Solar Cogeneration Research Articles

Spectral Splitting as a Route to Promote Total Efficiency of Hybrid Photovoltaic Thermal with a Halide Perovskite Cell

Integrating photovoltaic (PV) perovskite solar cells and photothermal (PT) collectors into a hybrid photovoltaic thermal (PVT) is a promising method to further improve the conversion efficiency of solar energy via salvaging the near‐infrared energy. Herein, a 1D photonic crystal of Si/GeO2 to construct a spectrally selective PV–PT splitter that selectively reflects solar energy in the PV band while absorbing the rest is utilized. The fabricated PV–PT splitter reveals a considerable reflectance of 92.3% in the PV band, a comprehensive absorptance of 52.1% in the PT band, as well as good angular independence over a wide incident range of 0–70°. The hybrid PVT design with the Si/GeO2 spectral splitter/absorber and a perovskite solar cell (PSC) acquires a solar‐to‐electrical efficiency of 29.3% higher than the single PSC (24.6%). In addition, the temperature of PSCs in the hybrid PVT design under 1 kW m−2 solar irradiation can be significantly reduced by 15 °C owing to suppression of ineffectively converted incident photons on the PV cells. This appealing strategy highlights a new avenue for further enhancing the total electrical efficiency via broadening the utilization of the entire solar spectrum in the hybrid PVT design integrated with wide‐bandgap perovskite solar cells.

An Analysis of the Effects of Nanofluid-Based Serpentine Tube Cooling Enhancement in Solar Photovoltaic Cells for Green Cities

In this work, the impact of the serpentine copper tube heat exchanger with nanofluids on 100 W solar photovoltaic thermal collectors (PV/T) was analyzed experimentally and numerically. The cooling fluids assessed in this system were distilled water, Al2O3 0.1%, and Al2O3 0.2% based nanofluids. Tests were accomplished at diverse coolant mass flow rate in India’s summer days of 2018. A computational fluid dynamics (CFD) investigation was carried out to perform a parametric study, identify surface and exit T profiles, and examine the cooling effectiveness. The impact of mass flow rate of nanofluid on the outside T and Reynolds number were studied. The Reynolds number obtained in the flow experiments and CFD analysis was in the range of 900–1,300. The maximum irreversibility occurred while using water, whereas minimum irreversibility obtained Al2O3 0.2% nanofluid. Exergy efficiency was found to be increased from 20% to 36% during the day. It was identified that the increase in PV/T scheme led to higher exergy losses. The thermal efficiency of a water-based cooling system resulted in 53.61%. Meanwhile, Al2O3 0.1% and Al2O3 0.2% based coolants provided 69.45% and 71.02%, respectively. A good agreement was obtained between the experimental results and the computer model.

Experimental and numerical study of the PVT design impact on the electrical and thermal performances

In terms of energy efficiency, photovoltaic thermal (PVT) systems have great potential to produce simultaneously heat and electricity. PVT solar air collectors are often used in various applications due to their simple structure and low installation cost. While the overall performance of PVT is closely correlated with its design. In this paper, one proposes to design a novel prototype of PVT air collector, in order to improve the electrical and thermal performances. The presented numerical and Experimental studies are carried out to evaluate the impact of the designed prototype on the PVT efficiency. The essential goal of this work is to identify the optimal geometrical and operational PVT air collector parameters with square tube channel. To achieve this goal, numerical simulation using COMSOL Multiphysics is combined with experimental validation of the PVT system. The objective of the optimization consists on improving the output temperature suitable for drying applications firstly, and cooling PV modules by reducing their temperature in order to improve the electrical characteristics such as power and voltage and thereby the efficiency of the photovoltaic modules. Therfore, the PV panel temperature dropped from 53.37 °C to 42.5 °C when the design varies from PVT-1 to PVT-6. Nevertheless, PVT-5 was retained because it has the most appropriate design which gives the best overall efficiency 58.48%. Finally, it should be remembered that the tests were carried out under the same operating conditions namely, the mass flow rate Qm = 0.0235 kg/s at the inlet of the PVT, the inlet temperature (Tint), the ambient temperature (Ta) and the solar irradiation (G).

Experimental Investigation of a Concentrating Bifacial Photovoltaic/Thermal Heat Pump System with a Triangular Trough

The heat absorbed by the heat transfer fluid for cooling a concentrated photovoltaic thermal (CPVT) solar collector can be used for purposes such as residential heating and cooking. Because of the combined production of heat and power, these systems are proposed for individual or commercial use in rural areas. In this study, a hybrid system was proposed to increase the electrical efficiency of the system. Experiments were conducted in winter conditions. Two operational modes were compared, namely a CPVT system with HP (HP-CPVT) and without HP (CPVT). The evaporator of the heat pump was settled inside the triangular trough receiver. The effects of cooling the PV system with a heat pump in the bifacial CPVT system on the electrical and thermal energy efficiencies were investigated. The electricity and thermal energy efficiencies of the CPVT system were calculated as 12.54% and 38.37% in the HP-CPVT system, respectively, and 10.05% and 81.97% in the CPVT system, respectively. The electrical exergy efficiencies of the CPVT system with and without HP were 14.65% and 10.73%, respectively. The thermal exergy efficiencies of the CPVT system with and without HP were 82.47% and 85.63%, respectively. The thermal heat obtained from the HP-CPVT system can be used for heating needs. Thus, the bifacial HP-CPVT system was an example of the micro-CHP system.

A hybrid system coupling spiral type solar photovoltaic thermal collector and electrocatalytic hydrogen production cell: Experimental investigation and numerical modeling

The sustainable cogeneration of hydrogen and electricity is one of the promising strategies to boost the world’s energy demand. This work introduces a detailed numerical modeling and experimental study for a small-scale tri-production of heat, electricity, and hydrogen via an electrocatalytic hydrogen production cell (EHPC) powered by a solar photovoltaic thermal collector (SPVTC). A novel type of spiral fluid SPVTC integrated with small-scale Hoffman's EHPC is designed and tested. The effect of type and flow rate of cooling fluid on the performance parameters of the hybrid SPVTC-EHPC; including PV electric power, surface cell temperature, cooling fluid exit temperature, electrical and thermal efficiency, and produced hydrogen yield is studied. The experimentations are carried out for the hybrid SPVTC-EHPC operating with two various cooling fluids, namely, water and air at various mass flow rates (20 and 40 L/h), and their results are compared with a standalone PV module without cooling. Moreover, CFD modeling of the water SPVTC, air SPVTC, and PV module designs is also conducted at different operating conditions. ANSYS software is applied to attain maximal efficiency from the collector by choosing the optimal spiral flow structure and determining the PV panel surface and coolant temperatures of the three proposed systems. The CFD simulation verification ensured a good fit between the computational and experimental results. The findings show that the reduction in the daily average PV surface temperature is obtained as 16.60% (54.46 °C) and 8.50% (59.75 °C) for the SPVTC-EHPC, compared to reference PV-EHPC system, when water and air are utilized as a coolant at flowrate of 40 L/h, respectively. Moreover, the daily hydrogen productivity is found as 4.41 kgH2/d for water-cooled SPVTC-EHPC (40 L/h), 4.03 kgH2/d for water SPVTC-EHPC (20 L/h), 3.60 kgH2/d for air-cooled SPVTC-EHPC (40 L/h), 3.24 kgH2/d for air SPVTC-EHPC (20 L/h), and 3.07 kgH2/d for the conventional PV module EHPC, respectively. This study offers an effective means to experimental and numerical aspects of both water and air-cooled SPVTC for the simultaneous production of electricity and hydrogen.

Thermodynamic analysis of a novel solar photovoltaic thermal collector coupled with switchable air source heat pump system

Solar photovoltaic panel can only convert a small part of solar energy into electricity, and the remaining energy in the form of heat is discharged into the environment. In this paper, a novel solar photovoltaic thermal collector coupled with switchable air source heat pump system was introduced to improve the power generation of photovoltaic panels and effectively use the solar thermal energy, which can meet the requirements of the heating in winter and the cooling in summer. At first, the energy model and exergy model of the system were developed. Meanwhile, R134a, R290, R410A and R717 were selected as the candidate working fluids to remove the heat from the back of photovoltaic panel. Furthermore, a numerical simulation was implemented in MATLAB based on the energy and exergy models, and NIST REFPROP database was associated to obtain thermodynamic properties of the working fluids. And then, the thermodynamic performance of the system using different working fluids was investigated and compared. Finally, the optimal working fluid was determined based on the electrical efficiency, energy utilization coefficient, and exergy efficiency of the system. The results indicated that the electrical efficiency of cooled photovoltaic panel in the system was 4.1%-13.7% higher than that of uncooled photovoltaic panel in winter, and 1.1%∼10.6% in summer. The exergy destruction of the compressor and PVT collector accounts for a large percentage. Interestingly, R717 is the optimal working fluid of the proposed system, where the system has the highest annual energy utilization coefficient of 1.654 and the highest annual exergy efficiency of 0.251. Therefore, the application of the system has the potential for achieving the coupling of the annual photovoltaic cooling and the solar thermal energy utilization.

Development of a small scale photovoltaic thermal hybrid (PV/T) system for domestic applications in Pakistan

Development of a small scale photovoltaic thermal hybrid (PV/T) system for domestic applications in Pakistan

Energetic and parametric studies of a basic hybrid collector (PV/T-Air) and a photovoltaic (PV) module for building applications: Performance analysis under El Jadida weather conditions

The photovoltaic thermal hybrid collectors represent one of the most used technologies in positive energy buildings, the device allows converting the available solar energy into heat and electricity at the same time. In this study, a comparative analysis is introduced between two different types of solar conversion devices: conventional hybrid solar air collector (PV/T-Air) and photovoltaic (PV) module. Also, a parametric study was performed to know the impact of different parameters related to the performance of both solar systems. A numerical system based on the fourth order Runge–Kutta iteration method, is used in this study, founded on a strong coupling between the heat balance equations and the different electrical and thermal parameters of both configurations that are included in this work. The energy performance evaluation was applied to the climatic conditions of El Jadida city, located in Morocco. The numerical results indicates that the estimated value of the daily average overall energy conversion efficiency attains: 30.22% for the PV module, and 52.14% for the examined hybrid air collector (PV/T-Air). These results are calculated with an air mass flow rate of 0.0215 kg/s, and these values are according to the meteorological data collected on the site of El Jadida city for a sunny day in July.

Experimental and numerical analysis of a grooved hybrid photovoltaic-thermal solar drying system

• CFD analysis of grooved plate, spherical turbulators and baffles in a PVT collector. • Testing of the developed PVT collector in a drying application at two flow rates. • Overall exergy efficiency of PVT system was found in the range of 10.65-11.17%. • Exergy efficiency of drying chamber was attained between the range of 59.16-68.31%. Photovoltaic-thermal (PVT) systems are sustainable applications that allows to produce thermal and electrical energies simultaneously. In this work, a sustainable solar drying system that contains a modified PVT-air collector has been designed, numerically analyzed, manufactured and tested. In the first step of this study, four different PVT collector configurations have been numerically analyzed in order to develop a new hybrid PVT drying system. According to the numerically obtained results, outlet temperature of the PVT collector with grooved absorber, spherical turbulators and baffle configurations was higher than the outlet temperature of the unmodified collector as 15.77%. This promising PVT collector was then fabricated and integrated with a drying chamber. The manufactured hybrid drying system has been tested under various air flow rates. The experimental findings illustrated that the average thermal efficiency and overall exergy efficiency of the PVT collector varied between 61.32-77.49% and 10.65-11.17%, respectively. In addition, mean exergy efficiency of the drying chamber was found in the range of 59.16-68.31%. Average sustainability index values of the collector and the drying chamber was obtained between the ranges of 1.12-1.14 and 3.74-5.82, respectively. Moreover, payback period of the dryer varied between 2.98-3.51 years according to the economic analysis.

Performance analysis of a novel solar cogeneration system for generating potable water and electricity

PurposeThe utilisation of renewable energy sources for generating electricity and potable water is one of the most sustainable approaches in the current scenario. Therefore, the current research aims to design and develop a novel co-generation system to address the electricity and potable water needs of rural areas.Design/methodology/approachThe cogeneration system mainly consists of a solar parabolic dish concentrator (SPDC) system with a concentrated photo-voltaic module at the receiver for electricity generation. It is further integrated with a low-temperature thermal desalination (LTTD) system for generating potable water. Also, a novel corn cob filtration system is introduced for the pre-treatment to reduce the salt content in seawater before circulating it into the receiver of the SPDC system. The designed novel co-generation system has been numerically and experimentally tested to analyse the performance at Karaikal, U.T. of Puducherry, India.FindingsBecause of the pre-treatment with a corn cob, the scale formation in the pipes of the SPDC system is significantly reduced, which enhances the efficiency of the system. It is observed that the conductivity, pH and TDS of seawater are reduced significantly after the pre-treatment by the corncob filtration system. Also, the integrated system is capable of generating 6–8 litres of potable water per day.Originality/valueThe integration of the corncob filtration system reduced the scaling formation compared to the general circulation of water in the hoses. Also, the integrated SPDC and LTTD systems are comparatively economical to generate higher yields of clean water than solar stills.

Design and analysis of new solar‐powered sustainable dryers: Alfalfa crop

AbstractDecreasing carbon emissions is possible with the usage of renewable energy sources. Therefore, the usage of renewable energy has increased in the last decade. Due to the fact that the drying process of agricultural products consumes a significant amount of energy, fossil fuel consumption can be reduced by using the solar dryer. In this study, two novel solar drying systems were designed and tested for alfalfa drying. Experiments were carried out in two different drying systems double‐pass solar air collector (DPSAC) and photovoltaic thermal solar air collector (PVT). In order to increase the heat transfer surface area, unlike the literature, a drying chamber consisting of two intertwined cylinders was designed and manufactured. The aims of this study are to bring the drying kinetics of alfalfa and the performance, energy, and exergy analysis of the designed system to the literature. The effective moisture diffusivity values were found to be in the range of 9.13 × 10−14 to 1.06 × 10−9 and the value for the highest drying rate was determined as 2.53 × 10−2gwater/gdrymatter.min. The highest thermal efficiency was obtained from DPSAC experiment as 73.7%, while the highest COP value was obtained from the PVT experiment as 12.5. The DPSAC dryer has shown the best performance in drying the alfalfa. The outcomes of the present study demonstrate that the use of DPSAC dryer is suitable when only heat energy is required for the drying system and the use of PVT when both heat and electrical energy are required. It is recommended that these systems can be used together in off‐grid agricultural areas.Practical applicationsAlfalfa (Medicago sativa L.), a type of forage crop, is a delicious, high‐energy, and protein food source for dairy cattle. By drying the alfalfa with high nutritional value in a quality method, several beneficial minerals and vitamins are preserved. The drying process is used since ancient times for the protection of the food material and for storage without degradation. Alfalfa is dried in two new solar‐powered sustainable dryers making an important contribution to reducing carbon emissions as well as providing cleaner and more reliable drying methods compared to the conventional solar drying method. This study presents an alternative for the drying process with high energy efficiency for food drying processes, according to the necessity of using both heat and electrical energy. In addition, sustainable solar dryers in this study can be used for drying agricultural products, textile, industry and dewatering municipal waste.

Thermal and exergy analysis of Pin-finned heatsinks for nanofluid cooled high concentrated photovoltaic thermal (HCPV/T) hybrid systems

• Cooling performance of HCPV/T is systematically investigated. • Different shaped pin-finned heat sinks (inline and staggered) are examined. • Thermal performance is determined for MWCNT nanofluids. • Exergy efficiencies of pin-fin heat sinks in HCPV/T are evaluated. • 2% MWCNT nanoparticle concentration is found to be the optimum. Cooling of High Concentrated Photovoltaic (HCPV) cells is a major concern among researchers due to higher heat generation in the cells from highly concentrated solar radiation. In the present investigation, a numerical study of the High Concentrated Photovoltaic Thermal (HCPV/T) system is conducted for the combined effect of nanofluids and pin-finned heatsinks on the cooling performance. The investigation is carried out for AZUR SPACE solar cell (Model: 3C44C) for 1000 Concentration Ratio (CR) and the Reynolds number ( Re ) varies within the laminar range (600 ≤ R e ≤ 2200). Different shapes of pin-fins and their orientations are systematically investigated for the effect of Multi-walled Carbon Nanotube (MWCNT) nanoparticles in a base fluid. The results show a significant reduction in the temperature (up to 18K) of the solar cells for the MWCNT nanofluid compared to its base fluid counterpart. A higher heat transfer characteristics (Nusselt numbers) and lower average temperature of top surface of HCPV cells are found to occur for the staggered arrangements of pin-fins. It is also noticed that the volume concentration of MWCNT in water affects heat transfer characteristics and reduction in temperature takes place up to the volume concentration of 2%. About 1.3% reduction in temperature is predicted for adding MWCNT nanoparticle concentration from 0.5% to 2%. However, in terms of exergy efficiency, maximum overall exergy (about 67% for water flow rate of 0.00167 kg/s) is found for square pin-fins with inline arrangements. The average increase in Nusselt number from inline to staggered arrangement are around 11%, 74%, and 22% respectively for circular, square and triangular fins. The maximum electrical efficiency reaches to 42.2% for both 2% and 4% MWCNT with staggered circular pin-fins for a mass flow rate of 0.0058kg/s. Finally, it appears that a combination of nanofluids and pin-finned heatsinks gives a better cooling rate in the HCPV/T system and could be a promising alternative along with other cooling techniques.

Experimental Investigation of Water Cooled Solar Photovoltaic Thermal Collector

With an increasing expected energy demand and current dominance of coal electrification world needs alternative sources which are abundant and ease of availability in nature such as Solar, wind, tidal etc., in which solar PV energy is one of the favorable energy sources. Various strategies are studied in this paper to improve the efficiency of solar PV modules. The efficiency of PV modules increases as the surface temperature of the modules is lowered using various cooling techniques. Experiments on solar PV modules with water circulation have been carried out, and the heat generated has been used for thermal applications. The reference panel was matched to an experimental observation for water circulation. It was observed that the water circulation system is 10.4 %, with a greater performance at 866 W/m2 solar radiation. Water is used as a cooling medium to extract heat from the PV panel. The project’s purpose is to improve the efficiency and power output of hybrid PVT(Photovoltaic Thermal Collectors)while also optimizing the design. The project’s purpose is to improve the efficiency and power output of the hybrid Photovoltaic Thermal Collectors(PVT) collector, as well as the power output of the PV panels. The tests are carried out with and without cooling on a 50W PV panel. The cooling of the PV panel is accomplished through forced and natural convection of water in the duct. The performances of forced and natural circulation are validated with the solar panels output power and efficiency.

Application and effect analysis of renewable energy in a small standalone automatic observation system deployed in the polar regions

Considering the difficulty of power supply for automatic observation equipment in the polar regions, this paper introduced a small standalone renewable energy system with wind–solar co-generation as the energy supply scheme. Mathematical models were given, including solar photovoltaic panels, wind turbines, solar irradiance, wind energy density, and renewable energy assessment. ERA-Interim atmospheric reanalysis data were used to evaluate solar energy resources, and the synergistic effect of wind–solar resources on renewable energy was also analyzed and discussed. The system composition of the small standalone renewable energy system was proposed in this study. This system deployed near Zhongshan Station was taken as the object of investigation to analyze the operation performance of each component of the system in different months, and the technical feasibility of the system has also been verified. The results showed that the wind–solar resources in the polar regions had a synergistic effect, which can provide an effective and feasible scheme for the power supply of automatic observation equipment. Through research and analysis, it was found that each component of the renewable energy system, including photovoltaic panels, wind turbines, and batteries, could meet the long-term power supply requirements of automatic observation regardless of the polar periods, polar day or polar night. This paper can not only provide theoretical and data support for the application of small independent renewable energy systems in the polar regions but also provide feasible solutions for clean energy supply of the systems and equipment for independent observation stations deployed in uninhabited islands and alpine regions.

Insight into the investigation of Fe3O4/SiO2 nanoparticles suspended aqueous nanofluids in hybrid photovoltaic/thermal system

This experimental study aims to evaluate the energetic performance of a photovoltaic-thermal system with a serpentine tube collector. A photovoltaic-thermal unit with a serpentine tube collector is used to compare the unit's performance metrics to those of a PV panel without cooling. The considered heat transfer fluid is the hybrid nanofluid prepared using water and Fe3O4/SiO2 nanoparticles. Using irradiance data from an average day in Aligarh, India, the experiment is conducted in indoor environment in a solar simulator under regulated operating circumstances. Effects of mono and hybrid nanofluids are examined at 3% wt. concentration for varying flow rates (20, 30, 40 LPM). The experimentation analysis showed that the maximum drop in PV temperature at 20 LPM is 25 °C, 24 °C, and then 16 °C for Fe3O4/water, SiO2/water, and Fe3O4/SiO2 nanofluids-based PVT systems, respectively with a highest possible increase in electrical efficiency of 12.6 percent, 18.46 percent, and 24.34 percent, respectively, when compared to traditional PV systems. At a flow rate of 40 LPM, the best performance is obtained using a hybrid PVT method coupled with an aqueous Fe3O4/SiO2 nanofluid. Additionally, it is discovered that hybrid nano-fluid-based PVT systems exhibit 10.5% and 5% greater thermal efficiency than Fe3O4-Water and SiO2-Water PVT systems, respectively. The overall highest efficiency of 67% is achieved for hybrid nanofluid at a flow rate of 40LPM. The hybrid Fe3O4/SiO2 nanofluid is capable of serving as an acceptable cooling fluid for the PV/T collector, as evidenced by the PV/T system's notable improvement in thermal and electrical efficiency and prominent cooling impact. Keywords : Solar energy, Hybrid nano-fluid, Heat transfer, Electrical Power, Thermal Efficiency, PVT system. • The role of hybrid nanofluids for the performance of PVT systems was studied. • Hybrid nature of nanofluid make it more stable than mono-nanofluid. • Electrical and thermal efficiency were analysed at fixed concentration and varying flowrate. • Comparison of Fe 3 O 4 /SiO 2 nanofluid is carried out with individual mono-nanofluid.

Improved thermophysical characteristics of a new class of ionic liquid + diethylene glycol/Al2O3 + CuO based ionanofluid as a coolant media for hybrid PV/T system

The purpose of this experimental research is to develop a new class of nanofluid as a replacement of conventional water based nanofluid for medium temperature range as PV/T coolant application. For the first time, hybridized Al 2 O 3 +CuO nanoparticles were dispersed into the binary mixture of ionic liquid (IL) and diethylene glycol (DEG) without the addition of any stabilizing agents or surfactants. The formulated Ionanofluid posed excellent dispersion stability together with better thermal stability compared to water-based nanofluid, as evidenced from thermogravimetric analysis. The experimental thermal conductivity assessment showed a maximum of 41.8% enhancement together with a 31% penalty in pressure drop at 0.15 wt.% concentration. A hybrid PVT system is constructed to numerically examine the effect of Ionanofluid as an active cooling medium under the COMSOL Multiphysics environment. Ionanofluids as coolants in a PVT panel showed a maximum of 69% thermal efficiency at 0.15 wt.% Al 2 O 3 +CuO, higher than 63% (0.10 wt.% Al 2 O 3 +CuO), 58% (0.05 wt.% Al 2 O 3 +CuO), and 56% (pure IL+DEG). The PV panel temperature was reduced from 65 to 40 °C when IL+DEG was replaced with 0.15 wt% Al 2 O 3 +CuO. At the same concentrations, an electrical efficiency of nearly 12.7% was observed, representing a 29.91% improvement over IL+DEG at a flow rate of 4LPM. The formulated Ionanofluid performed thermally better than water but somewhat lower than water-based nanofluids like MWCNT/Water. Nevertheless, Ionanofluid's electrical efficiency was better than MWCNT/Water. Ionanofluid can be a viable alternative to water-based nanofluids for medium-temperature-based coolant applications.

Thermodynamic Analysis and Modeling of a Novel Solar Absorption Cogeneration System With an Adjustable Cooling-to-Power Ratio

Abstract In this work, a novel solar double-effect absorption combined cooling and power (DECCP) system with an adjustable cooling-to-power ratio is proposed. This cogeneration system uses water–LiBr as the working fluid. The novel cycle upon which this system is based has been mathematically modeled, simulated, and parametrically analyzed to generate the system’s performance characteristics for several scenarios. The performance has been compared with those of other similar combined cogeneration cycles. It was found that the proposed cycle outperforms the other cycles from the vantage point of the power produced and the cycle’s ability to produce cooling. For specific operating parameters, the DECCP cycle achieves an exergetic efficiency that varies between 36.55% and 59.13% based on the refrigerant split ratio used. An effective operating strategy is proposed for the cycle when it is powered by solar energy.

Experimental investigation on the performance of an advanced bi-fluid photovoltaic thermal solar collector system

This paper aims to investigate the effect of various mass flow rates of working fluids on the performances of the bi-fluid photovoltaic thermal (PVT) system and the integrated air-based type. The experiments were conducted for two outdoor cases, Case I and Case II. In each case, the mass flow rate of air was fixed at a value in both systems, while the mass flow rate of water was varied between two values in the bi-fluid PVT system. The observed results showed the performance of both systems can be improved by the optimum mass flow rates. The bi-fluid PVT system working with 0.1190 kgs−1 and 0.0102 kgs−1 of air and water flows has given 64.57 %, 12.64 %, and 99.33 % of thermal, electrical, and overall efficiencies, respectively. Furthermore, when the air-based was operating at the mass flow rate of 0.0446 kgs−1, the corresponding findings were 35.56 %, 12.56 %, and 70.54 % of thermal, electrical, and overall efficiencies. However, the electrical performance was also investigated for the connected PV modules. The maximum power output was 248 W and 223.7 W for Case I and Case II, respectively, as the highest values for different operating conditions. The positive results suggest the technology to be used for various usages.

Experimental study of the effect of simultaneous application of the air- and water-cooled flow on efficiency in a Photovoltaic thermal solar collector with porous plates

• Effect of simultaneous use of air- and water-cooled flow on the efficiency of a PVT panel. • Evaluation of electricity generated, heat transfer and CO 2 production. • Increasing the number of fans reduces the efficiency. • Maximum and minimum amounts of CO 2 produced are 0.95 and 0.66 kg, respectively. This paper examines the effect of simultaneous use of air- and water-cooled flow on the efficiency of a solar photovoltaic thermal (PVT) panel. A copper pipe system is used for water cooling and some fans are used under the PVT for air cooling. Also, some porous plates are used at the bottom of the solar panel. By changing the volumetric flow rate (VFR) of water in the range of 0.5 to 2.5 L/min with 1, 2, or 3 fans under the PVT, the values ​​of electrical efficiency (ELE), thermal efficiency (THE), total efficiency (TOE), the amount of electricity generated by PVT and the heat transfer (HT) takes place in PVT are estimated. This experimental research is conducted in the summer from 10:00 to 16:00. Each test is performed in one day and the output power of PVT and a similar PV, water temperature in the inlet and outlet of PVT and the amount of solar heat flux are recorded. The results show that an increment in the VFR of water enhances the amount of ELE of PVT. Increasing the number of fans reduces the efficiency so that the maximum value of ELE of PVT for water VFR of 2.5 L/min without using the fans, which is equal to 11.99 %. Enhancing the number of fans and VFR increases THE and TOE of PVT. The maximum values of THE and TOE of PVT are 70.59 % and 81.61 %, respectively. In the best case, using a water VFR of 2.5 L/min and three fans, the power generation is enhanced by 22.56 W by the panel. The value of ELE can be improved by 5.62 % by cooling with a VFR of 1.5 L/min in the absence of fans.

Multi-aspect approach of electrical and thermal performance evaluation for hybrid photovoltaic/thermal solar collector using TRNSYS tool

• Hybrid solar photovoltaic/thermal collectors are investigated. • Multi-aspect approaches for electrical and thermal evaluation are conducted. • A new TRNSYS component of PV/T is created based on the Fortran language. • The PV/T system with a PID controller is the most efficient system for electrical conversion. • The PV/T with an ON/OFF controller is the best in thermal conversion. The integration of photovoltaic (PV) module and thermal solar collector shows a strong potential for incorporation into hybrid solar-thermal (PV/T) system, mainly due to space constraints and benefits of electrical and thermal concurrent power generation. This work verifies, analyses, and compares a new component of PV/T which was created and programmed based on factual specifications in the TRNSYS environment and built a dynamic model of PV/T system. The new component of the PV/T was validated and evaluated experimentally and numerically using multi-aspect evaluation approaches. Electrical and thermal behaviour were studied by examining the effects of temperature controllers, using the daily hot water consumption profile, ambient temperature, cell temperature, and slope angles. In addition, the new component of the PV/T was compared with standard solar collector units and PV systems. This study found that the results of simulations and experiments were remarkably consistent and matched well. The correlation coefficient was 0.983 and 0.9783 for the thermal and electrical efficiencies, respectively. The most efficient PV/T system in electrical conversion was the PV/T with a PID controller, and the most efficient system in thermal conversion was the PV/T with an ON/OFF controller. The fulfilment model can serve for further PV/T system performance assessments.