Photovoltaic Thermal Module Research Articles

Numerical Study of Integrated Solar Photovoltaic–Thermal Module with a Refrigeration System for Air-Conditioning and Hot Water Production under the Tropical Climate Conditions of Singapore

Thermal systems of buildings in the tropics are highly energy intensive. In this study, a novel integrated solar photovoltaic–thermal–refrigeration (PVTR) system used to produce hot water and air-conditioning in the tropical climate conditions of Singapore was analyzed. A dynamic simulation model was formulated for the analysis. Mathematical models were developed for the PV sandwich attached with a solar flat plate collector and for the main components of the refrigeration system. Thorough investigation of the electrical and thermal performances of the system were conducted through the analysis of coefficient of performance (COP), cooling capacity, water temperature and heat capacity in water heater, photovoltaic (PV) module temperature and PV efficiency. The results show that attractive electrical and thermal performance can be achieved with a maximum annual cooling COP of 9.8 and a heating COP of 11.3. The PV efficiency and power saving were 14% and 53%, respectively. The annual cooling, heating and PV energy produced were 9.7, 15.6 and 1.6[Formula: see text]MWh, respectively. The financial payback period of the system was 3.2 years and greenhouse gas (GHG) emission reduction annually was 12.6 tons of CO2 equivalents (tCO2e).

Design and performance study of a low concentration photovoltaic-thermal module

Design and performance study of a low concentration photovoltaic-thermal module

Tests and theoretical analysis of a pvt hybrid collector operating under various insolation conditions

The main goal of the study was to investigate the relationship between the orientation of the PVT (PhotoVoltaic Thermal) collector and the thermal and electric power generated. Extensive research was performed to find optimal tilt angles for hybrid solar thermal collectors, which combine photovoltaic as well as thermal collection in a single unit, known as PVT (PhotoVoltaic Thermal) modules for an office building with working hours between 7.00 and 16.00. The comprehensive study included field measurements of the modules in central Poland and tests under AM (air mass) 1.5 conditions in a certified laboratory KEZO (Centre for Energy Conversion and Renewable Resources) Polish Academy of Sciences in Jablonna. Furthermore, a PVT system was investigated using the simulation method based on the dedicated Polysun software. The PV characteristics and efficiency of the PV module and the relation between power or efficiency of the PVT module and incidence angle of solar-irradiance were studied. Optimal work conditions for commercial PVT modules were ascertained. In addition, it was found that the maximum efficiencies of PV module (ηPV), solar thermal-collector (ηc) and PVT hybrid collector (ηPVT) registered under field conditions were higher than the ones measured under laboratory conditions.

Optimal Utilization of Renewable Energy in Aquaponic Systems

Aquaponic systems require energy in different forms, heat, solar radiation, electricity etc. Typical actuator components of an aquaponic system include pumps, aerators, heaters, coolers, feeders, propagators, lights, etc., which need electrical energy to operate. Hybrid Energy Systems (HES) can help in improving the economic and environmental sustainability of aquaponic systems with respect to energy aspects. Energy management is one of the key issues in operating the HES, which needs to be optimized with respect to the current and future change in generation, demand, and market price, etc. In this paper, a Decision Support System (DSS) for optimal energy management of an aquaponic system that integrates different energy sources and storage mechanisms according to priorities will be presented. The integrated model consists of photovoltaic and solar thermal modules, wind turbine, hydropower, biomass plant, CHP, gas boiler, energy and heat storage systems and access to the power grid and district heating. The results show that the proposed method can significantly increase the utilization of HES and reduce the exchange with the power grid and district heating and consequently reduce running costs.

Performance evaluation of a novel solar photovoltaic–thermal collector with dual channel using microencapsulated phase change slurry as cooling fluid

In a photovoltaic–thermal solar collector, only a small percentage of the absorbed solar radiation can be converted into electricity, the rest is converted into heat. The waste heat gathering and transferring rate is the key to improve the module efficiency. In this work, a type of microencapsulated phase change slurry was employed in the photovoltaic–thermal solar collectors to improve the thermal and electrical performances. The designed photovoltaic–thermal collector was reduced to a 2–dimension physical model and numerically studied. Solar cells temperature, outlet temperature and pressure drop of the fluid, electrical, thermal and overall net efficiency were simulated and analyzed to evaluate the dynamic performance of the hybrid photovoltaic–thermal collector. Energetic efficiencies for photovoltaic–thermal model with various light concentrations versus the mass flow rate of the microencapsulated phase change slurry flow were investigated. When the concentration is 10wt%, the photovoltaic–thermal collector obtained the highest net efficiency with the flow rate of 0.02kg/s and the piping height of 10mm. And it was found that the temperature variation of both fluid and PV cells employing microencapsulated phase change slurry was much smaller than water, which would improve both thermal and electrical performances. Then the optimized photovoltaic–thermal module was simulated in a daytime with the comparison of conventional water type. It was found that overall net efficiency of the photovoltaic–thermal collector with microencapsulated phase change slurry reached 80.57% at 11:00, about 1.8% higher than the conventional water type. The maximum overall net exergy efficiency was 11.4% in the morning. Above all, the proposed photovoltaic–thermal collector with microencapsulated phase change slurry flow has potential for further development in solar collector.

A Three-Dimensional Comprehensive Numerical Investigation of Different Operating Parameters on the Performance of a Photovoltaic Thermal System With Pancake Collector

Performance of photovoltaic (PV) module decreases significantly with increasing cell temperature due to its overheating. Photovoltaic thermal (PVT) is an optimized technology that facilitates effective removal and utilization of this excess heat leading to enhanced electrical performance. In this article, a 3D numerical model has been developed and analyzed to investigate the PVT performance with a new pancake-shaped flow channel design. This flow channel is attached directly to the backside of PV module by using thermal paste. The governing equations are solved numerically by using Galerkin's weighted residual finite-element method (FEM), which has been developed using COMSOL Multiphysics® software. The numerical results show that the cell temperature reduces on an average 42 °C, and the electrical efficiency and output power increase by 2% and 20 W, respectively, for both aluminum and copper channels with an increase in inlet velocity from 0.0009 to 0.05 m/s. On the other hand, overall efficiency of the PVT system drops about 13% in both cases as the inlet temperature increases from 20 °C to 40 °C. Cell temperature is found to increase approximately by 5.4 °C and 9.2 °C for every 100 W/m2 increase in irradiation level of the PV module with and without cooling system, respectively. Regarding flow channel material, it has been observed that use of either copper or aluminum produces almost similar performance of the PVT module.

PVT 모듈에서의 유입수 온도에 따른 전력효율 특성에 관한 실험적 연구

A photovoltaic-thermal (PVT) system can generate thermal and electrical energy simultaneously. In general, photovoltaic panels are located on the front side and a thermal collector is on the back side of the PVT module. Therefore, thermal and electrical energy can be generated simultaneously. A photovoltaic-thermal system has another benefit by helping to overcome the decrease in power efficiency of the photovoltaic system increasing panel surface temperature. In this study, a photovoltaic-thermal SET (Separate effect test) system has been developed for testing air and/or fluid type photovoltaic thermal module. Several experiments were carried out with the module. performance test results showing the characteristics of the efficiency increase with the using water as the heat transfer media. Three experiments were conducted: Case A, Case B and Case C which were conducted at different inlet water temperatures. The results show that the efficiencies of power generation is increasing as 8.32% from 173.11 W to 187.51 W when the PVT module temperature is decreasing as 40℃ to 20℃ at the same test condition.

Performance of photovoltaic cells in photovoltaic thermal (PVT) modules

Integrating cooling systems with photovoltaic (PV) modules represents a very important aspect of keeping modules within acceptable operating temperatures. The objective of this study is to analyse the performance of each series-connected PV cell in photovoltaic thermal (PVT) modules. The importance of this analysis is due to the consideration of the variable operating temperature values of the PV cells, resulting in a different performance of each PV cell. The PVT modules are cooled with water serving as both a heat sink and a solar heat collector. This enhances the electrical efficiency value of the PVT modules by preventing them from elevated temperature values, while the recovered thermal energy can be utilised to increase the overall PV effectiveness. The new consideration in this study over the existing ones is the temperature distribution of each PV cell is applied for the calculation of the current voltage characteristics of the PV modules, which makes the analysis more accurate. The variance in the temperature values is a result of the temperature gradient of the fluid flowing through the pipes where the heat exchange differs in the flow direction. The potential of this study becomes more important for countries of high ambient temperatures and high solar intensity.

Performance monitoring and modeling of an uncovered photovoltaic-thermal (PVT) water collector

PVT technology presents many attractive features for a wide application in the building sector since it is able to produce electricity and thermal energy at the same time with better overall performances and reduced surfaces in comparison with the two separated solar technologies. However the effectiveness of the PVT modules is most evident when they are integrated in complex systems, capable of fully exploiting their multi-functionality (e.g. heat pump coupling, multi-storage interconnection, etc.). For that reason, the research work presents a mathematical model for energy simulation of PVT systems, which takes in account all factors and parameters involved in the energy performance of an uncovered hybrid collector; the model can be easily implemented in any performance calculation tool in order to carry out technical–economic assessment of PVT systems.The experimental calibration and validation of the proposed model was performed in outdoor conditions on a commercial PVT product, at the Test Facility of the Politecnico di Milano University, and finally the model was ran supposing the application in three different locations. The validation of the developed simulation model shows a good agreement with monitored data also if a mismatch occurred due to an assembling defect of the tested commercial PVT component.

Efficiency maximization and performance evaluation of hybrid dual channel semitransparent photovoltaic thermal module using fuzzyfied genetic algorithm

The work has been carried out in two steps; firstly the parameters of hybrid dual channel semitransparent photovoltaic thermal module has been optimized using a fuzzyfied genetic algorithm. During the course of optimization, overall exergy efficiency is considered as an objective function and different design parameters of the proposed module have been optimized. Fuzzy controller is used to improve the performance of genetic algorithms and the approach is called as a fuzzyfied genetic algorithm. In the second step, the performance of the module has been analyzed for four cities of India such as Srinagar, Bangalore, Jodhpur and New Delhi. The performance of the module has been evaluated for daytime 08:00AM to 05:00PM and annually from January to December. It is to be noted that, an average improvement occurs in electrical efficiency of the optimized module, simultaneously there is also a reduction in solar cell temperature as compared to un-optimized module.

Thermal and electric performances of roll-bond flat plate applied to conventional PV modules for heat recovery

Photovoltaic thermal (PVT) modules can increase the renewable energy production by combining the electricity and heat generation. PVT are seen as promising technology for residential applications where the heat can be exploited on site. In this work, the performances of three different PVT modules are evaluated in real operating conditions at the SolarTechLAB. Performance evaluation is conducted both by means of conventional and innovative performance indexes (corrected thermal efficiency and second law efficiency) which are expressly introduced in this work to take into account PVT peculiarities. Dedicated experiments outlined the importance of adopting these peculiar indexes when comparing different PVT modules. In terms of heat recovered, the best roll-bond configuration increases the thermal efficiency by 8% points with respect to the conventional sheet-and-tube one. PVT modules have lower thermal efficiency than commercial only thermal modules (41% vs. 55%), however, the second law efficiency outlines the advantages of producing electricity and heat instead of only heat (16% vs. 2%).

Experimental photovoltaic-thermal Power Plants based on TESPI panel

Solar energy can be used to produce thermal energy, by means of thermal solar panels and electrical energy, using photovoltaic (PV) modules. In urban and suburban areas, because of a limited number of surfaces apt for installation of solar systems, the full development of both technologies can be limited.The integration of solar, thermal, and PV modules into a single unit, the so-called photovoltaic thermal (PV-T) module, could be a possible solution to generate electrical energy and heat simultaneously on the same surface.Many technical solutions are currently available; however, in this study, the analysis is limited to liquid-cooled nonconcentrating PV-T collectors where c-Si cells are used. In particular, the experimental results of two pilot plants, based on patented panels, named TESPI – thermal electric solar panel integration, are presented. The main advantage of these modules is that they represent a retrofit of existing PV plants. In fact, they can be installed on top of conventional PV modules as they are based on the infrared filtering effect of water on solar radiation. A standard test for hybrid PV-T systems for developing new solutions and measuring their performance was designed. In order to improve the design of modules and check their behavior in typical domestic hot water systems, two different PV-T solutions, but with identical PV modules, were analyzed without the heat transfer system. The prototypes are made of two systems (PV and PV-T) installed on two Italian sites, Enna (Sicily) and Pisa (Tuscany), characterized by typical Mediterranean climate. In this study, PV-T systems were analyzed at a PV string level. Different operating conditions were tested and electrical and thermal critical operating conditions were detected.

Design, modeling and performance analysis of dual channel semitransparent photovoltaic thermal hybrid module in the cold environment

In this work, thermal modeling and performance analysis of the dual channel semitransparent photovoltaic thermal (DCSPVT) module has been carried out. For extracting heat associated with the lower and upper surface of the solar cell, two channels have been proposed; (i) one is above the solar cell called upper channel and (ii) second is below the solar cell called lower channel. Firstly, thermal modeling of DCSPVT module has been developed. After that, performance analysis of the above system has been carried out for Srinagar, Indian climatic condition. Performance in terms of electrical gain (EG), thermal gain (TG), overall exergy gain (OEG), overall thermal gain (OTG), electrical efficiency (EE) and overall exergy efficiency (OEE) of the DCSPVT module (case-I) have been compared with single channel semitransparent photovoltaic thermal (SCSPVT) hybrid module (case-II). The average improvement in EG, TG, OEG, OTG of the case-I have been observed by 71.51%, 34.57%, 5.78% and 35.41% respectively as compared to case-II.

Fabrication, experimental study and testing of a novel photovoltaic module for photovoltaic thermal applications

Solar Photovoltaic Thermal (PV/T) System is the integration of Solar Photovoltaic (PV) module and thermal system to serve the dual purpose of providing electricity and hot water/air simultaneously. But the high thermal resistance in a PV/T collector due to the thermal conductive adhesive, sheet and tube metal absorber reduces the heat transfer from the PV cells to the fluid and increases the overall cost of the system. This causes non-uniform and inefficient cooling of the PV cells. Hence, in this paper, a solar photovoltaic thermal module was developed by laminating a thin, flat copper sheet instead of Tedlar as the bottom layer. This modification is then integrated to a single water channel to make a PV/T collector. Primary energy saving efficiency of 35.32% was obtained at 0.01 kg/s mass flow rate, whereas the reference PV module attained only 20.87%. Theoretical calculations using material properties of the different layers of PV/T module and PV module showed a decrease in thermal resistance and an increase in thermal capacitance compared to the PV module. Also discussed in this paper was the positive results of few conformance tests conducted on the PV/T module according to IEC standards.

Thermal Features of the Module with Parabolic-Cylindric Solar Irradiation Concentrator

The work researched the thermal performance of the photovoltaic-thermal (PVT) cogeneration module with solar radiation parabolic-cylindrical concentrator. The advantage of this cogeneration module design is the possibility of both photovoltaic power generation and obtaining the thermal energy. These factors allow to increase the overall efficiency of solar energy conversion and to reduce the cost of produced energy. Research of PVT module thermal power characteristics using mathematical modeling of thermal processes and experimental measurements was carried out. Theoretical analysis of the module operation was based on the balance of incoming (solar), power dissipation, and utilizable energy flows and using similarity numbers (Nusselt, Prandtl, Reynolds). Experimental characteristics were studied under natural solar radiation. Parameters calculated by the balance of energy flows were consistent with the experimental data and have compliance with the accuracy better than 10% with similarity numbers calculations. The solar module showed in the experiment the maximum thermal power of 205 watts at 40 oC and thermal efficiency of 60%; when the water output temperature was 60 oC, the module delivers maximum output of 167 watts with thermal efficiency of 47 %.

PHOTOVOLTAIC FEATURES OF PV-T MODULE WITH ASYMMETRIC PARABOLIC-CYLINDRIC CONCENTRATOR AND PHOTORECEIVER ON THE BASIS OF MATRIX SOLAR CELLS

Design and development of photovoltaic-thermal (PV-T) modules is currently one of the important directions of solar energy application. These projects are aimed at increasing the effectiveness of solar energy conversion through combining electric and thermal energy generation in one device by decreasing solar energy losses and consequently decreasing energy generation costs. The paper discusses the new PV-T modules, including photoreceiver and solar illumination concentrator which provides efficient conversion of solar energy into heat and electricity. The mathematical modeling is used to create an algorithm for calculating of PV-T module design with the specified energy parameters. The laws of geometrical optics, photovoltaics, as well as heat and mass transfer are used. Such modules, based on a symmetrical parabolic-cylindrical concentrator and a photoreceiver with a coolant system flow may serve as a cogeneration installation for electricity and heat generation. Developed solar prototypes were investigated at testing ground and in field conditions with sun illumination. Solar module with asymmetric parabolic-cylindric concentrator with the midsection area 66х70 cm 2 and concentrated radiation photoreceiver on the basis of 6x68 cm 2 area matrix solar cells, with the flow coolant system provides 27 electrical powerwatts. The calculation of optic efficiency results in 0,64, which is not the limit for this concentrator module construction; and the comparison of photoelectric energy received from this module and a standard planar solar battery with the same area and equal effectiveness of photoconverters during the period between winter and summer solstice gives an increase of 26%. Increasing the optic efficiency up to 80%, which is realistic at current technologic reserves, this increase can reach 50%.

Exergetic and enviroeconomic analysis of semitransparent PVT array based on optimum air flow configuration and its comparative study

This paper carries out the exergetic and enviroeconomic analysis of semi-transparent photovoltaic thermal (PVT) array (size 10.08m×2.16m). Its exergetic and enviroeconomic performance has been compared with glass to tedlar i.e. opaque PVT array termed as case-A which has two integrated columns each having 18 PVT modules in series are connected in parallel and solar cell tile (SCT) based PVT array termed as case-B which has two integrated columns of 18 modules each having 36 PVT tiles (each solar cell having area 0.12m×0.12m) in the module is connected in series. The semi-transparent photovoltaic thermal (PVT) array considered as case-C which also has two integrated columns each having 18 semi-transparent PVT modules in series are connected in parallel. The size of all above array (10.08m×2.16m) is considered same. Four different climatic conditions of India (Delhi, Bangalore, Jodhpur and Srinagar) have been considered and the performances of the all above three cases have been compared on the basis of annual overall thermal energy and exergy gain. The comparative analysis shows that case-C has 28.8% and 12.1% lower cell temperature which yields 9.9% and 3.1% higher electrical efficiency than case-A and B respectively. Also the average outlet air temperature for case-C is higher by 40.6% and 19.1% than case-A and B respectively. The CO2 mitigation and enviroeconomic parameter for Bangalore in terms of overall thermal energy gain for case-C is 104.80tCO2/annum and 1519.56$/annum respectively, while in terms overall exergy gain is 48.76tCO2/annum and 707.09$/annum respectively. The CO2 mitigation potential of case-C is higher by 5.0% and 7.3% than case-B in terms of overall thermal energy and exergy gain respectively which indicates that case-C is a better performer than the other two cases.

Application of genetic algorithm with multi-objective function to improve the efficiency of glazed photovoltaic thermal system for New Delhi (India) climatic condition

The aim of this paper is to investigate an improvement in the efficiency of photovoltaic thermal (PVT) system with the help of Genetic Algorithm (GA) with multi-objective functions for New Delhi, India climatic condition. There are several parameters influencing efficiency of PVT system which inter alia include length and depth of the channel, velocity of air fluid flowing into the channel, thickness of the tedlar and glass, temperature of inlet fluid. All these parameters have been considered to optimize the efficiency of the PVT system. An attempt has also been made to model and optimize the parameters of glazed hybrid single channel PVT module considering the two objective functions separately which are: (i) the overall exergy efficiency (ii) the overall thermal efficiency. Using GA, both of the above objective functions are separately optimized and analyzed for each of the two cases: namely, Case-I: Improvement in exergy and thermal efficiency when overall exergy efficiency is optimized and Case-II: Improvement in exergy and thermal efficiency when overall thermal efficiency is optimized. The variables used in GA are those that could be varied, keeping parameters like solar radiation, ambient temperature unchanged in the algorithmic calculation. The electrical and thermal efficiencies after optimization were found 14.15%, 11.88% and 14.08%, 19.48% respectively. Similarly the overall exergy and thermal efficiency are 14.87% and 56.54% respectively for both the cases. It has been observed that there is improvement in overall exergy efficiency and overall thermal efficiency by 4.6% and 13.14% respectively during the optimization process.

Monitoring of solar cogenerative PVT power plants: Overview and a practical example

This paper introduces the topic of management and monitoring of photovoltaic/thermal (PVT) systems, highlighting the differences respect to photovoltaic (PV) and solar thermal (ST) systems. A PVT module is a collector that produces at the same time both electrical and thermal energy. Thereby, the monitoring architecture of a non concentrating PVT system, realised with crystalline silicon cells liquid-cooled, is described.In addition, a web application allows the on-line monitoring and control of that PVT system. Thus, daily reports of the remote PVT installations are elaborated and sent to the system operator. These data can be analysed off-line to calculate both energy performance indices and statistical values. Historical data analysis is useful not only to optimize the operation of the PVT system but also to design its retrofit. To check the effectiveness of the proposed remote monitoring system, the performances of two twin stand-alone systems a PVT plant, based on a patented PVT collector named TESPI, and a PV plant have been evaluated through an experimental campaign of measurements.The two twin systems (one PV and the other PVT) are installed in Enna (Italy), where typical Mediterranean climate is present. During the survey both electrical and thermal critical operating conditions have been detected such as: deep discharge of batteries, optical losses and stagnation.

Modeling and parameter optimization of hybrid single channel photovoltaic thermal module using genetic algorithms

The PV research community and industry has major focus on the new advancement and improvement on power efficiency of PV systems. An attempt has been made to model and optimize the parameter of hybrid single channel photovoltaic thermal (PVT) module. In this paper it has been observed that there are many parameters that affect the electrical efficiency of a hybrid single channel PVT module like thickness of the glass and tedlar, temperature of the inlet flow, and solar cell temperature. All equations for solar cell and thermal collector have been derived. By using genetic algorithms (GAs), thermal efficiency and electrical efficiency of the system may be optimized. All the parameters that are used in genetic algorithms are the parameters that could be changed, and the non changeable parameters, like solar radiation cannot be used in the algorithm. It has been observed that the GAs are very efficient technique to estimate the design parameters of hybrid single channel PVT module.