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With the escalating urgency for sustainable energy alternatives, solar power in urban landscapes has gained prominence. Building‐integrated photovoltaic (BIPV) systems are pivotal in this shift, blending efficient energy generation with architectural aesthetics. This review casts a spotlight on BIPV technologies, with a special emphasis on the less‐explored semitransparent photovoltaics (PVs). These systems are not only energy generators but also natural light facilitators, setting them apart from their opaque PV counterparts. Advancements in both transparent and opaque PV, such as crystalline silicon, are discussed. However, the paper prioritizes semitransparent PV's unique benefits, including harmonious integration with building design and simultaneous energy and daylight management. An exhaustive examination of current literature and developments sketches BIPV's trajectory, highlighting applications, challenges, and technological strides. The narrative extols the aesthetic, financial, and efficiency merits of BIPV, particularly the semitransparent variants' blend of functionality and design. Performance optimization of BIPV systems is scrutinized across various environments and architectural styles. This meticulous discussion seeks to clarify the status quo, emerging research avenues, and future prospects of BIPV in fostering a greener energy transition. The review compares BIPV configurations with traditional solar PV systems, charting a path for enhanced energy production, cost efficiency, and aesthetic integration, with semitransparent PV as a key player. By exploring the interplay between architectural design, energy efficiency, and urban planning, this paper aims to solidify the groundwork for future research, reinforcing the sustainability narrative in urban energy infrastructure. [ABSTRACT FROM AUTHOR]

The transition to sustainable transportation has fueled the need for innovative electric vehicle (EV) charging solutions. Building Integrated Photovoltaics (BIPV) systems have emerged as a promising technology that combines renewable energy generation with the infra‐structure of buildings. This paper comprehensively reviews the BIPV system for EV charging, focusing on its technology, application, and performance. The review identifies the gaps in the existing literature, emphasizing the need for a thorough examination of BIPV systems in the context of EV charging. A detailed review of BIPV technology and its application in EV charging is presented, covering aspects such as the generation of solar cell technology, BIPV system installation, design options and influencing factors. Furthermore, the review examines the performance of BIPV systems for EV charging, focusing on energy, economic, and environmental parameters and their comparison with previous studies. Additionally, the paper explores current trends in energy management for BIPV and EV charging, highlighting the need for effective integration and recommending strategies to optimize energy utilization. Combining BIPV with EV charging provides a promising approach to power EV chargers, enhances building energy efficiency, optimizes the building space, reduces energy losses, and decreases grid dependence. Utilizing BIPV‐generated electricity for EV charging provides electricity and fuel savings, offers financial incentives, and increases the market value of the building infrastructure. It significantly lowers greenhouse gas emissions associated with grid and vehicle emissions. It creates a closed‐loop circular economic system where energy is produced, consumed, and stored within the building. The paper underscores the importance of effective integration between Building Integrated Photovoltaics (BIPV) and Electric Vehicle (EV) charging, emphasizing the necessity of innovative grid technologies, energy storage solutions, and demand‐response energy management strategies to overcome diverse challenges. Overall, the study contributes to the knowledge of BIPV systems for EV charging by presenting practical energy management, effectiveness and sustainability implications. It serves as a valuable resource for researchers, practitioners, and policymakers working towards sustainable transportation and energy systems. [ABSTRACT FROM AUTHOR]

The purpose of this study is to evaluate the effect of CIS Building Integrated Photovoltaic as a shading device on building energy performance and PV life cycle. A multi-faceted BIPV energy evaluation approach is created. Energy performance is evaluated in two climate regions, in three scenarios for two transparency ratios of an office building. The case study indicated that when BIPV was used, in mild climates there was 24.82–41.05%, and in hot climates, 35.21–56.18% net energy consumption decreased. The PVs can produce 6.5–9.1 times the amount of energy consumed during manufacturing over the usage period. Finally, it was shown that the CIS technology contributes to sustainable architecture by reducing the integrated design difficulties in front of BIPV. [ABSTRACT FROM AUTHOR]

Building-integrated photovoltaic technologies have considerable potential for the generation of onsite renewable energy. Despite this, their market penetration is in a relatively embryonic phase with respect to grounded or building-attached solutions, and they have limited commercial application. Their integration into building façades may represent a key asset in meeting the net-zero emissions by 2050 scenario, in particular for high-rise buildings in which the roof-to-façade ratio is unfavorable for the fulfillment of the energy load using only roof photovoltaic technology. Moreover, different façade orientations extend the production time throughout the day, flattening the power generation curve. Because of the present interest in BIPV systems, several researchers have conducted high-quality reviews focused on specific designs. In this work, various photovoltaic technologies and methods used to manufacture façade BIPV devices are reviewed with the aim of presenting researchers with the recent technological advancements and providing an overview of photovoltaic systems designed for different purposes and their applications rather than a detailed analysis of a specific technology. Lastly, future prospects and the limitations of building-integrated photovoltaic devices are presented. [ABSTRACT FROM AUTHOR]

In the face of ongoing climate changes and the current geopolitical situation, Renewable Energy Sources (RES) are continuously gaining popularity in many countries. Objectives related to environmental protection and the use of RES set by different countries all over the world, as well as by the European Union (EU), are becoming priorities for many. The increase in the installed capacity of photovoltaic systems has been growing steadily for several years, leading to the creation of new systems accompanying PV installations; this phenomenon has also been observed in Poland. This paper presents a photovoltaic system in the form of a bicycle shed next to a school building as an example of building-integrated photovoltaics (BIPV) without connection to the power grid. It was shown that the energy consumption profile should be properly correlated with the production profile, otherwise significant losses occur. Alternative methods to improve the correlation of production and energy consumption by using SCADA systems or building automation to properly manage the electricity generation and consumption installation were also proposed. Furthermore, it was shown that adopting a fixed discount rate in financial analyses can distort the picture of real profits. An analysis of the changes in the NPV ratio using variable discount rates was carried out when analyzing the entire life of the solar plant. [ABSTRACT FROM AUTHOR]

In this work, we propose a new method for manufacturing busbars in photovoltaic modules for different solar cell generations, focusing on 1st and 3rd generations. The method is based on high-pressure spray coating using nanometric metallic powder. Our focus is primarily on optimizing conductive paths for applications involving conductive layers used in 3rd generation solar cells, such as quantum dot solar cell, dye-sensitized solar cell, and silicon-based solar cells on glass-glass architecture for building-integrated photovoltaic. The advantages of the proposed method include the possibility of reducing the material quantity in the conductive paths and creating various shapes on the surface, including bent substrates. This paper examines the influence of the proposed high-pressure spraying technique using metallic particles on the morphology of the resulting conductive paths, interface characteristics, and electrical parameters. Conductive paths were created on four different layers commonly used in photovoltaic systems, including transparent conductive oxide, Cu, Ti, and atomic layer deposition processed Al2O3. The use of high-pressure technology enables the production of conductive layers with strong adhesion to the substrate and precise control of the spatial parameters of conductive paths. Furthermore, the temperature recorded during the deposition process does not exceed 385 K, making this technique suitable for various types of substrates, including glass and silicon. Additionally, the produced layers exhibit low resistance, measuring less than 0.3 . Finally, the mechanical resistance, as determined through tearing tests, as well as environmental and time stability, have been confirmed for the produced paths. [ABSTRACT FROM AUTHOR]

This article aims to investigate the impact exerted by different types of covering an atrium with glazing on the energy performance of a kindergarten building, provided by the authors as a conceptual design. The considered types of atria included an open atrium, a glazed atrium, and an atrium that operated as a hybrid system. Additionally, the following aspects were taken into consideration: the effect of a glazing-integrated PV system (BIPV); the variety of thermal features represented by the inner boundary between the conditioned and the unconditioned space (Uiu); and the atrium space air-exchange ratio (nue) on the energy balance of the building. Energy performance indicators, including energy demands for space heating and cooling (Eu), delivered energy (Ed), and primary energy (Ep) indicators for heating and cooling mode were estimated for the moderate climates and two locations of the building model, i.e., for Warsaw (Central Poland) and Ahlbeck (Northern Germany). The research results prove that the glazed atrium exerts the most beneficial impact on the energy performance of the building. Nevertheless, certain variables must be considered, especially the air-exchange ratio of the atrium space, as they significantly influence the total annual energy performance. The results obtained with regard to the effect exerted by the presence of BIPV systems differ from those usually expected. This is due to the effect of the total solar-energy-transmittance value (g) modulation caused by the system and, finally, by a significant reduction in passive solar-gain harvesting, which is important for heating-mode results in examined climate conditions. Taking the present analysis into account, it can be concluded that the energy and environmental effects of the glazed integrated PV systems in temperate climates are strongly influenced by the environmental conditions, and, in some cases, these solutions may prove to be not efficient enough in terms of the energy and costs. [ABSTRACT FROM AUTHOR]

The problem of global warming has become a major global concern, and reducing greenhouse gas emissions is crucial to mitigate its effects. Photovoltaic power generation is clean, low-carbon energy. Photovoltaic products can convert solar energy into electricity, reducing CO2 emissions to an extent. This paper introduces the life cycle evaluation theory to assess the carbon emissions of photovoltaic curtain walls. PVsyst software allows for the simulation and calculation of power generation under different influencing factors, which provides valuable information about the carbon reduction potential of photovoltaic curtain walls. The evaluation of carbon emissions and their influencing factors using grey correlation analysis further enhances the understanding of the benefits and limitations of photovoltaic curtain walls. According to the results of grey correlation analysis, this paper concludes that the degree of various influencing factors on carbon emission of a photovoltaic curtain wall under different scenarios in descending order is as follows: orientation, location, inclination, shadow occlusion, and seasonal changes. The research findings of this paper provide a theoretical reference for the future development and application of photovoltaic curtain walls. By demonstrating the carbon reduction potential of this technology, this study contributes to promoting the adoption of photovoltaic curtain walls as a sustainable solution to mitigate the effects of global warming. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive performance assessment of a two-stage power electronic (PE) converter for interfacing the grid of a lithium-ion battery energy storage system (Li-BESS) for building-integrated PV (BIPV) applications. A performance assessment of the control system was conducted for the two-stage PE interface with a common DC-link, which consisted of a bi-directional boost converter with a cascaded PI controller and an AC/DC converter with proportional-integral (PI) and proportional-resonant (PR) controllers. The assessment covered loss analysis and useful lifetime estimation for the 10 kW PE interface with a wide-bandgap SiC power MOSFET at different loads for both the charging and discharging modes of a 50 kWh lithium-ion battery system. Additionally, a performance comparison of various switching frequencies was performed. It was observed that the system was stable up to a switching frequency of 30 kHz, and that increasing the switching frequency improved the responsiveness of the converter by decreasing the settling time; however, there were diminishing returns at higher switching frequencies. To obtain a proper balance between responsiveness and lower loss, a switching frequency of 10 kHz was selected. [ABSTRACT FROM AUTHOR]

Building-integrated photovoltaics (BIPVs) and vehicle-integrated photovoltaics (VIPVs) receive solar irradiance through non-uniform shading objects. Standard scalar calculations cannot accurately determine the solar irradiance of BIPV and VIPV systems. This study proposes a matrix model using an aperture matrix to accurately calculate the horizontal and vertical planes affected by non-uniform shading objects. This can be extended to the solar irradiance on a VIPV by applying a local coordinate system. The 3D model is validated by a simultaneous measurement of five orientations (roof and four sides, front, left, tail, and right) of solar irradiance on a car body. An accumulated logistic function can approximate the shading probability. Furthermore, the combined use of the 3D solar irradiance model is effective in assessing the energy performance of solar electric vehicles in various zones, including buildings, residential areas, and open spaces. Unlike standard solar energy systems, the energy yield of a VIPV is affected by the shading environment. This, in turn, is affected mainly by the location of vehicle travel or parking in the city rather than by the climate zones of the city. [ABSTRACT FROM AUTHOR]

An experiment was conducted to test the optical efficiency of the lenses of the Concentrating Photovoltaic Glazing (CoPVG) concept. The CoPVG is a seasonal glazing system consisting of longitudinal prismatic lenses. The lenses concentrate sunlight onto the focus where Photovoltaic (PV) cells are bonded, generating electricity while simultaneously preventing excessive glare indoors during summer. The system transmits sunlight for daylight purposes in winter. The experimental results were compared with an analytical model developed at Ulster University. Although there were discrepancies between the model and the experimental results, the model can still predict the optical performance of the lenses reliably, and can therefore still provide an overview of the concept's optical performance. The model was then used to create a visual representation of the glazing's annual optical performance, demonstrating how the glazing responds to changes in the sun's position in the sky throughout the year. This analysis allows for balancing the need for natural lighting and energy generation, and so enables designers to evaluate annual optical performance of the CoPVG lens quickly and accurately. A case study of a building in Belfast is presented to demonstrate the application of the model. As an example, the results indicate that utilizing the lenses in glazing towards the south leads to a shift in its performance from room lighting to shading on 1st April, and vice versa on 15 September. The analyses also show that utilizing the CoPVG lenses can potentially enhance the electrical output power of the glazing ranging between 5% and 8% and from 46% up to 52% during winter and summer, respectively, compared with traditional Semi-Transparent Photovoltaic (STPV) glazing with the same opaque area percentage. [ABSTRACT FROM AUTHOR]

Solar power forecasting is of high interest in managing any power system based on solar energy. In the case of photovoltaic (PV) systems, and building integrated PV (BIPV) in particular, it may help to better operate the power grid and to manage the power load and storage. Power forecasting directly based on PV time series has some advantages over solar irradiance forecasting first and PV power modeling afterwards. In this paper, the power forecasting for BIPV systems in a vertical façade is studied using machine learning algorithms based on decision trees. The forecasting scheme employs the skforecast library from the Python environment, which facilitates the implementation of different schemes for both deterministic and probabilistic forecasting applications. Firstly, deterministic forecasting of hourly BIPV power was performed with XGBoost and Random Forest algorithms for different cases, showing an improvement in forecasting accuracy when some exogenous variables were used. Secondly, probabilistic forecasting was performed with XGBoost combined with the Bootstrap method. The results of this paper show the capabilities of Random Forest and gradient boosting algorithms, such as XGBoost, to work as regressors in time series forecasting of BIPV power. Mean absolute error in the deterministic forecast, using the most influencing exogenous variables, were around 40% and close below 30% for the south and east array, respectively. [ABSTRACT FROM AUTHOR]

To reduce the pollution to a large extent in the transportation sector, it is important to charge the Electrical Vehicles (EV) from sustainable sources of electricity, such as solar or wind energy. Building integrated photovoltaic (BIPV) systems have gained popularity over the past 10 years and have been demonstrated to be a practical method of generating renewable energy that can be used to partially power buildings. One of the emerging technologies in EV charging systems is wireless charging technology; we realize that using this technology, fully automatic charging is simple. Compared to a plug-in charging system, wireless charging is free from rust, rain, and other environmental impacts like vandalization and visual pollution. By integrating wireless EV charging with BIPV shading systems, it offers a green and cutting-edge charging option. Building integrated solar panels are affected by different scenarios and causes due to their positioning. The direction of the solar panel, tilted position, and reflected irradiation, these all factors are to be considered in design of BIPV system. In this article, a system designed in way to analyze the effect of white and black color reflectors effect on solar panels (shading system) in different directions. In this work, a 256-W wireless charging system developed for E-bikes utilizing BIPV system. The proposed BIPV-fed resonant inductive charging system achieved efficiency of 95% for simulation and 91.6 for experimental analysis. The experimental analysis is verified by simulation and experimental results. [ABSTRACT FROM AUTHOR]

• Optimized 1D photonic crystal structure was proven to be efficient and sufficient for BIPV. • 5x5 cm samples were produced with sol–gel dipping technique with annealing at 110 °C. • Created structures had 2–3 higher CIE brightness compared to the commercial panels. • Tolerable deviations are +/- 0.05 for refractive index and +/- 2% for thickness. The growth of the building integrated photovoltaic (BIPV) sector is limited by the apparent lack of ways to create the visual impact of the building at acceptable cost efficiency rates in the current PV market. Thus, in this research digital simulations were combined with experimental studies to design and optimize novel 1D photonic crystal structures acceptable to expand and improve the color palette of PV panels. It was proved that the 3-layered system with TiO 2 /SiO 2 /TiO 2 was both efficient and sufficient for this purpose. Advanced light filtering was implemented experimentally on 5x5 size glass plates with a potentially cheap and simple sol–gel dipping technique with annealing only at 110 °C. The applicability of the proposed technology was validated by manufacturing the PV mini panels that showed 2–3 higher brightness in CIE color space compared to the panels made using commercial solar cells. Experimentally obtained efficiencies were: 18.75% (REF, black), 17.28% (light blue), 17.13% (greenish), 16.52% (yellowish), which is in the range to the commercial colored cells, but could be higher if better cells were used. The technology reliability and scalability were evaluated from analysis of the sensitivity of the 1D photonic crystal parameters to the optical properties of the colored device. The tolerable deviations from the color related numbers are approximately +/- 0.05 for the refractive index spectrum and less than approximately +/- 2% for the thickness. Therefore, the proposed coloring method should be a perspective solution for BIPV, but careful attention should be taken for the technological process optimization. [ABSTRACT FROM AUTHOR]

While colored photovoltaics are gaining popularity in the market for building-integrated photovoltaics (BIPV), several specific properties are not accounted for in standard PV performance models. This work shows how relying on the coloration efficiency alone can lead to significant errors regarding module temperatures. By comparing measured temperature data from a test installation featuring BIPV façade elements in multiple colors, little correlation is found between total optical losses (reflection and absorption losses) and module temperature. Instead, better correlation is found with total reflectance. This is attributed to the light absorbed in the pigment-based colored layers contributing to module heating, whereas reflected light does not. This is especially relevant for colors with high lightness, such as gray or beige, for which reflection losses are dominating absorption losses. When modelling colored BIPV products, it is therefore recommended to only consider reflection losses for the irradiance contributing to module heating, while continuing to also include absorption losses for the effective irradiance used in electrical performance modelling. [ABSTRACT FROM AUTHOR]

Iran is one of the most energy-consuming countries, especially in the construction sector, and more than 40% of its energy consumption is in the construction sector. Therefore, considering the very high potential of Iran in the field of solar energy, the need to pay attention to providing part of the energy required by buildings by solar energy seems necessary. The study of the effect of climate on the performance of a BIPV has not been done in Iran so far. Also, the use of ranking methods using the weighting of parameters affecting the performance of BIPV has not been done so far. The purpose of this study is to investigate the power supply of BIPV connected to the grid in the eight climates of Iran. Technical–economic–environmental energy analyses were performed by HOMER 2.81 software. In order to study different types of BIPV, four angles of 0°, 30°, 60°, and 90° were considered for the installation of solar cells. The effective output parameters of HOMER software were weighted by the Stepwise Weight Assessment Ratio Analysis (SWARA) method based on the opinion of experts, and it was observed that payback time (year) has the highest weight among the studied criteria. Then, different cities were ranked using the evaluation based on distance from the average solution (EDAS) method. The results showed that Jask is the most suitable and Ramsar is the most unsuitable city. Also, the results of the EDAS method were confirmed by Additive Ratio Assessment (ARAS), Weighted Aggregates Sum Product Assessment (WASPAS), and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods. [ABSTRACT FROM AUTHOR]

Building integrated photovoltaics (BIPV) is progressively achieving an advanced level of technical maturity and considerable market penetration. In the last kilometre for considerable market implementation, major challenges are today mostly related to improving cost‐effectiveness and product reliability. BIPV multifunctional products are still framed in complex and sometimes unclear qualification processes, in the grey area between electrotechnical and construction sectors, impacting commercialization and users' confidence. The EN 50583 part 1 and part 2 standards today represent the main regulatory framework in Europe for BIPV. However, acts in force for product certification, in the construction and electrical sectors, in most national and local contexts are not yet harmonized for BIPV and imply wide margins of interpretation. The product's qualification in the EU is therefore based on electrical standards for photovoltaics modules or, on the other hand, on standards for construction products. To overcome some of these barriers and challenges, the authors propose a newly developed procedure for testing the impact resistance of BIPV products, introducing a performance‐based approach with the goal of combining building and electrical‐related limit states and responding to the need for a harmonized assessment to ensure the product's safety in use. The methodology and preliminary findings resulting from the application of real test cases, taking also into account the effect of temperature, are presented and analysed. As a result, it is envisaged that the implementation will help operators and prospective normative upgrades, ensuring more outstanding product quality for BIPV's market and driving towards a drop in life cycle costs. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative concept for active wall-curtain façade modules aiming at high level of energy autonomy. The façade module consists of two opaque panels and one transparent panel integrating building integrated photovoltaics supported by façade integrated battery Peltier air-conditioning unit, active shading, and LED lighting. The developed demo-protype was deployed at testing facility and subjected to long-term experimental monitoring to assess the energy performance in real environment. The complex monitoring system captured key power and thermal fluxes, temperatures, mass flows and other operational states of the active wall-curtain façade modules. These measurements were assessed in form of monthly overview depicting total electricity consumption, on-site energy production, heating and cooling delivery as well as self-sufficiency and self-consumption indicators. [ABSTRACT FROM AUTHOR]

Research in asymmetric light transmission interfaces has been recently gaining traction. While traditionally considered for optical circuitry applications, there is a new interest to use these interfaces in luminescent solar concentrators. Previous studies have shown that applying them to the top surface of a concentrator could mitigate surface losses. This paper presents experimental results for proof-of-concept asymmetric light transmission interfaces that may have potential applications in luminescent solar concentrators. The interfaces and the underneath substrate were created in a single step from polydimethylsiloxane using silicon molds fabricated on <100> wafers via anisotropic wet etching. The resulting structures were pyramidal in shape. Large surface areas of nanostructures repeating at 800 nm, 900 nm, and 1000 nm were tested for backward and forward transmission using a spectrometer. Results showed a 21%, 10%, and 0% average transmissivity difference between the forward and backward directions for each periodicity, respectively. The trends seen experimentally were confirmed numerically via COMSOL simulations. [ABSTRACT FROM AUTHOR]

The PV temperature, Tpv, in a BIPV and BIPV/T structures was studied experimentally and theoretically. For this a holistic formula was used based on the Ross coefficient prediction under any environmental conditions accounting additionally for the building thermal parameters. It was shown that the slope of the PV temperature, Tpv, vs the solar radiation, IT, on the BIPV modules corresponds to a generalized expression of the Ross coefficient, f, which must account for the BIPV thermal conditions, too. The profiles of the Ross coefficient for BIPV/T, BAPV and free standing PV operating in the same site were determined, compared and discussed. The theoretical and experimental analysis of a BIPV/T test cell disclosed that Tpv vs IT is a linear function in all cases from sunrise till solar noon with a practically constant slope and coefficient of determination, R2>0.96. Correspondingly, from noon to sunset the linearity still holds but with a lower slope which depends on the insulation of the building and the increased ambient temperature during sunset compared to sunrise, which is the usual case. An improved version of a Tpv prediction holistic formula was developed to take into account the building thermal parameters, the ratio of the PV surface over the building surface, and the environmental parameters. This new and improved methodology for the f and Tpv prediction for both morning to noon and noon to sunset periods was tested against measured Tpv vs IT and the predicted results confirmed its validity. [ABSTRACT FROM AUTHOR]

In this paper, we propose a single-layer thin-film color glass manufacturing process for building-integrated photovoltaics (BIPV) with excellent aesthetics and high transmittance, through a solution process using pearlescent pigments. As a matrix for the color solution, ethylene vinyl acetate (EVA), which serves as an encapsulant and adhesive for the photovoltaic module (PV), was dissolved and used as a matrix for the color solution. The color glass produced is excellent in securing the aesthetics of buildings, has a high transmittance of 90% or more, outputs a maximum solar power generation efficiency of 91% from a solar cell, and can minimize the deterioration of power generation efficiency. In addition, the characteristics do not change over time, so it is suitable as color glass for BIPV. Through this study, the solution-based color glass manufacturing process for BIPV using dissolved EVA as a matrix forms a single-layer thin film with good color extensions. The choice of EVA as a matrix makes it possible for color glass to be easily attached to a solar panel using a heat press method. This proposed technique makes it easier and simpler to manufacture color glass as compared to the physical vapor deposition process. The adoption of this solution process technique to fabricate pearlescent pigment-based color glass can effectively reduce the time and cost of the process, so it is expected to be applied to the low-cost BIPV market with excellent aesthetics and high transmittance. [ABSTRACT FROM AUTHOR]

• The potential of rooftop solar photovoltaic (PV) in the context of the political, economic, social, technical and environmental (PESTLE) framework in Africa. • The prospect of dual use of building integrated photovoltaic (BIPV) in Africa. • Implementing appropriate energy policy and financing schemes in African cities. • Promoting a sustainable path for cost effective recycling and reuse of end-of-life PV in African cities. Power outage is a regular occurrence in most African cities due to increasing energy demand from population growth and commercial activities outstripping the grid capacity. This results in disruption to normal life putting stress on businesses and affecting development across the continent. This review paper investigates the potential of solar photovoltaic (PV) in African cities from three perspectives. Firstly, the potential of rooftop PV in the context of the political, economic, social, technical, legal and environmental aspects (PESTLE) is evaluated. Thereafter, sustainable waste management of solar PV panels is reviewed in anticipation for the upcoming wave of end-of life solar panels. Finally, the prospect of dual use building integrated photovoltaic (BIPV) as power generators and building components is investigated from case studies in Africa. Most studies highlight the strong potential of rooftop PV and BIPV due to the availability of high radiance in the continent. However, our review shows that affordability and lack of investment acts as a significant barrier to mass adoption of this technology which could be remedied by implementing appropriate energy policy and financing schemes. Alternative financing of PV products and service solutions such as leasing, pay monthly, pay-as-you-go, and subscriptions are emerging as popular options, and these approaches seem to act as drivers to market expansion. The review also emphasizes on the need for effective and sustainable waste management of solar PV products through implementing appropriately designed recycling schemes. This will need to be adopted now to ensure success and to prevent a waste management crisis in the future for the African continent. [ABSTRACT FROM AUTHOR]

• Prospective and consequential LCA and LCC are integrated in a PSK BIPV case study. • A prospective methodology links environmental and economic benefits of PSK systems. • Silicon-based PV results as more economically valuable than PSK modules in r-BIPV. • PSK f-BIPV systems will become more economically convenient than a glass façade. • f-BIPV results the most attractive PSK systems application to cut GHG emissions. This paper addresses an integrated economic and environmental assessment where a consequential and prospective life cycle approach is applied to perovskite (PSK) building integrated photovoltaic (BIPV) systems. Two configurations are considered: slanted roof (r-BIPV) installations, and the fenestration of façades (f-BIPV). Concerning r-BIPV, PSK systems are expected to compete with crystalline silicon (c-Si) modules; whereas a glass façade is chosen as an alternative reference for f-BIPV. Assuming economic rationality as the main criteria for the adoption of technologies, a deployment time for the PSK system is estimated and the economic and environmental advantages in the Italian context are evaluated. This assessment is based on three foreground scenarios addressing the gradual development of PSK systems. The results show that while c-Si modules are preferred in the market of r-BIPV systems, PSK modules will find space in f-BIPV applications. Depending on the selected scenario, the economic benefits accumulated by Italian energy users are assessed between −0.5 % and −10.3 %. On the other hand, PSK systems imply a variation of the national GHGs emissions that ranges between + 0.01 % and −7.5 %. Depending on the scenario, the PSK-based f-BIPV systems can provide either environmental benefits (i.e., cumulative energy demand) or burdens (i.e., ecotoxicity indicators). [ABSTRACT FROM AUTHOR]

• A novel CPV/T module using asymmetric compound parabolic concentrator was built. • The average total efficiency of the CPV/T system achieves 66.3%. • The concentrator tilt angle of 30° is most conducive to optimizing the performance. • The system has the best applicability in high latitude areas. Aiming at the problem that the efficiency of traditional photovoltaic thermal system is not high enough and the grade of heat energy generated is low, a novel concentrated photovoltaic-thermal system with asymmetric compound parabolic concentrator (ACPC-PV/T) integrated with facade was proposed. The system maximizes the contact area between the channel and the solar cell, which is beneficial for improving heat transfer efficiency. A comprehensive performance study was conducted on the proposed system and optimization methods were proposed. Through the experiments and simulation, the results show that the electrical efficiency of the system is 5% and 7.6% higher than that of traditional modules in summer and winter, respectively, and the thermal efficiency in summer and winter is 51% and 42%, respectively. Further research was conducted on the impact of different tilt angles of concentrators on thermoelectric performance and the global applicability of the device. The results showed that in Chengdu, a concentrator tilt angle of around 30 degrees can most effectively improve module performance. On a global scale, this module has shown good performance, even in areas with lower radiation level. [ABSTRACT FROM AUTHOR]

Photovoltaic modules are integrated into rooftop buildings, canopies, solar carports, bus stops, greenhouses, known as Building-Integrated Photovoltaics (BIPV). Rooftops may have curved surfaces. The incident diffuse irradiation on curved surface is not uniformly distributed along the surface because the slope of the surface varies with the distance along the curvature. The non-uniform diffuse irradiation stems from the variation of the local sky view factor along the curved surface, resulting in mismatch power losses. The variation of local sky view factors of curved surfaces, in presence of obscuring structures, was not investigate in the past. The purpose of the present study is to develop a methodology for calculating the local sky view factors and the annual incident diffuse irradiation along the curvature of the surfaces. The demonstrations apply to convex and concave parabolic and elliptic surfaces, including curved surfaces obscured by flat, convex and concave nearby rooftops. The effect of an obscuring building near a curved parabolic rooftop results in a decrease of the annual incident diffuse irradiation by 9 percent for 10 m separation between the rooftop and the building. The present study may assist the designer of BIPV systems to assess the generated electric energy on curved rooftops. [Display omitted] [ABSTRACT FROM AUTHOR]

• Long-term operational monitoring of a Zero Emission Building (ZEB) in Beijing. • An existing building being retrofitted into a Zero Emission Building (ZEB). • Key Building Mounted Photovoltaic (BMPV) technologies are practically utilized and their effects are estimated. • The ZEB realized its own net-zero carbon emission and net energy production. • The ZEB could be a comprehensive experimental platform. Building mounted photovoltaic (BMPV) technology is a promised way to achieve carbon peak in building sector. Focused on the influence of heat from PV modules on building envelope's heat transfer and energy saving performance, and the power generation, the coupling mechanism of power generation and heat transfer of integrated photovoltaic technology on building façades has been investigated. The synergy of solar energy generation and building energy consumption have been studied in this paper. The installation method of building PV system was proposed, with which can achieve the maximum energy saving. Furthermore, the achievements have been applied in Zero Emission Building (ZEB) of China Academy of Building Research (CABR), demonstrating way to realize zero carbon building by integration of photovoltaic technology. Total of 236.1 kWp PV systems were installed in ZEB. Monitoring data shows that the annual power generation of ZEB could reach 212,382 kWh, and the power generation per building area is 73.79 kWh/m2, which could meet all the energy demands. In addition, it can supply extra power to surrounding buildings. The ZEB can provide experience and practice data supporting carbon peak in building sector. [ABSTRACT FROM AUTHOR]

Modeling the photovoltaic (PV) energy output with high accuracy is essential for predicting and analyzing the performance of a PV system. In the particular cases of building-integrated and building-attached photovoltaic systems (BIPV and BAPV, respectively) the time-varying partial shading conditions are a relevant added difficulty for modeling the PV power conversion. The availability of laser imaging detection and ranging (LIDAR) data to create very-high-resolution elevation digital models can be effectively used for computing the shading at high resolution. In this work, an artificial neural network (ANN) has been used to model the power generation of different BIPV arrays on a 5 min basis using the meteorological and solar irradiance on-site conditions, as well as the shading patterns estimated from a digital surface model as inputs. The ANN model has been validated using three years of 5-min-basis monitored data showing very high accuracy (6–16% of relative error depending on the façade). The proposed methodology combines the shading computation from a digital surface model with powerful machine learning algorithms for modeling vertical PV arrays under partial shading conditions. The results presented here prove also the capability of the machine learning techniques towards the creation of a digital twin for the specific case of BIPV systems that complements the conventional monitoring strategies and can be used in the diagnosis of performance anomalies. [ABSTRACT FROM AUTHOR]

The use of solar energy incident on vertical surfaces in building integrated photovoltaic (BIPV) systems is shown as an opportunity to contribute to achieve sustainable energy consumption in buildings in urban spaces. In this study, a computational analysis of the optimal orientation for vertical surfaces in three thermal floors of Colombia is performed, using clear sky conditions and meteorological data. The results show the need to position the designs of vertical surfaces in a range of azimuthal angles given the energy variability for each city, both in the morning and evening hours and throughout the years. In addition, the energy generation potential of vertical surfaces is analyzed with respect to a horizontal panel considering the maximum radiant energy received, finding that a single vertical surface can receive 17% less radiant energy than a horizontal panel, but when considering a pair oriented according to the optimal angles, it can be exceeded up to 60%. • The energy of a vertical surface is affected by the Colombian geographic location. • Incident energy on vertical surfaces has two definite maxima during the day. • A pair of well-oriented vertical surfaces can surpass a horizontal one by up to 60%. [ABSTRACT FROM AUTHOR]

Building fenestrations are the key components maintaining the connection between building exterior and interior. However, they are also the weakest allowing heat loss, gain and light. To tackle the enhanced building energy demand, active and passive both ways must be included. Benign energy-generating components and passive energy-saving are both concomitantly possible using photovoltaic (PV) window fenestration. In this work, three different generations PV based fenestration integrated photovoltaics (FIPV) have been reviewed to understand how effective FIPVs are for low energy building. Later advanced technologies suitable for FIPV applications are also discussed. [ABSTRACT FROM AUTHOR]

In this study, we propose a solution process for realizing colored glass for building integrated photovoltaic (BIPV) systems by spin coating a color solution composed of pearlescent pigments mixed in a Norland Optical Adhesive (NOA) matrix. Color solutions are made from mixing pearlescent pigments in NOA63. Compared to a physical vapor deposition process, color coatings are achieved by spin coating in a relatively simple and inexpensive process at room temperature. The optical properties can be easily controlled by adjusting the spin coating speed and the concentration of the pearlescent pigments. The produced colored glass achieved a high transmittance of 85% or more in the visible wavelength range, except for the wavelength spectrum exhibiting the maximum reflectance. In addition, we propose a one-step lamination process of colored glass on a solar cell by leveraging on the adhesive property of the NOA matrix. This eliminates the cost and process of additional ethylene vinyl acetate (EVA) layer or other materials used in the conventional lamination process. The colored glass produced through this study has stability that does not change its properties over time. Therefore, it is expected to be applied to the BIPV solar module market where aesthetics and energy efficiency are required. [ABSTRACT FROM AUTHOR]

The authors optimized the thickness of the layers in the 1.67‐eV‐bandgap‐perovskite sub‐cell of a 2‐terminal perovskite/silicon monolithic tandem solar cell under standard test conditions to get the current matching between the top and the bottom sub‐cells. Based on that optimized structure of the tandem cell, we characterized, calculated, and analyzed the annual output energy and the annual efficiency of the tandem cells on the facades and the rooftop of buildings under realistic conditions composed of module temperature, realistic illumination irradiance, and incident angle directly measured in Gifu, Japan in 2015. Consequently, the obtained annual output energy is 279.52, 238.89, 129.99, and 115.21 kWh/m2 with the corresponding annual efficiency of 22.42%, 19.70%, 10.50%, and 9.19% for the tandem solar cells mounted on the rooftop, the south, east, and west facades of the buildings, respectively. Thus, the rooftop and the south face of the buildings are the preferred directions for the BIPV application to gain higher energy. [ABSTRACT FROM AUTHOR]

This paper presents a methodology for performing sensitivity analysis on the capital and energy production costs of off-grid Building Integrated Photovoltaic (BIPV) systems. The different influencing parameters that are considered in this study are the daily electric load on the system, available sunshine hours, per unit costs of components, maintenance and replacement costs, several design and rating factors, interest rates, and carbon credits. The probabilistic-based Latin hypercube sampling (LHS) technique and log-log regression were used to develop the correlations for the capital cost and energy production cost of the system. The results were validated by comparing them with case studies available in the published literature. Then, a standardized version of the dataset was used to derive the elasticity constants associated with each parameter, which quantified the change in costs when the parameter value was increased by a unit percentage. The effects on the costs of increasing the parameters by 10% were quantified, ranked and compared. For the capital cost, the three most sensitive parameters were the daily electric load on system, the fudge factor and the available sunshine hours. In contrast, for the energy production cost, the three most sensitive parameters were the annual maintenance cost factor, the fudge factor and the interest rate. The correlation trends between these parameters and the costs were also plotted. Precautions and potential stakeholder actions for reducing the costs of off-grid BIPV systems are suggested. [ABSTRACT FROM AUTHOR]

• Semi-transparent thermal assessment revealed that least transparency CdTe PV glazing can have U-values as low as 1.52 W/m2K. • The use of least transparency PV glazing can reduce 96% of solar heat gains and 23.2% of cooling energy compared to conventional clear glazing. • South-west building orientation achieved better energy saving over all sampled transparency. Semi-transparent PV glazing are promising in Building Integrated Photovoltaic (BIPV) applications. They provide daylight control, energy saving and power generation. The selection of optimal Photovoltaic (PV) glazing requires the accounting for various factors such as location, orientation and glazing transparency. In this work, thermal performance of Cadmium telluride (CdTe) based semi-transparent PV glazing of different transparencies was evaluated in UK for South and South-West orientations. Thermal performance was analysed in terms of U-value, SHGC and cooling load. Results revealed that least transparency CdTe PV glazing can have U-values as low as 1.52 W/m2K. The use of least transparency PV glazing can reduce 96% of solar heat gains and 23.2% of cooling energy compared to conventional clear glazing when used in South-West orientation. The selection of optimum glazing was discussed taking into consideration occupants' optical comfort and health. [ABSTRACT FROM AUTHOR]

A novel compact model is developed to predict the PV temperature T pv , coefficient f which relates T pv with the in-plane solar irradiance I T , and power output P m. The T pv , I T , ambient temperature T a , and wind velocity v w on a sun-tracking pc-Si PV and c-Si BIPV were monitored. f depends explicitly on v w , PV efficiency, heat losses coefficient, and implicitly on T pv , I T , T a , loosely on the module inclination at low v w , while this effect weakens at high v w. T pv prediction is provided by means of 5 functions, which cater for the deviation of the environmental conditions from the Standard Operating Conditions, the operating efficiency, the natural ageing, PV geometry and cell technology. The T pv prediction for the sun-tracking system has relative error 2.6% for PV operating temperatures around the NOCT, and may overestimate by up to 1.4 °C. Similarly, the relative error for the BIPV system is −2.1% for PV temperatures around the NOCT, with underestimation up to 1.6 °C. The model predicted P m with relative error 1.9% for PV operating near its nominal value. The model is compared to 3 well-known models and also applied to other BIPV/BAPV configurations in various countries proving its wide applicability, high accuracy and universality. • A novel universal PV temperature and power output prediction model is developed. • Validated with measured data and applicable to both free-standing PV and BIPV. • Incorporates the effects of deviations of environmental conditions from the SOC. • High accuracy in the prediction of PV temperature in free-standing PV and BIPV. • Best performance in comparison with well-known PV temperature prediction models. [ABSTRACT FROM AUTHOR]

The number of installed photovoltaic (PV) modules has increased significantly over the last years, and using available building surfaces to generate electricity by integrating PV modules in the construction is an attractive option. Building integrated photovoltaics (BIPV) or other vented claddings can spread fires rapidly to large parts of a building if the fire is allowed to propagate. To investigate this hazard, a large-scale SP FIRE 105 façade fire test was conducted. A façade measuring 4000 mm × 6000 mm covered with BIPV modules was exposed to flames that represent the fire plume from a window in a room at flashover. The results from the test show that critical failures, like falling objects and vertical flame propagation, can be expected in such constructions. These results highlight the importance of details in mounting of BIPV-façades and to require proper documentation from relevant fire tests of such systems. Small-scale cone calorimeter tests were conducted on the studied BIPV module to provide material properties of the combustible parts of the installation. These aspects should be considered when planning new or when retrofitting façades, to prevent escalation of fires. The results presented are, however, only valid for the configuration that was tested. Other BIPV-façades should also be investigated to study how these constructions can be built safely in the future with regard to critical details. • SP FIRE 105 façade fire test of a BIPV façade. • Fire spread in a ventilated cavity despite using cavity barriers. • A self-sustained fire was observed in the combustible materials on the modules. • Multiple large parts fell from the façade during the experiment. • Cone calorimeter tests of the BIPV materials in the horizontal and vertical orientation. [ABSTRACT FROM AUTHOR]

Building-integrated photovoltaic (BIPV) and building-integrated radiative cooling (BIRC) technologies are popular methods for utilizing renewable energy to address the energy crisis. However, limited facade areas of buildings restrict the amount of renewable energy that can be harvested. The design of reversible radiative cooling-photovoltaic (RRC-PV) module was introduced to address this issue. During the day, the PV side converts part of the incident solar radiation into electricity. At night, the module can be flipped and the RC side emits infrared radiation to the cold outer space, allowing for the free cooling energy exploitation. The performance of RRC-PV modules was tested in Shenzhen with hot summer and cold winter climate, by applying them as rooftop awnings and overhang shadings. Solar power generations were similar for both experiments, with daily electrical efficiencies in the range of 11.4–13.0 %. Meanwhile, the radiative cooling performance was better in the rooftop awning experiment, with an average nocturnal cooling power of 33.7–34.5 W/m2. In contrast, the average nocturnal cooling power reduced to 4.8–4.9 W/m2 in the overhang shading experiment. The results highlighted the importance of evaluating the radiative cooling potential by assessing the sky exposure of building facades. [ABSTRACT FROM AUTHOR]

This study evaluates three listed farmhouses in Ørland Municipality which are going to be relocated and rehabilitated according to current Norwegian standards and requirements. Accordingly, the study assesses possible challenges and solutions regarding energy upgrading and restoration while preserving their historic features and cultural heritage. The study suggests solutions for the energy rehabilitation of the three farmhouses based on a literature review, hygrothermal simulations and energy simulations. These solutions include thermal post-insulation of external walls and above the framework of joists against the cold attics with mineral wool, vacuum insulation panels (VIP), and aerogel blankets. Additionally, fenestration renovation options and the potential for implementation of building integrated photovoltaics (BIPV) are reviewed. Lastly, simulations of multiple energy-saving measures for each of the farmhouses have been conducted. A new foundation due to the relocation, together with post-insulation of the cold attic are found to be feasible measures considering the preservation of architectural appearance and authenticity. Regarding the external walls, post-insulating externally is preferable for the farmhouses considering moisture issues and interior space savings. However, it is important to consider any possible loss of cultural heritage value. Alternatively, internal thermal insulation with aerogel blankets may be a feasible solution due to its high thermal resistance applying small thicknesses. The results show that in some cases, enhancing old original windows with a secondary glazing is an equally good solution compared to a total replacement of the windows, and is recommended for cultural preservation. Implementation of BIPV contributed to meet the net energy demand requirement. Nevertheless, it is recommended that the chosen BIPV systems resemble an accepted roofing material from the regulatory requirements, e.g., slates, to accommodate the building's architectural aesthetics and authenticity. This study provides insight and recommendations for the rehabilitation of three listed traditional farmhouses in Trøndelag County, addressing energy efficiency while preserving their cultural significance. The findings show that it is possible to achieve today's energy requirements when rehabilitating listed heritage buildings. Results from energy simulations show that a reduction in net energy demand between 55 % and 75% is possible, while it is essential to note that each building is unique, and a case-by-case approach is needed. Nevertheless, the findings can be applicable for a general energy upgrading of heritage buildings. [ABSTRACT FROM AUTHOR]

• Existing common color characterization techniques are limited for BIPV modules. • Glass thickness above the color layer reduces the reflectance signal. • This study investigates the limitations of existing color characterization devices. • A novel colorimeter for BIPV is proposed. • The novel colorimeter reduces measurement artifacts on glass samples. Accurate and reproducible color characterization is essential for colored building integrated photovoltaic products, both for manufacturing quality control and assessing long-term color stability. However, existing characterization techniques struggle to accurately determine color when a surface is behind a transparent layer like a solar PV laminate. In this study, we compare different colorimetric techniques and propose an innovative colorimeter based on a fiber optic spectrometer and large area illumination to address this issue. Samples with varying transparent glass thicknesses and underlying colors are laminated and characterized using a scanner, an integrated sphere spectrometer, a commercial portable colorimeter, and the proposed large area illumination colorimeter. Results show that common scanners produce darker images and inaccurate color determination due to light losses in the glass. As glass thickness increases, reflectance decreases with the integrated sphere spectrometer and portable colorimeter. However, the large area illumination colorimeter exhibits only minimal signal reduction. High reflective foils experience more reflectance reduction with thicker glass than low reflective ones. All devices yield comparable results without the glass layer. The large area illumination colorimeter, compensating for light losses, proves to be a suitable solution for accurately measuring color under glass laminates using reflected light. For example, it reduces the color change from 57 (commercial portable colorimeter) to only 3 for an ivory colored glass laminate. This innovative tool has the potential to improve color characterization in building integrated photovoltaic products, enabling better manufacturing quality control and assessment of long-term color stability. [ABSTRACT FROM AUTHOR]

• Explored the influence of CdTe thickness on the quality of CdTe thin-films. • Presented a method for precise control of Cu doping amount and diffusion. • Explored the impact of IWO thickness on semi-transparent CdTe solar cells. • Achieved semitransparent CdTe solar cells with a bifacial factor of 0.7. • The first-time fabrication of semi-transparent CdTe solar cells suitable for BIPV. In the current context of renewable energy development, CdTe polycrystalline thin-film solar cells are expected to have broad prospects in fields such as Building Integrated Photovoltaics. It is crucial to fabricate sub-micron-thick, semitransparent CdTe solar cells for photovoltaic glass curtain walls that require a certain degree of transparency. As a result, we have employeded a high-quality deposition technique for sub-micron-thick CdTe polycrystalline films. We have analyzed the influence of post-treatment processes on the film properties and investigated the impact of solution-based CuCl back buffer layer preparation on device performance. By improving the quality of sub-micron-thick CdTe polycrystalline films, and optimizing the concentration and process of Cu doping, we have successfully fabricated semitransparent CdTe solar cells with an average visible light transmittance of 14.21%, η Front : 6.2%, η Rear : 4.4%, and bifacial factor:0.7. [ABSTRACT FROM AUTHOR]

• This work estimated PV energy potentials of building rooftops, walls and windows. • The analysis was conducted at various spatial resolutions from city to building scale. • Multiple urban form indicators were highly correlated with the PV energy estimates. • PV Production could cover up to 74% of electricity consumption in the City of Melbourne. • PV potential from windows became more prominent in central urban areas. Many cities across the world are committing to deep decarbonisation efforts. While solar photovoltaics (PV) will play a critical role in this pursuit, the role of rooftop and facade-integrated PVs within the urban landscape is yet to be fully understood. This work presents an analysis into the solar energy harvesting potential of PVs integrated as building rooftops, walls, and windows at various spatial resolutions that range from city to building scale within the City of Melbourne, Australia, as a contemporary case study. It further investigates the relationship between calculated electricity production from such PVs with the urban morphology, seasonal variation and the measured electricity consumption by the local distribution network service providers. The results indicate that PV rooftops are responsible for the largest share of the city's solar energy potential. However, for individual blocks with high densities of high-rise and glazed buildings, it is shown that the PV potential from windows becomes more prominent. The technical workflow presented here will enable different cities to facilitate decision-making on the PV implementation in urban environments. [ABSTRACT FROM AUTHOR]

• Methodology for quantification of wind-driven rain intrusion is presented. • Water leakages measured during investigation of three different BIPV systems for roof integration are identified and quantified. • Watertightness level of tested BIPV systems are evaluated. • BIPV systems details and installation procedure are provided. 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. [ABSTRACT FROM AUTHOR]

In this paper, an optimal design method of micro-lens light trapping structure for thin film solar cells applied to building integrated photovoltaic (BIPV) is proposed. Under three common scenes of BIPV, including lighting roof, sunshade and building facade, the optimal design and photoelectric performance study of Copper Indium Gallium Selenium (CIGS) thin film solar cells with micro-lens light trapping structure are studied. Among the three kinds of micro-lens light trapping structures, V-shaped, semi-cylindrical and concave, the light capture performance of V-shaped micro-lens light trapping structure is the best. The V-shaped micro-lens light trapping structure with a vertex angle of 70° and a groove depth of 100 μm has the best light capture performance in lighting roof and sunshade scene, which can increase the annual radiation flux of the absorption layer incident surface by 4.45% and 2.84% respectively. The V-shaped micro-lens light trapping structure with a vertex angle of 60° and a groove depth of 200 μm has the best light capture performance in building facade scene, which can increase the annual radiation flux of the absorption layer incident surface by 7.63%. When the light source is vertically incident, these two V-shaped micro-lens light trapping structures can increase the short-circuit current density by 15.57% and 7.11% respectively. [ABSTRACT FROM AUTHOR]

• Solar potential in urban scenarios needs of high quality solar radiation data as input. • Satellite derived solar radiation is now available for the public with very high quality. • Open solar radiation data, DSM from LIDAR and open modeling tools are used in the methodology presented. • Special remarks and methods are needed to deal with deciduous trees affecting the shadowing of facades. Solar radiation incident at building façades and elements in an urban context is essential in determining the energy production on building rooftops and vertical façades. The proper determination of solar irradiance incident on a vertical façade needs quality input of the components of solar radiation and a high resolution digital surface model with the heights of buildings and other elements in the urban area of study. In this work a thorough methodology for modeling PV generation, in hourly basis, at building façades with open available data and methods is presented. Hourly data of satellite-derived solar irradiance is used with high resolution digital model from LIDAR information to estimate with the Sandia model the PV generation of five small arrays at west, south and east façades of a building in Madrid. PV output modeled for west and south arrays are in rather good agreement with the monitored experimental data of the production. RMSE of 8% and 12% was observed for the monthly power predicted for west and south facades, respectively. The east façade case was much more challenging due to variability of shadows it receives from the nearby large deciduous trees throughout the year, which results in high uncertainty in the shading influence estimation. Anyway, the methodology proves the benefits and possibilities of detailed estimation of PV production in building façades from open available information regarding both solar resource, open modeling tools and urban topography, even in a very challenging conditions associated to the variability of trees canopy. [ABSTRACT FROM AUTHOR]

• Evaluation of insolation when BIPV panel is subjected to shadow due to adjacent buildings. • Optimum azimuth and tilt angle of BIPV panel for harnessing maximum insolation. • Optimum azimuth angle changes with change in plan orientation of adjacent building. • Efficiency of the BIPV panel increases when water is assumed to be flown over it. Development of a BIPV system with appropriate azimuth and tilt angle on top of a suitable existing or new building in urban areas is a possible option to generate both electrical and thermal energies and also to create an additional living space. These azimuth and tilt angles are significantly influenced by the shadow of the neighborhood's buildings. The relative height, plan orientation, plan area, position, and horizontal distance of the neighborhood's buildings are critical parameters for determining optimum azimuth and tilt angle to receive maximum insolation. Present proposed model accurately calculates these angels and the energy, and the model also works well when water flows over the BIPV panel from an overhead tank through gravity with an aim to increase the efficiency of PV panel. The periodic nature of relevant parameters is considered in the thermal modeling of the BiSPVT system. Results indicate that the optimum azimuth angle from south-facing increases with a rise in the latitude angle of the place. The optimum tilt angle depends on the corresponding latitude and the different contributing parts of total insolation. The electrical output of a south-facing BiSPVT system with a tilt angle equal to latitude is increased by 3.7% when BiSPVT system is installed at optimum azimuth and tilt angle. The output is further enhanced by 4.3% when water is flown at the rate of 1.1 kgs−1 over the PV panel. [ABSTRACT FROM AUTHOR]

Low concentrating photovoltaic (LCPV) system has been studied extensively, which showed excellent potential for the building integration application. However, such a system suffers from higher operating temperatures due to the concentrated light exposed into the solar cell. In this work, two different methods have been used to regulate the operating temperature of the solar cell without the interference of any other external mechanism. Two concepts were used to study the operating temperature of the solar cells are: i) use of Argon gas within the concentrator element, ii) incorporation of polymer-dispersed liquid crystal films (PDLC) on top of the module. In both cases, the power was improved by 37 mW–47 mW when temperature was reduced by 10 °C and 4 °C for the Argon gas-filled module and PDLC integrated module, respectively. In addition, the temperature effect of the PDLC integrated module showed a unique nature of reduction of the short circuit current due to the orientation of the liquid crystal particle, which increased at a higher temperature. The current study, therefore, shows the greater potential of improving the operating efficiency and reduction of solar cell temperature, without the need for additional pumping power such as needed for photovoltaic thermal application. • Optical and thermal performance were analysed at laboratory environment for LCPV SEH system. • Output of the system is demonstrated using different strategies, Argon filled and PDLC on the top of the module. • Operating temperature was reduced by 10 °C and 4 °C for both states respectively. • Increment in power was 37 mW and 47 mW respectively. [ABSTRACT FROM AUTHOR]

The presented work is focusing on optical interference coatings on the back side of the front glass for crystalline silicon-based photovoltaic modules. We present results on how such coatings can be designed to obtain desired visual properties combined with a limited loss in power conversion efficiency. This colouring technology may therefore be very attractive for building integrated photovoltaics. Coating design parameters such as number of layers, design wavelength, layer thicknesses, and layer refractive indices affect both the visual appearance parameters and the efficiency. Important colour parameters are lightness, chroma, and hue, and we demonstrate how these colour parameters are influenced by the design parameters of the optical interference coating. Using optical interference coatings to create colours results in colours that are dependent on the observation angle. We have introduced a new parameter for quantification of angular colour dependence. Our results show that the angular colour dependence can be reduced by increasing the refractive indices of the interference coating. For many building projects it may be highly desired to combine high power conversion efficiency with certain visual properties. The results from our work also indicate some of the possibilities and challenges in this regard. [ABSTRACT FROM AUTHOR]

• The importance to assess the actual reliability of the PV technology is discussed. • The PV degradation mechanism on the first Italian public-funded BIPV was presented. • The laboratory testing on the modules after 20 years of operation was carried out. • The needs to continuous monitoring the degradation rate after 20 years is emerged. Assessing the long-term reliability of PV systems is important for understanding their energy and cost efficiency. Typically, estimates and predictions are based on indoor tests and accelerated ageing. However, fluctuating and differently interacting outdoor factors such as solar radiation, dust, and shadowing in real environment can impact the actual performance. This paper examines alterations related to ageing of c-Si PV modules, firstly by classifying the main factors that affect aged c-Si PV modules and then assessing the impact on their performance degradation by analysing a pilot BIPV system at Politecnico di Milano after 20 years of actual operation. Such system, which is highly representative since is the first public BIPV plant funded in Italy, was carefully and continuously monitored during its operating life. In particular, according to the visual/IR inspection carried out after the 20th year of operation, the main observed alteration in the modules were discoloration of the encapsulant, delamination, and chalking of the backsheet. The I-V characterization shown that all sampled modules had an overall degradation rate of less than 20 %, which is within the warranty limit, although in many cases the degradation rate over time shows a non-linear trend. Only one module experienced a severe fault that caused the complete loss of functionality. Obtained results confirm the reliability of c-Si technology, stressing the importance of a careful monitoring especially after the 15th year, when an increase of the degradation rate might occur. [ABSTRACT FROM AUTHOR]

• Genetic optimization algorithms reveal the potential of PV glazing. • Multi-objective optimization is effective in balancing contrary objectives. • Window-based variables influence the power output of PV glazing. • PV glazing has the potential to reduce glaring risks in hot climate areas. The potential of fenestration systems is increased by incorporating photovoltaic technology into windows. This recently developed technology enhances the ability to generate energy from the building façade, improve the thermal and daylight performance of buildings, and visual comfort of occupants. Integrating an evolutionary optimization algorithm into this technology is one of the possible sustainable solutions to enhance building performance and minimize environmental impact. This paper uses a genetic evolutionary optimization algorithm to explore the optimum performance of photovoltaic glass in an architecture studio regarding annual energy consumption, energy generation, and daylight performance. Design variables include a window-to-wall ratio (i.e., window size and location) and amorphous-silicon thin-film solar cell transparency to generate optimum Pareto-front solutions for the case building. Optimization objectives are minimizing annual thermal (i.e., heating and cooling) loads and maximizing Spatial Daylight Autonomy. Optimized results of low-E semi-transparent amorphous-silicon photovoltaic glass applied on the façade show that the spatial daylight autonomy is increased to 82% with reduced glare risk and higher visual comfort for the occupants. Photovoltaic glass helped reduce the selected room's seasonal and annual lighting loads by up to 26.7%. Lastly, compared to non-optimized photovoltaic glass, they provide 23.2% more annual electrical energy. [ABSTRACT FROM AUTHOR]

• A digital methodology for environmental performance analysis of urban buildings is proposed. • An automated workflow was run over 2187 iterations to inform the best energy performing urban residential buildings. • Results show the important role of BIPV technology in shifting towards nearly Zero energy districts. • Indicators for the energy performance of urban buildings with one-hour, one-month, and one-year resolution data. • Performance Indicators analyzed cover many aspects: thermal indoor comfort, visual comfort, energy needs, solar production and load match. • Influence of the urban residential building's morphological parameters on the energy performance metrics in the Mediterranean climate. • The proposed graphs provide a useful way to concentrate a large quantity of information and highlight the relevance of data science. Given the looming threats of climate change and the rapid worldwide urbanization, it is a necessity to prioritize the transition towards a carbon-free built environment. This research study provides a holistic digital methodology for parametric design of urban residential buildings with regard to the Mediterranean semi-arid climate zone of Morocco in the early design phase. The morphological parameters of the urban residential buildings, namely the buildings' typology, the distance between buildings, the urban grid's orientation, and the window-to-wall ratio, are evaluated in order to identify the key combinations of passive and active solar design strategies that determine the high energy performing configurations, based on the introduced Energy Performance Index (EPI), which is the ratio between solar BIPV production to maximum available installed BIPV capacity and the normalized thermal energy needs. Through an automated processing of 2187 iterations via Grasshopper, we simulate daylight autonomy, indoor thermal comfort and solar rooftop photovoltaic and building integrated photovoltaic (BIPV) energy potential. Then, we analyze the conflicting objectives of energy efficiency measures, active solar design strategies, and indoor visual comfort in the decision-making process that supports our goal of getting closer to net zero urban residential buildings. The digital workflow showed interesting trends in reaching a balanced equilibrium between performance metrics influenced by the contrasting impact of solar exposure on indoor daylight autonomy and thermal energy demand. Furthermore, the study's findings indicate that it is possible to achieve an annual load match exceeding 66,56 % while simultaneously ensuring an acceptable visual indoor comfort (sDA higher than 0.4). The findings also highlight the important role of the BIPV system in shifting towards the net zero energy goal, by contributing up to 30 % of the overall solar energy output and covering up to 20 % of the yearly self-consumption. Moreover, the energy balance evaluation on an hourly basis indicates that BIPV system notably enhances the daily load cover factor by up to 5.5 %, particularly in the case of slab SN typology, throughout the different seasons. Graphical representations of the yearly, monthly and hourly load matches and the hourly energy balance of the best performing configurations provide a thorough understanding of the potential evolution of the urban energy system over time as a result of the gradual integration of active solar electricity production. [ABSTRACT FROM AUTHOR]

This paper introduces an enhanced version of Concentrating Photovoltaic Glazing (CoPVG) device. The original CoPVG system was designed as a seasonal glazing, that concentrates sunlight onto the focus of the lens during summer. Whilst, in winter, the system transmits light for indoor daylighting purposes. The newly developed version, entitled Concentrating Photovoltaic/Thermal Evacuated Glazing (CoPVTEG), is capable of simultaneously harvesting thermal energy and electricity while vacuum glazing (VG) has been integrated into the device. A finite element method was employed to simulate the glazing computationally. The developed model was validated by conducting experiments verifying that the model predicts the glazing performance reliably. Two different configurations were considered: placing the VG facing either outside, called disposition A, or inside, called disposition B. These dispositions were analysed computationally to determine the thermal and electrical output powers of the device in Belfast, UK. It was found that locating the VG inside potentially doubled the output electrical power ranging from 63.32 W/m 2 to 92.56 W/m 2 and from 36.03 W/m 2 to 43.88 W/m 2 at noon throughout the year for disposition B and A, respectively. However, the thermal harvesting potential of disposition A is higher than disposition B. In this case, the device potentially generates from 216.46 W/m 2 to 406.20 W/m 2 thermal power at noon. While the potential will be reduced from 163.54 W/m 2 to 396.11 W/m 2 in disposition B. Disposition A is more advantageous for cold-dominant climate zones while disposition B is the suggestion for temperate climate zone like the studied case. • This study presents Concentrating Photovoltaic/Thermal Evacuated Glazing, a semi-transparent and energy-efficient building façade. • The device serves multiple functions by not only passively managing energy, but also generating clean electricity and heat. • An experiment campaign was conducted to characterize the concept and validate a FEM model. • This research investigates the interaction of vacuum glazing and its placement within the device. [ABSTRACT FROM AUTHOR]