Solar Cell Electrical Efficiency Research Articles

Impact of solar cell materials on the energy performance of SPVT air collector

The impact of roof-integrated semitransparent photovoltaic thermal (SPVT) air collectors connected in series for cold climates has been assessed using a new model established in this research. Numerical calculations have been performed using analytical formulae derived for the temperatures of the room air, roof, and solar cells. These findings have led to evaluations of the thermal, electrical, and overall exergy of various solar cell materials (Single-crystalline, Multi-crystalline silicon, Nanocrystalline -Silicon, Amorphous silicon, Cadmium Telluride and copper indium gallium selenide). According to the findings, amorphous silicon has the maximum peak solar cell electrical efficiency of 10.8% and single-crystalline has the minimum peak efficiency of 7.0% for the proposed system. Further, performance analysis has also been done based on different packing factor and mass flow rates.

Numerical analysis in thermal management of high concentrated photovoltaic systems with spray cooling approach: A comprehensive parametric study

High concentrator photovoltaic (HCPV) systems receive concentrated solar irradiation and operate at higher temperatures. It is challenging to control the cell temperature in a permittable range preventing overall performance destruction. In the present study, a comprehensive 3D numerical solution is performed to simulate spray cooling on a multijunction HCPV. The effective parameters are categorized as the distance from the nozzle to the surface, the thickness of the thermal paste, and the spray mass flow rate. The results indicate that the spray cooling method reduces the cell temperature below the allowable operating range (353 K). Increasing the distance from the nozzle to the surface raises the maximum cell temperature by 2–14 % in different concentration ratios, causing the cell temperature to exceed the permittable temperature range. Also, the temperature non-uniformity is within an acceptable range between 1.4 and 7.1 K for the minimum distance from the nozzle to the surface. Increasing the thermal paste thickness negatively affects the cell efficiency by increasing the cell temperature and non-uniformity. The cell temperature is reduced by spray mass flow rate, but the net cell output power is also reduced by 1–7 % as the required pumping power increases. At a fixed distance from the nozzle to the surface, the liquid film temperature increases with the concentration ratio, while the thermal efficiency remains almost constant. The best cooling performance was achieved at the minimum distance from the nozzle to the surface (5 mm) and minimum thermal paste thickness (0.5 mm), improving the solar cell's electrical efficiency by increment rate of 0.2 to 1.4 % (corresponding to concentrations of 250 to 1500 suns).

Investigation of Thermal Collector Nanofluids to Increase the Efficiency of Photovoltaic Solar Cells

Active cooling technology of photovoltaic thermal (PVT) system allows lowering the working temperature to increase the efficiency of photovoltaic (PV) solar cells. In addition, the absorbed heat produces thermal energy simultaneously through the working fluid in the collector. Therefore, in this study, the modeling of the riser configuration of the PVT collector for cooling PV solar cells was carried out using a working fluid and varied mass flow rates. It is used to find the effect of working fluid and mass flow rate on the resulting efficiency. ANSYS 18.2 system analysis software is used to simulate phenomena that occur. The natural convection phenomena of the PV cell layer were explored using ANSYS Steady State-Thermal. The simulation of the heat transfer phenomenon between the PV cell layer and the liquid was done using ANSYS Fluent. The improvement in energy generation efficiency achieved by utilizing a thermal collector system to cool PV solar cells reaches 49.8%. The maximum PV solar cell electrical efficiency value comes when the rectangular collector riser arrangement is modeled with SiO2 nanofluid working fluid and a mass flow rate of 0.01 kg/s. Each variation used was not significantly different from the efficiency of the PV solar cells produced.

Thermal Modeling of Opaque and Semi-Transparent Photovoltaic (PV) Module

Photovoltaic (PV) module is one of the simplest technologies to convert the solar energy into the useful electrical energy. In the present paper, an attempt has been made to develop a simplified analytical expression for solar cell temperature and solar cell electrical efficiency of opaque and semi-transparent photovoltaic module in the terms of design and climatic parameters. Based on the energy balance of opaque and semi-transparent PV module, the performance parameters, namely, solar cell temperature, solar cell electrical efficiency, module efficiency and electrical power output have been evaluated for a typical clear day of May month of New Delhi climatic condition data taken from IMD (Indian Meteorological Department), Pune, India. The numerical simulations have been made on the MATLAB software. Based on the numerical computation, the effect of back cover opaque and semitransparent tedlar of module on the performance parameters has been investigated. From the results and discussion, it is found that the performance of photovoltaic module is very sensitive to the module temperature. Further, it is concluded that the semi-transparent photovoltaic module is more efficient than the opaque one. Thus, by the application of semi-transparent PV module in the design of stand-alone and rooftop PV system, the overall energy requirement and performance can be improved for same occupied area.

Parametric study to understand the effect of various passive cooling concepts on building integrated semitransparent photovoltaic thermal system

In this paper, parametric study has been conducted for a Building integrated Semitransparent Photovoltaic Thermal (BiSPVT) system with various passive cooling parameters like water mass (heat capacity), water flow (evaporative cooling) and daylighting in one model. Study has been conducted for both hot climatic conditions. Also, effect of each parameter on the system has been studied and illustrated on various temperatures, electrical energy and solar cell electrical efficiency. A comparative study has been conducted for 4 cases namely (a) BiSPVT system (b) BiSPVT system with water flow (c) BiSPVT system with heat capacity and (d) BiSPVT system with water flow along with heat capacity to understand the impact of each and every parameter on the BiSPVT system. It has been observed that case (d) offers maximum cooling when compared to other cases (with cases b, c and a respectively following it). A drop of 38.84 °C in peak room temperature is found in case (d) when compared to case (a). The paper also presents the best cases suited for thermal heating and thermal cooling purpose.

New model for building-integrated semitransparent photovoltaic thermal system

A new model has been developed in this paper to evaluate the impact of different photovoltaic modules on room, floor, and solar cell temperature, along with daylight savings and solar cell electrical efficiency. Computations have been carried out on a building-integrated semitransparent photovoltaic thermal system integrated with the roof of a room for Varanasi climatic conditions in winter months. The electrical efficiency of the module and temperature coefficient impact the system's performance significantly. Mono-Si, poly-Si, amorphous Si, and Photovoltaic Thermal (PVT) systems are discussed. Compared with the previous model, the results of the study indicate that there is a 4.39% decrease in the overall exergy efficiency; hence, the PVT system is recommended for energy efficiency, and m-Si is suitable for electrical exergy.

Performance study and analysis of an inclined concentrated photovoltaic-phase change material system

The performance of an inclined concentrated photovoltaic-phase change material (CPV-PCM) system is investigated. The influence of a CPV-PCM system inclination angle in the range of −45° to 90° in an interval of 45°, with a concentration ratio (CR) of 5, and 20, and a phase change material thickness of 50, and 200mm, is considered. To determine the effect of these variables on the thermal and electrical behavior of the system, a comprehensive model comprising of the energy equations for CPV layers and a transient melting-solidification thermo-fluid model for the phase change material is developed. The model is numerically simulated, and the predicted results are validated using the available experimental and numerical data. Results indicate that the CPV-PCM system inclination angle has a notable effect on the time required to reach the complete melting state, the transient variation of average cell temperature, and PV local temperature uniformity. It is found that a remarkable reduction of the average solar cell temperature with enhanced uniformity is achieved, as the inclination angle varies from 0° to 90°. On the contrary, at an inclination angle of −45°, the maximum average temperature along with an unfavorable abrupt change of local cell temperature is obtained. In addition, at an inclination angle of 45°, the highest cell electrical efficiency is attained for the entire time period until complete melting occurs, whereas at an inclination angle of −45°, the solar cell electrical efficiency is dramatically reduced with time. The findings of the present study reveal that the CPV-PCM at an inclination angle of 45° reaches the minimum average temperature with reasonable uniformity of local solar cell temperature. These conditions achieve the highest solar cell electrical efficiency and help to prevent hot spots in the solar cell.

Exergy analysis of building integrated semitransparent photovoltaic thermal (BiSPVT) system

In this paper, an exergy analysis of building integrated semitransparent photovoltaic thermal (BiSPVT) system has been carried out. In the proposed system, the room below building integrated semitransparent photovoltaic thermal system has been considered as an air-conditioned (constant room temperature). Energy balance equation for each components namely semitransparent photovoltaic roof, floor and room air have been given. Based on energy balance, an analytical expression for room air, solar cell and room floor temperatures have been derived along with solar cell electrical efficiency. Further by considering the day lighting parameters, an overall exergy of the proposed system has been derived for different number of air change between the room and ambient air. It has been observed that there is reduction in room air and solar cell temperatures with an increase of number of air changes. However, solar cell electrical efficiency increases with decrease in temperature of solar cell. Further, it is found that an electrical power and illumination inside the room are more dominating in comparison with thermal exergy. An increase of 1.15% in an overall exergy is observed for the number of air changes varies from 0 to 4. Experimental validation of theoretical model has also been carried out.

Performance enhancement of concentrated photovoltaic systems using a microchannel heat sink with nanofluids

A new cooling technique for low concentrated photovoltaic–thermal (LCPV/T) systems is developed using a microchannel heat sink with nanofluids. In this study, Aluminum Oxide (Al2O3)–water and Silicon Carbide (SiC)–water nanofluids with different volume fractions are used as cooling mediums. The influence of cooling mass flow rate and nanoparticles volume fractions on the performance of LCPV/T system is investigated at different values of concentration ratio. A comprehensive model is developed which includes a thermal model for the photovoltaic layers, coupled with thermo-fluid dynamics of two-phase flow model of the microchannel heat sink. The model is numerically simulated to estimate the performance parameters such as the solar cell temperature and the electrical and thermal efficiency. Results indicate that a significant reduction in solar cell temperature is attained particularly at the high concentration ratio by using nanofluids compared to using water. Using SiC–water nanofluid achieves a relatively higher reduction in cell temperature than Al2O3–water nanofluid. By increasing the volume fraction of nanoparticles, both SiC–water and Al2O3–water nanofluids accomplish a major reduction of cell temperature. As a result, the use of nanofluids achieves higher solar cell electrical efficiency, particularly at lower Reynolds number (Re) and higher concentration ratio, than the use of water. The influence of nanofluids on thermal efficiency varies according to the concentration ratio. Furthermore, friction power increases with the increase in both Reynolds number and nanoparticle volume fraction. By increasing the volume fraction of the nanoparticle, the net electrical power increases at high concentration ratio while the thermal power decreases. The results of this study indicate that the use of nanofluids is effective cooling technique, particularly at high solar concentration ratios where the solar cell temperature reduces to 38°C, and electrical efficiency improves up to 19%.

A simple procedure to study the performance of individual solar cells in a linear concentrating photovoltaic/thermal integrated system

Performance analysis of photovoltaic/thermal (PV/T) integrated systems has drawn considerable interest among the researchers throughout the world. Recent publications on PV/T integrated systems, focussing mostly on the efficiency of a PV module, emphasise the need for studying the performance of individual solar cells within the module. In the present paper, the effects of temperature and water mass flow rate on both the system energy and exergy efficiencies are studied by illustrating the variation in individual solar cell temperature and its corresponding water temperature along the length of the module for multiple receiver configurations connected in series. For the system, it is found that, for a water temperature rise of 5°C and 50°C with water flowing at a rate of 0.0425kg/s at an inlet water temperature of 25°C, the solar cell electrical efficiency decreases by 0.4% and 3.7% respectively with respect to its rated efficiency of 16.8%, at 25%.

A simple procedure to study the performance of individual solar cells in a linear concentrating photovoltaic/thermal integrated system

Performance analysis of photovoltaic/thermal (PV/T) integrated systems has drawn considerable interest among the researchers throughout the world. Recent publications on PV/T integrated systems, focussing mostly on the efficiency of a PV module, emphasise the need for studying the performance of individual solar cells within the module. In the present paper, the effects of temperature and water mass flow rate on both the system energy and exergy efficiencies are studied by illustrating the variation in individual solar cell temperature and its corresponding water temperature along the length of the module for multiple receiver configurations connected in series. For the system, it is found that, for a water temperature rise of 5°C and 50°C with water flowing at a rate of 0.0425kg/s at an inlet water temperature of 25°C, the solar cell electrical efficiency decreases by 0.4% and 3.7% respectively with respect to its rated efficiency of 16.8%, at 25%.