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Utilizing thermochemical reactions for thermal energy storage and solar fuel production has been an emerging research topic. Thermal transport properties of the materials are an important parameter that can determine the kinetics and efficiency of thermochemical reactions. With the increasing number of new thermochemical materials (TCMs); however, there is a lack of reliable techniques to monitor the thermal transport property of the materials and their changes as a function of reactions in real time. In this work, we report the in situ monitoring of thermochemical reactions using modulated photothermal radiometry (MPR). The thermal conductivities of two TCMs, namely, calcium hydroxide (Ca(OH)2) and Ba0.15Sr0.85FeO3−δ (BSF1585), were measured as a function of temperature and time using the MPR technique. The measured thermal conductivities were correlated to the reaction. The work has two significant contributions to the research communities. First, it provides a non-invasive diagnostic tool for monitoring the thermal transport properties of TCMs that can potentially be a high-throughput measurement technique conducive to optimizing TCMs, reactors, and related thermal systems. Second, for TCMs that show observable changes in thermal transport properties, a correlation between the measured thermal conductivity and the conversion fraction of the reaction can be established for monitoring the reaction kinetics based on thermal characterization. [ABSTRACT FROM AUTHOR]

This work reports a series of yellow-green near-infrared (NIR) reflective pigments, Ba(Mg 6-x-y Zn y Ti 6-x Cr 2x)O 19 (x = 0–1.0, y = 0–2.5), with strong NIR reflectivity for solar thermal energy regulation. Comprehensive analyses were carried out to characterize the obtained pigments including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV–Vis–NIR spectrophotometry, and CIE L*a*b* color measurement. Absorption spectra of Ba(Mg 6-x Ti 6-x Cr 2x)O 19 showed that the yellow-green absorption is attributed to the octahedrally coordinated Cr3+ with d-d electron transitions of 4A 2 (F)→4T 1 (F) and 4A 2 (F)→4T 2 (F). However, their broad absorption peak centered at 1200 nm severely deteriorated the insulating properties of the pigments. Through substituting Mg with Zn, the obtained pigment Ba(Mg 2.5 Zn 2.5 Ti 5 Cr 2)O 19 showed an excellent NIR solar reflectance (R* = 67 %) with color performances (L* = 61.98, a* = −18.72, b* = 22.23). EnergyPlus simulation results show that for a warm city (Haikou), the Ba(Mg 2.5 Zn 2.5 Ti 5 Cr 2)O 19 coating for the external surface of a model house (TSR = 35 %, R* = 55 %) can reduce annual cooling energy consumption by 8 % of the house. [ABSTRACT FROM AUTHOR]

Alloy phase change materials (PCM) are key materials in latent heat storage systems for solar thermal power generation, however, their application is limited by the high corrosion and oxidation problems of alloys. To reduce the erosion problem of alloy PCM, SiC-based ceramic encapsulated flake graphite (EG) modified Al-Cu28-Si6 alloy was used to successfully prepare composite PCM with high compatibility and oxidation resistance. Adopting static erosion test method, the composite PCM was subjected to 50 thermal cycles (25–1000 °C holding time of 10 h was recorded as 1 cycle). The results showed that SiC-based ceramics have excellent corrosion resistance to composite PCM with 10 wt% EG added, which due to the excellent reticulation and encapsulation of EG. Based on the Young-Laplace equation and the contact angle, the erosion resistance mechanism of silicon carbide ceramic alloys has been revealed. SiC-based ceramic-PCM sensible heat-latent heat composite heat storage material was expected to be used for high-temperature heat storage in solar thermal power generation. [ABSTRACT FROM AUTHOR]

Purpose: In today's world, the demand for energy to power industrial and domestic activities is increasing. To meet this need and enhance thermal transport, solar energy conservation can be tapped into via solar collector coating for thermal productivity. Hybrid nanofluids (HNFs), which combine nanoparticles with conventional heat transfer fluids, offer promising opportunities for improving the efficiency and sustainability of renewable energy systems. Thus, this paper explores fluid modeling application techniques to analyze and optimize heat transfer enhancement using HNFs. A model comprising solar energy radiation with nanoparticles of copper (Cu) and alumina oxide (Al2O3) suspended in water (H2O) over an extending material device is developed. Design/methodology/approach: The model is formulated using conservation laws to build relevant equations, which are then solved using the Galerkin numerical technique simulated via Maple software. The computational results are displayed in various graphs and tables to showcase the heat transfer mechanism in the system. Findings: The results reveal the thermal-radiation-boost heat transfer phenomenon in the system. The simulations of the theoretical fluid models can help researchers understand how HNFs facilitate heat transfer in renewable energy systems. Originality/value: The originality of this study is in exploring the heat transfer properties within renewable energy systems using HNFs under the influence of nonlinear thermal radiation. [ABSTRACT FROM AUTHOR]

Translation abstract Energy‐activated steel solutions for climate‐positive buildingsThe overall research project “Energy‐activated steel solutions for climate‐positive buildings” is developing, investigating and evaluating new solutions with a highly innovative character and considerable potential in terms of the energy transition. The aim is the further dissemination and application of steel as a material in the building sector as a contribution to the energy and heat transition and to increasing sustainability in the construction industry. In order to structure the extensive objectives of the project, the overall project was divided into four sub‐projects. In the first three sub‐projects, different topics are addressed that fall under the main theme of “Energy‐activated steel solutions for climate‐positive buildings”. These topics will be investigated, optimized and evaluated using real demonstrators. In the fourth sub‐project, the individual solutions developed for energy generation from the ground and the environment, optimization of the building envelope, technical solutions for energy storage and energy transfer to the room are brought together in a virtual building demonstrator. In this virtual environment, the components for energy generation (geothermal energy, solar thermal energy, photovoltaics) can be tested and evaluated in combination with the energy conversion and transfer components. At the end of the project, the aim is to show how the goal of a climate‐positive building can be achieved through the systematic use of steel solutions. [ABSTRACT FROM AUTHOR]

Practical Application Lemon balm (Agastache mexicana) and rosemary (Rosmarinus officinalis) were dried using a mixed‐mode solar dryer. A 23‐factorial design was carried out: operation mode (mesh shade and direct irradiance), airflow (natural convection and forced convection), and type of flat plate solar collector cover (polycarbonate and glass). The drying kinetics of lemon balm and rosemary ranged from 4.5 to 6.5 h and 4 to 7 h, respectively, according to the operation mode of the solar dryer. The highest percentage of antioxidant activity in the 2,2‐diphenyl‐1‐picrylhydrazil tests was lemon balm, with values between 88% and 93% (100 µg/mL), and rosemary, 88% and 92% (100 µg/mL). When forced convection was applied, solar collector thermal efficiency increased from 3.97%–5.11% to 17.20%–24.75%, dryer efficiencies ranged from 4.78% to 6.05%, and drying efficiencies between 14.17% and 44.23%. The lowest color difference (6.01) for lemon balm was shown with the mesh shade, forced convection, and glass cover collector, and for rosemary, the lowest color difference (12.87) resulted from using the mesh shade and natural convection; according to the analysis of variance, the cover collector did not affect significantly the color difference. Dehydrated lemon balm and rosemary could be used as an additive for medicinal, gastronomic, and food preservative applications.The results are significant for designing dryers for community centers in areas where the production and losses of fruits, vegetables, aromatic herbs, and edible flowers are high. The novelty of this research is to introduce a new product for the consumer; in this case, the traditional dried rosemary and lemon balm in powder form as a nutritional source, both for the preparation of remedies and for direct consumption in dishes, powders, or healthy pills and food supplements. [ABSTRACT FROM AUTHOR]

[Display omitted] Nanofluids-based direct absorption solar collectors are promising candidates for medium–high-temperature solar energy harvesting. However, nanofluids' complicated preparation process and undesirable high-temperature stability have hindered their practical applications. Herein, we propose a facile method for synthesizing gold/carbon quantum dots (Au-CQDs) nanofluids by directly carbonizing the base fluid and spontaneously assembling with Au nanoparticles (AuNPs) triggered by high temperatures. The results indicate that the self-assembled Au-CQDs nanofluids can maintain high stability at 110 °C for 100 h without precipitation and keep excellent photothermal conversion performance under 10 sun irradiation. The concentration and particle size of AuNPs are crucial factors affecting the self-assembly process. By modulating the microscopic morphologies of the self-assembled nanoparticles, the extinction coefficient of the prepared nanofluids is up to 88.7 % at a low loading of 30 ppm. The nanofluids can reach an equilibrium temperature of 50 °C under 1 sun irradiation, 10.4 °C higher than the base fluid due to the enhanced plasmonic effects and stability resulting from the CQDs dotted AuNPs. This work offers a new strategy to fabricate highly stable nanofluids with excellent light absorption properties for efficient solar thermal applications. [ABSTRACT FROM AUTHOR]

Among metal‐based phase change materials (PCMs), Al and its alloys have garnered significant attention due to their high latent heat and high thermal conductivity. However, challenges such as leakage, corrosion, and oxidation have limited their widespread application. Numerous researches have demonstrated that encapsulating Al and its alloy PCMs is one effective way to address these problems. This review provides a comprehensive overview of the characteristics, encapsulation strategies, and applications of Al and its alloy PCMs. First, the advantages and thermal properties of Al and its alloy PCMs are introduced, and their problems are then discussed. Subsequently, various encapsulation strategies that are expected to solve the above problems are summarized and compared. Additionally, the applications of Al and its alloy PCMs in solar thermal energy storage, catalysis, and electric vehicles are reviewed. Finally, current challenges, potential solutions, and the key direct of future study are presented. [ABSTRACT FROM AUTHOR]

Phase change material (PCM)‐based heat storage systems utilize the absorption or release of latent heat during a phase change of the storage material to store thermal energy. Nevertheless, the effectiveness of these systems is restricted by the shape and structure of their confinement, as well as the heat conductivity of the storage material. This work investigates a novel method to enhance the effectiveness of PCM systems by concurrently utilizing two techniques: the inclusion of nanoparticles and the alteration of the system's geometry. Introducing nanoparticles enhances the thermal conductivity of the storage medium while altering the shape, which improves heat transfer efficiency by adjusting the surface area available for heat exchange. RT‐35 was tested for use in latent heat thermal energy storage systems for space heating and cooling. With a melting point of 35°C, RT‐35 was chosen to moderate building temperatures by storing and releasing thermal energy for space heating and cooling. The results indicate that using nanoparticles and adjusting shape can greatly enhance the effectiveness of PCM systems. By incorporating Al2O3 nanoparticles, the melting time of the PCM was reduced by 20% compared to the pure PCM, and it is more efficient than the best case of shape modification. These findings indicate that including nanoparticles and modifying the shape are effective methods to improve the performance of heat storage devices. This technology's potential surpasses this study's limits and can be utilized in diverse applications, including solar thermal energy storage, district heating and cooling, and industrial process heat. [ABSTRACT FROM AUTHOR]

Molten salts (MSs) thermal energy storage (TES) enables dispatchable solar energy in concentrated solar power (CSP) solar tower plants. CSP plants with TES can store excess thermal energy during periods of high solar radiation and release it when sunlight is unavailable, such as during cloudy periods or at night. This capability allows these plants to provide reliable, dispatchable power, ensuring a continuous electricity supply to the grid. This paper examines the challenges and opportunities of utilizing higher‐temperature molten salt formulations to enhance power cycle efficiency. Drawing on existing literature, performance analysis of existing power plants, and novel simulation results, we project the expected technological improvements by the end of this decade. By using 15 h of TES and a higher temperature MS formulation, with heat transfer fluid hot temperatures of 700°C, and a power cycle 350 bar 700°C of efficiency 48%, the annual electricity production from a 115 MW power plant in Daggett, California is 688 GWh, the total installed cost is $684 m while the 25‐year LCOE is 6.37 c/kWh. [ABSTRACT FROM AUTHOR]

The utilization of the water–zeolite pair as an adsorbate–adsorbent system has garnered significant attention in the realm of thermochemical energy storage, offering great potential for various applications. Despite promising results in laboratory settings, widespread implementation of this technology has yet to be realized. Recent advancements in mobile thermal energy storage (m‐TES) employing thermochemical materials have opened new avenues for enhancing the practicality and cost‐effectiveness of solar thermal energy harnessing and waste heat recovery. This experimental study investigates the feasibility of storing thermal energy in zeolites, charged externally to the heat recovery reactor, and discusses the potential applications of externally charged zeolites for m‐TES over short distances, shedding light on their practicality and significance in advancing the field of mobile thermal energy storage. Our findings reveal that zeolites charged at 200°C and subsequently stored outside the discharging unit exhibit an impressive energy storage density (ESD) exceeding 110 kWhth/m3 under conditions of 0.45 m/s air velocity and 60% relative humidity during zeolite discharging. These ESD values are comparable to previously reported figures in the literature. Moreover, ESD values of 30.6 kWhth/m3 were achieved by charging zeolite beads contained within packed transportable tubes constructed from stainless‐steel mesh. [ABSTRACT FROM AUTHOR]

As the world progresses towards achieving carbon neutrality, there is an urgent need to explore renewable energy sources, such as solar and geothermal energy, for greenhouse heating. Integrating these energy sources not only reduces greenhouse gas emissions but also ensures reliable and efficient heating, which is essential for maintaining optimal growing conditions in greenhouses. This study specifically focuses on the challenges associated with ground source heat pump (GSHP) systems, which have gained widespread attention for their stability when operating under low ambient temperatures. However, a well-documented issue with GSHP systems is the thermal imbalance in the soil, where prolonged use causes the ground temperature to drop, thereby reducing the system's efficiency over time. To address this issue, this study explores the operational characteristics of coupling seasonal solar thermal energy storage (SSTES) and solar thermal energy direct heating (STEDH) with the GSHP system. These methods aim to mitigate thermal imbalance and enhance the overall performance of the heating system. An experimental platform was constructed in northern China to facilitate this investigation, consisting of a 112 m² Venlo-style glass greenhouse heated by a GSHP system integrated with solar energy. Over two heating seasons, the study conducted a series of experiments to compare the performance of the GSHP system with and without the integration of SSTES and STEDH. During the first heating season, which spanned from January 1st to March 15th, the GSHP system operated independently without SSTES. The results showed significant diurnal fluctuations in the greenhouse heat load, leading to intermittent operation of the GSHP system. This caused the soil temperature in the boreholes of the GSHP working wells to exhibit daily cyclical fluctuations, with a local temperature drop of up to 2.5 ℃ during heat extraction. The rate of soil temperature recovery was approximately 1.8 times faster than the rate of temperature decline, indicating a good daily thermal balance self-recovery capability. By the end of the heating season, a total of 16,934 kWh of heat had been extracted, with an annual heating coefficient of performance of 2.79. The soil temperature in the working wells dropped by 2.40 to 2.97 ℃ compared to the initial soil temperature, while the soil temperature in the monitoring wells within the well field decreased by 0.60 to 1.00 ℃. This temperature drop indicates that the soil thermal imbalance persisted, and even by early June, the soil had not recovered to its initial temperature, highlighting the severity of the thermal imbalance issue. In the subsequent non-heating season, from June 10th to November 7th, SSTES experiment was conducted. A total of 10,173 kWh of heat was stored in the soil, accounting for 60.1% of the total heat released during the previous heating season. The soil temperature at the monitoring points increased by approximately 0.2 ℃, demonstrating the effectiveness of SSTES in mitigating thermal imbalance. In the second heating season, from November 8th to March 15th of the following year, STEDH was coupled with the GSHP system. The results showed a 14.3% increase in the annual heating coefficient of performance, raising it to 3.19. At the same time, the rate of soil temperature decrease was slowed, indicating a reduction in thermal imbalance. In conclusion, coupling SSTES and STEDH with GSHP systems effectively addresses the issue of thermal imbalance and significantly enhances heating efficiency. Additionally, to further improve the overall efficiency of the system, it was recommended that the load-side return water temperature for the heat pump unit be maintained at 30 ℃, with the upper and lower temperature limits for SSTES set at 40 ℃ and 30 ℃, respectively. These findings provide valuable data and case studies for optimizing the design, operation, and control of greenhouse heating systems in engineering applications. This study contributes to the broader goal of sustainable energy use and carbon neutrality in the agricultural sector. [ABSTRACT FROM AUTHOR]

A photovoltaic thermal panel (PV/T) is an integrated module that harnesses both photovoltaic and solar thermal technologies to convert solar energy into electricity and heat, thereby enhancing overall energy efficiency. This paper aims to explore the suitability of PV/T solar heat pump systems across various climate zones and assess their potential for widespread application. By analyzing the operating principles of an indirect expansion PV/T solar heat pump system in conjunction with the climate characteristics of different regions, MATLAB R2019b/Simulink software was employed to evaluate the photoelectric performance of PV and PV/T systems in representative cities across five distinct climate zones in China during typical winter days. Key metrics, such as power generation, hot water storage tank temperature, indoor temperature, and system COP, were chosen to assess the heating performance of the PV/T solar heat pump system. The findings indicate that the winter ambient temperature significantly affects the photoelectric efficiency of both the PV and PV/T systems. While higher latitudes with lower ambient temperatures yield greater photoelectric efficiency, the southern regions exhibit higher power generation during winter. The winter heating effectiveness of the PV/T solar heat pump system is mainly influenced by indoor and water tank temperatures, with Harbin's system performing the poorest and failing to meet heating demands, whereas Nanjing's system shows the best results. [ABSTRACT FROM AUTHOR]

The solar radiations are absorbed in the form of heat energy by using the solar centering systems in solar collectors, this energy is then transmitted to nanofluid. This study concerns the production of entropy in a Maxwell nanofluid passed over an infinite horizontal surface. Then the non-linear stretching of the surface causes a flow in parabolic trough solar collector (PTSC). The similarity transformations are employed to transmute the system of PDEs into a system of solvable ODEs provided with the boundary conditions. Eventually, the classical Keller box scheme is applied to find the numerical solutions of transmutes ODEs. The analysis of two distinct nanofluids including copper-engine oil (Cu-EO) and zirconium dioxide-engine oil ZrO2-EO is taken into account and the results for both of them are discussed. The extracted results demonstrate a decline in Nusselt number with growing permeable media parameter and augmentation for increasing values of skin friction coefficient. A recent study is presented to provide information related to the enhancement of heat collector in the PTSC with Maxwell nanofluid. The minimal level of efficiency of Cu-EO over ZrO2-EO is 7.1% and the maximum level is up to 18.7%. [ABSTRACT FROM AUTHOR]

The world's attention is currently focused on the energy transition to sustainable energy. The drive to reduce greenhouse gas emissions in order to limit global warming, energy security, and the generalization of access to energy have contributed to the adoption of the Moroccan Energy Strategy, with a strong focus on renewable energy (RE). Morocco is notoriously poor in conventional primary fossil energy resources, with energy dependence on the order of 90%. In addition, the energy crisis that resulted from the COVID-19 pandemic and geopolitical conflicts, compounded with steady increase in demand, has heavily affected the security and stability of the country's energy situation. The transition to RE by strongly engaging in the implementation of several solar, wind, and hydro energy projects has made the country the leader in RE in Africa. These projects benefit from the country's excellent solar and wind energy potential. As a consequence, by 2030, the share of RE in the installed capacity is expected to reach 52%. An overview of the current situation of RE (particularly solar energy) in Morocco is provided, including the potentials, obstacles, challenges, and future perspectives. Thanks to its high solar potential, it is predictable that Morocco's effort will be focused on this field: the Erasmus plus INNOMED project is a virtuous example of international cooperation, aiming at promoting solar energy through capacity building and the creation of solar energy networks, in synergy with EU Partners. [ABSTRACT FROM AUTHOR]

The elite implementations of the trihybrid nanoliquid are converting solar thermal energy, photovoltaic heat collectors, and power storage. This work explores the irreversibility analysis in an upright microchannel subjected to convective ternary hybrid nanoliquid flow with quadratic thermal radiation. The consequences of the Darcy Forchheimer rule, heat source coefficient, and no slip condition on the thermal performance are studied. In the base liquid engine oil, the three distinct types of nanoparticles having different shapes including spherical (Ti), cylindrical (MgO) and platelet (Cu) configurations were considered in this scrutiny. The combined model is used to approach trihybrid and hybrid nanoliquid thermophysical properties. The governing partial differential equation is transferred into the ordinary differential equation by employing dimensionless terms. In the next step to solve the ordinary differential equations, the RKF45 numerical technique is used. The acquired upshots divulge that the improved temperature parameter strongly supports the flow profile. Thermal profile inflates with increased Darcy number. The entropy production shows dual behaviour for the escalated quadratic radiation parameter. With an enhanced darcy number of 400%, the entropy generation rises by 14% in the ternary hybrid nanoliquid circumstances and rises by 11% in the hybrid nanoliquid situation. In addition, when the combination of spherical, cylindrical, and platelet nanoparticles is considered the rate of thermal transfer is greater compared to spherical and cylindrical nanoparticle combinations. [ABSTRACT FROM AUTHOR]

The climate crisis necessitates the development of non-fossil energy sources. Harnessing solar energy for fuel production shows promise and offers the potential to utilize existing energy infrastructure. However, solar fuel production is in its early stages of development, constrained by low conversion efficiency and challenges in scaling up production. Concentrated solar energy (CSE) technology has matured alongside the rapid growth of solar thermal power plants. This review provides an overview of current CSE methods and solar fuel production, analyzes their integration compatibility, and delves into the theoretical mechanisms by which CSE impacts solar energy conversion efficiency and product selectivity in the context of photo-electrochemistry, thermochemistry, and photo-thermal co-catalysis for solar fuel production. The review also summarizes approaches to studying the photoelectric and photothermal effects of CSE. Lastly, it explores emerging novel CSE technology methods in the field of solar fuel production. [ABSTRACT FROM AUTHOR]

This research introduces a novel hybrid system integrating solar drying, solar distillation, and photovoltaic thermal panels, aimed at drying agricultural products, producing clean drinking water, and conserving energy. The system enhances the drying air temperature using thermal energy storage materials and a solar dish concentrator connected to a hot water storage tank, ensuring continuous operation even after sunset. The solar distiller, equipped with energy storage materials and an air injection system, is integrated with an external condenser to condense water vapor before expulsion, thereby increasing freshwater productivity. The results revealed that the developed system achieved an accumulative freshwater productivity of 87.1 L per day. The rates of water removal from dried potato slices ranged from 0.18 to 0.91 kg/h between 8:00 am and 10:00 pm. Additionally, the system achieved a gain output ratio of 1.38, indicating a significant improvement in energy efficiency. This innovative system offers practical solutions to address energy and freshwater scarcity, especially in remote regions of the Middle East and North Africa (MENA) region, which are characterized by high solar irradiance. The implementation of such hybrid systems could contribute to sustainable development by reducing reliance on conventional energy sources and mitigating environmental pollution. [ABSTRACT FROM AUTHOR]

Highlighting the next era of hydrogen production, this review delves into innovative techniques and the transformative power of solar thermal collectors and solar energy, addressing the global demand for sustainable and efficient hydrogen solutions. The study examines hydrogen production from both fossil fuels and renewable sources, emphasizing the technologies involved and the critical role of solar thermal collectors. It delves into various aspects such as methods used, major equipment and cycles, solar thermal collector systems, heat transfer fluids, types of feedstock, thermodynamic aspects (including energy, exergy, and solar-to-fuel efficiency), operating parameters, and cost analysis. Linear and point-focused solar thermal collectors, which achieve higher concentration ratios and outlet temperatures, are preferred for solar farms. Steam reforming remains the most economical method for hydrogen production. Water electrolysis, with efficiencies around 70–80%, and solar thermochemical water splitting, achieving up to 50% efficiency at 800–1500 °C, shows promising potential in clean hydrogen production. Biomass conversion through thermochemical processes provides practical hydrogen yields at pressures of 0.1–0.5 MPa and temperatures of 773–1173 K. Future research should focus on advancing materials and designs for solar collectors to improve hydrogen production efficiency and scalability. [Display omitted] • Hydrogen production from the solar thermal collectors were reviewed. • Steam reforming, prevalent in the chemical industries, operates effectively with methane and steam. • Thermochemical processes efficiently convert biomass into hydrogen for large-scale production. • This review reports on the limitations and challenges associated with scaling up for industrialization. [ABSTRACT FROM AUTHOR]

To achieve carbon neutrality, hydrogen and solar energy are receiving increasing attention. Concentrated solar thermal energy by parabolic trough collectors can be used to drive methanol cracking reactions for distributed hydrogen-rich syngas production. In this scenario, the collector is characterized by its small size and easy to integrate with hydrogen utilization equipment. However, parabolic trough collectors use a single-axis strategy with inherent large cosine loss, resulting in a low annual efficiency. The partially rotatable tracking is an advanced tracking strategy, which considers the trade-off between performance and cost compared to double-axis tracking strategies, and shows great potential for applications in distributed solar thermochemical reactions. In this study, solar to hydrogen-rich fuel production integrating parabolic trough collectors with the partially rotatable tracking strategy is proposed. The effect of the partially rotatable tracking strategy on the solar thermochemical conversion of methanol cracking is revealed. An annual normalized optical improvement of 40%∼54% is realized over a latitude range of 0∼50° by means of an optimal daily rotation angle. The solar thermochemical reactor with the partially rotatable tracking strategy has the less irreversibility loss during the concentrating process and the higher thermochemical efficiency. The results show that in three Chinese cities (Beijing, Lhasa and Guangzhou) with different latitudes and irradiation conditions, a partial north-south rotation strategy yields an additional 17.42%, 11.62% and 6.22% of chemical energy per year from the sun, while a partial east-west rotation strategy yields an additional 14.91%, 19.35% and 15.37% per year from the sun. The encouraging results indicate a promising method for the effective conversion of solar energy to chemical energy of hydrogen-rich fuels. • A new solar hydrogen-rich fuel production method is proposed. • The annual optical and solar thermochemical efficiencies are significantly improved. • This significant application potential in the distributed energy systems is clarified. [ABSTRACT FROM AUTHOR]

About one-third of world energy production is destined to the industrial sector, with process heat accounting for about 70% of this demand; almost half of this quota is required by endothermic processes operating at temperatures above 400 °C. Concentrated solar thermal technology, thanks to cost-effective high-temperature thermal energy storage solutions, can respond to the renewable thermal energy needs of the industrial sector, thus supporting the decarbonization of hard-to-abate processes. Particularly, parabolic trough technology using binary molten salts as heat transfer fluid and storage medium, operating up to 550 °C, could potentially supply a large part of the high-temperature process heat required by the industry. In this work, four industrial processes, representative of the Italian industrial context, that are well suited for integration with molten salt concentrators are presented and discussed, conceiving for each considered process a specific coupling solution with the solar plant, sizing the solar field and the thermal storage unit, and computing the cost of the process heat and its variation with the storage capacity. Considering cost data from the literature associated with the pre-COVID-19 era, an LCOH comprising the range 5–10 c€/kWhth was obtained for all the cases studied, while taking into account more updated cost data, the calculated LCOH varies from 7 to 13 c€/kWhth. [ABSTRACT FROM AUTHOR]

Integrating solar thermal conversion with phase change materials (PCMs) offers a promising pathway for continuous thermal energy generation with a zero‐carbon footprint. However, substantial infrared radiation losses at elevated temperatures often hinder the efficiency of such integrated systems. Inspired by the thermoregulation mechanisms of polar bears, this work introduces composite PCMs with spectrally selective absorption to enhance solar thermal energy storage efficiency. These composite phase change materials (CPCMs), featuring densely packed SiC ceramic grains with high porosity, exhibit a thermal conductivity of up to 14 W m−1 K−1 and an energy storage density of 195.1 kJ kg−1. The incorporation of nanoparticle‐coated foil induces a plasmonic effect that increases solar absorptivity to 90.57% and reduces infrared emissivity from 71.94% to 7.47%. Consequently, the solar thermal storage efficiency is significantly increased from 54.56% to 81.65% at 500 K, effectively addressing the challenges associated with high‐temperature solar thermal storage. Additionally, the low infrared emissivity of the c (PNC), combined with the inherent heat absorption properties of PCMs, enables infrared stealth functionality. These multifunctional CPCMs demonstrate considerable potential for advancing high‐temperature solar thermal storage technologies and other heat‐related applications. [ABSTRACT FROM AUTHOR]

The Inconel 718 superalloy, a precipitation-hardenable material, is of particular interest for applications involving components operating under extreme conditions due to its excellent mechanical properties, high corrosion resistance at temperatures up to 700 °C, and good workability. At high temperatures, thermal transfer processes are crucial for temperature distribution across the component's section, structural transformations, and variations in the alloy's properties. The history of accidental overheating events is critical for the microstructure and properties of the alloy. Studies on thermal transfer in the Inconel 718 alloy available in the literature typically focus on the alloy in its as-delivered state. The experimental research presented in this paper examines the influence of repeated overheating history on the thermal diffusivity of the alloy. [ABSTRACT FROM AUTHOR]

Solar thermal selective coatings (STSCs) are crucial for enhancing the thermal efficiency of receivers in solar power applications. Enhancing the photothermal conversion performance of STSCs is crucial for improving the thermo-economic efficiency of these sustainable high-temperature applications. Wherefore, in this study, we comprehensively review the ongoing technologies and enhanced strategies of solar thermal selective coatings, highlighting their advantages, drawbacks, technological advancements, and mechanisms. This review comprehensively examines the latest advancements in material synthesis, coating structure designs, and induced aging mechanisms of STSCs. It critically discusses the various types of STSCs, and the research techniques employed to assess photothermal performance and enhance thermal stability. Lastly, the limitations and future expectations of STSCs are also highlighted. This paper serves as a detailed guide for planning and implementing various types of STSCs in diverse solar power applications. [ABSTRACT FROM AUTHOR]

The mismatch between solar radiation resources and building heating demand on a seasonal scale makes cross-seasonal heat storage a crucial technology, especially for plateau areas. Utilizing phase change materials with high energy density and stable heat output effectively improves energy storage efficiency. This study integrates cascaded phase change with a cross-seasonal heat storage system aimed at achieving low-carbon heating. The simulation analyzes heat distribution and temperature changes from the heat storage system to the heating terminal. The results indicate that although the solar collectors operate for 26.3% of the total heat storage and heating period, the cumulative heat stored is 45.4% higher than the total heating load. Heat transferred by the cross-seasonal heat storage system accounts for up to 61.2% of the total heating load. Therefore, the system reduces fuel consumption by 77.6% compared to conventional fossil fuel heating systems. Moreover, radiant floor heating terminals, with a wide range of operating temperatures, match well with cascaded phase change heat storage and can reduce operation time by 19.5% and heat demand by 5.2% compared to conventional radiators. In addition to demonstrating the feasibility of applying cascaded phase change technology in cross-seasonal heat storage heating, this study reveals the lifecycle sustainability due to the shortened heat storage period. The configuration, parameters, and simulation results provide a reference basis for system application and design. [ABSTRACT FROM AUTHOR]

The high thermal storage density of phase change materials (PCMs) has attracted considerable attention in solar energy applications. However, the practicality of PCMs is often limited by the problems of leakage, poor solar‐thermal conversion capability, and low thermal conductivity, resulting in low‐efficiency solar energy storage. In this work, a new system of MXene‐integrated solid‐solid PCMs is presented as a promising solution for a solar‐thermal energy storage and electric conversion system with high efficiency and energy density. The composite system's performance is enhanced by the intrinsic photo‐thermal behavior of MXene and the heterogeneous phase transformation properties of PCM molecular chains. The optimal composites system has an impressive solar thermal energy storage efficiency of up to 94.5%, with an improved energy storage capacity of 149.5 J g−1, even at a low MXene doping level of 5 wt.%. Additionally, the composite structure shows improved thermal conductivity and high thermal cycling stability. Furthermore, a proof‐of‐concept solar‐thermal‐electric conversion device is designed based on the optimized M‐SSPCMs and commercial thermoelectric generators, which exhibit excellent energy conversion efficiency. The results of this study highlight the potential of the developed PCM composites in high‐efficiency solar energy utilization for advanced photo‐thermal systems. [ABSTRACT FROM AUTHOR]

This research examines the potential of utilizing the solar energy to produce raw beeswax from old combs and capping wax byproducts. The solar beeswax melter comprises a stainless steel tank, a lean-to structure with polycarbonate sheet covers, an electric heater, and parallel rows of PV solar panels. Three different beeswax melting methods were used. The traditional water bath method, solar thermal energy method, and solar thermal energy combined with electric energy from solar panels. The efficiency of the melting process and the bulk temperature of the melted beeswax were measured during the conventional water bath method. For the solar wax melters, the melting process efficiency, bulk temperature of the melted wax, and various macroclimatic factors such as solar radiation, temperature, and relative humidity were recorded. Based on the experimental findings, the beeswax melting efficiency was determined to be 73.4%, 85.5% and 87.2% for the traditional water bath method, solar thermal energy method, and the combined solar method, respectively. [ABSTRACT FROM AUTHOR]

Natural gas and renewable energy carriers play critical roles in the energy supply chain due to rising energy consumption demands and a significant shift toward cleaner energy. However, the requirement to liquefy and regasify liquefied natural gas (LNG) and renewable energy carriers for transportation makes the entire process expensive and challenging. Hence, a floating storage and regasification unit (FSRU) plant provides a solution to the aforementioned problems with the additional benefit of being more affordable, time‐efficient, and having less land footprint requirement than the conventional onshore facility. The proposed integrated FSRU in this study, is powered by renewable energy, including solar and ocean thermal energy. The subsystems of integrated FSRU consist of parabolic dish collectors (PDC), Rankine cycle, organic Rankine cycle (ORC), multi‐stage flashing (MSF) desalination unit, decomposition, reliquefication, and regasification plants, which provide valuable commodities such as freshwater, electricity, hydrogen, and heating. It can also cater to standard multi‐gas harboring vessels for storage and regasification of sustainable energy carriers. The study assesses the performance of the proposed system thermodynamically by analyzing mass, energy, entropy, and exergy balance equations using the engineering equation solver (EES) software. Furthermore, parametric studies were conducted to understand the interlinkage among various variables. The analytical results show that the proposed system is able to produce 1.82 MW of electricity, 2056 kg/day of fresh water, and 338.3 kg/day of hydrogen, achieving an overall system energy efficiency of 32.7% and exergy efficiency of 79.3%. This approach aims to foster energy diversification, enhance energy security, and support the transition toward sustainable energy systems, as well as further the advancement of maritime transport systems. [ABSTRACT FROM AUTHOR]

An absorption chiller is an alternative cooling system that operates using heat from renewable energy sources and employs environmentally friendly working fluids, such as ammonia–water or lithium bromide–water. Given Indonesia's high solar energy potential, solar cooling systems using absorption chillers are particularly promising. Solar thermal energy has been demonstrated to effectively power absorption chiller systems through both simulations and experiments. In Indonesia, there is significant potential to utilize small-capacity solar absorption chillers for buildings, particularly those employing air-cooled condensers and absorbers, which can reduce operational and maintenance costs. This research aimed to design a prototype of a 5 kW solar-assisted ammonia–water absorption chiller system specifically for residential applications. The system will be air-cooled to minimize space requirements compared to traditional water-cooled systems. The study addressed the design and specifications of the system's components, dimensional considerations, and an analysis of the impact of the measurement instrument on the research outcomes. The results provide precise dimensions and specifications for the system components, offering a reference for the development of more advanced systems in the future. [ABSTRACT FROM AUTHOR]

This study introduces a novel hybrid solar–biomass cogeneration power plant that efficiently produces heat, electricity, carbon dioxide, and hydrogen using concentrated solar power and syngas from cotton stalk biomass. Detailed exergy-based thermodynamic, economic, and environmental analyses demonstrate that the optimized system achieves an exergy efficiency of 48.67% and an exergoeconomic factor of 80.65% and produces 51.5 MW of electricity, 23.3 MW of heat, and 8334.4 kg/h of hydrogen from 87,156.4 kg/h of biomass. The study explores four scenarios for green hydrogen production pathways, including chemical looping reforming and supercritical water gasification, highlighting significant improvements in levelized costs and the environmental impact compared with other solar-based hybrid systems. Systems 2 and 3 exhibit superior performance, with levelized costs of electricity (LCOE) of 49.2 USD/MWh and 55.4 USD/MWh and levelized costs of hydrogen (LCOH) of between 10.7 and 19.5 USD/MWh. The exergoenvironmental impact factor ranges from 66.2% to 73.9%, with an environmental impact rate of 5.4–7.1 Pts/MWh. Despite high irreversibility challenges, the integration of solar energy significantly enhances the system's exergoeconomic and exergoenvironmental performance, making it a promising alternative as fossil fuel reserves decline. To improve competitiveness, addressing process efficiency and cost reduction in solar concentrators and receivers is crucial. [ABSTRACT FROM AUTHOR]

Water scarcity is a serious threat to the survival and development of mankind. Interfacial solar steam generation (ISSG) can alleviate the global freshwater shortage by converting sustainable solar power into thermal energy for desalination. ISSG possesses many advantages such as high photothermal efficiency, robust durability, and environmental friendliness. However, conventional evaporators suffered from huge heat losses in the evaporation process due to the lack of efficient thermal management. Herein, hydrophilic Tencel yarn is applied to fabricate a three-dimensional double-layer fabric evaporator (DLE) with efficient multi-stage thermal management. DLE enables multiple solar absorptions, promotes cold evaporation, and optimizes thermal management. The airflow was utilized after structure engineering for enhanced energy evaporation efficiency. The evaporation rate can reach 2.86 kg·m−2·h−1 under 1 sun (1 kW·m−2), and 6.26 kg·m−2·h−1 at a wind speed of 3 m·s−1. After a long duration of outdoor operation, the average daily evaporation rate remains stable at over 8.9 kg·m−2, and the removal rate of metal ions in seawater reaches 99%. Overall, DLE with efficient and durable three-dimensional multi-stage thermal management exhibits excellent practicality for solar desalination. [ABSTRACT FROM AUTHOR]

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This study employs numerical and statistical approaches to investigate the entropy optimization of steady Casson nanofluid flow over three different geometries subject to boundary conditions induced by convective flow. Multiple linear regression is employed to statistically examine. The present model incorporates several novel elements, such as Arrhenius activation energy, Brownian motion, the Cattaneo-Christov dual flux, thermophoresis, thermal radiation, and so on. Moreover, a comparison is presented between Newtonian and non-Newtonian fluids. By applying the proper similarity transformations, ordinary differential equations (ODEs) are ob- tained by converting foundational partial differential equations (PDEs). The Runge-Kutta fourth- order method is utilised to solve the obtained ODEs along with the shooting technique. The out- comes are visually depicted via tables and graphs. The velocity drops with increasing Grashof number, and the magnetic field becomes progressively more forceful as the suction parameter in- creases. The temperature gets reduced with the increase of the suction parameter, solute Grashof number increases with the magnetic field, thermophoresis, and radiation parameters. The entropy is observed to rise with the increase of the effective parameters (magnetic field, Brinkmann num- ber and radiation). The MAD (mean absolute deviation), MSE (mean squared error), and RMSE (root mean square error) values are approaching zero, indicating that the derived outcomes are highly accurate. A lower MAPE (mean absolute percentage error) suggests that the model has a higher level of precision. Therefore, the outcomes of the present model are more precise and eliable. This study has various potential applications such as power plant heat exchangers, ma- terial processing industries, and solar thermal energy systems. [ABSTRACT FROM AUTHOR]

A thermal efficiency analysis of an organic Rankine cycle (ORC) system enables its performance to be evaluated; for this purpose, critical system components, including the turbine and the boiler, must be scrutinized. ORC plants can operate under various regimes, such as simple, regeneration, and reheat work modes. Organic fluids such as R-245fa integrate low-temperature sources such as solar radiation. However, a literature review revealed limited research on the impact of a solar collection system on the overall thermal efficiency of an ORC system during the regeneration stage. In this study, we examined the thermal efficiency behavior of an ORC plant with a 1 kW generator operating in simple and regeneration modes with a solar collection stage. The results show that the thermal efficiency in simple mode was 35.27%, while in regeneration mode with solar collection it reached 51.30%. Improving the thermal efficiency of a thermodynamic cycle system can reduce CO2 emissions. The operating temperature ranges facilitate the development of a methodology for industries to implement ORC systems in their manufacturing processes, thereby utilizing waste heat from industrial operations. [ABSTRACT FROM AUTHOR]

This paper examines the viability of introducing solar thermal desalination technology as a means to supplement existing water production methods in the Republic of South Africa (RSA). The study provides an overview of the current state of desalination technology in the country. A key aspect of this study involves comparing the RSA with the Middle East and North Africa (MENA) region, using publicly available studies and reports. The focus of this comparison is to highlight the potential implementation of large-scale solar desalination in the RSA by evaluating the respective resources and environmental data that directly impact the input and output of a thermal desalination system. The study comparatively analyzes the environmental conditions and seawater salinity of the RSA and the MENA region. The RSA receives a higher solar irradiation range of 4.5–6.5 kWh/m2, whereas the MENA region experiences a range of 3.5–5.5 kWh/m2. Additionally, the salinity of the RSA's seawater ranges between 35 and 35.5 parts per thousand, which is lower than the MENA region's range of 36–40 parts per thousand. The study also reviews and proposes the adoption of an emerging thermal desalination method that has been successfully tested in the MENA region and other countries, based on its performance. [ABSTRACT FROM AUTHOR]

Interfacial solar water evaporation has emerged as an effective technique for converting solar energy to thermal energy, which can then be applied to clean water production and sewage treatment. This review discusses the primary characterization techniques used to evaluate the key aspects of interfacial solar water evaporators: the intrinsic and performance evaluation. Each technique is discussed with a brief explanation of its foundations, followed by carefully selected examples. This review is aimed at assisting materials chemists and physicists, particularly students, in choosing the most appropriate techniques for characterizing photothermal materials. [ABSTRACT FROM AUTHOR]

The conversion of solar‐thermal (ST) power into electrical power along with its efficient storage represents a crucial and effective approach to address the energy crisis. The thermoelectric (TE) generator can absorb ST power and transform it into electrical energy, making it a highly viable technology to achieve photo‐thermal conversion (PTC). However, the practical application of the pristine TE generator devices on a larger scale is still facing several challenges. On the one hand, the pristine TE generator device has low inherent PTC efficiency, thereby leading to low power conversion. On the other hand, such solar‐thermoelectric (STE) conversion does not provide the functionality of electric energy storage. Herein, an effective strategy has been proposed that employs a CoAl2O4 PTC coating to decorate the pristine TE generator for developing the STE generator device with the remarkable STE performance and then coupling this device with a supercapacitor (SC) for effective storage power. In comparison to the pristine TE generator, the developed STE device exhibited considerable enhancement in both the open‐circuit voltage (Voc) and its maximum power density, displaying more than a 4‐ and 15‐fold improvement, respectively. In addition, the feasibility of coupling this solar‐driven STE generator device in series with a SC for ST conversion and storage was verified, and the working mechanism has been elucidated. This work presents a promising approach to effectively convert and store clean solar power into electrical energy, enabling practical applications of STE generator devices in conjunction with other electrochemical energy storage devices. [ABSTRACT FROM AUTHOR]

Amidst the growing challenges of water and energy scarcity, the following research presents an innovative solar desalination system that integrates predictive models with advanced thermal energy storage (TES) to optimize freshwater production. The system adjusts feed water flow dynamically, ensuring consistent and continuous top feed water temperature (TBT). Comprehensive mathematical modeling and simulations reveal significant enhancements in system performance, with an optimized TES tank volume of 500 m3 and a solar collector area of 4245 m2. The economic analysis indicates the system is cost-effective, with a production cost of approximately USD 5.86 million, competitive with conventional methods. Additionally, the system achieved an average daily feed water flow rate of 10 kg/s, ensuring stable operation even under fluctuating solar radiation. The system also achieved a global warming potential (GWP) of 2.24 kg CO2-eq per cubic meter, a favorable and environmentally sustainable measure. This study stresses the potential for scalable, sustainable desalination solutions to enhance water security in arid and remote regions. [ABSTRACT FROM AUTHOR]

This paper is devoted to improve the design solution of combined thermo-photovoltaic systems which works in concentrated solar radiation. The main problem is ensuring the efficient heat removing from the photoreceiving surface of such systems and transferring this heat energy to liquid heat carrier. In case of using concentrated solar radiation with high density of energy onto the photoreceiving surface the problem of intensifying the heat exchange processes is critical for ensuring the efficient and long-term work of combined thermo-photovoltaic systems. Based on the analysis of thermal processes, the design of a heat exchange unit for a combined photovoltaic plant is proposed. The main design feature of proposed solution is microchannels made on the back plate of photoreceiving surface. It is shown that this design creates a transient regime of coolant flow, which allows efficient cooling of solar cells under conditions of concentrated solar radiation and potentially will allow to receive record values of heat exchange coefficient between the coolant and the upper plate of the radiator. An analysis technique using criterial hydrodynamic equations and numerical modeling were used; the results obtained in both cases are in good agreement. The efficiency, thermal and electrical characteristics of a combined photovoltaic system with solar radiation concentration have been assessed. Preliminary estimations have been made for the specific parameters of installed energy characteristics of a heat-electric power plant, which under AM1 conditions and 400 times the concentration of solar radiation for solar cells with an efficiency of 30 % have the following values: electrical power 650 W, thermal power 2370 W, total installed net power 3020 W, overall efficiency 87 % which are significantly higher than parameters achieved for existing solar power plants. [ABSTRACT FROM AUTHOR]

Abstract The mismatch between solar radiation resources and building heating demand on a seasonal scale makes cross-seasonal heat storage a crucial technology, especially for plateau areas. Utilizing phase change materials with high energy density and stable heat output effectively improves energy storage efficiency. This study integrates cascaded phase change with a cross-seasonal heat storage system aimed at achieving low-carbon heating. The simulation analyzes heat distribution and temperature changes from the heat storage system to the heating terminal. The results indicate that although the solar collectors operate for 26.3% of the total heat storage and heating period, the cumulative heat stored is 45.4% higher than the total heating load. Heat transferred by the cross-seasonal heat storage system accounts for up to 61.2% of the total heating load. Therefore, the system reduces fuel consumption by 77.6% compared to conventional fossil fuel heating systems. Moreover, radiant floor heating terminals, with a wide range of operating temperatures, match well with cascaded phase change heat storage and can reduce operation time by 19.5% and heat demand by 5.2% compared to conventional radiators. In addition to demonstrating the feasibility of applying cascaded phase change technology in cross-seasonal heat storage heating, this study reveals the lifecycle sustainability due to the shortened heat storage period. The configuration, parameters, and simulation results provide a reference basis for system application and design.

The transition to renewable energy sources comes along with the search for new energy storage solutions. Molecular solar thermal systems directly harvest and store solar energy in a chemical manner. By a suitable molecular design, a higher overall efficiency can be achieved. In this study, we investigate the surface chemistry of oxa-norbornadiene/quadricyclane derivatives on a Pt(111) surface. Specifically, we focus on the energy storage and release properties of molecules that are substituted with ester moieties of different sizes. For our model catalytic approach, synchrotron radiation-based x-ray photoelectron spectroscopy measurements were conducted in ultra-high vacuum (UHV) and correlated with the catalytic behavior in the liquid phase monitored by photochemical infrared reflection absorption spectroscopy. The differences in their spectral appearance enabled us to unambiguously differentiate the energy-lean and energy-rich isomers and decomposition products. Next to qualitative information on the adsorption motifs, temperature-programmed experiments allowed for the observation of thermally induced reactions and the deduction of the related reaction pathways. We analyzed the selectivity of the cycloreversion reaction from the energy-rich quadricyclane derivative to its energy-lean norbornadiene isomer and competing processes, such as desorption and decomposition. For the 2,3-bis(methylester)-substitution, the cycloreversion reaction was found to occur between 310 and 340 K, while the thermal stability limit of the compounds was determined to be 380 K. The larger 2,3-bis(benzylester) derivatives have a lower apparent adsorption energy and a decomposition onset already at 135 K. In the liquid phase (in acetonitrile), we determined the rate constants for the cycloreversion reaction on Pt(111) to k = 5.3 × 10−4 s−1 for the 2,3-bis(methylester)-substitution and k = 6.3 × 10−4 s−1 for the 2,3-bis(benzylester) derivative. The selectivities were of >99% and 98% for the two molecules, respectively. The difference in the catalytic behavior of Pt(111) for both derivatives is less pronounced in the liquid phase than in UHV, which we attribute to the passivation of the Pt(111) surface by carbonaceous species under ambient conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] The scarcity of freshwater resources and increasing demand for drinking water have driven the development of durable and sustainable desalination technologies. Although MXene composites have shown promise due to their excellent photothermal conversion and high thermal conductivity, their high hydrophilicity often leads to salt precipitation and low durability. In this study, we present a novel Cellulose (CF)/MXene paper with a Janus hydrophobic/hydrophilic configuration for long-term and efficient solar-driven desalination. The paper features a dual-layer structure, with the upper hydrophobic layer composed of CF/MXene paper exhibiting convexness to serve as a photothermal layer with exceptional salt rejection properties. Simultaneously, the bottom porous layer made of CF acts as an efficient thermal insulation. This unique design effectively minimizes heat loss and facilitates efficient water transportation. The Janus CF/MXene paper demonstrates a high evaporation rate of 1.11 kg m−2h−1 and solar thermal conversion efficiency of 82.52 % under 1 sun irradiation. Importantly, even after 2500 h of operation in a simulated seawater environment, the paper maintains a stable evaporation rate without significant salt deposition and biodegradation due to an antibacterial rate exceeding 90 %. These findings highlight the potential of the Janus CF/MXene paper for scalable manufacturing and practical applications in solar-driven desalination. [ABSTRACT FROM AUTHOR]

The focus of this study is to investigate the energy performance of a direct-expansion solar-assisted heat pump water heating system (DX-SAHPWH). The system consists of an unglazed solar collector-evaporator, which can absorb heat from solar energy and air ambient simultaneously, a condenser in the form of a coil immersed in a hot water storage tank, a thermostatic expansion valve and a hermetic reciprocating compressor. The performance of the heat pump system is evaluated using a developed mathematical model under Matlab code. The modelling method is based on lumped and distributed parameter approach of different system components. Numerical calculations were carried-out to study the influence of different parameters, such as ambient temperature, solar radiation intensity and polytropic index on the system performance. Additionally, in order to evaluate the long-term system performance, the system’s model was applied on a case study of a single-family building located in Djelfa (Algeria), which represents the coldest arid region of the country. The results showed that the solar radiation intensity and ambient temperature have significant effects on the heat pump performance. A COP of 5.9 and a collector-evaporator efficiency of 1.9 were obtained at high solar radiation of 850 W/m2 resulting in lower heating time (29 min). In addition, results revealed that the system can operate even at lower ambient temperature due to its ability to take advantage of heat from the ambient air. The results from the case study gave a COP ranging from 2.3 to 3.8, which enhance the promising adoption of this system in domestic hot water production to respond to people daily life needs with clean, abundant and renewable energy.

This study focused on the development and characterization of multi-layered nickel coatings doped with WS2 nanoparticles and electrodeposited on copper substrates. To enhance the solar collector's performance by improving the solar radiation conversion into heat, two distinct undercoatings were evaluated, along with the incorporation of WS2 nanoparticles in the black nickel layer. X-ray diffraction (XRD) analysis revealed that the bright and dull nickel undercoatings consisted of metallic nickel, whereas the black coatings comprised amorphous nickel oxide, inferred to be Ni2O3 based on energy-dispersive X-ray spectroscopy (EDS) analysis. Scanning electron microscopy (SEM) analysis of the undercoatings and black nickel morphology showed a compact surface with a relatively homogenous microstructure composed of polyhedric grains, which was free of visible cracks or pinholes. The undercoating influenced the brightness, the reflectivity and the reflectance of the black nickel films, with the dull undercoated sample showing the most promising results, with a total absorbance of 0.94. The incorporation of WS2 nanoparticles induced the formation of cracks and increased the porosity of the black nickel film. With an appropriate content of WS2 nanoparticles and the use of a dull undercoat, these drawbacks can be avoided. Concerning the integration of WS2 nanoparticles, a minor decrease in the brightness of the black films and a subsequent increase in the total absorbance ultimately led to an enhancement of the conversion of solar energy into thermal energy. [ABSTRACT FROM AUTHOR]

In this study, tubes filled with PCM as a thermal energy storage unit with an indirect air heater are used to store and recover solar thermal energy. Two different configurations of PCM-filled tubes (inline and staggered) in the unit are considered and compared with the PCM-filled plate unit. In all cases, the amount of the PCM is the same. The effects of airflow rate, diameter of tubes and inlet temperature on the charging and discharging rates are studied. Results showed that the PCM tube unit is more efficient than the PCM plate unit. The thermal performance is enhanced with the increase of the air mass flow rate. Results also revealed that the phase change rate in staggered configurations is between 7% and 36% (depending on the airflow rate) greater than that in the inline ones. By reducing the tube diameter, the melting and solidification processes are performed more quickly due to the rise of the overall heat transfer surface area. The influence of the temperature difference between the inlet air and PCM is more effective than the other considered effects where the 10 °C increase of the temperature difference enhances the charging rate by a factor of 2. [ABSTRACT FROM AUTHOR]

Solar thermal energy-based electricity is capital-intensive, and complex while technically evolving to achieve an optimal design. Global commitments and timelines to increase renewable energy share in the grid have promoted technically mature solar photovoltaics and wind. However, the potential of solar thermal energy for industrial applications, cogeneration and polygeneration is on the back foot for lack of policy, complexity, technical readiness level, cost of components and workable business models. Solar collectors that can generate high-quality steam for power generation is complex and costly; while, modified version of linear Fresnel reflector's (LFR) are prospective for various requirements. The current work looks into the possibility of an LFR and heliostat combination to generate steam at 45 bar, 400C temperature to produce electricity. The levelized cost of electricity (LCOE) and levelized cost of water (LCOW) is found to be INR 5.11 kWh−1 and INR 43.03 m−3, in a 70:30 debt–equity scenario. An IRR of 8.55% is achieved with a payback of 12.5 years, with the sale of electricity at INR 10.11 kWh−1 and water at INR 45 m−3. To reduce the LCOE, LCOW and have an attractive IRR, the viability gap funding (VGF) as an option is tried out. The impact of VGF at, 0%, 10%, 20% and 30% on water generation, electricity generation, IRR, NPV and payback are found. It is found that as the VGF increase, there is a better generation cost for electricity and water, with an improved IRR. However, with the VGF trend and corresponding reduction in electricity and water production cost, it will be ideal to have the VGF close to 15% to keep the electricity sale price at approximately INR 8.5 kWh−1 and water pricing at INR 46 m−3. [ABSTRACT FROM AUTHOR]

The need for water can be seen in many aspects of our daily lives. It is used for drinking, washing, cooking, and cleaning. Water is an essential and invaluable resource that maintains an unceasing demand, warranting prudent conservation efforts. In the present experimental investigation, sensible heat energy storage and nano-enhanced latent heat energy storage are utilized in the SSS to augment thermal performance. Doping commercial paraffin wax with 50-nm zirconium oxide nanoparticles improves heat stability and thermal characteristics. The thermophysical properties of the ZrO2 nanoparticle-doped paraffin wax is examined, and it is found that the thermal conductivity of the nano-enhanced paraffin wax with a maximum concentration of 0.5% by mass is enhanced by about 54.83% while compared to paraffin wax. Waste soda cans can store latent heat thermal energy with nano-enhanced PCM. Rubber and nano-enhanced latent heat thermal energy storage improve heat transfer and thermal performance in the SSS basin. Results showed that the SSS without any thermal energy storage produced a cumulative yield of 2.76 kg m− 2, whereas the SS with modified nano-enhanced PCM and sensible heat as rubber sheet produced a maximum of 5.02 kg m− 2. Similarly, the combined effect of nano-enhanced PCM and sensible heat energy storage augmented the SS performance by about 19.3 and 45.01% than the SS with nano-enhanced PCM and without any thermal energy storage, respectively. Before undergoing desalination, the initial water quality parameters of pH, TDS, and electrical conductivity were determined as 8.2, 2654 ppm, and 1.12 dS cm− 1, respectively. After completion of the desalination process, these values were notably lowered to 7.2, 552 ppm, and 0.12 dS cm− 1, respectively. Importantly, the results of the water quality analysis adhere to the drinking water standards outlined by the WHO guidelines. [ABSTRACT FROM AUTHOR]