Photovoltaic Thermal Research Articles

Investigating the influence of nanofluid on photovoltaic-thermal systems concerning photovoltaic panel performance

Solar energy has much promise to replace the planet's finite supply of fossil fuels as it is sustainable and eco-friendly. Photovoltaic (PV) panels are one example of the proper technology that may transform solar energy into electrical energy. On the other hand, high temperatures may reduce photovoltaic cells' ability to produce power efficiently. As a result, a study was carried out to use the PV/T (Photovoltaic Thermal) collector system and evaluate the effects of CuO, TiO2, and Al2O3 nanofluids as cooling agents on the performance and operating temperature of PV panels. In Surakarta, Indonesia, an experimental study was conducted with nanoparticle concentrations of 0.2 vol% and a flow rate of 3 L/m at an intensity of radiation of 1000 W/m2. The results showed that, in comparison to uncooled PV panels, employing CuO, TiO2, and Al2O3 nanofluids in the PV/T system resulted in temperature reductions of 18.84 °C, 18.12 °C, and 17.62 °C, respectively. Moreover, measurements of the electrical efficiency produced by PV and PV/T panels using CuO, TiO2, and Al2O3 nanofluids showed that the respective values were 10.98%, 13.92%, 13.65%, and 13.39%. This study contributes to the development of solar energy technology by demonstrating the potential of nanofluid-based cooling devices to improve solar panel performance in hot conditions.

Applications of Graphene Nanoplatelets as Working Fluids in Photovoltaic Thermal Systems: A Review

Applications of Graphene Nanoplatelets as Working Fluids in Photovoltaic Thermal Systems: A Review

Numerical and experimental investigation of a single-body PVT using a variable air volume control algorithm

Photovoltaic thermal (PVT) collectors that can achieve maximum efficiency from solar irradiation can be critical concepts for meeting energy demand in residential applications. Even though there is much research on increasing heat transfer, multifunctional designs that provide homogeneous results are limited. This study explores the production of electricity and hot air from a novel design of a PVT. A new perforated copper plate design has been proposed to achieve maximum efficiency by providing homogeneous cooling in the PVT. Firstly, numerical analysis of this design was performed using Ansys Fluent software, then tested experimentally. The highest and average electrical and thermal efficiency of PVT are obtained as 17.62 %, 15.63 %, and 76.75 %, 43.68 %. In experiments conducted under winter conditions, the maximum temperature value in the PVT was measured as 41.54 °C. Moreover, the payback period of the PVT system was calculated as 6.1 years. The proposed PVT collector can be used as a new model for integrating solar energy in buildings with almost zero energy. Considering the eco-design, this PVT design can contribute net positive carbon, ecological footprint, and green manufacturing.

Performance enhancement of photovoltaic/thermal collector semicircle absorber tubes using nanofluid and NPCM

This experimental measurement examines Photovoltaic/Thermal (PVT) systems with semicircle absorber tubes, focusing on the impact of nanoparticle-enhanced phase change material (NPCM). Four PVT systems are analyzed, all using a standard PV module: a. PVT1: cooled by water; b. PVT2: cooled by water and NPCM; c. PVT3: cooled by nanofluid; d. PVT4: cooled by nanofluid and NPCM.The research evaluates their thermal, electrical, and overall performance and efficiencies at volumetric flow rates of 1–5 LPM under harsh outdoor conditions. The results reveal that the PVT4 system demonstrates the highest efficiency. At a volumetric flow rate of 5 LPM and a surrounding temperature of 47.94 °C, it achieves electrical, thermal, and total efficiencies of 12.70 %, 78.99 %, and 91.83 %, respectively. By enhancing the heat transfer between nanofluids and NPCMs, system cooling is enhanced and thermal efficiency is greatly increased. Additionally, the use of such systems notably reduced the surface temperature, exhibiting a decrease of about 35.09 % compared to the standard PV module while the use of nanofluid cooling only without NPCM caused a reduction of 29.93 % compared to the PV module. Importantly, the PVT4 setup outperforms the unenhanced PV module (PVT3) in overall efficiency by 14.04 %. In this study, PV modules are cooled by a heat exchanger made up of semicircular tubes attached to their backs. The study confirms that a PCM enhanced with nanoparticles performs well in the PVT system when semicircular absorption tubes are used. A significant reduction in surface temperatures is achieved with the use of this heat exchanger, resulting in remarkable thermal efficiency. As a result of this cooling effect, the PV module is more efficient than a traditional solar module in terms of electrical output. This type of system is likely to influence the development of more convenient and efficient solar energy systems. It is possible to use the heat absorbed by PV modules in other ways as well.

Assessment and analysis of polydimethylsiloxane-coated solar photovoltaic panels for cost-efficient solutions

Solar photovoltaic (PV) is a crucial renewable energy source in the fight against carbon dioxide emissions, aligning well with growing energy demands. However, solar PV efficiency naturally degrades over time, primarily due to uncontrollable outdoor factors such as irradiance, humidity, shading, soiling, aging, and temperature. These collectively lead to decreased efficiency in PV systems. Soiling on PV glass surfaces significantly impacts light penetration and subsequently reduces power generation. To combat this, a self-cleaning nano-calcium carbonate coating has been proposed. The effectiveness of this method is compared with a developed solar PV thermal (PV/T) system, evaluating both performance and cost-effectiveness. After six months of outdoor exposure, the coated glass solar PV achieved an efficiency of 7.6%, surpassing bare glass solar PV at 6.0%. Moreover, the coated glass solution boasts exceptional cost-effectiveness, incurring only an annual expense of 17.6 USD per panel compared to the PV/T system of 59.8 USD per panel. These findings highlight the potential of coatings to enhance solar PV performance and economics, particularly in addressing challenging uncontrollable factors like soiling.

Experimental study on the performance of enhanced air-cooled photovoltaic thermal energy-supplied manure treatment technology

Implementing renewable energy technologies for manure treatment to reduce energy consumption and environmental damage is steadily becoming more prevalent. In this work, an air-cooled photovoltaic thermal (PV/T) device was enhanced and constructed to provide energy for bio-composting manure treatment. Experiments were conducted to analyze the performance data such as air supply temperature, energy and exergy efficiency, and mass flow rate. When calculating the mass flow rate of the PV/T-supplied manure treatment technology, factors such as exergy efficiency, and hot air temperature must be considered. The results of the study indicate that the thermal performance of the developed equipment is adequate for manure composting treatment. The thermal exergy efficiencies of the V2, V3, and V4 cases are approximately 1/3 greater than the thermal exergy efficiency of the V1 case, indicating a considerable change in thermal efficiency. The mass flow rate of 0.020 kg/s is determined to be a more suitable set value. Its total exergy efficiency can reach 46.79%, and the apparatus could heat up to 43.63 kg/m2 of compost to begin the bio-composting process. This study lays the groundwork for future research and deployment of PV/T-powered manure treatment devices.

Day-ahead optimal scheduling considering thermal and electrical energy management in smart homes with photovoltaic–thermal systems

The environmental impact on the energy sector has become a significant concern, necessitating the implementation of Home Energy Management Systems (HEMS) to enhance the energy efficiency of buildings, reduce costs and greenhouse gas emissions, and ensure user comfort. This paper presents a novel approach to provide optimal day-ahead energy management plans in smart homes with Photovoltaic/Thermal (PVT) systems, aiming to achieve a balance between energy cost and user comfort. This multi-objective problem employs the Non-dominated Sorting Genetic Algorithm III as the optimization algorithm and the Nonlinear Auto-regressive with External Input to forecast the day-ahead meteorological variables, which serve as inputs to predict the PVT electrical and heat production in the thermal resistance model. The HEMS benefits from the time-of-use tariff due to the flexibility provided by the energy storage from a battery bank and a boiler. Furthermore, it performs a load scheduling for 10 controllable loads based on three feature parameters to characterize occupant behavior. A study case analysis revealed a cost reduction of approximately 66% in the solution close to the knee of the Pareto curve (S3 solution). The environmental impact on the energy sector has become a The PVT heat production was sufficient to meet the thermal demand of the showers. The proposed hybrid battery management model effectively eliminated the export of electricity to the grid, reducing consumption during peak periods and the maximum peak demand.

Parametric optimization for enhancing the electrical performance of hybrid photovoltaic/thermal and thermally regenerative electrochemical cycle system

Globally, the efficient utilization of solar energy has garnered significant attention. A hybrid system of photovoltaic/thermal (PV/T) modules integrated with thermally regenerative electrochemical cycle (TREC), i.e., PV/T-TREC has emerged recently and shows higher efficiency for solar-to-electrical conversion than a standalone PV system. However, there is a trade-off between the electricity generation from PV/T and TREC because the thermal energy from PV/T degrades the efficiency of the PV/T but improves that of TREC. Previous studies have failed to investigate this problem. This study therefore focuses on the key parameters that significantly affect the thermal output of PV/T, i.e., different PV materials, air gaps, heat storage tank volumes, and working fluids to investigate the maximum electrical efficiency of the hybrid system. The mathematical and transient-state numerical models are developed with the validation/refinement from the experiments. The results show that the hybrid system with PV material of cadmium telluride presents the best overall electrical efficiency of 25.37 %. The case of the air gap fosters the solar-to-electrical conversion. The electrical efficiency versus heat storage tank volume shows a convex curve, peaking at 200 L. The nanofluid performs the best. This study may help guide the practical application of such a high-efficiency electricity generation system.

Thermal and electrical performance evaluation of single and double pass photovoltaic-thermal solar collector with cross-flow baffles and varying transparency: A computational analysis

The present work deals with the development of a semi-transparent photovoltaic thermal (PV-T) solar collector (STPVT) through computational fluid dynamics (CFD) modelling using COMSOL Multiphysics. The study was carried out in three stages; firstly, the CFD model was developed for STPVT and validated with experimental data. Secondly, three different configurations of semi-transparent PV-T collector were investigated, i.e., single pass with PV module on top (SPC), double pass with PV module on top followed by glass cover and absorber plate (DPT), and double pass with PV module in between the glass cover and absorber plate (DPS). The absorber plate was incorporated with cross-flow baffles for improved thermal performance due to increased surface area and turbulence. The study found a thermal efficiency of 76.94 % for DPS configuration and a total heat utilisation of 289.63 W at 50 % transparency level, i.e., 2–4 times higher than other configurations. Furthermore, the DPS model was investigated for thermal and electrical performance with different PV module transparency levels (52,42,27,13 %). The DPS with 18 solar cells having 13 % transparency exhibited peak power density (8 %) at 717 W/m2 and 101.89 °C panel temperature, achieving superior thermal efficiency (84 %) and total heat utilisation (315.09 W), surpassing configurations with higher transparency.

Modeling and performance analysis of a new integrated solid oxide fuel cell and photovoltaic‐thermal energy supply system by heat current method

AbstractEfficient and reliable utilization of renewable energy at the user's end is the key to achieving a low‐carbon life. This paper proposed a new distributed energy system around the comprehensive utilization of solar energy by integrating solid oxide fuel cell (SOFC), energy storage equipment, photovoltaic thermal (PVT) collector, and heat pump. By integrating the use of SOFC and PVT, we can further minimize reliance on fossil fuels, while employing the coupling of PVT and heat pump effectively mitigates the inherent challenges of solar energy's variability and intermittency, all while enhancing overall system efficiency. On this basis, we apply the heat current method to construct a cross‐scale heat current model of the components and the system by considering the energy transfer, conversion, and storage characteristics of the system. By employing this model, we simulate the system's operation throughout an entire typical day, assess the COP enhancement of the PVT‐coupled heat pump system, analyze the influence of diverse operating conditions on daily system performance, and evaluate the economy of the energy storage devices in the system.

Integrating insulated concrete form (ICF) with solar-driven reverse osmosis desalination for building integrated energy storage in cold climates

This research addresses the pressing global challenges of clean energy and water supplies, emphasizing the need for sustainable solutions for the building sector. The study integrates Reverse Osmosis (RO) systems with building energy systems, incorporating Solar Thermal Collectors (STC)/Photovoltaic Thermal (PVT), water-to-water heat pumps, and an Insulated Concrete Form (ICF) based building foundation wall thermal energy storage. It explores the effectiveness of four configurations—STC-ICF, STC-ICF-RO, PVT-ICF, and PVT-ICF-RO—using sensitivity analysis on collector area (25 % and 50 % increase) and weather data from four Canadian cities: Winnipeg, Toronto, Halifax, and Vancouver and two non-Canadian cities: Helsinki, Finland and Bergen, Norway. Key outcomes highlight the benefits of integrated RO scenarios, such as reduced ICF wall temperature, diminished unwanted heat in the cooling season, reduced RO pump consumption, and enhanced solar energy production. The STC-ICF-RO and PVT-ICF-RO systems achieved energy savings of 653 kWh and 131 kWh, respectively, compared to their non-integrated RO counterparts. Both systems also contributed to lowering CO2 production levels. The STC-ICF-RO system's payback period is 2 years, affirming its economic viability. Compared to the base system without ICF and RO integration, the STC-ICF-RO and PVT-ICF-RO configurations reduced energy consumption by 20 % and 32 %, respectively. The sensitivity analysis suggests potential system improvements under specific conditions, primarily when implemented in communities of buildings.

Performance test of a heliostat field integrated PVT solar collector using organic phase change material and carbon black additives

The rising global awareness of environmental issues has brought about a rise in the adoption of green energy throughout our daily activities in recent decades. The radiation from the sun is utilized for thermal heating, electrical generation, and agriculture by Phase change materials (PCM) integrated PVT collector. However, the lower concentration ratio of solar radiation on flat plate collectors and the lower thermal conductivity of PCMs are the major drawbacks. In this present study, a Heliostat field concentrator was designed to integrate with a hybrid photovoltaic thermal (PVT) collector for the increase of the solar irradiance, and carbon black additives incorporated stearic acid (SA) were used in the underneath PVT collector to enhance the thermal conductivity of SA as well as the thermal efficiency of the system. The performance tests were carried out for both SA with carbon black and SA without carbon black additives for varying water flow rates of 0.0025 kg/s, 0.0035 kg/s, 0.0045 kg/s, and 0.0055 kg/s. The efficiency of the PV panels ranged from 10 % to 13 %. The maximum thermal efficiency was found to be 46.56 % when using SA with carbon black for the water flow rate of 0.0035 kg/s whereas the maximum thermal efficiency was 45.45 % in the case of SA without carbon black for that water flow rate. Especially contrasted with the other flow rates throughout the investigation, the average thermal efficiency increases by 6.83 % for the flow rate of 0.0035 kg/s after integrating carbon black with PCM. The experimented results showed the outlet temperature of water in the range of 50 °C-59 °C throughout the day which is sufficient for domestic hot water applications.

Year-round performance evaluation of photovoltaic-thermal collector with nano-modified phase-change material for building application in an arid desert climate zone

This study provides a comprehensive analysis of the energetic and thermoelectric characteristics of a solar photovoltaic-thermal (PVT) collector equipped with a nano-modified phase-changing material (NPCM) for PV cooling. The operational effectiveness of the collector is evaluated using various parameters such as PV temperature, electrical and thermal powers, melting time, PCM liquid fraction, and PV cooling duration. These factors are meticulously examined under different operating conditions of solar irradiance, ambient air temperature, and the thickness of the NPCM layer. Hail, Saudi Arabia, a city known for its arid desert climate, is chosen as the geographic setting for the study. A numerical methodology based on finite volume discretization is used to solve the governing mathematical models. The year-round performance of the combined PVT and NPCM unit is systematically assessed in terms of monthly averages across the four seasons, considering varying NPCM layer thickness over different time frames. The results indicate that an NPCM with a nanoparticle volumetric concentration of 5% and an appropriately chosen NPCM layer thickness provides effective PV cooling, with cooling durations ranging from 54 to 305 min throughout the year. In terms of electrical performance, months with high solar irradiance yielded a greater power output, peaking at approximately 52.5 Watts, while the winter months exhibited the lowest output. The thermal performance followed a similar pattern, demonstrating the significant influence of solar irradiance on thermal efficiency, with peak outputs reaching up to 225 Watts during high solar intensity months.

State-of-the-Art Review: Nanofluids for Photovoltaic Thermal Systems

State-of-the-Art Review: Nanofluids for Photovoltaic Thermal Systems

Enhanced performance of a hybrid adsorption desalination system integrated with solar PV/T collectors: Experimental investigation and machine learning modeling coupled with manta ray foraging algorithm

This study explores the performance augmentation of a solar adsorption desalination system (SADS) powered by a hybrid solar thermal system with evacuated tubes and photovoltaic thermal (PV/T) collectors, both numerically and experimentally. The system concurrently generates both electrical power via the PV/T system and desalinated water through the SADS. The cooling of photovoltaic cells is achieved through the utilization of chilled water produced during the desalination process of the SADS, which aims to enhance the electrical efficiency of photovoltaic cells and optimize the overall utilization of the adsorption distillation cycle. The SADS is examined under different operational scenarios and thoroughly assessed in terms of specific cooling power, specific daily freshwater product, and the coefficient of performance (COP). More so, a hybrid machine learning framework integrating an adaptive network-based fuzzy inference system (ANFIS) fine-tuned through the utilization of a manta ray foraging optimization algorithm (MRFOA) is also developed to predict the performance parameters of the SADS. The experiments indicated that the modified PV/T system improved the PV efficiency by 18 % at peak time, where the yielded electrical power and electrical efficiency reached 112 W/m2 and 11.13 %, respectively. The specific freshwater product (SWP), specific cooling power (SCP), and COP of the SADS are estimated as 53.3 L/ton-cycle (6.30 m3/ton-day), 153 W/kg, and 0.25, respectively. Furthermore, Furthermore, the simulated findings showed that the deterministic coefficient and RMSE of the predictive SWP are 0.989 and 1.314 for ANFIS-MRFOA and 0.965 and 2.323 for typical ANFIS, respectively. Hence, the ANFIS-MRFOA exhibited the highest prediction accuracy and can be deemed a potent optimization tool for forecasting the energetic performance of adsorption distillation systems.

Investigation of the energy performance of thermal energy sharing for photovoltaic-thermal systems in a thermal prosumer network

This study analyzes the potential for energy saving through the integration of a photovoltaic-thermal (PVT) system with a heat pump (HP) in a community with a small-scale thermal network. An empirical study was conducted in a community to analyze and compare the performance of a HP and small-scale thermal network with hub thermal energy storage system that utilizes the surplus thermal energy produced by a PVT system installed in a residential house from other buildings with that of an existing electric hot water boiler. The energy saving analysis of the proposed system revealed that the energy consumption could be reduced by more than 70 % compared to the existing system. The HP exhibited a COP ranging between 4.2 and 4.7. Throughout the experiment, the integrated system collected an average of 23.77 kWh of heat energy daily from the PVT units. The annual domestic hot water load coverage from PVT through the thermal network was found to be 50.4 %. These results indicate that PVT systems combined with thermal networks and HPs can effectively reduce energy consumption in individual buildings and enhance energy efficiency within communities.

Simulation and optimization on a novel air-cooled photovoltaic/thermal collector based on micro heat pipe arrays

To further enhance the performance of an air-cooled photovoltaic/thermal (PV/T) system, this study integrates micro heat pipe arrays (MHPAs) and serrated fins as the primary heat dissipation components. The lumped-parameter method was utilized to establish a mathematical model for the previously proposed PV/T system based on MHPAs. The model reliability was validated with the test data (errors within ± 10 %). Subsequently, the influence of solar irradiance, ambient temperature, airflow velocity inside the duct, and component structure on the air-cooled PV/T system performance was analyzed and optimized using the method of controlling variables. The impact of varying the condensing section length of the MHPA from 4 to 28 cm on the system performance was analyzed, and it was found that the condensing section length had a relatively small effect on the system thermoelectric performance. When the optimal comprehensive performance was achieved with fin heights ranging from 6 to 18 mm, heat collecting efficiency remained stable at around 19.5 %. When the cross-sectional dimension of the duct was 25 cm, the power generation efficiency reached its maximum value of 12.59 %. Such research findings provide data support for the promotion, development, and wider applications of air-cooled PV/T systems in energy utilization.

Geometrical Aspects of the Optics of Linear Fresnel Concentrators: A Review

Linear Fresnel concentrators (LFR) are widely seen by the scientific community as one of the most promising systems for the production of solar energy via thermal plants or concentrated photovoltaics. The produced energy depends on the optical efficiency of the LFR, which is mainly dictated by the geometry of the plant. For this reason, the analysis of LFR geometry and its effects on optical behavior is a crucial step in the design and optimization of a Fresnel plant. The theoretical and computational tools used to model the optics of a LFR are fundamental in research on energy production. In this review, geometrical aspects of the optics of linear Fresnel concentrators are presented, with a detailed discussion of the parameters required to define the geometry of a plant and of the main optical concepts. After an overview of the literature on the subject, the main part of the review is dedicated to summarising useful formulas and outlining general procedures for optical simulations. These include (i) a ray-tracing procedure to simulate a mirror field, and (ii) a fast quasi-analytical method useful for optimizations and on-the-fly computations.

Lifetime optimisation of integrated thermally and electrically driven solar desalination plants

We compare the performance of photovoltaic (PV), flat-plate and evacuated-tube solar-thermal (ST), and hybrid photovoltaic-thermal (PV-T) collectors to meet the energy demands of multi-effect distillation (MED) desalination plants across four locations. We consider three scales: 1700 m3day−1, 120 m3day−1 and 3 m3day−1. We find a strong dependence of the capacity and configuration of the solar collectors on both the cost of sourcing electricity from the grid and the specific collector employed. We find specific costs as low as 7.8, 3.4 and 3.7 USDm−3 for the three plant capacities. We find that solar-driven systems optimised for the lowest specific cost result in CO2eq emissions equal to, or higher than, those from grid-driven reverse osmosis (RO) and in line with PV-RO. This highlights the need to consider the environmental footprint of these systems to ensure that desalination is in line with the United Nations’ Sustainable Development Goal 6.

The reversed circular flow jet impingement (RCFJI) PV/T collector: Thermohydraulic and electrohydraulic analysis

AbstractSolar energy could be used to generate both electricity and heat with the aid of photovoltaic thermal (PV/T) systems. Although the systems have a variety of advantages, they nevertheless hold a significant constraint. The system suffers a susceptible constraint wherein the photovoltaic (PV) module experiences an increase in temperature due to exposure to solar irradiation. The integration of a cooling system is necessary to enhance its operational efficiency. A novel approach, known as the reversed circular flow jet impingement (RCFJI), was proposed as a means to improve the performance of a PV/T collector. The current work seeks to assess the thermohydraulic and electrohydraulic performance of the RCFJI PV/T collector. The experiment was conducted under an irradiance level of 500–900 W/m2. From the result obtained, the thermohydraulic efficiency reached its maximum value of 59.20% under 900 W/m2 at 0.14 kg/s. Conversely, the electrohydraulic efficiency attained the highest reading of 10.91% under 500 W/m2 at 0.13 kg/s. It was concluded that a higher flow rate reduces the friction coefficient while increasing the pressure drop. The thermohydraulic and electrohydraulic analyses emphasize the importance of assessing the friction coefficient and pressure drop to attain optimal performance. This study addresses the lack of research by presenting a new cooling approach that utilizes jet impingement. In addition, this study provides an understanding of the thermohydraulic and electrohydraulic performance of a RCFJI PV/T collector.