm, achieving an average absorption of 98%. Uniform CNT distribution in Ecoflex elastomer on the 3D mogul pattern reduces stress concentration, ensuring a robust, elastic platform. This platform withstands stretching, deformation, intense pulsed light, and salt‐aging without compromising optical properties across the UV–vis–NIR range. Under a 1‐sun solar simulator, the structure's photothermal effect is evident, reaching 74.6 °C. The floatable nature of the composite makes it ideal for solar desalination, achieving a 0.52 kg m−2 h−1 evaporation rate under 1‐sun. Furthermore, the curved CNT–Ecoflex mogul structure embedded in ice melts within 30 min under 2 sun exposure, regaining its flat, stable form. This multifunctional material offers high mechanical resilience, excellent light absorption, and versatile deployment for renewable energy harvesting and environmental sustainability.

Solar Energy Based Sea Water Desalination Machine with RO and UV Purifier

Access to clean and potable water is a growing global concern, particularly in coastal and arid regions where freshwater sources are scarce. Traditional desalination tech- niques, such as thermal distillation and conventional reverse osmosis, rely heavily on fossil fuel-based energy sources, leading to high operational costs and significant environmental impacts, including greenhouse gas emissions. Additionally, these systems often require complex infrastructure, making them inaccessible to remote and off-grid communities. To address these challenges, this research presents a novel solar-powered desalination machine that integrates Reverse Osmosis (RO) and Ultraviolet (UV) purification technologies. The proposed system harnesses solar energy to power high-pressure pumps, eliminating dependency on non-renewable energy sources. The RO unit effectively removes dissolved salts and contaminants, while the UV purification stage ensures microbial disinfection, delivering high-quality drinking water. By utilizing renewable energy, the system significantly reduces operational costs and minimizes carbon emissions, mak- ing it an environmentally sustainable and economically viable solution. The impact of this research extends to enhancing water security in remote and disaster-prone areas, providing a decen- tralized, self-sustaining water purification solution. Experimental results demonstrate the system’s efficiency in reducing Total Dissolved Solids (TDS) to potable water standards, ensuring safe and reliable water supply. Future advancements will focus on optimizing energy utilization, improving membrane longevity, and integrating smart automation for real-time performance monitoring. This study contributes to the global effort of sustain- able desalination, paving the way for cleaner and more accessible water resources. Index Terms—Solar Energy, Seawater Desalination, Reverse Osmosis (RO), UV Purification, Water Scarcity, Renewable En- ergy Photovoltaic (PV) Systems, Membrane Technology.

Concentrated solar supercritical water desalination and multi-effect distillation hybrid systems for efficient zero liquid discharge

Concentrated solar supercritical water desalination and multi-effect distillation hybrid systems for efficient zero liquid discharge

MXenes for Various Applications: Recent Trends and Future Aspects

ABSTRACTTwo‐dimensional (2D) MXene structure, versatile surface reactivity, flexibility, wearability, and outstanding thermal attributes make them highly suitable for numerous applications. This comprehensive review based on MXenes delves into the potential uses of fewer assessed applications, such as materials, solar thermal desalination, energy harvesting, electrochemical sensing, environmental remediation, and removal of heavy metal ions. Several industries associated with the summarized applications include hybrid photovoltaic thermal systems, energy storage, energy conversion, soft electronics, and other industries. Further, the review underscores the importance and future guidance of continued research in the MXene field to harness the potential benefits of not only summarized applications but also diverse applications.

Enhancing solar water desalination with wax infused glass for sustained distillate yield

Enhancing solar water desalination with wax infused glass for sustained distillate yield

Enhancing efficiency in solar non-intrusive desalination: Solar still prototype optimization in Southwest Europe

Enhancing efficiency in solar non-intrusive desalination: Solar still prototype optimization in Southwest Europe

Techno-economic of solar-powered desalination for green hydrogen production: Insights from Algeria with global implications

Techno-economic of solar-powered desalination for green hydrogen production: Insights from Algeria with global implications

Improving solar desalination in high-salinity brine through zwitterionic salt containing hydrogels

Improving solar desalination in high-salinity brine through zwitterionic salt containing hydrogels

Highly efficient solar desalination enabled by a spiral-layered hydrogel with omnidirectional salt rejection

Highly efficient solar desalination enabled by a spiral-layered hydrogel with omnidirectional salt rejection

In-depth analysis of solar desalination systems integrating heat storage and wick materials: A multi-dimensional evaluation

In-depth analysis of solar desalination systems integrating heat storage and wick materials: A multi-dimensional evaluation

Design of a facile self-floating bio-based Janus evaporators for efficient and stable solar desalination

Design of a facile self-floating bio-based Janus evaporators for efficient and stable solar desalination

Global advancement of solar photovoltaic thermal technologies integrated with membrane distillation systems: a comprehensive review.

Energy is crucial to progress toward development, modernization, and economic prosperity. Energy and water are both crucial to human survival and play significant roles in the growth and development of society. The need for desalination has risen significantly as freshwater environments have declined. Membrane distillation can be used to successfully purify highly brackish water. The high energy needs of membrane distillation processes can be handled by low-grade heat sources such as solar photovoltaic thermal. In this paper, analyzing the several types of solar thermal sources, and exploring how the membrane distillation process could be configured to optimize performance on minimizing costs. This study also considered the various applications of this technology, its potential benefits, and the challenges that needs to be overcome for it to be successful. Finally, using solar photovoltaic thermal-based membrane distillation systems, to explore the membrane distillation existing implementation, as well as the challenges and potential benefits associated with it are reviewed. In this review article, both the benefits and drawbacks of desalinating water throughout the world using solar energy are analysed and a comprehensive overview of solar desalination technologies has been developed in recent years. Also, the most significant initiatives in solar desalination, including its economic and environmental impacts are reviewed in this paper.

Rattan‐Inspired Salt‐Resistant Elevated 3D Solar Evaporators with Multi‐Scale Aligned Fluid Channels for Efficient and Continuous Seawater Desalination

AbstractEmerging solar desalination technology shows great potential in response to the growing global water crisis owing to its convenience and low environmental impact. Boosting the exposure height of solar evaporators helps enhance evaporation efficiency. However, the elevated 3D solar evaporator confronts the crucial challenges of poor salt tolerance and insufficient fluid transport height. Herein, inspired by natural rattan, a salt‐tolerant elevated 3D solar evaporator with multi‐scale long‐range aligned fluid channels is fabricated by a continuous bubble freeze casting technique. The capillary‐driven vertical transport in aligned fluid channels endows the evaporator with an elevated exposure height, which helps increase environmental energy utilization, breaking the energy conversion efficiency limitation of conventional 2D evaporators. Moreover, the aligned fluid channel helps to quickly replenish the interfacial water loss and reduce the tortuousness of salt return paths to promote salt circulation, overcoming the long‐standing challenge of salt accumulation in traditional elevated 3D solar evaporators. With rattan‐like structures employed, apparent solar‐to‐steam efficiency of 209.3%, and water evaporation rate of 3.51 ± 0.1 kg m−2 h−1 are gained for seawater desalination under 1 sun radiation without salt accumulation. The creation of rattan‐inspired solar evaporators offers important insights into the structure design of efficient and salt‐tolerant elevated 3D solar evaporators.

Exploring the role of phase change materials in low-temperature solar thermal applications: an extensive overview with challenges and opportunities.

Solar energy is widely acknowledged as a renewable and environmentally friendly energy source. Efficient storage of heat energy is a crucial challenge in solar thermal applications. Phase change materials (PCMs) have gained prominence due to their unique ability to store and release thermal energy through phase transition. The advantageous characteristic of PCMs is their low melting point, facilitating efficient heat storage and retrieval through latent heat of vaporization. This comprehensive review focuses on selecting suitable PCMs for diverse applications, considering their melting point and thermal properties. PCMs with high heat capacity and excellent solar radiation absorption are favored in solar applications, especially for systems requiring large thermal energy storage capacities. This review article underscores the importance of PCMs in low-temperature (0-120°C) solar thermal applications such as solar desalination, solar water heaters, solar cookers, solar dryers, solar air heaters, and solar chimneys, emphasizing their role in practical heat storage and release. By carefully selecting PCMs based on melting point and thermal properties, the performance and efficiency of solar thermal systems can be optimized, contributing to a greener and more sustainable future.

Multilayered CWO/MXene/PANI-Coated Thermoplastic Expanded Microsphere Sponge for Enhanced Solar Desalination Efficiency.

Interfacial solar-driven evaporation (ISDE) is a promising method for addressing the global freshwater shortage. However, it remains challenging to develop an ISDE system that combines high evaporation rates, low cost, ease of processing, and self-floatability. In this study, we present a flexible, porous sponge photothermal material based on three-dimensional thermoplastic expanded microspheres (TEMs). TEMs feature a unique hollow structure, which provides thermal insulation and minimizes heat loss. Flexible porous sponges were selected as the water transport medium in the evaporation zone, while CWO, MXene, and PANI were used as photothermal absorbing coatings on the TEMs. These three photothermal materials possess distinct absorption spectra, allowing for multilayered light absorption and enabling full-spectrum sunlight utilization. The resulting flexible multi-TEMs@PANI/MXene/CWO sponge exhibits excellent properties, including low thermal conductivity, high absorption, and efficient thermal conversion. The system achieved an evaporation rate of 2.07 kg·m-2·h-1 under primary light and a photothermal conversion efficiency of 89.7%. This work offers a controllable, environmentally friendly, and stable strategy to address the pressing issue of freshwater scarcity.