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A review of photovoltaic (PV) cell operating temperature ( $T_{\textrm {c}}$ ) steady-state models developed from the year 2000 onward is shown in the present article. The goal is to help researchers and professionals in the field to choose the most significant parameters and suitable experimental arrangements to compose an accurate steady-state model. Initially, a brief description of $T_{\textrm {c}}$ is given and an overview of the models for calculating $T_{\textrm {c}}$ is presented. We present a summary of 33 correlations found in the literature for estimating $T_{\textrm {c}}$ and the synthesis of those correlations in three general forms. Additionally, we highlight the main parameters in the analyzed correlations along with their most accurate data collection methods. The parameters with the greatest influence on $T_{\textrm {c}}$ , appearing in a significant number of formulations, are discussed: solar absorbance, electrical efficiency, and transmittance of the PV cell/module glass cover; irradiance; ambient temperature; wind speed. Strategies of obtaining $T_{\textrm {c}}$ —using the module back side temperature or an internal sensor for direct measurement—for model validation purposes are also discussed.

A numerical analysis of a basin-type solar still with a double glass cover is done under winter circumstances of solar radiation, ambient temperature, and wind speed. Equations defining thermal balances of different components of traditional and double glass cover solar stills are used to describe the physical issue, which is then solved using the Gauss-Seidel numerical technique. The effects of solar radiation, ambient temperature, and wind speed on the daily production, internal efficiency, and overall performance of solar stills are calculated and illustrated. The findings demonstrate that a solar still with a double-glass cover is more productive and efficient than a solar still with a single glass cover.

Transparent ceramics are typically used as the strike-face layer owing to their superior mechanical properties, such as high strength and high hardness. For typical transparent ceramic armor, the ceramic layer is usually divided into small ceramic tiles because of the size limitations. However, the tiled structure is restricted in application due to the discontinuity between ceramic tiles, which can be solved by covering the outer surface with a glass plate. In this study, the effect of the glass cover layer on the ballistic performance of transparent ceramic armor is investigated through a combination of experimental testing and finite element (FE) simulation. The results exhibited that under the impact of 7.62 mm armor-piercing incendiaries, the ceramic tiles were prematurely damaged when the glass cover was added. Besides, the reduction of the ceramic energy dissipation was greater than the energy dissipation of the glass cover itself, thus reducing the ballistic performance of the transparent ceramic armor. The results also revealed that the pre-damage area increased as the thickness of the glass cover increased from 1 mm to 4 mm.

The aim of this research is to carry out the heat transfer analysis of PVT hybrid active solar still (HASS) at different water depth to obtain maximum output. Experimentation is performed for validation of thermal modeling with and without flowing water, having water depth of 0.15m in the solar still basin. During experimentation, water flows above the glass cover. Theoretically calculated values of basin water, basin liner, glass temperature and yield obtained using thermal modeling are very near to the experimental values having correlation coefficients 0.988, 0.981, 0.999 and 0.985 respectively. It is also found that thermal efficiency and daily exergy output increases by 4% and 8.2% respectively for this hybrid system whose glass cover is getting cooled by water flowing over it. Theoretical calculation for distillate output of the system was also calculated out for various climatic conditions of India using developed thermal modeling and it is found that proposed system gives higher annual yield of 2756.67 kg/m2 for the climate of Mumbai. The experimental uncertainty of the HASS is obtained as 14.82%.

A massive bird dropping (BD) deposition on the common rectangular flat plate (RFP) of photovoltaic (PV) module is a matter of great concern in Western Rajasthan (WR) that diminish the overall energy production capacity of the system remarkably. In this research article, a prototype novel flat plate (NFP) design of a front glass cover of PV module is proposed to prevent the impact of BD settlement by the restriction of bird’s sitting/movement on the front glass cover. In this regard, the performance analysis of PV module with common RFP and newly designed NFP glass covers has been assessed at the different inclination β° (0–90). The BD accumulation onto the both glass covers was explored by the optical transmittance profiles at the different tilt angles, i.e., explained by bird movement on each flat glass surfaces. Consequently, a significant amount of output electric energy has been gained in NFP design rather than RFP corresponding to particular tilt regions TR I (0° ≤ β ≤ 25°), TR II (25° ≤ β ≤ 60°), and TR III (60° ≤ β ≤ 90°). According to the results achieved, an excellent level of improvement in average power loss, ~ 97.85%, corresponding to optimal TR (III) has been detected by employing NFP glass collector.

This study is carried out with the domestic solar still with cotton gauze over the glass cover with the help of desalination process. Water flowing over the glass cover not seems to be evenly distributed over the width of the glass cover. A new innovative method of water desalination using domestic solar still with the presence of cotton gauze resulted in increasing the output and efficiency of the distillate. The production rate of this new still with cotton gauze was observed to be 4.285 lit/m2/day. On the other hand, without cotton gauze conventional solar still gives the rate of 2.925 lit/m2/day. However, with cotton gauze production rate is increased to 1.36 lit/m2/day. The parameters glass temperature, ambient temperature, solar radiation and distillate output, recorded during March–April in Puducherry, India, are considered to play a major role in this study. The increase in thermal conductivity leads to increase in evaporation rate, and simultaneously, the condensation rate was increased ultimately leading to the increased output. The glass solar still with cotton gauze is more efficient and cost-effective than basic conventional still and should be promoted for coastal regions of Puducherry.

In the current study, a passive single-slope solar distillation unit has been proposed. An incorporated condenser has been integrated into the system to promote the condensation rate and hence improve the unit productivity. External fins have been used as a means to enhance the condenser performance further. The system performance has been examined experimentally for seven consecutive summer days in Mashhad city located at 36° 18′56.12″ N latitude and 59° 34′4.66″ E longitude. The unit yield and efficiency have been compared to the corresponding data for a conventional solar still tested in Tehran city. The results reveal that using fins increases the distillate in the condenser by 35%. But, there is only a 5% increase in the total unit productivity due to a reduction in distillate on the glass cover by 8%. Compared to the typical solar still tested in Tehran, up to 92.3 and 86% increase in daily productivity can be achieved using the current still with and without fins, respectively. The thermal efficiency of the currently proposed structure is about double than is it for the traditional solar still. The economic feasibility of the current solar still has been compared to some passive and active designs found in the literature, where it has been found not only efficient but less costly as well. The system without fins is the least expensive with C P L = 0.007 $ / l / m 2 , while the one with fins is slightly more expensive with C P L = 0.0117 $ / l / m 2 but still economically outstanding.

This p aper presents a theoretical and experimental investigation on the optimization of a solar still. The theoretical approach is based on the simulation of the solar desalination system, the influenced parameters were isolated and their corresponding effects were numerically evaluated. According to these results, the optimization methodology is based on the concept of recuperation of the condensed heat. Two solar stills having the same dimensions were constructed. A descending film of salt water cools the glass cover of the first still. The cooling water is then recycled and fed into the supply of the solar still. The other still is simple and conventional, it is used only for comparison and reference purpose. Both stills are similar in geometry, and inclination angle. The theoretical and experimental results show that the productivity increase with cooling the glass cover. The experimental results show important increment in productivity, reaches in some cases 60%. The influence of cooling water flow rate was also investigated. The experimental investigation has shown the non-linear behavior of the flow rate on the performance. The objective of the present research work is to reach an optimum system configuration in order to provide a simple and high effect solar distillation unit.

The hemispherical distiller characteristics are having a large surface area for receiving and condensing compared to a conventional single-slope distiller. To achieve the maximum possible utilization of this feature, in first the Al2O3 nanoparticles were adding to the basin water to increase the evaporation rate, in the second modification the glass cover cooling technology was utilized to increase the condensation rate. To investigate the influences of Al2O3-water nanofluid and the glass cover cooling technology by a water sprinkler on hemispherical solar distiller performance, three hemispherical solar distillers were designed and tested in the same climate conditions. The first is the reference case (conventional hemispherical solar distiller), second is the modified hemispherical solar distiller with Al2O3-water nanofluid, and the third is the modified hemispherical solar distiller with Al2O3-water nanofluid and water sprinkler. Three different concentrations of Al2O3 nanoparticles 0.1, 0.2, and 0.3% were studied. Results showed that, the accumulative yield of traditional hemispherical solar distiller reached 3280 ml/m2/day, while the utilization of Al2O3-water nanofluid and the water sprinkler improve the accumulative yield to 6750, 6900, and 7250 ml/m2/day, with improvement 105.8, 110.4, and 121% of the volume friction of 0.1, 0.2, and 0.3%, respectively. Also, the improvement in the daily efficiency for utilizing the Al2O3 nanoparticles and water sprinkler reached 105.7, 109.7, and 120.1% for nanoparticle concentrations 0.1, 0.2, and 0.3%, respectively as compared to the reference case.

Developing solar still glass cover is an important key to increasing both productivity and thermal efficiency. In present work, a new glass cover shape adopted of a vertical cylinder with spherical...

The authors previously proposed and experimentally investigated a new standalone desalination system that is composed of a parabolic trough collector put under conventional solar still. In this study, an unsteady theoretical model is developed using the energy balance equations for the main components of the system to investigate the effect of different parameters on the performance of the new solar still. The model is used for calculation of productivity, and the absorber, saline water, and the glass cover temperatures. Results obtained using the present model are compared with the experimental results and a good agreement is observed between them. Moreover, as the experimental study was limited to the winter period, to thoroughly understand the new system performance at different climates conditions, its performance in four seasons is considered. Results show that in Kerman weather conditions, on average the present solar still system produces 0.961 L of freshwater per day in summer which is 55% more than the yield in winter for the Fixed parabolic trough collector. For the parabolic trough collector with tracking systems, the system would produce 1.266 L per day in summer.

In this work, an experimental study has been conducted on a solar still to investigate the influence of stone bed layer thickness on the productivity of the solar still. These present experimental study involves two identical solar stills: one of the stills is conventional and the other has a layer of fine stones on the base of the still. The fine stones were divided into three layers. Each experiment starts without stone layer. Then readings were taken from the still for one stone layer, two stone layers and three stone layers on the basin. The thicknesses of this layers are 10mm, 15mm and 20 mm, respectively. The experiments were conducted at Mansoura University, Egypt (31° 04 ′N, 31° 21 ′ E), durin g November month, 2016. Temperatures at different locations in the still (water in the still, glass cover surface, stone and air – vapor mixture) are measured and recorded with time. In addition, solar radiation, ambient temperature and amount of distillated water are recorded during the experiments at various operating days. The present results indicated that the enhancement of 3.79%, 7.06% and 11.8% for one, two and three fine stones bed layers, respectively more than the conventional still. Also, it was showed that the efficiency was highest with the maximum stone bed thickness.

Intestinal worm disease is one of the parasitic diseases that still infect humans, especially children. School-age children, especially elementary school children, are generally less familiar with self-sanitation. Most diseases of the worms are transmitted through dirty hands. Community service at SD Inpres Pampang 1 was done to educate students about the implementation of good self-sanitation and precisely how to wash hands based on WHO standards. The tools used in this study were chalkboard, camera, microscope, reaction tube, glass object, glass cover, container/basin, stirrer rod, glass beaker, tube rack, petri dish, nail clippers, and pens. The materials used in this training were hand nails students SD Inpres Pampang 1, water, and salt. Based on the results and evaluation, it concludes 1) Worm infections can occur when there are worm eggs attached to the nails that are swallowed in with food. 2) improving participants ' understanding and knowledge of self-sanitation for everyday life, especially the right-hand washing way.

A survey was made to see how to improve the productivity of a solar distiller via different angles of inclination of the glass cover. For this, six identical solar stills with different angles of c...

A thermal modeling of advanced design solar still is shown in the present paper. The aim of the present experiment is to show the performance of solar still with variation of tilt angles. The objective is to see the effect of solar still on the productivity due to differential tilt angles of glass cover. To achieve this, three different angles-based solar stills (11°, 26°, and 41°) have been installed at the M.I.T.S, Gwalior Campus (latitude of Gwalior city is 26.2183° N). As a result, it was found that the latitude angle-based solar still has higher productivity than other angle-based solar still. The productivity of latitude angle-based (26°) solar still was 31.95% and 20.96% higher than 11° and 41°-based solar stills, respectively.

The present article highlights the implementation of differential evolution (DE)-assisted metaheuristic optimizer to provide the solution of an inverse multi-variable problem related to a flat absorber solar collector consisting of a single glass. For satisfying a given heating requirement from the solar collector, the necessary tilt angle and the thickness of the glass cover are simultaneously predicted using the proposed DE methodology. The existing study of inverse multi-variable optimization analysis has been done for dynamic values of solar energy radiation and different ambient conditions commonly encountered in various geographical locations of India. Formulation of the current research involves the minimization of a newly proposed cost function involving the required and the acquired heat transfer rates from the solar collector in Euclidean space. The solution approach then utilizes a dynamic exchange between evolutionary metaheuristic DE and a well-validated forward solver containing analytical expressions of heat energy balance within the solar collector. Variations of cost function and the estimated design variables are mainly studied to visualize the algorithm’s behavior for a single gazing-based solar thermal device. Multiple possible groupings of the unknown parameters of the solar collector are revealed, which always collectively result in a desired heating requirement from the solar collector. Sensitivity indices related to the design variables are evaluated for ascertaining the relative importance of parameter selection. Encouraging opportunity is found towards the system’s size reduction through sparing selection of inclination angle. The current study provides a convenient and cost-effective tool to select the necessary inclination and glass covers to obtain low to medium heating requirements from the available incident solar energy.

In this study, thermo-economic optimization of single-pass SAHs (solar air heaters) with obstacles of arcuate shape has been carried out. The research is conducted in order to compare the exergy efficiency of three different types of flat plate SAHs. Also, using NSGA-II (non-dominated sorting genetic algorithm) influencing factors were optimized. The SAHs were two different arcuate obstacles (type II and type III), and the other one had no obstacles (type I). All heater types with single and double glass cover were evaluated. The results showed that the heater with double glass cover and the obstacles (type III) had the highest function in both economic and exergetic aspects. Based on the NSGA-II results, collector with flow rate, area and the outlet temperature of 0.017 kg s−1, 2.6 m2 and 78 °C, respectively, had the best performance.

The photovoltaic-thermal (PVT) collector system is a relatively mature technology to harvest energy from the sun and convert to electrical and thermal energy. Recent developments in this field have shown that the PVT system can yield electrical, thermal and combined PVT efficiencies of 13.8%, 54.6% and 68.4% respectively. This introduces the application of a semi-transparent PV to a photovoltaic thermal collector (PVT) system. A new design is proposed with two semi-transparent PVs (STPVs) to enhance the PVT performance. The semi-transparent PV (STPV) will replace the conventional glass cover, and hence will permit a certain percentage of solar radiation to pass through it. The performance of the new PVT configuration with double and single glazing was analysed, where in the double glazing, the STPV replaces the lower glazing. The thermal and electrical efficiencies of the new design configuration were investigated under different climatic conditions at Malaysia, Sudan and UK. The simulation results reveal that the new PVT system could achieve electrical, thermal and combined PVT efficiencies of 20.76%, 65.7% and 86.5% respectively, enhancing the electrical efficiency due to the use of two semi-transparent PV panels and thus improving the energy harvested per unit area, putting a positive step toward the application of a multilayer semi-transparent mono-crystalline silicon PV. However, the PVT glazing is more effective in locations with relatively low ambient temperature, while it is found not feasible in locations with considerably higher temperature. Moreover, the study indicates that the PVT system is not effective for sites with low solar radiation and ambient temperature.

The vertically allocated free-standing SU-8 microstructures are typically bonded to a glass cover by the usage of uncrosslinked SU-8 adhesives. Such a phenomenon can easily cause SU-8 protrusion and eventually result in the SU-8 cantilever to be immovable. Traditional methods are sensitive to the bonding conditions and have a short bondable thickness of SU-8 adhesives. In this study, we propose an approach, that is, improved structural features, to alleviate the protrusion problem while extending the bondable thickness for the freestanding SU-8 microstructures in an enclosed channel. We used concave and moat microstructures as solutions of the improved structural features. We investigated the influence of both microstructures on the bonding quality and compared the bondable thickness with the previous one. THB-151N was used in another example to demonstrate the availability of our method. The bonding quality at the interfaces was evaluated by SEM images and direct inspection through a transparent glass cover. The bonding method is advantageous to other microfluidic systems, particularly those with long narrow channels.

This paper reported the experimental testing of a triangular and conventional basin solar still (TBSS and CBSS). Solar basin and absorber are made of glass and a polyethylene cover, respectively, with an area of 0.25 m2. Square and triangular absorber with the same area of 0.25 m2 with square and triangular glass cover for condensation was fixed. Experimentations were conducted during the month of December 2018, and different natural criteria such as intensity, wind speed, and surrounding ambient temperatures were considered. Also, the modified model was compared to the CBSS on its performance and efficiency characteristics. The experimental results also revealed that the temperature of the water inside the TBSS was higher as compared with that of the CBSS. The daily yield obtained from CBSS and TBSS was found to be 2.7 and 3.2 kg/m2, respectively. Also, the daily efficiency of the TBSS was improved by 11.36% than the CBSS.

Globally, parabolic trough solar collector installation is in high demand among the various concentrating solar power (CSP) technologies due to the high energy demand. The design involves the bending of a flexible reflective material that concentrates the solar irradiation that lands on the collector surface to the focal line; this is where the absorber pipe is positioned. This paper presents a modified parabolic trough solar collector with the aim of controlling the output temperature and protecting the glass cover from damage during rainfall with hailstones. The design focused on the incorporation of a polymeric cover. The design takes into consideration the position of the focal line of the collector, therefore, the cover slider was placed at a point above the absorber pipe. A prototype of the resulting product will be installed on the roof top of Building 2 of the Faculty of Engineering and the Built Environment, Tshwane University of Technology, Staatsartillerie Road, 0183, Pretoria West Campus, Pretoria, South Africa.

In this work, a new solution to prevent the overheating of solar collectors in the case of stagnation is presented. The solution proposed consists of inserting a reflective sheet inside the solar collector between the absorber and the glass cover to reduce the incoming energy by reflecting solar radiation. This protection is switched ON or OFF according to the absorber temperature. A prototype has been manufactured and tested in outside conditions and in laboratory. The prototype was tested with different percentages of protection. With 50% of protection, the overheating problem is eliminated. A simplified numerical model of the solar collector with the protection was developed and has been validated. The calculated temperature values are very close to the measured data. The experimental and numerical results showed the good behaviour of the proposed solution.

Output power of Solar PV modules is significantly dependent on optical properties of the glass cover which may start degrading due to dust deposition on its surface from its very first day of installation. As dust concentration in atmosphere varies over different seasons, it causes variation of dust accumulation and also the optical properties of module glass cover. A dust chamber has been developed designed and fabricated in the laboratory to assess the change in optical properties (transmittance, reflectance and absorbance) of glass with respect to the amount of Shibpur roof-top dust accumulated on it. Experiment shows that transmittance due to dust deposition reduces from 85% to 35% depending on the deposited amount. From the study of PV power plant of IIEST, Shibpur, it is seen that dust deposition is the highest during spring. Similar results are also observed in two running PV power plants in Kolkata.

The Solar power plants with parabolic trough collectors (PTCs) represent more than 92% of the solar thermal power plants currently in operation. It is also the most suitable technology for most plants under construction and planned [1]. The present study evaluates the thermal performance of LS-2 parabolic trough collector of Solar Electric Generating System (SEGS VI) plant. A thermal model is developed for the solar receiver based on comprehensive energy analysis. The model has been validated with the experimental data from Sandia National Laboratory. Besides, the predictions from the model were compared with the published modeling studies (both on sun and off sun tests have been considered). In all cases, the results of the developed model show a good agreement with the experimental tests and the prediction results of the other models. Particular interest has been given for the impact of the glass cover diameter on the efficiency of the solar receiver.

Water and energy scarcity is one of the most important and biggest challenges facing many countries around the world. In rural communities, the traditional energy sources utilized for produce the freshwater may be not available. So, the hemispherical solar distillers are a good choice to produce the freshwater, which characterized by having a large surface area for receive and condensed compared to traditional single-slope solar distillers. The present work aims to achieve the highest freshwater productivity from the hemispherical solar distillers by combining two of the most effective modifications, namely, use of CuO nanoparticles to increase the evaporation rate, and use of glass cover cooling technology to increase the condensation rate. To obtain the influences of combining two effective modifications on the productivity of hemispherical distillers, three hemispherical distillers were constructed and tested at same climate conditions, namely; the conventional hemispherical distiller which represent the reference distiller, modified hemispherical distiller with CuO nanoparticles, and modified hemispherical distiller with CuO nanoparticles and glass cover cooling technology. The results presented that the combination between two effective modifications (CuO nanoparticles with 0.3% concentration and glass cover cooling technology) represents the good option which improving the freshwater productivity to 7.9 L/m2/day compared to 3.85 L/m2/day for reference distiller with an improvement of 105.2%. Also, the utilization of these two combined effective modification with 0.3% CuO nanoparticles concentration improves the daily efficiency by 101.5% compared to reference distiller.

The mechanism of formation and propagation of shear bands on the surface of a model Co69Fe4Cr4Si12B11 alloy amorphous wire 90 μm in diameter without a glass cover, which was subjected to different types of loading, such as uniaxial tension, drawing, bending, and torsion, is studied. For all applied loadings, the wire exhibits the ability to forming at a retained amorphous state. Depending on the type of loading, deformation is distributed either uniformly along the wire or is localized in a stress concentration zone. In this case, the contributions of forming mechanisms, namely, elastic deformation, ductile flow in the volume, and formation of shear bands on the wire surface, change. The wire is concluded to exhibit the pseudoplasticity effect.