Building Integrated Photovoltaic Thermal System Research Articles

A 4E Comparative Study between BIPV and BIPVT Systems in Order to Achieve Zero-Energy Building in Cold Climate

The growing demand for energy has led to the popularity of building integrated photovoltaic (BIPV) systems. However, photovoltaic (PV) system efficiency decreases as the temperature increases. To address this issue, a study was conducted on a BIPV thermal (BIPVT) system, which can generate both thermal and electrical energy, to enhance its efficiency. In this study, for the cold weather in Tabriz city in Iran, BIPV and BIPVT systems are compared with each other in terms of energy, economy, exergy, and environment (4E) and the goal is to fully supply the thermal and electrical load of the desired building. The studied criteria are electrical power and heat recovery, payback time (PBT), exergy efficiency, and saved carbon dioxide (SCD) from the energy, economic, exergy, and environmental point of view, respectively. Finally, it is concluded that in cold weather, the BIPVT system can achieve a 7.15% improvement in produced power compared to the BIPV system and 52.2% of the building’s heating needs are provided. It also causes the exergy efficiency to improve by an average of 1.69% and saves 34.98 ton of carbon dioxide. The PBT of this study is calculated as 5.77 years for the BIPV system and 4.78 years for the BIPVT system.

Cooling performance of all-orientated building facades integrated with photovoltaic-sky radiative cooling system in summer

In response to the pressing need of urban high-rise high-density building sectors, the rapid development of energy-plus building façades in conjunction with power generators, such as building integrated photovoltaic/thermal systems (BIPV/T), has been regarded as one of the critical ways to achieve zero energy consumption buildings. Thermal dissipation technology based on building envelopes, on the other hand, is scarce, and building-integrated solar technologies are mostly focused on rooftop PV/T systems. Meanwhile, the ongoing solar heat collection on the south wall is insufficient to fulfill the summer interior cooling need. As a result, the current study suggests an all-oriented building facade combined with a photovoltaic-sky radiative cooling system (PV-RSC), with the PV module installed on the south wall and the sky radiative cooling system installed on the north wall. To investigate cooling performance, a numerical model for the energy transfer of PV-RSC systems is developed and verified. The results suggest that the PV-RSC system with a 0.61 m2 area has mean electrical and cooling powers of 7.7 W and 130–220 W, respectively, which would have a positive effect on the building cooling in the summer.

Performance study of air-type BIPVT coupled water-cooled wall

Building-integrated photovoltaic-thermal (BIPVT) systems can provide both electrical and thermal energy for building, realizing efficient use of solar power and decreasing the energy consumption of the building. In this study, water-cooled walls were installed on both sides of the air flow channel to improve the heat exchange between the photovoltaic (PV) panels and the air by cooling the air, thus realizing an improvement in the thermal/electrical performance of air-type BIPVT. An experimental system of coupled BIPVTs was conducted to study the influence of cooling water temperature on performance of the system. The results show that a 10 K reduction in cooling water temperature increases the heat efficiency by 26% and the electrical efficiency by approximately 2%. The results can be used for the optimized operation of BIPVT system.

Using machine learning in photovoltaics to create smarter and cleaner energy generation systems: A comprehensive review

Photovoltaic (PV) technologies are expected to play an increasingly important role in future energy production. In parallel, machine learning has gained prominence because of a combination of factors such as advances in computational hardware, data collection and storage, and data-driven algorithms. Against this backdrop, we provide a comprehensive review of machine learning techniques applied to PV systems. First, conventional methods for modeling PV systems are introduced from both electrical and thermal perspectives. Then, the application of machine learning to the analysis of PV systems is discussed. We focus on reviewing the use of machine learning algorithms to predict performance and detect faults, and on discussing how machine learning can help humanity to achieve a cleaner environment in the worldwide drive towards carbon neutrality. This review also discusses the challenges to and future directions of using machine learning to analyze PV systems. A key conclusion is that the use of machine learning to analyze PV systems is still in its infancy, with many small-scale PV technologies, such as building integrated photovoltaic thermal systems (BIPV/T), not yet benefiting fully in terms of system efficiency and economic viability. The wider application of machine learning to PV systems could therefore forge a shorter path towards sustainable energy production.

Artificial neural network coupled building-integrated photovoltaic thermal system for indian montane climate

Indian Himalayan Region (IHR) encompass approximately 16.2% of India’s geographical area and characterized as a montane climatic zone. The ambient temperature of this region is extremely low, with a minimum average temperature of 2–18 °C. Major settlements in this region are located at an altitude of more than 1000 m above sea level. Therefore, according to The Energy and Resources Institute (TERI), India, there is excessive thermal and electrical energy consumption in these regions pertaining to space heating. Moreover, the current energy sources utilized are not clean sources and hence contribute towards CO2 emissions. A building-integrated photovoltaic thermal (BIPVT) system is modelled to provide the necessary thermal energy alongside electricity for space heating intended for the climatic conditions of Srinagar. The study utilized an application-centric approach in modelling and analyzing the BIPVT system and, hence quantifying the annual outputs for Srinagar, India. Furthermore, the developed mathematical model is used for training an artificial neural network to predict the annual thermal and exergy outputs of the system based on six different model parameters. Three designs, one operational and two application-based parameters are considered as inputs to the network. Moreover, a multi-criteria decision-making method is employed to determine the best set of BIPVT parameters giving optimum annual thermal and exergy outputs along with electrical, thermal and exergy efficiencies of the modelled system. The modelled neural network performed reasonably well against the unseen test dataset in predicting the BIPVT yield with an R2 value >0.97. An optimum annual thermal and exergy gains of 2,25,459 kWh and 67,132.38 kWh, respectively, are quantified for the best set of BIPVT parameters. The system’s optimum average electrical (power conversion), thermal and exergy efficiencies are observed to be 14.87, 56.28, and 17.59%, respectively.

Energy renovation of an existing building in Nicosia Cyprus and investigation of the passive contribution of a BIPV/T double façade system: A case-study

The European regulatory shift towards energy-efficient buildings and nearly zero energy buildings (NZEB) leads architects and engineers to the need for investigation of new innovative design methodologies. The reduction of the energy demand for cooling, heating and artificial lighting is now mandatory for new buildings and for large renovations of existing buildings, in order to comply with these new regulations. This is a challenge since the majority of the current building stock is consisted by over than 25-year-old existing buildings, which are inefficient in terms of energy needs. The aim of this study is to completely renovate an existing building in the centre of Nicosia, Cyprus, by applying a novel double façade system. This is consisted by a combination of a novel Building Integrated Photovoltaic/Thermal system (BIPV/T) and a Corridor Type Double façade system, which acts autonomously in every floor. The proposed research starts with an analysis of building and site geometry and moves through a literature review, along with the presentation of case studies where active solar energy systems are integrated on double building facades. Digital energy simulations are performed where the proposed double façade’s passive contribution is investigated. At the same time, these simulations aim to analyse whether the system can cover the energy needs of the aforementioned building. The investigation focuses into calculating the façade’s electricity production potential, whilst its passive contribution is recorded through the reduction potential of the building’s energy needs for heating, cooling and artificial lighting. Through a 3D simulations modelling, the existing energy needs are recorded and then compared to the calculated needs of the renovated building. The ultimate aim of this research is to determine whether the use of BIPV/T double façade solutions for the refurbishment of existing buildings consist an environmental viable solution.

Performance Assessment of a Building-Integrated Photovoltaic Thermal System in a Mediterranean Climate—An Experimental Analysis Approach

The experimental investigation of building-integrated photovoltaic thermal (BIPVT) solar systems is essential to characterise the operation of these elements under real conditions of use according to the climate and building type they pertain. BIPVT systems can increase and ensure energy performance and readiness without jeopardising the occupant comfort if correctly operated. The present work presents a case study’s experimental analysis composed of a BIPVT system for heat recovery located in a controlled test room. This work contribution focuses on the presentation of the obtained measured value results that correspond to the BIPVT main boundary conditions (weather and room characteristics) and the thermal behaviour and performance of the BIPVT system, located in the Solar XXI Building, a nZEB exposed to the mild Mediterranean climate conditions of Portugal.

Comparison of the performance of different designs of a combined system consisting of a photovoltaic thermal unit and a sensible rotary heat exchanger

Steady-state energy and exergy evaluation are performed on two designs of a hybrid building integrated photovoltaic thermal (BPT) unit and a thermal wheel (SRX). The working principles of these designs in summer are similar such that the warm outside air is precooled by exchanging heat with air coming out of the building in SRX and then enters the building. Also, other outlet air from SRX passes through the BPT unit and cools PV modules, boosting their efficiency. The working principle of the design A in winter are that the outside air is preheated by receiving heat from the building exhaust air in SRX and then preheated again by passing through the BPT system. The design B works in the same way in winter, with the air passing through the BPT system first and then the SRX. The outcomes revealed that the annual total rate of thermal energy, electrical energy and thermal exergy outputs of the design A are 23183.4 kW h, 5994 kW h, 261.6 kW h, respectively, while these values for the design B are respectively 22785.2 kW h, 6030. 6 kW h and 243 kW h. In addition, it was found that the overall energy/exergy performance of design A is better/worse than design B.

Building-integrated photovoltaic/thermal (BIPVT) systems: Applications and challenges

A key medium for energy generation globally is the solar energy. The present work evaluates the challenges of building-integrated photovoltaic (BIPVT) required for various applications from techno-economic and environmental points of view. Many challenges are found for applying solar photovoltaics (PVs) modules combined with building systems: supplying hot and cold water and ventilation for the residential and non-residential building. Moreover, efforts and advances achieved in enhancing the BIPVT thermal and electrical performance are explored. Additionally, the review provides further insight into recognizing the fundamental science of the BIPVT systems, explaining its rapid developments and the thermal performance mechanisms. The BIPVT systems designed for rooftops, windows, and facades are specifically highlighted in the present review. Furthermore, the status of PV modules and BIPVT system, benefits, applications, barriers and challenges, and future prospects are discussed. The BIPVT systems require governmental support and a more economically convenient and efficient tariff to maintain the economic feasibility of the system. The key factors impeding the commercialization of BIPVT systems are the implementation of the feed-in tariff, customers’ perception, national economic support, technical aspects such as the performance, system management, and architectural and material considerations. Finally, this review indicates that further works concerned the BIPVT systems to enhance the technology and advancements are still required.

Development and Performance of Roof-Based Building-Integrated Photovoltaic-Thermal Systems: A Review

Abstract A building-integrated photovoltaic-thermal (BIPVT) system integrates building envelope and photovoltaic-thermal collectors to produce electricity and heat. In this paper, the electrical and thermal performance of roof-based BIPVT systems developed in the recent two decades and their effects on heating and cooling load of the building are reviewed. According to the use of thermal energy from the photovoltaic (PV) panels, the roof-based BIPVT are classified into three classes: cooling of PV, air heating, and water heating. Each class is further divided into several types according to the designs of the integrated PV roofs. Compared with BIPV systems, the total efficiency of most BIPVT systems is significantly improved. However, the decrease in electricity output and adverse impact on the indoor environment is also found for some designs of BIPVT systems in some climates. The advantages and disadvantages of various designs are discussed. Issues to be further studied in the future are also provided in this review.

Exergetic Performance Assessment of Optimally Inclined BIPV Thermal System by Considering Cyclic Nature of Insolation

Abstract The structural and architectural elements of building-integrated photovoltaic-thermal (BIPVT) systems are made up of photovoltaic (PV) modules and these are required to be fixed at an optimum inclination angle for generating maximum exergy. This work presents an attempt to determine the amount of exergy generated by an optimally inclined double-storied BIPV thermal system by considering the actual cyclic nature of insolation, surrounding air temperature, PV cell temperature, intermediate slab temperature, and the chamber temperature. The insolation value, which is computed by an anisotropic sky model along with these cyclic variables, is used for solving the set of governing differential equations for evaluating the exergy of the system. Other influencing parameters of the BIPV thermal systems such as air changes in both chambers, packing factor of PV module, the orientation of PV module, and thickness of the intermediate slab are considered for finding its effect on the total exergy of the system. Numerical results show that for packing factor more than 0.6, there is no significant change in total heat exergy with respect to the inclination angle. For packing factor more than 0.3, the generation of electrical exergy exceeds the heat exergy, and the overall exergy of BIPVT system decreases with rise in packing factor (βm) up to 0.3 and then rises nonlinearly.

A review of designs and performance of façade-based building integrated photovoltaic-thermal (BIPVT) systems

A façade-based building integrated photovoltaic-thermal (BIPVT) system combines solar photovoltaics (PV) and solar collectors for integration with building façades to generate electricity and produce thermal energy. As a result, solar energy efficiency can be increased significantly while heating/cooling load of buildings can be reduced. Thus, BIPVT application provide a promising method to significantly reduce building energy consumption for developing low-energy or even zero-energy buildings. This paper presents a review on BIPVT development and focuses on the designs of integrated solar systems with building façades and its influence on electricity generation, thermal performance of PV cells, and energy consumption of buildings for space heating and cooling. Façade-based BIPVT systems are first classified into 7 types: cooling of PV by air, space heating, ventilation, water heating, PV-PCM, BIPVT with heat pump and photovoltaic thermoelectric wall according to the uses of the thermal energy from the claddings. The electrical output, thermal performance and impacts on building’s heating/cooling load are then comprehensively reviewed for various typical and novel designs developed globally over the past two decades. The advantages and disadvantages of various designs are discussed. Future research directions are also outlined. The results of this review are useful for researchers and engineers to select appropriate BIPVT designs for renewable energy application in buildings.

Performance Assessment of a Building Integrated Photovoltaic Thermal System in Mediterranean Climate—A Numerical Simulation Approach

This study addresses the thermal and energy performance assessment of a Building Integrated Photovoltaic Thermal (BIPVT) system installed on the façade of a test room in Solar XXI, a Net Zero Energy Building (NZEB) located in Lisbon, Portugal. A numerical analysis using the dynamic simulation tool EnergyPlus was carried out for assessing the performance of the test room with the BIPVT integrated on its façade through a parametric analysis of 14 scenarios in two conditions: a) receiving direct solar gains on the glazing surface and b) avoiding direct solar gains on the glazing surface. Additionally, a computational fluid dynamics (CFD) analysis of the BIPVT system was performed using ANSYS Fluent. The findings of this work demonstrate that the BIPVT has a good potential to improve the sustainability of the building by reducing the nominal energy needs to achieve thermal comfort, reducing up to 48% the total energy needs for heating and cooling compared to the base case. The operation mode must be adjusted to the other strategies already implemented in the room (e.g., the presence of windows and blinds to control direct solar gains), and the automatic operation mode has proven to have a better performance in the scope of this work.

Method to improve performance of building integrated photovoltaic thermal system having optimum tilt and facing directions

A building integrated photovoltaic (BIPV) system can be installed at optimum tilt and orientation angle to maximize the electrical output. PV output is negatively correlated with the increase in the PV panel temperature. This paper aims at investigating the influence of water flow over the BIPV roof of a two-storied single-family house on the performance of the proposed optimally tilted semi-transparent BIPV thermal system having different facing directions. The periodic nature of insolation, ambient air temperature, BIPV cell temperature, slab temperature, water flow temperature and room temperature have been considered while solving energy equilibrium differential equations. The insolation values used in the energy equilibrium equations are computed employing periodic HDKR (Hay, Davies, Klucher and Reindl) model, which is based on anisotropic sky concept. Results indicate that the average BIPV cell temperature is reduced annually by approximately 10 °C and efficiency is enhanced by 6% when a water flow rate of 1.1 kg s−1 is provided over the BIPV roof. It is also observed that on the most critical day of the year, the temperature of outlet water is 11.5 °C higher than that of inlet water temperature which resulted in 4 kW extraction of exergy.

Solar Strategies for net-zero energy housing in Canadian North

The North imports most of its energy for fuel and cost of fuel is much higher than the national average, consequently, cost for space heating relying on fuel is very high. The North has an abundance of solar energy available. With the growing concerns on climate change, the region desires to be less dependent on fossil fuels. Significant energy savings for little added cost in housing could be achieved by building high performing envelope systems and integrating solar design strategies. The objective of this paper is to investigate the potential of integrating solar design strategies in improving energy efficiency of housing suitable for the Canadian Northern climates through modelling by optimizing passive solar design and optimal use of thermal and electrical energy from Building Integrated Photovoltaic/Thermal system (BIPV/T) to achieve net-zero energy housing. A reference home with typical construction built in Northern region is modelled using EnergyPlus. The key solar design strategies and building envelope parameters are optimized to minimize energy consumption and maximize the energy production for the reference home. The parameters investigated include thermal resistance of building envelope components, window-wall ratios, thermal mass, night window shutters, shading schedules, and ventilation rates. The optimal use of thermal energy produced by BIPV/T system by integration with Heat Recovery Ventilation (HRV) and air-source Heat Pump (ASHP) is evaluated. Modelling results show that 43% energy saving can be achieved by optimizing the passive solar design and overheating can be eliminated by proper solar shading and natural ventilation. The integration of BIVP/T with HRV can reduce the frost cycle by 10.4%. These preliminary findings demonstrate the potential of integrating solar design strategies to reduce energy consumption and develop net-zero energy housing for the Canadian North.

Energy and exergy analysis of two novel hybrid solar photovoltaic geothermal energy systems incorporating a building integrated photovoltaic thermal system and an earth air heat exchanger system

In this paper, two novel configurations of the building integrated photovoltaic thermal (BIPVT)-compound earth-air heat exchanger (EAHE) system are proposed. Both the configurations operate in two modes, namely heating and cooling modes. In the heating mode of the configuration A, the cold outdoor air is twice preheated by passing through the EAHE and BIPVT systems. In the cooling mode of the configuration A, the hot outdoor air is precooled by flowing inside the EAHE system and the PV modules are cooled using the building exhaust air. The cooling mode of the configuration B is similar to the configuration A, while in the heating mode of the configuration B, the outdoor air first enters the BIPVT collector and then passes through the EAHE system. The energetic and exergetic performances of the configurations are investigated for climatic conditions of Kermanshah, Iran. In addition, the impacts of length, width, and depth of air duct located underneath the PV panels, air mass flow rate, length and inner diameter of the pipe of EAHE system on the annual average energetic and exergetic aspects of the best configuration of the BIPVT-EAHE system are evaluated. The outcomes revealed that the annual rate of thermal energy, electrical energy, and thermal exergy captured from the configuration A are respectively 3499.59, 5908.19, and 55.59 kWh, while these values for the configuration B are respectively 3468.16, 5969.87, and 51.76 kWh. In addition, it was found that the configuration A has superior energetic performance than the configuration B, while the overall exergetic performance of the configuration B is higher than the configuration A. Furthermore, it was depicted that both the energetic and exergetic performances of the suggested configurations intensify by augmenting the duct length, duct width, and tube diameter whereas they decline with an increase in the air mass flow rate and duct depth.

Multi-objective energy and exergy optimization of different configurations of hybrid earth-air heat exchanger and building integrated photovoltaic/thermal system

Multi-objective optimization of a hybrid building integrated photovoltaic/thermal (BIPVT) system and earth-air heat exchanger (EAHE) is studied. According to the position of the BIPVT and EAHE systems, two different configurations (i.e. configuration A and configuration B) are examined. In the heating mode of the configuration A, the cold outdoor air is twice preheated by passing through the EAHE and BIPVT systems. In the cooling mode of the configuration A, the hot outdoor air is precooled by flowing inside the EAHE system and the photovoltaic (PV) modules are cooled using the building exhaust air. The cooling mode of the configuration B is similar to the configuration A, while in the heating mode of the configuration B, the outdoor air first enters the BIPVT collector and then passes through the EAHE system. The annual total amount of produced energy and exergy are considered as the objective functions. The effective parameters in the optimization process include the air mass flow rate, the length, width and depth of BIPVT channel and the length and depth of EAHE system. The outcomes revealed that the annual total energy and exergy outputs of the optimum configuration A are 96448.6 kWh and 10015.5 kWh, respectively, while these values for the optimum configuration B are respectively 98537.5 and 9888.4 kWh.

A Novel Investigation and Comparative Study on Building Integrated Photovoltaic Thermal (BIPVT) System

An analysis of BIPVT system has been carried out in this paper based on arrays named as solar cell tile array and semi-transparent array. Previously comparisons and performance analysis were carried out for opaque and semitransparent system in non-optimized way but in the present case it has been optimized to get better results. As far as energy efficiency and exergy is concerned semitransparent PVT has an edge as compared to others in all respect. Semitransparent PVT has higher useful energy gain by 2.5 KWH as compared to SCT. Further the electrical and thermal efficiency has been derived and a conclusion has been made that semitransparent PV cell has an edge in all respects as compared to SCT. The electrical efficiency has been increased to 17.17% from the previous 16% and overall exergy to 18.4% from previous 17.1%. i.e. an overall growth of 6.8% and 7.6% respectively.

The feasibility of genetic programming and ANFIS in prediction energetic performance of a building integrated photovoltaic thermal (BIPVT) system

The main motivation of this study is to evaluate and compare the efficacy of three computational intelligence approaches, namely artificial neural network (ANN), genetic programming (GP), and adaptive neuro-fuzzy inference system (ANFIS) in predicting the energetic performance of a building integrated photovoltaic thermal (BIPVT) system. This system is capable of cooling PV panels by ventilation/exhaust air in winter/summer and generating electricity. A performance evaluation criterion (PEC) is defined in this study to examine the overall performance of the considered BIPVT system. Then, the mentioned methods are used to identify a relationship between the input and output parameters of the system. The parameter PEC is considered as the essential output of the system, while the input parameters are the length, width, and depth of the duct underneath the PV panels and air mass flow rate. To evaluate the accuracy of produced outputs, two statistical indices of R2 and RMSE are used. As a result, all models presented excellent performance where the ANN model could slightly perform better performance compared to GP and ANFIS. Finally, the equations belonging to ANN and GP models are derived, and the GP presents a more suitable formula, due to its simplicity of use, simplicity of concept, and robustness.

Performance of building integrated photovoltaic thermal system with PV module installed at optimum tilt angle and influenced by shadow

Abstract Building integrated photovoltaic (BIPV) thermal system is an efficient system for urban applications to convert a building to net zero energy buildings by utilizing solar insolation. In this study, HDKR/S (Hay, Davies, Klucher, Reindl/shadow) model is developed which is a modified HDKR model where influence of shadow is incorporated in the mathematical model. Four discrete rectangular buildings situated in four directions (North, South, East and West) around a BIPV thermal system are considered for creating adverse effect of shadow. Variation of width (B), storey height (H) and horizontal distance (D) of these surrounded buildings are taken into account for evaluating optimum tilt angle, insolation and performance of BIPV thermal system by introducing corresponding shadow effects. The performance of the system is adversely affected because of the presence of surrounded building located at close proximity i.e., due to higher influence of shading and sky view blocking effects.