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AbstractAmong the four available concentrating solar-thermal (CST) power systems, parabolic dish systems show great potential as the preferred technology for renewable electricity generation. Nonetheless, the weight of the support structure poses a major hurdle to its development. As of present, solar dishes utilize steel structures to hold the reflective panels which amount to a lot of weight, necessitating large and expensive drive units and increases energy consumption. Hence, for the dishes to advance and further become economically feasible in the near future, the structures found need to be replaced with cost-effective materials that not only diminish the weight but still maintain the structural integrity found with the steel. Hence, this investigation embodies the first effort in literature to explore the viability of utilizing honeycomb sandwich composites as a lightweight and robust support structure for solar dishes, with the ability to cope with the aerodynamic loads imposed upon them during operation. Through combined fluid-structure interaction (FSI) and ray tracing analysis, the wind-induced structural behavior and optical performance of the sandwich composite-based paraboloidal solar dish were investigated under various loading scenarios at various azimuth and elevation angles. Under dissimilar operational conditions, the proposed system exhibited varying behavior characteristics, with the worst conditions being assessed according to relevant material failure and optical standards. With the worst operational condition taking place at 0° azimuth and 30° elevation, the detailed FSI-ray tracing analysis demonstrated that the dish managed to satisfy the set specifications, highlighting the potential and effectiveness of using honeycomb sandwich composites as a support structure for parabolic dish systems. [ABSTRACT FROM AUTHOR]

The performance of solar thermal power systems using cavity receivers and parabolic dishes highly depends on the effective absorption of concentrated solar radiation by cavity receivers. Correct measurement of convection losses is challenging due to non-isothermal surface temperatures and unpredictable flow conditions inside the cavity. Correct prediction of radiation losses can help to predict convection losses. Effect of increasing the area ratio of normal cavity using cylinder in cylinder arrangement to increase the surface area for heat transfer, is studied experimentally. The specially designed heaters for model cavity size using nichrome wires sheathed between ceramic sheets were used to apply the thermal load, and the heat transfer rate was observed. Experimental temperatures were used for calculating the radiation heat losses using radiosity network method. Modified cavity surface is divided in parts and radiosity values for each part is calculated by solving simultaneous equation obtained by network method, using Gauss-Seidel method. Finally, the radiation heat loss from each surface is added to get total radiation heat loss. More heat transfer area for cylinder in cylinder arrangement and with the same heat input modified cavity shows higher surface temperatures. Network representation provides a better understanding of radiative interaction between different parts of the cavity. Radiosity network method predicts more accurate results than mean radiation heat loss calculations by calculating actual radiosity values for different parts of cavity. The difference in prediction is high at lower temperatures, emissivity and reduces with increasing temperature and emissivity. Effect of inner cylinder surface temperature was studied with three different cases and found that the radiation heat losses are less affected by inner cylinder surface temperatures. Effect of aspect ratio on radiation heat losses is presented in this work. Experimental results show that proposed cavity receiver design provide double surface area for heat transfer with increased surface temperatures for same heat input and total heat loss. [ABSTRACT FROM AUTHOR]

An autoclave is a device for sterilizing medical and surgical tools in hospitals and healthcare centers. The lack of electric power supply in some hospitals and rural health centers, in addition to pollution caused by fossil fuels, reinforces the need to search for other energy sources to operate the autoclave. Solar autoclaves can be utilized as an alternative choice in such circumstances. This work describes the effectiveness of the solar-powered autoclave, which is used for wet sterilization. The device is designed from a parabolic dish reflector covered with mirrors that reflect solar radiation toward the center of a focus for heating a vessel. It was found that the highest value of the average energy efficiency was 19 % and the average exergy efficiency was 2 % at 9:00 am and the lowest value of the average energy efficiency was 1.5% and the average exergy efficiency was 0.4 % at 12:00 noon. The effectiveness was tested against (pseudomonas aeruginosa) bacteria, where the highest values of steam temperatures for sterilization were recorded between 121 °C to 122 °C. It was also found that the sterilization efficiency was 100 % under steam pressure of 1.18 bar for every 30 minutes of the sterilization cycle for the periods 11:00 am to 11:30 am, 11:30 am to 12:00 noon, and 12:00 noon to 12:30 pm). [ABSTRACT FROM AUTHOR]

An innovative parabolic sound reflector has been developed using a combination of hot-melt adhesive material, cotton, and plastic reinforcement, along with an aluminium coating. This reflector is designed for effective long-range sound capture both indoors and outdoors. The system is particularly well-suited for moderate to large-sized auditoriums and is especially beneficial for scenarios like video conferencing. Compared to traditional individual-microphone sound systems, a limited number of these parabolic microphone-based setups are significantly more cost-effective. Experimental testing reveals that the proposed sound reflector can lead to a substantial enhancement of up to 20–30 dB in the captured sound pressure level when recording sound from approximately 10 feet away. This improvement is observed across the sound wave frequency range of 100 Hz to 20 KHz. In addition to indoor applications, this economical parabolic microphone system is excellently suited for outdoor field recording tasks, such as high-quality long-range wildlife sound capture. [ABSTRACT FROM AUTHOR]

This study uses solar energy to convert steam from a saturated to a superheated state using a solar steam superheater system. This collector system comprised a parabolic dish with a cylindrical cavity. The parabolic dish is of 2 m diameter and 0.83 m focal distance, covered with a reflective surface made of 1,283 rectangular pieces of mirrors, each of 3.5 cm × 4 cm that were fixed in place with glue type (FnTai). The receiver is a stainless-steel cylindrical cavity having a diameter of 17 cm and a length of 25 cm. A helical copper coil with a diameter of 10 mm and a length of 6 m was inserted inside the cylindrical cavity. The experimental work utilized saturated steam produced separately from an auxiliary electric boiler system, which was made along with other system components. A 0.011 kg/s of saturated steam at a temperature of 112°C enters the copper coil and is heated by the solar radiation reflected by the parabolic dish onto the receiver. As a result, the temperature of the steam is increased to 169.5°C at the receiver outlet. It was found that the collector efficiency is 55.6%. In addition, the convection and radiation heat losses are 12.14 and 10.98%, respectively. Also, the heat losses of (spillage, reflection, and conduction) were estimated to be 21.18%. The mass flow rate and pressure of the saturated steam from the boiler and entering the receiver affected the superheated steam production process. The process of superheating the steam, coupled with the subsequent improvement in thermal performance, indicates an increased efficiency of the collector. This is achieved by boosting the generation of useful heat and mitigating heat losses.

The goal of this study is to optimize and examine the effect of different rim angles and focus lengths on the performance of a solar parabolic dish. To achieve these goals, a solar parabolic dish concentrator was constructed with different focus point positions and tested under the climatic conditions of the Upper Egypt region in Qena city, with the location of (Latitude: 26.16°, Longitude: 32.71°). The preliminary experimental days started on 18th and lasted on 20th of September 2022, and the tested rim angles were 70°, 80°, and 60°. The results showed that the performance of the proposed solar parabolic dish concentrator was enhanced when the rim angle was between 60° and 70°, otherwise, the performance was regressed when the rim angle was between 70° and 80°. To optimize the rim angle, another available rim angle was selected to increase the performance of the solar dish fixed at 65°, and this angle was tested on 21st of September 2022. The results demonstrated that the thermal efficiency of the solar parabolic dish with rim angle of 65° was higher than that of 70°, 80°, and 60°, and the recorded thermal efficiency reached up to 79.5%, 39.4%, 5.84%, and 28.4%, respectively, under the tested rim angles. [ABSTRACT FROM AUTHOR]

This paper describes the design of a 5.5:1 bandwidth feed antenna and reflector system, intended for use in hydrogen intensity mapping experiments. The system is optimized to reduce systematic effects that can arise in these experiments from scattering within the feed/reflector and cross-coupling between antennas. The proposed feed is an ultra-wideband Vivaldi style design and was optimized to have a smooth frequency response, high gain, and minimal shadowing of the reflector dish. This feed can optionally include absorptive elements which reduce systematics but degrade sensitivity. The proposed reflector is a deep parabolic dish with f / d = 0. 2 1 6 along with an elliptical collar to provide additional shielding. The procedure for optimizing these design choices is described. [ABSTRACT FROM AUTHOR]

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A solar-powered autoclave, made of a parabolic dish reflector that collects solar radiation at the focal point to heat a vessel, was established and tested. Thermal performance was tested and compared between months June and December 2022 through thermal energy efficiency equations and the total required thermal energy to evaporate water and the required thermal energy, where the highest values in June 2022 were 9%, 46 W, and 18 W, respectively at 9:00 am. Because solar radiation values are low, the energy required for heating is high and the lowest values were 0.2%, 1.9 W, and 0.5 W, respectively at 12:30 pm Because solar radiation values are high, the energy required for heating is less. While the highest values on December 2022 were 22%, 23 W, and 14 W, respectively, at 9:00 am, the lowest values were 0.6%, 1.16 W, and 6.6 W, respectively. At 12:00 pm, the values of December are considered higher for several reasons, including the values of solar radiation and the ambient temperature are lower than those of June, as well as the difference in the angle of incidence of solar radiation, so the thermal energy required for heating is higher. The effectiveness was tested against pseudomonas aeruginosa bacteria and samples of surgical kits made of stainless steel, where the highest values of steam temperatures for sterilization were recorded between 122 °C to 132 °C. Under a steam pressure of 1.3 to 1.9 bar between 11:00 am to 3:00 pm, one sterilization cycle took 30 minutes in June 2022, and for the month December 2022 the highest values of steam temperatures for sterilization were between 101 °C to 117 °C. Under steam pressure 0.7 to 1.03 bar between the hours 10:30 am to 12:30 pm, where the sterilization cycle was between 40 to 60 minutes, as a result of the decrease in solar radiation.

Environmental degradation, harmful emissions, and an increase in the prices of fuel and electricity are driving factors for the need of renewable energy sources such as solar energy which is an abundant and viable renewable resource. In this study, a Parabolic Dish Solar Collector (PDSC) is fabricated and used with high heat transfer 'nanofluids' for cooking application. The nanofluids comprise of Al2O3 and ZnO nanoparticles which are synthesized by the sol–gel and conventional precipitation methods, respectively. The results indicate that the collector efficiency with 1% volume fraction of Al2O3 and ZnO nanoparticles is 69.13% and 65.5% respectively. Whereas the collector efficiency with 2% volume fraction of the nanoparticles is 71.63% and 67.99% respectively. The collector outlet temperature for 1% volume fraction of Al2O3 and ZnO nanoparticles in the nanofluid is 183 and 176 °C, respectively. Likewise the outlet temperature for 2% volume fraction of Al2O3 and ZnO nanoparticles in the nanofluid is 185 and 181 °C, respectively. MgCl2·6H2O is used as thermal energy storage material. During charging process the time, sensible energy, latent energy and total energy stored are 125 min, 1.92 MJ, 1.436 MJ and 3.35 MJ, whereas during the discharging process, these are 161 min, 1.57, 1.35 and 2.92 MJ, respectively. The nanofluids with Al2O3 nanoparticles show better heat transfer characteristics compared to ZnO based nanofluid. The maximum value of the first figure of merit (F1) is 0.31 K m2/W. The second figure of merit (F2) for the cooker evaluated from the water boiling test is 0.42 K m2/W s [ABSTRACT FROM AUTHOR]

Most of the household relies on an LPG cooking stove for meal preparation, with approximately 20 crore families across India consuming 1.5 lakh crores of LPG annually. Due to their dependency on open areas, present solar cookers are useless at night and morning, restricting usage to the afternoon despite sufficient solar radiation for 9–10 months. Phase-change materials and expensive thermal energy storage (TES) devices are needed for conventional solar thermal power facilities. An economical TES system using parabolic sun dish collectors is needed to decrease LPG import costs and pollution. In response, this project aims to design a solar parabolic dish collector coupled with a TES system, utilizing specially engineered carbon bricks to enhance heat storage and retrieval capacities while reducing initial costs. Employing ANSYS-CFX software, the TES system undergoes thorough examination. Computational fluid dynamics analysis is conducted to evaluate heat transfer coefficients for both the hot fluid, responsible for heating the bricks, and the cold fluid, which cools them. The results reveal heat transfer coefficients ranging from 15 to 20 W/m2 K for the hot fluid and 25 to 40 W/m2 K for the cold fluid, with the latter demonstrating higher coefficients attributed to air's higher density compared to the hot fluid's lower density. Overall, the TES system exhibits an estimated heat transfer coefficient of 20–25 W/m2 K, facilitating efficient heating and recovery of heat. [ABSTRACT FROM AUTHOR]

Solar cookersare not all-weather cooking devices and operate poorly during cloudy and low sunshine conditions. Their performance is evaluated usually during high solar radiation conditions. The objective of this study is to compare two solar cookers under variable non-ideal weather conditions. The comparison is carried out under variable solar radiation conditions to compare the all-weather performance of these two cookers. This is a major novelty compared to previous work reported where solar cookers are tested under high and ideal solar radiation conditions. Experiments to compare a PV DC battery-powered solar cooker and a parabolic dish solar cooker are presented in this paper. A total of six water heating tests are carried out to comprehensively compare these two types of solar cookers under different solar radiation conditions. Also, four food cooking tests are carried out with different types of food. The PV solar cooker shows almost constant input electrical power in the range of 160–180 W during the experimental tests whereas the input thermal power for the parabolic dish is highly variable depending on the solar radiation conditions (200–1200 W). The output water heating powers obtained using the PV cooker (66–100 W) are comparable to those obtained with parabolic dish solar cookers (78–142 W), regardless of the significantly lower input heating power. Water is boiled in all the heating tests with the PV cooker, whereas water is boiled for tests with low solar radiation variability for the parabolic dish solar cooker. Higher water heating efficiencies within a small range (0.38–0.57) are obtained for the PV cooker compared to the parabolic dish solar cooker (0.11–0.42). The water heating efficiency of the parabolic dish solar cooker is highly affected by ambient solar radiation and windspeed conditions. Food was well cooked with the PV cooker in all four food cooking tests, whereas food in only two tests with low solar radiation variability was well cooked for the parabolic dish solar cooker. The PV cooker proves to be an all-weather cooker from the experimental results obtained. Future work will extend the use of the PV system for other domestic applications such as lighting and refrigeration together with solar cooking for a multipurpose DC decentralized system for communities without grid connectivity.

Thin parabolic geometries are used in solar power generators and antennas, wherein the aerodynamic load on the structure is an important parameter. Flows over parabolic troughs been studied extensively because most solar panels have parabolic trough geometries. Meanwhile, some solar panels and most antennas located in windy highlands and open fields have parabolic dish geometries. So far, very little has been done for LES studies on flows past parabolic dishes at high Reynolds numbers. Thus, this study uses the LES method to scrutinize the flows over parabolic dishes with different focal ratios (f/D = 0.25–0.45) at a Reynolds number of 1.5×105. The effects of the focal ratio on the recirculation bubble length, flow characteristics, and drag coefficients are examined. The results indicated that the recirculation zone size is not significantly affected by the focal ratio until the ratio is very small; the recirculation zone becomes noticeably enlarged only when the dish is largely curved, such that f/D ≤ 0.35. The pressure spectrum analysis shows that there are three different dominant frequencies, which are associated with the pulsation of the recirculation bubble, vortex shedding from the dish edge, and separated shear layer instability, respectively. The overall frequency trends for the parabolic dish with f/D = 0.25 are similar to those past the circular disk, except for the three dominant frequencies being shifted to lower values. The drag coefficient tends to decrease with an increase in the focal ratio. [ABSTRACT FROM AUTHOR]

Solar thermal is a kind of renewable energy that converts solar radiation to heat using a concentrator that concentrates the heat in the focal point. The receiver is located in the focal and transfers heat to the flowed water, rising the water temperature beyond boiling. To harvest the most solar efficiency, a dual tracking system is used that tracks the sun during the daytime. This paper proposes implementing Arduino Uno dual axis tracking system for the solar parabolic concentrator dish. The tracking system is controlled and managed by using an Arduino microcontroller and light sensors. The proposed system has been installed in the city of Erbil and the testing results showed the success of the proposed system in which the dual tracking system tracked the sun precisely and the concentrator with the help of the receiver raised the flowed water to the desired temperature.

Concentrated solar power has the potential to produce large-scale renewable energy sources. Concentrated solar energy is produced using mirrors, reflective materials, or lenses on conical surfaces such as a parabolic dishes, parabolic troughs, towers, Fresnel reflector systems, and dish sterling collectors. The concentrated light source was converted into heat energy, which drove the heat engine into an electrical power generator. To gain more heat energy, the solar rays must be trapped and concentrated on their conical focus points. To increase the net overall efficiency of the system, it is vital to know the optical performances of the subsystem formed by the solar receiver and the parabolic concentrator. In this study, a beam of incident solar rays was traced on a parabolic dish collector, and a simulation is performed for concentrator behaviour using the ray-tracing code SolTrace developed by the NREL laboratory. For an incident radiation of 1000 W/m2 (considering 10000 photon rays), their optical performance and solar heat flux were simulated. The results show that the number of elements in SolTrace varies depending on the CFD mesh density, the number of rays utilised in the Monte Carlo technique and their impact on generating a resolution-independent solution. Investigating the ray tracing of the disc concentrator, the propulsive energy for viable applications can be analysed.

A hybrid solar lighting/ thermal system utilized a parabolic solar dish as a solar collector illustrated in this paper. A two-axis tracking system was developed and employed to improve the energy output of a concentrating solar system (CSP) that produces hot water and light. During the daytime, sunlight is transmitted by fiber optics to an indoor photovoltaic PV device to generate electricity, or it can be used directly as daylighting. The heat generated is used to heat water. The findings show that the proposed system is a low-cost, high-performance approach for solar energy use in building energy efficiency, and readily available tracking components and tools. The experimental work shows that the maximum efficiency of the hybrid solar lighting/ thermal system controlled with a dual-axis solar tracking system was 32.2%.

The use of direct thermal energy storage can improve the reliability of solar dish technology by providing a steady source of heat, even when solar radiation levels are low or intermittent. In this experimental study, a solar-thermal hybrid system that transmits light to interior photovoltaic panels through an optical fiber while producing hot household water was developed. The system employs a parabolic solar dish (PSD) with a cylindrical solar receiver designed to capture both heat and solar radiation. Fiber optics are used to transport light from the solar collector to the building as a source of illumination. To improve the system efficiency, a design of a direct storage system with phase change material (PCM) of petroleum Jelly was employed in this experimental work to heat water for a longer discharge duration. Furthermore, Al2O3 nanoparticles account for 1% of the total volume of the PCM material are added to the PCM material to improve heat transfer during heat charge and discharge. In addition, a low-cost two-axis tracking system for a PSD was developed. The study examined the efficiency of the system and analyzed the temperature profiles inside the solar receiver using a direct energy storage system. The discharge time is approximately six hours with a water temperature of more than 30 °C. The results revealed that the use of Al2O3 nanoparticles boosted thermal efficiency by around 5.68%. The proposed system could assist in solving the limited space challenges by utilizing the roof of the building.

The parabolic dish system is viable for meeting high-temperature requirements by harnessing solar energy. The receiver has a significant impact on the thermal efficiency of the solar parabolic dish system. Historically, the cavity receiver (CR) has been preferred over other receivers due to its reduced heat loss. Over the past two decades, numerous CR geometries have been developed in an effort to further improve thermal performance. The influence of several heat transfer fluids, including water, thermal oil, thermal oil/Al2O3 nanofluid, and thermal oil/MWCNT nanofluid, was investigated in this research using a three-dimensional numerical simulation on a modified conical cavity receiver (MCCR). Heat transfer fluids are considered to flow through copper tubes in a MCCR. The temperature contours, the inlet and outlet temperatures were numerically predicted. The experimental results were used to validate the numerical conclusions for the outlet temperature of the heat transfer fluid (water). According to the numerical results, Al2O3/thermal oil nanofluid attained the maximum exit temperatures (83.8°C to 95.1°C) and exergy efficiency (7.68%). The average thermal efficiency of systems with working fluids MWCNT/Thermal oil, Thermal oil, and Al2O3/Thermal oil was found to be 15.3%, 21.8%, and 28.2% greater than water, respectively. For the given solar radiation, the thermal oil/Al2O3 nanofluid achieved the highest average thermal efficiency of 59%. Whereas the average thermal efficiency of thermal oil and thermal oil/MWCNT was found to be 56%, and 53%, respectively. In addition, a correlation for the Nusselt number was developed in terms of the Prandtl number and the Reynolds number. [ABSTRACT FROM AUTHOR]

Energy demands have been increasing worldwide, endangering the future supply–demand energy balance. To provide a sustainable solution for future generations and to comply with the international goal to achieve Carbon Neutrality by 2050, renewable energies have been at the top of the international discussions, actively contributing to the energy transition and climatic policies. To achieve the international goal, Angola proposed a long-term strategy that promotes a fair and sustainable development of the national territory by means of improving the electric sector. Among all the renewable resources, solar energy is found to be the most promising solution since it has the second major renewable energy potential in Angola. However, the main problem related to solar energy is the efficiency of the solar systems and the electrical and thermal energy storage. As part of the solution, Concentration Solar Power (CSP) can make a sounder contribution to the transformation of the Angolan energy sector since it enables a significant increase in energy intensity through the concentration of solar energy. Moreover, the large applicability of this technology can contribute to the development of the rural regions which still struggle for energy equity. By considering the potential of CSP, this work presents the status of the Angolan energy sector, and focus is provided on the solar potential of the country. The advantages of the CSP technologies with emphasis on the parabolic dish systems are presented, and the contribution and innovative solutions for the enhancement of thermal efficiency are presented. [ABSTRACT FROM AUTHOR]

Energy consumption has increased withthe population increase, and fossil fuel dependency has risen and causing pollutions. Solar energy is suitableto provide society's thermo-electric needs. Thermal energy storage-based concentrated solar receivers are aimed at store heat energy and transportable to the applications. Acavity receiver with two-phase change materials (PCM) is experimentally investigated using a parabolic dish collector to act as the solar heat battery. The selected PCMs are MgCl2.6H2O and KNO3-NaNO3. PCMs are chosen and placed as perthe temperature zones of the receiver. The outdoor test wasconductedto determine the conical receiver's storage performance using cascaded PCMs. The complete melting of PCM attainsat an average receiver surface temperature of 230°C. The complete melting of the PCM in the receiver took around 30 minutes at average radiation around 700 W/m2, and heat stored is approximately 5000 kJ. The estimated number of cavity receivers to be charged on a sunny day is about 10-15 according to the present design and selected PCMs, for later use

This article explores the patents of solar energy technologies in the organic Rankine cycle (ORC) applications. The conversion of low-quality thermal energy into electricity is one of the main characteristics of an ORC, making efficient and viable technologies available today. However, only a few and outdated articles that analyze patents that use solar energy technologies in ORC applications exist. This leads to a lack of updated information regarding the number of published patents, International Patent Classification (IPC) codes associated with them, technology life cycle status, and the most relevant patented developments. Thus, this article conducts a current investigation of patents published between January 2010 and May 2022 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and keywords. One thousand two hundred ninety-nine patents were obtained as part of the study and classified in F and Y groups of the IPC. The time-lapse analyzed was between January 2010 and May 2022. In 2014 and 2015, a peak of published patents was observed. China (CN) was the country that published the most significant number of patents worldwide. However, the European Patent Office (EP), the World Intellectual Property Organization (WO), and the United States (US) publish the patents with the highest number of patent citations. Furthermore, the possible trend regarding the development of patents for each technology is presented. A high-performance theoretical ORC plant based on the patent information analyzed by this article is introduced. Finally, exploration of IPC revealed 17 codes related to solar energy technologies in ORC applications not indexed in the main search. [ABSTRACT FROM AUTHOR]

In a solar paraboloidal dish collector system, the receiver is critical for transforming converged solar flux to heat energy. A cavity receiver is the most common type of receiver, as it lowers heat loss. An experimental investigation is carried out in this article to evaluate the thermal performance of a novel cavity receiver for dish system under real direct solar environments. The performance of the modified conical cavity receiver under stagnation condition and with heat transfer fluid was studied experimentally. A solar parabolic dish concentrator of 1.83 m rim diameter and rim angle of 66° was used for the experimentation. For both cases, the experiments were carried out for two days. The highest stagnation temperature of 167.2°C was recorded with a direct irradiance of 803 W/m2, according to the data. For day average direct irradiance of 555 W/m2 and 663 W/m2, the receiver’s average thermal efficiency was found to be 53% and 69%, respectively. For 694 W/m2 direct irradiance, a maximum thermal efficiency of 75% was achieved. The thermal efficiency was shown to be significantly dependent on direct irradiation. According to the results of the experiments, the proposed modified conical cavity receiver is a viable solution for solar parabolic dish collector systems. [ABSTRACT FROM AUTHOR]

Energy consumption has increased with the population increase, and fossil fuel dependency has risen and causing pollutions. Solar energy is suitable to provide society's thermo-electric needs. Thermal energy storage-based concentrated solar receivers are aimed at store heat energy and transportable to the applications. A cavity receiver with two-phase change materials (PCM) is experimentally investigated using a parabolic dish collector to act as the solar heat battery. The selected PCMs are MgCl2.6H2O and KNO3-NaNO3. PCMs are chosen and placed as per the temperature zones of the receiver. The outdoor test was conducted to determine the conical receiver's storage performance using cascaded PCMs. The complete melting of PCM attains at an average receiver surface temperature of 230°C. The complete melting of the PCM in the receiver took around 30 minutes at average radiation around 700 W/m², and heat stored is approximately 5000 kJ. The estimated number of cavity receivers to be charged on a sunny day is about 10-15 according to the present design and selected PCMs, for later use. [ABSTRACT FROM AUTHOR]

Summary: The intensity of the solar radiations falling on the earth surface ranges between 5 and 7.5 kWh/m2/day. For the non‐directed solar thermal application, higher intensity level is required. The Concentrating Solar Power (CSP) technology incorporating reflecting mirrors reinforces the solar radiations with high intensity. It is suitable for various applications; that is, space heating, space cooling, and cooking, steam, and power generation without any polluted emissions. Meanwhile, among the various CSP technologies, the Concentrating Solar Parabolic Dish Stirling engine System (CSP‐DSS) has got attention of the research community due to its various attractive features. The output power and efficiency of the CSP‐DSS depend upon their geometrical, optical, and operating parameters. It is therefore, necessary to mathematically investigate the influence of these parameters on system performance before its design and installation. In the existing literature reported, only some specific parameters of the CSP‐DSS have been focused and considered to investigate the system performance. To the best of author's knowledge, no literature has been found to provide the mathematical modeling of all the system parameters in a single manuscript to study and investigate their influence on the system performance. Hence, this review article aims to compile, expansively review and organize the systematical mathematical modeling for all optical, geometrical, and operating parameters of the CSP‐DSS along with the system design methodology. Likewise, the effects of these parameters on the system output power and efficiency under various operating conditions have been investigated. In addition, comprehensive study of CSP‐DSS components along with their classification have been painstakingly discussed to determine optimal system configuration. Finally, the latest review study in the field of CSP‐DSS have been deeply and comprehensively discussed. This review study concludes that, the kinematic gamma type Stirling engine coupled with Permanent Magnet DC generator (PMDC) and Azimuth‐Altitude Dual Axis Tracker (AADAT) could be the better CSP‐DSS design and configuration in context of the standalone off‐grid electricity generation system. [ABSTRACT FROM AUTHOR]

Renewable energy has become essential to address fuel scarcity and greenhouse gas emissions like carbon dioxide. Experts are very interested in developing solar energy and finding solutions to the issues that arise when using it because it is one of the most significant forms of renewable energy. However, solar concentrators are employed to focus and transform solar radiation into a form more suitable for use in engineering application. Solar concentrators include parabolic troughs, towers, linear Fresnel collectors, and dishes. This review study examines Parabolic dish solar concentrator (PDSC) research because of its high radiation intensity, temperature, ease of installation, and maintenance. This research article examines PDSC performance and the factors affecting it. PDSC efficiency depends on receiver shape. Thus, various studies have compared conical, cylindrical, hemispherical, and spiral geometries to find the ideal shape for performance. Previous research shows that the conical shape performs well. Many studies have examined heat loss and tried to boost system efficiency by minimizing losses with insulators. The review study discusses solar radiation tracking programs, concentrated ray distribution in the receiver area, and PDSC optical efficiency. A 45 ° rim angle maximizes optical efficiency, the study found. Researchers have employed various working fluids for heat transfer. Research has compared nanofluids to estimate efficiency gains. This review study concludes with PDSC applications in desalination, power generation, solar cooking, and others. [ABSTRACT FROM AUTHOR]

Parabolic dish concentrators (PDCs) exhibit superior efficiencies compared to other concentrating solar power systems, positioning them as the preferred renewable electricity generation technology. However, their high costs hinder the technology's development, compelling the industry to explore innovative cost-effective designs integrating lightweight composites. However, PDC manufacturers encounter challenges ensuring these designs can withstand the aerodynamic forces imposed on them. These challenges are intensified by the limited characterization of aerodynamic loading, often reliant on simplified geometry, fixed pedestal heights, or low-resolution data, overlooking wind incidence and height impacts. Hence, an investigation into wind incidence effect at varying tilt angles and pedestal heights was conducted using computational fluid dynamics. ANSYS/FLUENT was utilized for three-dimensional analysis of fluid flow over a developed detailed PDC model, incorporating key components not previously studied together. 90° to −90° tilt angles and 0°–90° wind incidences were investigated in 15° increments, considering various pedestal heights. The analysis demonstrated that tilt and wind incidence significantly affected the aerodynamic coefficients. The pedestal height significantly affected the base overturning moment results while also affecting the hinge moment at higher incidence values. Furthermore, wind incidence and pedestal height variations distinctly influenced the airflow field around the PDC, revealing different behavioural characteristics. Alongside providing an improved aerodynamic coefficients' characterization than previously offered, correlations relating those coefficients to the PDC's orientation and height were derived, providing an analytical tool for designers to determine wind loads on PDCs, assess structural forces and moments on the PDC's key components, and enhance cost-effective PDC development, thereby advancing their widespread commercial use. [ABSTRACT FROM AUTHOR]

This study aims to propose a simulation as well as mathematical model to carry out the performance assessment and efficiency improvement of a stand-alone Parabolic Solar Dish Stirling (PSDS) system. The simulation for a 25 ​kW PSDS system is performed in the System Advisor Model (SAM) under the environmental conditions of Jamshoro, Sindh, Pakistan. The results show that the city has a good potential of direct solar irradiance with yearly average value of 1719.15 ​kWh/m2/y. The system can generate yearly 38.6 ​MWh with overall system net efficiency of 23.39%. Whereas, the maximum energy of 3.38 ​MWh is produced in month of January, due to high solar irradiance. However, the lowest energy of 2.15 ​MWh is produced in July, due to the monsoon spell in selected city. Furthermore, from the techno-economic analyses of the proposed system, the levelized cost of energy is found to be 0.13 $/kWh, which is quite low. As the Stirling Engine (SE) works at higher temperature, so, increasing the diameter of concentrator results more thermal energy at the cavity. The solar radiations are high around the solar noon, therefore, the operating temperature can damage the hot-side of SE due to thermal overloading. In future, to protect the hot-side of SE, it is recommended to use thermo electric generator.

A concentrated solar absorber with finned phase change materials was experimentally studied using a Scheffler type parabolic dish concentrator. The absorber's inner surface was fixed with hollow cylindrical containers filled with phase change material (PCM) for heat transfer augmentation. The absorber's selected PCM was acetanilide (Melting point of 116 °C)—the cylindrical capsules protruding into the fluid side to create turbulence and mixing and acting as fins. The absorber surface temperature was observed to be about 130–150 °C during the outdoor tests while passing fluid through the absorber. The fluid flow rate varied from 60 to 100 kg/h during the outdoor experiments. The peak energy and exergy efficiency of parabolic dish collector (PDC) at the fluid flow rate of 80 kg/h with PCM integrated solar absorber was found to be about 67.88% and 6.96%, respectively. The integration of cylindrical PCM containers resulted in more heat transfer augmentation in the solar absorbers. The optimized solar absorber could be suitable for various applications like steam generation, biomass gasification, space heating, and hydrogen generation. • Uniform heat output of PCM integrated solar absorber attained due to PCM. • Heat storage is effective after the complete melting of the PCM in the absorber. • Cylindrical PCM containers assist the smooth fluid flow inside the solar absorbers. • The energy efficiency of concentrated solar absorber with PCM reaches up to 67.88%. • The exergy efficiency of concentrated solar absorber with PCM reaches up to 7%. [ABSTRACT FROM AUTHOR]

Summary: In this study, a stand‐alone parabolic solar dish/Stirling (PSDS) system model is developed and investigated. The techno‐enviro‐economic performance of a 25‐kW stand‐alone PSDS system is simulated in the System Advisor Model (SAM) tool under ambient conditions of Jamshoro, Pakistan. The avoided CO2 emissions due to the installation of the proposed system are calculated in an Excel spreadsheet. The methodology for emissions calculation is based on the average value of emissions per kWh recommended by the Intergovernmental Panel on Climate Change (IPCC). The results indicate that the proposed PSDS system generates 38.6 MWh of electrical energy annually, and the maximum energy of 3.38 MWh is achieved in January. The main reason for that is the highest value of DNI in that month. The system has attained a net efficiency of 23.39% and a levelized cost of energy (LCOE) of 0.13 $/kWh. The yearly emissions from PSDS are 762 kg, which is only 2.2% and 4.69% of coal and natural gas, respectively. Moreover, the sensitivity analysis of the PSDS system showed that the projected mirror area and collector cost affects the power output and cost of generation significantly. [ABSTRACT FROM AUTHOR]

This article explores the patents of solar energy technologies in the organic Rankine cycle (ORC) applications. The conversion of low-quality thermal energy into electricity is one of the main characteristics of an ORC, making efficient and viable technologies available today. However, only a few and outdated articles that analyze patents that use solar energy technologies in ORC applications exist. This leads to a lack of updated information regarding the number of published patents, International Patent Classification (IPC) codes associated with them, technology life cycle status, and the most relevant patented developments. Thus, this article conducts a current investigation of patents published between January 2010 and May 2022 using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology and keywords. One thousand two hundred ninety-nine patents were obtained as part of the study and classified in F and Y groups of the IPC. The time-lapse analyzed was between January 2010 and May 2022. In 2014 and 2015, a peak of published patents was observed. China (CN) was the country that published the most significant number of patents worldwide. However, the European Patent Office (EP), the World Intellectual Property Organization (WO), and the United States (US) publish the patents with the highest number of patent citations. Furthermore, the possible trend regarding the development of patents for each technology is presented. A high-performance theoretical ORC plant based on the patent information analyzed by this article is introduced. Finally, exploration of IPC revealed 17 codes related to solar energy technologies in ORC applications not indexed in the main search.

Water desalination is the method of saltwater separating into two parts by using various types of energy. This paper offers an experimental work for solar distillation system to the production of drinking water by single slope solar still integrated with a parabolic dish. The result was compared with different solar still designs in the literature. The proposed solar thermal performance of the suggested solar still has been investigated to show its applicability in Iraq, Najaf (32.1N°, 44.19E°) during winter session (Nov., Dec., Jan.) 2018-2019. The assessment based on the effects of operational parameters, including solar irradiance, ambient temperature, wind speed, absorption wall temperature. A copper helical conical coil was used to compare steam condensation generated from the evaporator. The productivity of this study was 11.45 L.day-1, 8.2 L.day-1 freshwater with and without coil condenser respectively, and average direct solar irradiance was 753.6 W.m-2. Comparison different types of solar stills, especially those that have used as concentrators of solar irradiance, with comparable periods of work time, indicate excellent performance. Also, this system can be considered acceptable because it can provide distilled water from the use of materials available in local markets and low cost, enough to cover the daily needs of water for at least two adults. [ABSTRACT FROM AUTHOR]

The charging of phase change material (PCM) in a concentrated solar receiver is experimentally carried out in a parabolic dish collector. Rectangular PCM filled enclosures of 30 mm width in the solar receiver are investigated to study the effect of vertical and horizontal orientations. The selected PCM was a eutectic mixture of KNO3 and NaNO3 in 60:40 M ratio with melting point of 210–220 °C. Fin conductive batch heat transfer occurs from the incident surface of the solar receiver to the PCM. The PCM temperatures are measured at five points inside the receiver to observe the temperature distribution and melting conditions. The average temperature of the PCM in the vertical PCM enclosure is observed to be 3.5% more than that of the horizontal PCM enclosures under similar solar radiation and operational duration. Complete melting of the PCM in the vertical container is attained 12.5% earlier than that of the horizontally placed PCM enclosures. The PCM-filled solar receiver possesses the ability to retain the temperature of the receiver, about three times more than the non-PCM receiver due to the constant temperature melting of PCM. Such PCM-filled solar receivers are useful to provide heat for several thermal applications.

This work aims to compare the cavity surface contour's thermal performance to that of the solar absorber's plain surface contour for Scheffler type parabolic dish collectors. The absorber is tested for the temperature range up to 600°C without working fluid and 180°C with the working fluid. The modified absorber surface's thermal performance is compared with the flat surface absorber with and without heat transfer fluid. The peak temperature reached by the surface modified absorber (534°C) is about 8.6% more than that of the unmodified absorber (492°C) during an outdoor test without fluid. The energy efficiency of cavity surface absorber and plain surface absorber are 67.65% and 61.84%, respectively. The contoured cavity surface produces a more uniform temperature distribution and a higher heat absorption rate than the plain surface. The results are beneficial to the design of high-temperature solar absorbers for concentrated solar collectors. [ABSTRACT FROM AUTHOR]

Summary: The present study investigates the performance of a multi‐generation plant by integrating a parabolic dish solar collector to a steam turbine and absorption chiller producing electricity and process heat and cooling. Thermodynamic modeling of the proposed solar dish integrated multi‐generation plant is conducted using engineering equation solver to investigate the effect of certain operating parameters on the performance of the integrated system. The performance of the solar integrated plant is evaluated and compared using three different heat transfer fluids, namely, supercritical carbon dioxide, pressurized water, and Therminol‐VPI. The useful heat gain by collector is utilized to drive a Rankine cycle to evaluate the network output, rate of process heat, cooling capacity, overall energetic, and exergetic efficiencies as well as coefficient of performance. The results show that water is an efficient working fluid up to a temperature of 550 K, while Therminol‐VPI performs better at elevated temperatures (630 K and above). Higher integrated efficiencies are linked with the lower inlet temperature and higher mass flow rates. The integrated system using pressurized water as a heat transfer fluid is capable of producing 1278 and 832 kW of power output and process heat, respectively, from input source of almost 6121 kW indicating overall energy and exergy efficiencies of 34.5% and 37.10%, respectively. Furthermore, multi‐generation plant is evaluated to assess the exergy destruction rate and steam boiler is witnessed to have the major contribution of this loss followed by the turbine. The exergo‐environmental analysis is carried out to evaluate the impact of the system on its surroundings. Exergo‐environmental impact index, impact factor, impact coefficient, and impact improvement are evaluated against increase in the inlet temperature of the collector. The single‐effect absorption cycle is observed to have the energetic and exergetic coefficient of performances of 0.86 and 0.422, for sCO2 operating system, respectively, with a cooling load of 228 kW. [ABSTRACT FROM AUTHOR]

The application of the nanofluids is suggested to enhance and improve the efficiency of solar thermal power system. In the present study, three different nanofluids (Fe2O3/therminol VP1, SiO2/therminol VP1, and Cu/therminol VP1) are numerically investigated in parabolic dish solar collector that is further integrated to a combined cycle for power and hydrogen production. Heat rejects from the power cycle is also utilized to drive a single effect absorption (LiBr-water) system. Furthermore, a comprehensive energy, exergy and exergo-environmental analysis are carried out by varying several input parameters and their influence on overall energetic and exergetic efficiencies, network output and rate of hydrogen generation is assessed. The engineering equation solver is employed to conduct the parametric study. Outcomes of the study demonstrate that the SiO2/VP1 has the better characteristics among the investigated nanofluids. The overall energetic efficiency of the SiO2/VP1, Fe2O3/VP1, and Cu/VP1 is almost 38.79%, 38.74%, and 37.53%, while overall exergetic efficiency is 41.72%, 41.66%, and 40.36%, respectively at 1000 Wm-2. The exergoenvironmental impact coefficient and impact index are noticed to be reduced for all the three nanofluids as mass-flow rate increases. The hydrogen production rate for SiO2/VP1 is maximum and has observed to be increased by increasing the ambient temperature. Increase in nanoparticles concentration also rises the exergetic efficiency but reduces the thermal conductivity of the nano-fluids. Coefficient of performance is noticed to be increased with rise in evaporator temperature, whereas, it is reduced by increasing the generator temperature. [ABSTRACT FROM AUTHOR]

Summary: This work presented the performance analysis of a solar parabolic concentrator prototype. The purpose of this paper is to achieve most quantity of vapor production with different water flows. The principal component of the solar concentrator is a new absorber concept that absorbs reflected solar rays and transports it to a heat exchanger in order to generate vapor. Climatic conditions, inlet/outlet oil temperatures of the tubular solar heat exchanger, water tank temperature, and inlet/outlet water temperatures of the mixed heat exchanger were recorded experimentally during three days in November 2018. The absorbed energy, losses energy, concentrated energy, and vapor heat energy of the system were determined. Results of this work, the solar system provides thermal energy efficiency varied from 60% to 70% and a concentration factor around 350 for three water mass flow rates. In this experiment, the optimum value of vapor mass is 6 kg/h with 0.016 kg/s of water flow. Consequently, to achieve the most quantity of vapor, the water flow should be decreased. [ABSTRACT FROM AUTHOR]

Here, performance of 11 kW solar‐powered lithium bromide water absorption chillers in cogeneration mode is investigated. A 40 m2 solar parabolic dish of 19 kWth capacity is used for both processes heating and cooling. Extensive thermodynamic design and analysis are carried out, and the results obtained are validated. Parabolic dish and cavity receiver are sized for Chennai (13°N, 80.18°E), India. In the present analysis, a new performance parameter COPWE is introduced by replacing the thermal input component in the calculation of COP, by an equivalent amount of high‐grade energy. Both physical and chemical exergy at all state points of the chiller are estimated and found that total irreversibility is about 2.37 kW in desorber followed by absorber which is 0.41 kW. The developed model estimates solution concentration at the exit of solution expansion valve (SEV) that is important since it affects absorption of refrigerant in the absorber. [ABSTRACT FROM AUTHOR]

The solar brightness model is widely applied in modeling and optimization of concentrated solar energy system. In this paper, the influence of various solar brightness models on the solar dish system are evaluated. The spline interpolation to the test data of solar brightness distribution is applied as the standard model, and the performance simulation and optimization code for solar dish system with the standard model are built and validated by Soltrace. The optical efficiency of different solar brightness models are calculated. The prediction and optimization error of 11 solar brightness models are estimated under different optical error, rim angle of reflector, concentration ratio, and circumsolar ratio. Although prediction results are rather good when optical error is more than 5 mrad, the prediction and optimization results exists much error between the present solar brightness model and the standard model especially when the optical error is less than 5 mrad, in which the maximum error of 40% exists when considering the influence of CSR for the performance modelling and maximum relative error of 3.5% for optimization. As the optical error of the solar dish system has been greatly reduced recently, it is recommended that the precise model for solar brightness distribution should be applied for obtaining better performance prediction and optimization. • Solar brightness distribution. • Solar dish collector. • Performance prediction and optimization. • Optical performance model. • The relative error caused by simple solar intensity distribution. [ABSTRACT FROM AUTHOR]

A cavity receiver finds substantial application to improve the thermal performance of a solar parabolic dish collector. However, its limited surface area shortens the scope of utilization and bars thermal efficiency. This research has intercepted such problems by including a cascaded cavity receiver, which offers more surface area and high-temperature distributions, representing more heat absorption and utilization to convert into thermal energy. The crucial design of a cascaded receiver consists of two concentric steel cylinders with different heights attached at one end. The design is tested theoretically with the help of CFD analysis, and the heat loss results are compared with the traditional cavity receiver. Furthermore, according to design, an experimental set-up is fabricated, and experimentations are conducted in off-flux mode using an electric heater. The Pyromark coatings minimize radiation losses and implement the working conditions in the lab testing scenario. The convective heat losses estimated reduction of 4.3 % at 0°–24.8 % at 90° due to the application of coatings in the normal cavity and 3.4 % at 0°–16.4 % at 90° due to the application of coatings in the cascaded cavity. Also, the cascaded cavity receiver minimizes 6.98 %–13.93 % convective heat losses compared to traditional cavity receivers. • A cylindrical cascaded cavity receiver is designed for high-temperature applications. • Experiments are carried out in off-flux mode to evaluate heat losses. • The modified cavity receiver with pyromark coating shows better performance. [ABSTRACT FROM AUTHOR]

The objective of this research was to design a low cost parabolic solar dish concentrator with small-to moderate size for direct electricity generation. Such model can be installed in rural areas which are not connected to governmental grid. Three diameters of the dish; 5, 10 and 20 m are investigated and the focal point to dish diameter ratio is set to be 0.3 in all studied cases. Special attention is given to the selection of the appropriate dimensions of the reflecting surfaces to be cut from the available sheets in the market aiming to reduce both cutting cost and sheets cost. The dimensions of the ribs and rings which support the reflecting surface are optimized in order to minimize the entire weight of the dish while providing the minimum possible total deflection and stresses in the beams. The study applies full stress analysis of the frame of the dish using Autodesk Inventor. The study recommends to use landscape orientation for the reflective facets and increase the ribs angle and the distance between the connecting rings. The methodology presented is robust and can be extended to larger dish diameters.

Renewable energy resources like solar energy, wind energy, hydro energy, photovoltaic etc. are gaining much importance due to the day by day depletion of conventional resources. Owing to the lower efficiencies of renewable energy resources, much attention has been paid to improving them. The concept of utilizing phase change materials (PCMs) has attracted wide attention in recent years. This is due to their ability to extract thermal energy when used in collaboration with photovoltaic (PV), thus improving the photoelectric conversion efficiency. In this paper, the objective is to design and fabricate a novel thermal energy storage system using phase change material. An investigation on the characteristics of Potash Alum as a phase change material due to its low cost, easy availability and its usage as an energy storage for the indoor purposes are taken into account. The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantage of high-energy storage density and the isothermal nature of the storage process. In the current study, potash alum was identified as a phase change material combined with renewable energy sources, that can be efficiently and effectively used in storing thermal energy at compartively lower temperatures that can later be used in daily life heating requirements.A parabolic dish which acts of a heat collector is used to track and reflects solar radiation at a single point on a receiver tank. Heat transfer from the solar collector to the storage tank is done by using a circulating heat transfer fluid with the help of a pump. The experimental results show that this system is capable of successfully storing and utilizing thermal energy on indoor scale such as cooking, heating and those applications where temperature is below 92 °C.

Small-scale hybrid parabolic dish concentrated solar power systems are a promising option to obtain distributed electricity. During the day, solar energy is used to produce electricity, and the absence of sunlight can be overwhelmed with fuel combustion. This study presents a thermo-economic survey for a hybridized power plant in different regions of Spain, considering the local climatic conditions. The developed model considers the instant solar irradiance and ambient temperature dynamically, providing an estimation of the power output, the associated fuel consumption, and the most relevant pollutant emissions linked to combustion. Hybrid and combustion-only operating modes at selected geographical locations in Spain (with different latitudes, mean solar irradiances, and meteorological conditions) are analyzed. The levelized cost of electricity indicator is estimated as a function of investment, interest rate, maintenance, and fuel consumption actual costs in Spain. Values of about 124 €/MWhe are feasible. Fuel consumption and emissions in hybrid operation can be reduced above 30% with respect to those of the same turbine working in a pure combustion mode. This model shows the potential of hybrid solar dishes to become cost-competitive against non-renewable technologies from the point of view of costs and reduction in gas emission levels in regions with high solar radiation and low water resources.

Concentrating solar power (CSP) is a solar thermal technology that generates electricity from thermal energy through the sun.The electricitycan be generated with four different types of CSP technologies that include Parabolic Dish (PD) systems. In order to make this technology more practical, the efficiency of the solar technology should be improved.Solar concentration is one of the main aspects that can affect the system'sefficiency. This paper reviewed solar secondary concentrators and discussed their designs and performance. Besides, their strengths and weaknesses were compared. Generally, thesecondary concentrators couldincrease the solar concentration of the solar technologyup to 93 percent. [ABSTRACT FROM AUTHOR]

Here we propose a forced air circulation system to reduce the convective heat loss across the aperture of a dish concentrator. The function of the proposed system was validated with computational fluid dynamics (CFD) simulations. Compared to a concentrator without such a system, the modified solar dish cavity receiver could clearly reduce the convective heat loss and its fluctuation in the receiver. In the best case studied, the convective heat losses could be suppressed by up to 58%. In addition, two types of air circulation modes (clockwise and anticlockwise) were compared, showing that the anticlockwise mode yields better performance. [ABSTRACT FROM AUTHOR]