Temperature Of Photovoltaic Panel Research Articles

Thermal Profile of a Low-Concentrator Photovoltaic: A COMSOL Simulation

With the gradual reduction of fossil fuels, it is essential to find alternative renewable sources of energy. It is important to take advantage of substitutes that are less expensive and more efficient in energy production. Photovoltaic concentrators (CPVs) are effective methods through which solar energy can be maximized resulting in more conversion into electrical power. V-trough concentrators are the simplest types of low-CPV in terms of design as it is limited to the use of two plane mirrors with a flat photovoltaic (PV) plate. A consequence of concentrating more solar radiation on a PV panel is an increase in its temperature that may decrease its efficiency. In this work, the thermal profile of the PV plate in a V-trough system will be determined when this system is placed in different geographical locations in Saudi Arabia. The simulation is conducted using COMSOL Multiphysics software with a ray optics package integrated with a heat transfer routine. The 21st of June was chosen to conduct the simulation as it coincides with the summer solstice. The employment of wind as a cooling method for V-troughs was investigated in this work. It was found that with the increase in wind speed, the PV panel temperature dropped significantly below its optimum operating temperature. However, due to the mirrors’ attachment to the PV panel, the temperature distribution on the surface of the panel was nonuniform. The temperature gradient on the PV surface was reduced with the increase of wind speed but not significantly. Reducing the size of the mirrors resulted in a partial coverage of solar radiation on the PV surface which helped in reducing the temperature gradient but did not eliminate it. This work can assist in testing numerous cooling models to optimize the use of V-troughs and increase its efficiency especially in locations having high ambient temperatures.

Strategies for effective cooling of photovoltaic panels integrated with solar chimney

Solar chimney is a self-functioning technology to meet human’s daily power requirements. These days research on solar chimney for power generation has been more focused among scientific community. Many previous designs have been proposed to increase the performance of the solar chimney. To increase the turbine power Pwt generation the airflow velocity V at the turbine location has to be enhanced as Pwt∝V3. The present study demonstrated a numerical study of hybrid solar chimney power plant (HSCPP) where collector inlet has been integrated with bell-mouth shape opening and photovoltaic (PV) panel at the collector bottom. New hybrid designs of converging collector channel-divergent chimney integrated with bell-mouth design inlet improved the flow velocity by 71% and decreases the PV panel temperature by 8–12 °C. The increased flow velocity enhances the turbine power output beyond 200%.

Photovoltaic Panel Temperature Monitoring and Prediction by Raman Distributed Temperature Sensor With Fuzzy Temperature Difference Threshold Method

Solar cells can operate at a lower efficiency after a certain temperature, which is caused by a negative thermal coefficient. Therefore, the temperature prediction of photovoltaic (PV) modules is critical to accurately evaluate the efficiency of photovoltaic devices. We propose and experimentally demonstrate a Fuzzy Temperature Difference Threshold Method (FTDTM) based on Raman Distributed Temperature Sensor (RDTS) system for the detection and prediction of PV module temperature. The FTDTM consists of four steps, i.e., division of the universe, establishment of fuzzy relationships, definition of relationship matrix and calculation of predicted temperature. The experimental results show that the proposed RDTS can detect and accurately predict temperature trends by using the FTDTM. When the system window base of the FTDTM is set to 2, the average absolute error of the predicted temperature is 1.08 °C, and the fluctuation range of prediction error is ±3.7 °C. In addition, the experiment studied some factors affecting temperature distribution characteristics of PV modules, including solar radiation intensity, surface dust and inclination angle. We provide a solution for large-scale PV module temperature detection and early warning through RDTS systems with FTDTM.

Experimental and economical performance investigation of V-trough concentrator with different reflectance characteristic in photovoltaic applications

Lack of consideration of photovoltaic panel temperature in a concentrating photovoltaic (CPV) system causes a great misconception and leads to the financial risk of system installation since the increment in PV cell temperature significantly reduces the performance. In this study, an energy-efficient and cost-effective V-trough PV system with low-temperature configuration was proposed to achieve better performance by using easily accessible reflector material instead of the high reflective anodized aluminum reflector with high cost. The concentrating photovoltaic systems were designed, produced, and installed. Anodized aluminum reflector (AAR) protected with nanocomposite using a coil-coating, and polished stainless steel (PSSR) were used as reflector mirrors. The electrical performance parameters of CPVs were experimentally analyzed as a function of cell temperature and compared with a 1-Sun PV system. The net present value (NPV) method was used for the economical evaluation of the system. The results indicate that high reflectivity can cause the temperature elevation in the PV cell thereby decreasing the fill factor, voltage, and power output of the system. The power generation of the AAR-CPV system was about 17.4% lower than that of the 1-Sun PV system due to higher cell temperature. On the other hand, a low reflective PSSR-CPV system generates about 17.84% and 42.7% higher power compared to 1-Sun PV and AAR-CPV systems, respectively. The payback period of PSSR-CPV appears to be 6 years and is equal with that of the PV system on a yearly basis, however, PSSR-CPV yields a greater return. An easily accessible polished stainless steel having reasonable reflectivity may be a better attitude for increasing the incident solar irradiation with a slight increase in the PV cell temperature for a CPV system based upon the economical and experimental analysis for a cost-effective and energy-efficient design of CPV technology.

Advances of Solar PV System Output Improvement through Cooling Technologies in Malaysia

Solar photovoltaic (PV) panel is the most widely used renewable energy technology in Malaysia due to constant irradiation throughout the year as the country is located near the equator. According to the current state of the Malaysian weather, the ambient temperature is around 25°C and can go up to 30°C. The electrical efficiency of a PV panel is sensitive towards temperature where it is known that the power and efficiency decrease at the rate of ±0.5%/°C and ±0.05%/°C respectively as the ambient temperature increases [1]. This paper discusses the cooling of solar PV technologies, the methodologies of the cooling system and its effectiveness. Generally, the effectiveness of the studies conducted were derived from the solar PV panel temperature reduction and solar PV electricity power output increment. This paper elaborates the trend of methodologies for cooling of solar PV in Malaysian climate. The methodologies that were used by the researchers vary according to the specific objectives which can be categorized as active cooling and/or passive cooling. The gaps of the studies were also identified alongside with the possible solutions to mitigate the problems.

Modelling of a Single Passage Air PV/T Solar Collector: Experimental and Simulation Design

The hybrid photovoltaic/thermal solar collector has attracted research attention for more than five decades. Its capability to produce thermal energy simultaneously with electrical energy is considered attractive since it provides higher total efficiency than stand-alone photovoltaic or thermal systems separately. This paper describes theoretical and experimental studies of a finned single pass air-type photovoltaic/thermal (PV/T) solar collector. The performance of the system is calculated based on one dimensional (1D) steady-state analysis using one dimensional energy balance equations, where simulation was carried out using MATLAB. Experiments were carried out to observe the performance of the solar collector under changes in air mass flow rate. Experimental values on photovoltaic panel temperature and air temperature on both air inlet and outlet, together with the ambient temperature and solar radiation were measured. The simulation results were validated against the results obtained from experiments using the error analysis method, Root Mean Square Error. At a solar irradiance level of 800 to 900 W/m2, the thermal efficiency increases to 20.32% while the electrical efficiency increases to 12.01% when the air mass flow rate increases from 0.00015 kg/s to 0.01 kg/s. The error analysis shows that both experimental and simulation results are in good agreement.

Thermal properties of a new type of calcium chloride hexahydrate-magnesium chloride hexahydrate/expanded graphite composite phase change material and its application in photovoltaic heat dissipation

PV-PCM technology can not only achieve higher photoelectric conversion efficiency, but also has the advantages of energy saving, high efficiency, and economical applicability. In this paper, a new type of CaCl2·6H2O-MgCl2·6H2O composite PCM for PV-PCM was prepared by physical blending method using calcium chloride hexahydrate-magnesium chloride eutectic mixture as PCM and expanded graphite as carrier. The shape stability, thermal properties and thermal reliability of CaCl2·6H2O-MgCl2·6H2O eutectic materials under EG conditions were discussed. The change of temperature and output power of PV panel combined with PV-PCM was studied. The experimental results show that the CaCl2·6H2O-MgCl2·6H2O composite with 8 %EG has high phase change enthalpy (171.4 kJ/kg), suitable phase change temperature (27.1 °C), and negligible supercooling degree (0.11 °C) and excellent thermal conductivity (3.359 W/m·K). After 100 heating–cooling cycles, the modified composite phase change material still has excellent thermal reliability. Surface temperature of photovoltaic panels can be significantly reduced, and the average temperature of photovoltaic panels can be kept below 40 °C. The photovoltaic panel power can work for a long time (3.5–4 h) close to the rated power, keeping the photovoltaic panel power at a high and stable state, and producing 7.9% more power than using only photovoltaic panels to generate electricity.

Operation of a PV Power Plant during Overpower Events Caused by the Cloud Enhancement Phenomenon

Partly cloudy days possess two characteristics that can significantly increase the photovoltaic (PV) generator power: the operating temperature of the PV panels can cool down during the shade periods, and the irradiance can be enhanced due to the cloud enhancement phenomenon. If an overirradiance event is preceded by a long shade period, the maximum power of a PV generator can occasionally be much higher than the nominal nameplate power. During the overpower events, the inverter is operating in power-limiting mode whereby the operating voltage is increased to decrease the power of the PV generator. We created a simulation model of a 31.9 kW PV generator and used 12 months of irradiance and PV panel temperature measurement data to analyze its operation. We analyzed the PV generator power during the overirradiance events and applied various static power limits to calculate the operating voltage ranges in case of power curtailment. During the observation period, the maximum power produced by the PV generator was 1.42 times its nominal power. The duration of the overpower events was up to several minutes, but the typical duration was only some tens of seconds. The strongest overpower events occur seldom and their duration is only some seconds. Due to the overpower events, the operating voltage may receive high values, especially if the DC-to-AC power ratio is large.

Performance enhancement of photovoltaic panels using two types of nanofluids

AbstractOne of the main problems that limit the extensive use of photovoltaic (PV) systems is the increase in the temperature of PV panels. Overheating of a PV module decreases the performance of the output power by 0.4% to 0.5% per 1°C over its rated temperature that in most cases is 25°C. An effective way of improving electrical performance (power output and efficiency) and reducing the rate of thermal degradation of a PV module is to reduce the operating temperature of the PV surface by a cooling medium. To achieve this, nanofluids can be considered as a potentially effective solution for cooling. In this study, two types of nanofluids, namely Al2O3 and TiO2 water‐based mixture of different volume flow rates and concentrations (0.01%, 0.05%, and 0.1%) by weight, were used. Also, three PV panels were cooled simultaneously using nanofluids, water, and natural air, respectively. Results showed that nanofluids for cooling enhanced heat transfer rate much better than water and natural air. Best results were achieved for TiO2 nanofluids at the considered concentration (0.1 wt%). Nanofluid cooling of turbulent flows for such an application has not been investigated before. These results represent the first application of nanofluid cooling in the turbulent flow regimes and in outdoor conditions including real solar irradiation.

Southerly winds increase the electricity generated by solar photovoltaic systems

The urgent need to decarbonise energy supplies has prompted exponential growth of solar photovoltaic (PV) systems across the world. As the penetration of renewable energy sources increases, the need to accurately forecast electricity output heightens to ensure efficient energy system operation. While exposure to high temperatures and moisture are known to significantly reduce PV panel efficiency, the effects of wind on both PV panel temperature and electricity output are poorly resolved. Here, meteorological and PV panel production data from Westmill Solar Park, Oxfordshire, were examined to determine the influence of wind, cloud, ambient temperature and relative humidity. We found that, after solar radiation, relative humidity and cloud cover were the dominant controls of PV electricity output; increases in relative humidity and cloud cover were associated with decreased electricity outputs. However, when all other variables were held constant, the mean electricity generated under southerly winds was 20.4 – 42.9% greater than under northerly winds, with the difference greater at higher electricity outputs and attributable to differences in surface cooling capabilities caused by the PV array asymmetry. This finding suggests that PV electricity output predictions could be improved by incorporating wind direction into computer models. Moreover, there is potential to modify solar park design and deployment location to capitalise on wind benefits, especially in areas where panel temperatures are a leading cause of efficiency loss. Ensuring deployments are optimised for site environmental conditions could boost electricity outputs, and therefore profitability, with implications for system viability in post-subsidy markets.

Intelligent Nero modelling methods for PV panel system

Nonlinear system identification modelling for the temperature of photovoltaic (PV) panel has been conducted in this work. In the beginning, an experimental work has been extracted from previous work in order to collect the input (ambient temperature, humidity, irradiance and wind speed) and output (PV module temperature) parameters. Then, Neural Network time series and Adaptive Neuro-Fuzzy Inference System (ANFIS) models represented as system identification method to predict the temperature of PV panel as an output for the system. Both of modelling methods verified using mean square error (MSE). The effectiveness of all methods has been compared to know which method is the batter. Finally, the achieved results stated that the ANFIS method recorded the lowest MSE of 2.2627*10−7 compared with NARX method which recorded of 5.078. ANFIS technique proved that will be able to use it in the control process in future.

The influence of dust deposition on the temperature of soiling photovoltaic glass under lighting and windy conditions

Module temperature has significant influence on the energy harvest and energy conversion efficiency of solar cells, which varies greatly with dust deposition and the wind-blowing. In this paper, several sets of experiments were carried out to test the temperature of soiling photovoltaic glass plate under lighting and windy conditions. The results indicate that the temperature of the upper and lower surface is much higher than that of the clean glass plate, and the dust deposition can exert great impact on the temperature of lower surface compared with that on the upper surface. At the same time, under the lighting and windy conditions, the maximum temperature of the photovoltaic glass plate decreases exponentially with increasing wind speed. The final temperature of clean glass plate tends to be consistent with the ambient one, while the temperature of dusty glass plate is much higher than air temperature. Through simulating the external electromagnetic field of spherical particle irradiated by the plane wave, we firstly found that the deposition particles can result in light convergence in its wavefront direction, and the light intensity can also be enhanced, significantly heating the glass plate. All our preliminary results throw light on the effect of dust deposition on the photovoltaic panel temperature in the desert, which can be helpful to establish a more reliable physical model of photovoltaic power generation efficiency involving environmental factors.

Climate response of a BiPV façade system enhanced with latent PCM-based thermal energy storage

Building-integrated photovoltaic (BiPV) systems applied within a building envelope exhibit limited efficiency and durability due to their insufficient cooling capabilities. Thus, the need to decrease their operating temperature and increase overall electricity production poses relevant research challenges. The application of a phase change material (PCM) to the rear side of a PV module can provide both a decrease in PV panel temperature and thermal energy storage as well. The objective of the presented study is to identify the climate response of latent thermal energy storage (TES) integrated into a ventilated photovoltaic (PV) façade system. The main attention is focused on the thermophysical properties of the employed PCM in terms of the utilization of its overall latent heat capacity through the diurnal cycle of a day in the context of the mutual interaction between incident solar radiation and outside air temperature. A comparative investigation was conducted using experimental measurements taken during outdoor climate tests with the aim of determining the real performance of the façade system. The experimental results revealed that the effect on PV panel operating temperature of installing the selected PCM on the rear side of the panels is significant mainly at midday when high solar radiation is present.

Enhancement of wind speed using converging duct for cooling off‐grid mast‐mounted flat solar PV panels to improve its power generation

The potential of wind speed for cooling a mast-mounted solar photovoltaic (PV) panel is tapped by placing a converging duct in the windward direction of the PV panel mounting. Owing to this arrangement, the wind speed beneath the PV panel is increased, which resulted in decrease of the operating temperature of PV panel and increase in PV electrical power generation. The wind speed is increased by a factor of 1.5, which reduced the temperature of PV panel by 2–3°C and increased the electrical output power by 0.7 W. Correlations in terms of ambient temperature, solar irradiation and wind velocity were developed for predicting the PV panel temperature and were validated with the experimental values.

Numerical and Experimental Investigation of Air Cooling for Photovoltaic Panels Using Aluminum Heat Sinks

An increase in the operating temperature of photovoltaic (PV) panels caused by high levels of solar irradiation can affect the efficiency and lifespan of PV panels. This study uses numerical and experimental analyses to investigate the reduction in the operating temperature of PV panels with an air-cooled heat sink. The proposed heat sink was designed as an aluminum plate with perforated fins that is attached to the back of the PV panel. A comprehensive computational fluid dynamics (CFD) simulation was conducted using the software ANSYS Fluent to ensure that the heat sink model worked properly. The influence of heat sinks on the heat transfer between a PV panel and the circulating ambient air was investigated. The results showed a substantial decrease in the operating temperature of the PV panel and an increase in its electrical performance. The CFD analysis in the heat sink model with an air flow velocity of 1.5 m/s and temperature of 35°C under a heat flux of 1000 W/m2 showed a decrease in the PV panel’s average temperature from 85.3°C to 72.8°C. As a consequence of decreasing its temperature, the heat sink increased the open-circuit photovoltage (VOC) and maximum power point (PMPP) of the PV panel by 10% and 18.67%, respectively. Therefore, the use of aluminum heat sinks could provide a potential solution to prevent PV panels from overheating and may indirectly lead to a reduction in CO2 emissions due to the increased electricity production from the PV system.

Simulation study on photovoltaic panel temperature under different solar radiation using computational fluid dynamic method

The electrical production is the primary performance of any solar photovoltaic (PV) system. The PV panel operating temperature is inversely proportional to the electrical production of the PV panel. The operating temperature of PV panel is influenced by solar radiation absorbed and the ambient temperature. In the present work, Computational Fluid Dynamics (CFD) method is used to investigate a three-dimensional (3-D) model of a PV panel. It is also essential to estimate the thermal behaviour of the PV panel under various environmental conditions. The primary purpose of this current work is to analyse temperature distribution from the PV panel under given operating conditions. The model geometry is built by using CATIA design software. ANSYS software was simulated the different intensity of solar radiation that applied to the PV panel in order to observe the temperature distribution on each layers of the PV panel. The ambient temperature of the simulation is fixed 35 °C according to the maximum ambient temperature captured in Malaysia. The simulation results show that an increase in solar radiation intensity along with the PV panel operating temperature increase.

Progress of MWCNT, Al 2 O 3 , and CuO with water in enhancing the photovoltaic thermal system

Hybrid photovoltaic thermal system is an effective method to convert solar energy into electrical and thermal energy. However, its effectiveness is widely affected due to the high temperature of photovoltaic panel, and it can be minimized by employing nanofluids to the PV/T systems. In this research, the effect of various nanoparticles on the PV/T systems was studied experimentally. The nanofluids Al2O3, CuO, and multiwall carbon nanotube (MWCNT) were dispersed with water at different volume fractions of 0, 0.5, 1, 2.5, and 5 (vol%) using ultrasonication process. The effect of nanomaterials on viscosity and density was classified. All tests were carried out in an outdoor laboratory setup for calibrating the PV temperatures, thermal conductivity, electrical power, electrical efficiency, and overall efficiency. In addition, the energy analyses were also made to estimate the loss of heat owing to the nanofluids. Results show that use of the nanofluid increased the electric power and electrical efficiency of PV/T compared with water. Furthermore, MWCNT and CuO reduced the cell temperature by 19%. Consequently, the nanofluids MWCNT, Al2O3, and CuO produced the impressive values of 60%, 55%, and 52% increase in an average electrical efficiency than conventional PV. Particularly, the MWCNT produced superior results compared with other materials. It is evidently clear from the result that the introduction of the nanofluid increases the thermal efficiency without adding any extra energy to the system. Moreover, insertion of Al2O3, CuO, and MWCNT on PV/T system increases the exergy efficiency more than conventional PV module.

Experimental study conducted for the identification of best heat absorption and dissipation methodology in solar photovoltaic panel

The solar PV technology has become a significant alternative for conventional fossil fuel resources. The recent researches are focusing on techniques to increase the efficiency of the solar photovoltaic (PV) systems to address the growing needs of the global electricity demand. Maintaining the PV panel temperature according to the specified standard helps in harnessing the optimal power output consistently. Although there are various PV panel cooling techniques available in the existing literature, there is always a huge expectation among the energy sectors in terms of rising the efficiency value, as well as lowering the cost of investment.In this aspect, the proposed method provides the best solution by improving the efficiency of the solar photovoltaic panel by regulating the temperature using a material called as the Phase Change Material which is entrenched with an external finned heat sink to improve the thermal conductivity of the material PCM. In this work, the concept is investigated by an experimental setup under direct sun rays in the natural environmental conditions for four different cases (Case A, Case B, Case C, and Case D). The concept of temperature regulation is recorded through FLIR thermal imaging camera and the observations are presented. After thorough experimental investigations of all the four cases, it is found that PCM entrenched with heatsink (Case D) can certainly be an efficient approach to drop the operating temperature of the PV panel with lowest cost and enhance the efficiency of the PV panel to the maximum extent.

Agrivoltaics provide mutual benefits across the food–energy–water nexus in drylands

The vulnerabilities of our food, energy and water systems to projected climatic change make building resilience in renewable energy and food production a fundamental challenge. We investigate a novel approach to solve this problem by creating a hybrid of colocated agriculture and solar photovoltaic (PV) infrastructure. We take an integrative approach—monitoring microclimatic conditions, PV panel temperature, soil moisture and irrigation water use, plant ecophysiological function and plant biomass production within this ‘agrivoltaics’ ecosystem and in traditional PV installations and agricultural settings to quantify trade-offs. We find that shading by the PV panels provides multiple additive and synergistic benefits, including reduced plant drought stress, greater food production and reduced PV panel heat stress. The results presented here provide a foundation and motivation for future explorations towards the resilience of food and energy systems under the future projected increased environmental stress involving heat and drought. Agrivoltaics can achieve synergistic benefits by growing agricultural plants under raised solar panels. In this article, the authors showed that growth under solar panels reduced tomato and pepper drought stress and increased production, while simultaneously reducing photovoltaic panel heat stress.

Hybrid photovoltaic-thermal systems utilizing liquid-gas phase change material

ABSTRACT The efficiency of photovoltaic (PV) panels is a function of temperature. Efficiency decreases by 0.5%°K−1 after 25°C. Phase change material (PCM) technology due to its ability to store and transmit heat is widely adopted as a cooling medium in the present-day research. This research articulates MATLAB simulation and modeling of integrated photovoltaic-thermal (PV-T) system, utilizing acetone to attain the desired objective of cooling PV panels and generating hot water in a simultaneous manner under the climatic conditions of Jalandhar, India. The reduction in temperature of PV panel with cooling system was 8.8°C compared to standalone PV systems. The thermal system is designed for generating hot water at 50°C.The temperature of the water can be increased up to 70°C by reprogramming the microcontroller.