Rethinking BIPVs: Evaluating the thermal trade-offs of building-integrated photovoltaics

In this chapter, we considered a building-integrated photovoltaic (BIPV) system, which was installed at Yasar University in Izmir, Turkey, within the framework of an EU/FP7-funded project and has been successfully operated since February 8, 2016. The BIPV system consists of 48 crystalline silicon (c-Si) modules in 4 rows and 12 columns, and the total capacity is 7.44 kWp. We applied the specific exergy costing (SPECO) method to the BIPV system for the first time to the best of the authors’ knowledge. In this regard, we briefly introduced the BIPV system in this study first. We then used the SPECO method for assessing the performance of the BIPV system. Exergetic costs associated with the generated electricity varied between 0.21 and 0.36 €/kWhex for the selected days, with an average exergetic cost of 0.368 €/kWhex for the whole year.

Performance assessment of partially shaded building-integrated photovoltaic (BIPV) systems in a positive-energy solar energy laboratory building: Architecture perspectives

Wind-driven rain (WDR) impact is a serious exposure that affects performance of the building envelope components and systems. This study presents results from a laboratory investigation of a testing methodology of WDR intrusion in building-integrated photovoltaic (BIPV) systems. The major aspect proposed in this work is a quantification of water intrusion through BIPV systems. For that matter, a water collection system was designed and tested. When water intrusion is quantified, it may enable categorisation and comparison of various BIPV systems according to their watertightness level. This methodology was applied to three BIPV systems designed for roof integration. The methodology can also be modified and used for various building envelope systems, including traditional roof and facade systems without PV or BIPV systems. As the methodology was developed with climate conditions in northern Europe in mind, WDR exposure of extreme levels was applied. Wind speed ranges from 12.9 m/s (strong breeze) to 35.3 m/s (hurricane) were used. When it comes to newly developed and not well-studied building envelope systems, such as various BIPV systems, they should be subjected to a more extensive investigation. The proposed testing methodology could become an extension of the standard investigations of BIPV systems carried out at accredited laboratories.

Recently, As a result of government policy to promote renewable energy sources, BIPV(Building Integrated Photo Voltaic) System replacing building finishing material with photo voltaic module has been increasing. Building integrated photo voltaic system is installed in a building by inserting a solar cell in the building finishing material. Thus BIPV systems have possibility of an electric shock accident due to decreased insulation performance because it is easy to contact human body from conductor. Especially, in case of a system using transformerless inverter system, it is structurally vulnerable to safety, so that the risk of accidents may increase. Therefore, the risk of human shock due to accidents should be studied through actual accident experiments. In this paper, as a study for the development of standards for securing human body electrical safety in BIPV system, we considered the hazard of electrical safety in the BIPV systems applied transformerless inverter and conducted analysis risk of electric shock through verification experiment.

This report analyses the Technological Innovation System (TIS) of Building Integrated Photovoltaics (BIPV) in Austria. The study’s scope is consistent with the IEA PVPS Task 15 report [1].The analysis aims to facilitate and support the innovation, development, and implementation of industrial solutions of BIPV technologies. In Austria, the use of BIPV is still a niche application and covers under 2% of all implemented PV systems [1]. BIPV technology in Austria has historically developed with the support of different public financial incentives, national and European. The history of BIPV is somehow tightened to the history of PV. The first BIPV prototypes were developed by PV companies in the framework of national or European research activities, with the first development and innovation projects starting around 2003. In general, it should be mentioned that in the last years, PV and BIPV companies have increased specialization in the production of BIPV, especially colored and semitransparent PV modules. In this regard, a wide range of variants are offered (printing, coating, films). The colored components are mainly purchased from glass companies or polymer film producers. Another trend in Austria is the production of transparent glass/glass modules for integration in facades, skylights, winter gardens, or courtyard roofing. In 2020, the government of Austria presented a program called EAG (Erneuerabre Ausbau Gesetz) or Renewable Expansion Act [3.3.1 Hard institutions]containing certain working points to be implemented by 2024. Some of the measures are directly or indirectly relevant to the BIPV development and installation. Such as the PV encapsulation films using interference pigment technology from Lenzing Plastics. This TIS assessed the BIPV market through eight functional areas and provided the following results: ⁃ The analysis of knowledge development showed that it can be classified as moderate. On the one hand, there are not enough training and further education opportunities in the field of BIPV available, but on the other hand, the PV manufacturers and research institutions are driving forward the development of knowledge in the field of BIPV. ⁃ Knowledge dissemination is well advanced internationally within the research community but insufficient at the practical, national level, particularly between the PV industry and the construction sector. Architects are demanding more information from PV manufacturers and suppliers, who share their information only irregularly with the architectural community. Usually, architects obtain this information from PV technology platforms through workshops, brochures, and projects. However, architects have to engage with it more extensively. The goal is to make BIPV more appealing to architects. Thus, we have to summarize that knowledge dissemination is inadequate/weak. ⁃ Entrepreneurial willingness to experiment can be classified as moderate. Overall, it can be said that there are four players in the Austrian BIPV market and a substantial number of newcomers and small innovative players who could take the role of innovation drivers. However, there are too few opportunities for highly specialized small companies. ⁃ Resource mobilization is well positioned financially and in terms of network services. However, and this is essential if we want to expand the BIPV market strongly, there is a lack of skilled personnel (human resources) to carry out the expansion, which is why this function is rated to only be moderate. ⁃ The scoring of social capital is weak. The connection where there is a lack of communication is between the (BI)PV planner and the architects. In most projects, the (BI)PV planner is not involved in the early stages of the building design process. In addition, conventional PV planners have no experience or are hesitant of planning BIPV systems. ⁃ The legitimacy is moderate, but as the acceptance of PV improves from year to year, the chance of better acceptance of PV integrated into the building, i.e., BIPV, also increases. However, there are still reservations and resistance towards individual, specific BIPV projects. This resistance could be reduced by increasing knowledge about the multifunctional possibilities of BIPV at the decision-maker and customer stage as well as by showing best practice examples - Guidance of the search is moderate, as there are no specific political targets for BIPV, but there are for PV. However, the government and relevant authorities aim to implement clean energy development positively and apply applicable policies and regulations. There is an increased subsidy for innovative PV solutions [2] which also includes BIPV. ⁃ It can be stated that the market formation of BIPV in Austria still offers room for improvement. When it comes to governmental-driven incentives and support for the BIPVmarket development, the missing technical standards (e.g., fire safety regulations) and the absence of regulatory obligations on renewable energies in the local building codes are the biggest weaknesses. The structural and functional analysis is followed by a coupled structural-functional analysis. This assessment will help identify weaknesses and strengths and recommend strategies that will enable the growth of BIPV from a niche market to a major market segment. The aim is for photovoltaics (PV) on buildings to be primarily designed as Building Integrated Photovoltaics (BIPV) to reduce additional costs. This, combined with the avoided costs for other components of the building, should result in cost parity with Building-Applied Photovoltaics (BAPV). It is also crucial to encourage all manufacturers of building envelope components to ensure that their products offer the dual benefit of serving as building components while also generating electricity. By doing so, such products can become standard in the industry. The transition from BAPV to BIPV was already analyzed in a 2015 BIPV brochure [2] from the Austrian Photovoltaics Technology Platform (TPPV), which discussed the advantages of an integrated solution versus an attached solution and outlined the necessary steps to make BIPV the standard for building PV. The recommendations are summarized as follows: i) It is important to involve (BI)PV in the early stages of the building planning process. ii) successful implementation projects must be made public through various channels to increase knowledge about BIPV technology and its possibilities (e.g., lighthouse projects in public buildings). iii) PV standards and construction codes have to be harmonized. iv) The Austrian government should stipulate the use of PV in the obligatory building specifications. v) Another recommendation would be to enact a law requiring every sealed area to be checked for dual use with (BI)PV. One positive development worth mentioning is the Climate Fund's Lighthouse call, which focuses specifically on integrated PV and offers higher grants for BIPV than the Renewable Expansion Act] , demonstrating increased interest and commitment to this technology. In addition, the TPPV Innovation Awards, which were awarded for the first time specifically for building-integrated PV and now include other topics of PV integration outside of buildings, are a sign that the industry is broadening its perspective and recognizing the importance of BIPV beyond traditional applications. These developments could help to further promote the acceptance and deployment of BIPV and drive innovation in this area. Nevertheless, it is important to consider the significantly higher costs of BIPV products, as well as the greatly increased planning effort that arises when PV becomes an integral building product.

The rising operating temperature of Building-Integrated Photovoltaic (BIPV) systems is a critical factor that limits their electrical efficiency in real building applications. Addressing this issue is essential for improving both the performance and the reliability of BIPV systems under outdoor conditions. In particular, the demand for colored BIPV has been increasing due to its aesthetic integration with building façades, making it important to clarify its temperature behavior and electrical performance. However, most existing studies have focused on conventional BIPV modules, and research on the thermal and electrical characteristics of colored BIPV remains relatively limited. This study analyzes the temperature characteristics and electrical performance of conventional and colored BIPV systems installed in a full-scale mock-up building. Outdoor experiments showed that the maximum module temperature of the conventional BIPV system reached 75 °C, whereas the colored BIPV system remained lower at 68 °C. The temperature difference between the two systems ranged from 3 to 8 °C depending on solar radiation, mainly due to the retention of thermal energy in the rear insulation structure of BIPV systems and differences in incident energy conversion. These variations directly influenced the power generation and electrical efficiency of the modules. Compared with Standard Test Conditions (STCs), electrical efficiency decreased by approximately 15% in the conventional BIPV system and 10% in the colored BIPV system. The results demonstrate that colored BIPV systems not only mitigate the adverse impact of temperature rise on efficiency but also provide reliable performance and enhanced aesthetic adaptability, offering a promising solution for real building applications.

Objectives: Recent technological advancements have significantly improved the energy conversion efficiency of Building-Integrated Photovoltaic (BIPV) modules and Photovoltaic (PV) modules in general. These improvements have facilitated the widespread adoption of PV systems across various sectors, including residential, commercial, and industrial applications. The modular and distributed characteristics of PV systems make them a preferred choice among the diverse renewable energy technologies available. Methods: This study involves simulation analysis of a BIPV system using the PVSol solar PV system analysis tool and a comparison of energy generation & performance ratio with an actual rooftop PV system installed at Integral University, Lucknow, India. The study presents and discusses various parameters of the 70.6 kWp BIPV system for a geographical location of Lucknow having coordinates 26.84 N, 80.94 E. Findings: The BIPV technology is key to reducing global building energy consumption, which accounts for approximately 40% of total energy use, contributing to lower greenhouse gas emissions. 70.6 kWp rooftop PV system at Integral University in Lucknow, India, serves as a reference for BIPV system simulation, helping to validate its performance and improve system reliability. Novelty: The BIPV system of Integral University, Lucknow, is analysed and also simulated on PVSol, which is industrial software. When the technical parameters are compared and analysed, it is found that the average PR of the simulated system is 80.15, whereas the average PR of the installed system is 67.76%. This shows that system efficiency is approx. 84.54%. Keywords: Building Integrated Photovoltaic System (BIPV System), MPPT, PVSol, Performance Ratio (PR), PVSyst Energy Generation Tool, Solar PV System

Around the world, one-third of all fossil fuels and CO2 gas are produced and consumed by the building sector. Energy efficiency and the utilization of renewable energy are regarded as the two main approaches to tackling the issues of increasing emissions and energy consumption. Solar energy is an admirable solution for addressing this problem because it is a plentiful renewable energy source. While the use of solar energy through building-integrated photovoltaic (BIPV) systems is becoming more popular worldwide due to its ability to generate clean energy and reduce building energy usage. However, in Bangladesh, the use of BIPV systems is minimal. Nonetheless, there is no government legislation addressing this prospective construction technology, nor is there extensive research on the BIPV system. Considering this research shortfall, the purpose of this study is to provide a general overview of BIPV systems and technologies. Furthermore, provide an overview of the published literature on BIPV systems that considers Bangladesh and finds out its future prospects. Besides, list the major obstacles and difficulties in adopting the BIPV system in Bangladesh. The implementation of feed-in tariffs, public acceptance, government financial support in the form of subsidies, and appropriate policy for spreading this promising technology are the main obstacles to BIPV systems. On the other hand, a few recent studies demonstrate that in Bangladesh, BIPV window systems have a lot of potential for power generation, building energy conservation, and CO2 reduction. It was found that a 12.5 kWp BIPV facade system put in a Dhaka city commercial building could generate 22,600 kWh of power yearly, which could lower the release of about 15 tons/yr. of CO2.

Limited fossil energy resources and the potential danger of nuclear power plants led to growing popularity of solar energy. In Switzerland, Building Integrated Photovoltaic (BIPV) is expected to be responsible for up to quarter of the energy production from renewable resources by the time of 2035. In order to protect the existing natural landscape, BIPV must be concentrated in urban spaces, which means that certain amount of existing building envelopes have to be turned into energy generators. There is a growing concern about BIPV retrofits because they may change the visual appearance of the existing city images to a large extend and/or in a negative way. In order to manage the potential visual impact resulting from BIPV expansion in urban spaces, evaluation methods should be able to measure it appropriately. Existing evaluation methods show insufficiencies for this purpose: either they cannot guarantee objectivity and continuity of evaluation standards throughout assessments of different BIPV projects, because their qualitative criteria are vulnerable to subjective preferences; or they only use formal design parameters to evaluate the visual integration quality of BIPV and therefore lack neuroscientific base. In order to tackle these insufficiencies, an objective evaluation method is proposed that is capable of measuring the BIPV visual impact in building retrofits in a quantified approach based on neuroscience knowledge. The assessment should be made in concept phase of the project, so as to identify the BIPV designs that have the least negative visual impact. The proposed evaluation method integrates saliency model, which imitates the mechanism of human visual attention, into assessment procedures. First, the probability of a BIPV installation attracting human visual attention in the respective visual scene is calculated quantitatively with the saliency model. Then the modifications of saliency values in this very visual scene before and after the BIPV retrofit are assessed. In the end, the modifications of saliency values are transformed into BIPV visual impact and objectively expressed as single values. The analyses are based on renderings generated from RADIANCE and programming in MATLAB. This method is demonstrated with a small case study that simultaneously serves as proof-of-concept. The proposed evaluation method is applied on a realistic case study: BIPV designs for a church roof. In total, 5 designs were developed with variations in BIPV installation location, roof coverage percentage, module size, PV material und design approach. The lowest visual impact value was induced by the BIPV design with the most careful and considerate integration approach, the design with the boldest integration approach obtained the highest visual impact value. The evaluation method proved to be feasible to a large extend. It is believed that the synergy between architecture and neuroscience can contribute to a growing understanding of human responses to the built environment. Hopefully the findings from this thesis can help in minimizing the negative visual impact induced by BIPV expansion in urban spaces, and also aid architects in gaining new understandings for visual aspects in architecture design.

Performance evaluation of a building integrated photovoltaic (BIPV) system combined with a wastewater source heat pump (WWSHP) system

This paper proposes an integrated simulation framework for both building design and energy performance analysis. Literature review shows that, although many studies exist, most of them did not fully consider the integrated techno-economic evaluation of building-integrated photovoltaic (BIPV) system. Therefore, this research aims to use the interoperability potential offered by applying a building information modelling BIM-friendly software to an integrated simulation tool to conduct a comprehensive techno-economic evaluation of a BIPV system in a building cluster. Through visual integration in a digital mock-up, the solar irradiation, surrounding shadings, BIPV location, BIPV components/system (string, inverter, battery), and economic analysis have been performed on a residential building cluster located in Ludvika, Sweden. The results show the optimal location for the 615 m2 BIPV system with a yielding of 27,394 kWh/year. Under the defined boundary conditions, the payback period is 10 years in the mixed feed-in and self-consumption mode, over its 20 years’ life span. Further sensitivity analysis of 18 cases is carried out in order to evaluate the impact of installation position (capacity), future climate change, shadings, and operating mode. This study will help improve decision-making by analysing the impact of the aforementioned factors on a BIPV system techno-economic performance.

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.

In sustainable development concept, energy efficiency and conservation measurements are paramount to reduce the level of building energy consumption. Utilization of such device diminishes the building dependency to the grid which is still dominated by energy from fossil fuels. Implementation of BIPV (Building Integrated Photovoltaic) system is expected to be one of the best possible choices for a tropical country such as Indonesia with abundance of solar radiation. With the existence of BIPV system, it is also expected to reduce the burden of electricity cost for the building management and occupants. This research is considerably new for government building and it also generates a formula to calculate minimum area and the amount of PV panels needed for apartment in Jakarta. Pasar Jumat Apartment is selected to be a subject for this research as the apartment is classified government building which was built and managed by Ministry of Public Work and Housing. Moreover, the apartment has modelled with BIM and already had green building concept. It is expected that BIPV system can enhance the building performance through energy efficiency. However, more in-depth research work to the efficiency and economic feasibility of BIPV system installation are required before implementing the system on the building. Several options of PV panel installation are measured to figure out the most optimal PP (Payback Period) and BCR (Benefit Cost Ratio). Based on the physical feasibility and financial analysis, BIPV system is found to be more promising and profitable if it is implemented at "Pasar Jumat Apartment" for a long term in the future.

The renewable energy can be utilized to satisfy the energy demand. Moreover, the solar energy as the most abundant energy resource among renewable energies plays a crucial role to provide the energy demand. The BIPV (building integrated photovoltaics) systems can be considered to supply the required energy demand from renewable sources. The essential advantage of BIPV systems is that they can be utilized as building component such as roof, window, shading systems and building façade and they can generate electricity simultaneously. Even though the photovoltaic technologies have been improved within past few years, however the utilization of the BIPV systems will be considered expensive. For this reason, the payback period calculation is considered a vital parameter in evaluating the BIPV systems. In this study, the overall energy consumption for producing one m2 of a mono-crystalline photovoltaic module is calculated 1334 kWh. Additionally, the photovoltaic module data for three companies were investigated and the annual energy productions for one m2 of each company’s product were obtained. The results showed that the average energy payback time for 270 and 280 watt modules are 5.565 and 5.254 respectively. Moreover, the energy payback time for 290, 325 and 340 watt modules were calculated 4.903, 5.437 and 4.965 respectively.

This paper presents some of the research activities on building-integrated photovoltaic (BIPV) systems developed by the Solar and Daylighting Laboratory at Concordia University. BIPV systems offer considerable advantages as compared to stand-alone PV installations. For example, BIPV systems can play a role as essential components of the building envelope. BIPV systems operate as distributed power generators using the most widely available renewable source. Since BIPV systems do not require additional space, they are especially appropriate for urban environments. BIPV/Thermal (BIPV/T) systems may use exterior air to extract useful heat from the PV panels, cooling them and thereby improving their electric performance. The recovered thermal energy can then be used for space heating and domestic hot water (DHW) heating, supporting the utilization of BIVP/T as an appropriate technology for cold climates. BIPV and BIPV/T systems are the subject of several ongoing research and demonstration projects (in both residential and commercial buildings) led by Concordia University. The concept of integrated building design and operation is at the centre of these efforts: BIPV and BIPV/T systems must be treated as part of a comprehensive strategy taking into account energy conservation measures, passive solar design, efficient lighting and HVAC systems, and integration of other renewable energy systems (solar thermal, heat pumps, etc.). Concordia Solar Laboratory performs fundamental research on heat transfer and modeling of BIPV/T systems, numerical and experimental investigations on BIPV and BIPV/T in building energy systems and non-conventional applications (building-attached greenhouses), and the design and optimization of buildings and communities.