Performance Evaluation and Integration Strategies for Solar Façades in Diverse Climates: A State-of-the-Art Review

Abstract

This review article discusses the performance evaluation and integration strategies for solar façades, focusing on photovoltaic (PV) façades in diverse climatic conditions. It examines recent technology developments and methodologies for performance assessment, highlighting the potential of solar façades to enhance energy performance through on-site electricity generation. This study offers novel insights into the economic viability of façade-mounted photovoltaics, highlighting their potential in urban areas with constrained rooftop availability. Additionally, it emphasizes their distinct advantages in cold climates, such as reduced maintenance requirements and extended operational lifespans. Additionally, it addresses challenges such as technical complexity, esthetic considerations, and market awareness, emphasizing the balance between efficiency and design. Novel findings underscore the promise of advanced materials like perovskites in improving the flexibility and performance, as well as strategies to optimize BIPV integration in different climate zones. For stakeholders, this research highlights the importance of supportive policies and innovative solutions to overcome barriers, while offering researchers valuable perspectives on the advancement of solar façades toward zero-energy and zero-carbon building targets.

1. Introduction

Countries worldwide are progressively transitioning towards renewable energy sources [1] to mitigate climate change and reduce the negative environmental impacts of conventional energy production. The electricity demand is increasing more rapidly than the overall energy demand, driven by established uses such as cooling and emerging needs, including electric mobility and data centers.

Solar energy, in particular, has undergone significant expansion in recent years, driven by its ubiquitous availability and continuous technological advancements [2]. Solar energy ranks as the second-largest renewable energy source globally in terms of installed capacity, following hydropower. Solar PV energy sources are leading the growth in electricity generation, advancing at a pace sufficient to cover the projected rise in the electricity demand. Notably, there is potential for even more significant expansion: the solar manufacturing capacity is approximately 1100 GW per year, but the industry can install and bring online almost three times as much new solar power capacity annually compared to what was deployed in 2023 [3].

According to the International Energy Agency (IEA) and the UN Environment Programme (UNEP), buildings account for about 30–40% of the total global energy use [2]. The Global Alliance for Buildings and Construction (GlobalABC) confirms this range, frequently citing 36–40% for energy use when including operational and embodied energy in materials.

Buildings contribute to approximately 28–33% of the global GHG emissions [4], depending on the scope of analysis (whether indirect emissions related to production are included). UNEP’s Global Status Report for Buildings and Construction estimates emissions at about 28% for direct operations, rising to roughly 33% when indirect emissions are included.

Recent studies reveal that, with the increasing rate of urbanization, the energy demand for buildings is expected to rise by over 50% by 2050, exacerbating their environmental impact [3]. As a result, the building sector is now recognized as a critical target for energy efficiency measures and decarbonization strategies, with efforts focusing on integrating renewable energy sources, such as solar façades, to reduce the energy demand and emissions significantly.

Solar irradiance is one of the most widely utilized, practical, and economically viable renewable resources for energy generation. It can be effectively implemented across diverse geographic regions and climates worldwide [5]. This potential highlights its adaptability, scalability, and relevance in contributing to global energy needs.

In the EU, solar photovoltaics (PV) and wind energy are expected to contribute 42.5% of the total energy mix, reflecting a binding target for the share of energy from renewable sources by 2030 [3,6,7]. Several EU initiatives, such as PVSITES and BIPVBOOST, have aimed to advance BIPV technology. The BIPVBOOST project, in particular, analyzed the regulatory framework for BIPV and developed new assessment procedures addressing energy efficiency, mechanical safety, electrical safety, and fire safety. Furthermore, broader EU programs like the European Green Deal, the REPowerEU plan, and the EU Solar Energy Strategy have been instrumental in promoting photovoltaics, including BIPV. Various countries within the EU have implemented policy measures, such as subsidies for photovoltaic systems and green building certification standards, to encourage the integration of PV technology into building designs, which in turn impacts the construction industry by driving innovation and sustainability practices. Among these policies, green tradable certificates, feed-in tariffs, capital subsidies, tax credits, and net metering have been used to a large extent, providing significant incentives for the adoption of BIPV systems.

The United States aims for carbon-free electricity by 2035, with renewable sources projected to account for about 50% of all electricity generation by 2030 [8]. Federal tax incentives, along with state-specific programs, have significantly promoted the adoption of BIPV systems, making them an attractive option for sustainable building projects. Net metering policies in several states further support BIPV adoption by allowing building owners to offset energy costs with the electricity generated.

Meanwhile, China aims for non-fossil fuels to comprise 25% of its primary energy consumption by 2030 [9], with solar and wind significantly contributing to the new capacity [10], with the solar PV capacity alone reaching 216 GW [11,12]. Subsidies for solar installations and mandatory energy efficiency standards for new buildings have accelerated the use of photovoltaic façade systems in urban areas. Feed-in tariffs and capital subsidies have been particularly effective in encouraging both large-scale and distributed photovoltaic applications.

India plans to achieve 500 GW of renewable energy capacity by 2030, aiming for renewables to constitute 50% of its total power generation [13]. Policies such as reduced tariffs for solar equipment, incentives for green-certified buildings, and net metering regulations have bolstered the adoption of BIPV systems across the country.

In the Middle East, the UAE aims for clean energy to represent 50% of its energy mix by 2050 [14], while Saudi Arabia’s Vision 2030 includes generating 58.7 GW from renewables, primarily solar [15]. These goals are supported by government-led initiatives to encourage the use of photovoltaic technology in building designs through subsidies, feed-in tariffs, and energy efficiency regulations.

Latin America sees Brazil aiming for 48% of its electricity from renewables by 2030 [16,17,18] and Chile targeting 70% by 2050 [19]. Both countries have introduced policies that promote solar energy, including tax reductions, capital subsidies, and net metering incentives for the use of BIPV technology in residential and commercial buildings.

In Africa, the African Union is focused on enhancing energy access through solar power, with a target of 300 GW of renewable capacity by 2030 [20,21]. Supportive policies, such as grants for renewable energy projects and international partnerships, have encouraged the growth of BIPV systems across the continent. Feed-in tariffs and tax credits have also been used in some regions to stimulate investment in solar technologies.

Building-integrated photovoltaics (BIPV) include various installation types, with rooftop-mounted PV systems currently the most popular due to their straightforward installation and high solar exposure [22]. However, façade-mounted PV systems hold significant potential, as building façades offer a much larger surface area than rooftops [23]. Façade-integrated PV can serve as an additional architectural layer or even as the primary finishing layer of the building exterior, adding both functional and esthetic value. Integrating PV into façades allows these surfaces to contribute considerably to a building’s energy generation capacity, with the potential to surpass the output of rooftop PV installations, both in mid-rise and high-rise buildings [24]. BIPV can maximize renewable energy production and advance sustainability targets in the built environment by utilizing roof and façade surfaces.

Façade-mounted PVs have the potential to deliver substantial energy generation and demonstrate economic viability, particularly in highly urbanized areas, where vertical surfaces are abundant but roof space is limited [25]. In northern countries, façades are more exposed to the sun due to the low solar elevation angle, which allows vertical surfaces to capture more direct and diffuse sunlight, especially during the winter months and under cloudy weather conditions. Façade-mounted PV systems in northern regions can achieve energy yields of 50–150 kWh/m² annually, making them a viable alternative to rooftop installations in urban environments. According to the International Energy Agency’s (IEA) report on PV installations in 2023, the total capacity of photovoltaic systems can be categorized as follows: 55% are utility-scale installations (solar parks), 35% are building rooftop installations, and the remaining 10% consist of façade-integrated PV systems [3].

Active research is ongoing to evaluate the performance of active solar thermal façades, including their classification, standards, and performance assessment [26]. Solar technologies are being integrated into building façades to improve their energy performance by controlling the solar heat gains, natural lighting, and on-site electricity generation [27,28]. In hot-climate countries, the potential of cooled façades or the use of BIPV for significant cooling energy savings and reduced indoor operative temperatures has been discussed [29].

Despite their recognized potential, challenges related to solar façades need to be addressed, such as technical complexity, the lack of knowledge among market participants [30], and insufficient education among architects [31,32].

The industry is actively working on innovative solutions to overcome these challenges and promote the widespread deployment of solar façades. It focuses on integrating solar technologies into building envelopes and achieving zero-energy or zero-carbon building targets [30,33].

Due to the importance of this topic, more direct information must be provided on the specific applications of solar façades in cold- and warm-climate countries. Emerging technological advancements and forthcoming policies are anticipated to reshape the integration of photovoltaics into buildings, driving widespread adoption [34].

2. Materials and Methods

This review systematically examines case studies of solar PV applications on building façades. We followed a seven-step methodology: (1) defining the aim of the review; (2) formulating the research questions; (3) conducting a search for similar review studies; (4) conducting a comprehensive search for relevant studies; (5) assessing the studies’ quality and extracting data; (6) synthesizing the findings; and (7) interpreting the synthesized data (Figure 1).

Figure 1. Seven-step methodology within the review’s development.

The recent relevant review articles were collected in the first step of this study. The used keywords included (“solar panels”, “BIPV”, “PV façade”) AND (“review”), excluding from the selection those with the keywords (“photovoltaic-thermal”, “hybrid solar systems”, “PVT”) so as to deal only with purely photovoltaic systems. The study period for this review was defined as 2020 to 2024 to ensure distinctiveness and avoid overlap with prior reviews.

Sixteen relevant review articles that met the criteria of this research were found using the WOS, ScienceDirect, SCOPUS, and Google Scholar databases. The existing review studies cover a broad spectrum of topics related to building-integrated photovoltaics (BIPV), each contributing unique perspectives and findings. These reviews collectively address the technological, methodological, and design aspects of BIPV systems, focusing on different applications, innovations, and challenges.

• The most recent BIPV-related review at the time of this study synthesized technological advancements, the actual market, and the regulatory environment affecting BIPV [35]. It was published in 2024 and gave general insights for policymakers and stakeholders. This review strongly supports claims about declining costs driven by technological advancements, the importance of harmonizing standards, and the optimization potential of digital tools. However, areas like the market impact of PV module recycling, ethical production, and life cycle cost analyses lack sufficient evidence.
• Another 2024 review was performed on BIPV windows. It reviewed the development of BIPV façade technologies related to PV and smart windows and summarized the related experimental and simulation studies [36]. It highlights advances in materials and building physics for PV smart windows but lacks evidence for practical energy-saving applications. While switchable building envelopes show potential for energy efficiency, challenges in different climates and building types are underexplored. The need for long-term studies to verify the energy-saving benefits and user acceptance is noted, but this is not supported by sufficient data or case studies.
• An overview performed by Italian scientists [37] focused on bifacial and semi-transparent BIPV systems and covered mostly technological and modeling aspects. It analyzed the electrical, optical, and thermal modeling procedures. However, its conclusions lack depth in critical areas, such as the optimization of semi-transparent perovskite and organic solar cells, where evidence remains insufficient or contradictory. Moreover, the proposed effectiveness of unified models integrating the thermal, optical, and electrical domains is more aspirational than substantiated, leaving significant gaps in addressing practical implementation challenges.
• Another review study, published in 2024, highlights the use of digital twin technologies throughout the entire life cycle of BIPV systems [38]. It identifies key DT applications, including real-time monitoring, predictive analysis, and robotic technologies for installation and maintenance. However, the practical implementation of real-time data optimization and continuous virtual model updates requires further investigation and evidence.
• A recent review analyzes the materials used for solar cells and considers their life cycle analysis using 24 case study projects with BIPV [39]. It emphasizes the role of eco-design in reducing these impacts and suggests that emerging solar technologies, although promising, require further attention to material use and toxicity.
• A group of authors from Australia and Malaysia, in their review [40], emphasize the need for esthetically appealing BIPV systems to overcome the monotonous appearance of traditional PV modules. This review explores high-definition colored PV technology for BIPV systems, focusing on micropatterning to enhance the light transmission and efficiency. While promising, this technology needs optimization to balance the image quality and energy performance for commercial use. Further research is required on non-toxic inks and improving the efficiency in thin-film PV modules. Practical implementation remains uncertain, with more data needed for real-world applications.
• A review study about methods for the potential harvesting of solar energy in urban areas at the district level considers 17 studies of façade and roof solar modeling with the application of GIS [41]. This review emphasizes the need for comprehensive evaluation methods to assess the urban potential of BIPV systems for sustainability. It reviews the current CAD- and GIS-based solar potential analysis approaches, highlighting gaps in integrating architectural features and addressing urban challenges like glare and heat island effects.
• A related review examines approximately 120 case studies of BIPV implementation from 2012 to 2022 across various countries, highlighting that BIPV systems are more advantageous in low-latitude regions. This study finds higher implementation rates in temperate, subtropical, cold, moderate, and Mediterranean climates. Interestingly, due to supportive government policies, BIPV adoption is significant in certain cold-climate countries despite the relatively low solar gains. In contrast, despite the high solar potential in hot and desert climates, BIPV is less commonly deployed. This disparity may stem from the potential of BIPV on vertical surfaces to increase the interior temperatures in hot regions [42].
• Another review, which focuses only on BIPV windows, covers the period from 2005 to 2022 [43] and gives data collected from different case studies of energy savings, locations, countries, and climates according to the Köppen climate classification, window types, and window orientations. This review highlights that, in cold-climate countries, 36% of the building energy is used for heating and 20% for lighting, whereas, in hot-climate countries, 55% of the energy consumption is dedicated to HVAC systems. This review provides valuable insights into the potential of BIPV windows, especially for energy-efficient applications in diverse climates and urban environments. However, while the findings are promising, the conclusions are based on global estimates and limited studies, indicating the need for broader experimental validation and region-specific analyses to fully understand the real-world potential of BIPV window technologies.
• Another review focuses on double-skin façade technology, gives an analysis of recent research on this topic, and discusses the physical properties and parameters of DSF to achieve building sustainability [44]. The review provides a thorough evaluation of PV-DSF systems, offering regulatory insights and a strong foundation for future research. Its focus on both static and dynamic regulation is practical, and the proposed recommendations are well supported. However, the review could benefit from more empirical data and real-world case studies to validate the suggested frameworks. The identified research gaps, particularly regarding dynamic regulation and occupant comfort, highlight the need for multidisciplinary approaches to fully realize PV-DSF’s potential.
• A group of Italian researchers published a review study showing the most common façade PV solutions and their effects on building energy savings. Various photovoltaic technologies and methods used to manufacture façade BIPV devices designed for different purposes are reviewed [45]. This review highlights the growing potential of BIPV technologies in improving buildings’ energy efficiency, particularly through multifunctional and esthetically integrated solutions such as hybrid and semi-transparent systems.
• A study performed in 2022 and published in 2023 by researchers from China and Australia analyzed the bibliographic data of most journals, authors, and countries dedicated to BIPV, giving an analysis of the used keywords and their development. This study takes into account around 1000 research papers. It focuses on the period of 2012 to mid-2022 [46].
• Another research work in the form of a dissertation reviews software workflows for the evaluation of BIPV solar gains at a neighborhood scale [47]. This study reveals significant variability in the results of different tools when predicting solar irradiation under similar input conditions, especially for façades and complex geometries, with deviations reaching up to 40% in some cases. While small variations are observed for flat, unobstructed roofs, complex scenarios like heterogeneous districts lead to larger discrepancies due to shading and geometry intricacies. The findings emphasize the importance of understanding tool-specific assumptions, such as sun position calculations, diffuse models, and reflections, while acknowledging that some deviations remain unexplained, underscoring the need for the further analysis of simulation engines.
• An older (published in 2022) review summarizing the research on fenestration integrated PV [48] is similar to the previously mentioned review of BIPV windows [43]. This review concludes that, in hot climates, single-glazed BIPV windows with high U-values offer better thermal performance but require solar energy penetration control to prevent excess heat and light, making shading or selective transmission critical. In cold climates, double- or triple-glazed BIPV windows are more effective due to their low U-values, with vacuum-integrated BIPV emerging as a promising solution for improved insulation.
• A review of the technological design options for building-integrated photovoltaics (BIPV) [23], conducted in 2021, provides a comparative analysis of various PV panel materials, interlayers, electrical module configurations, and the use of color to conceal PV cells. This review also explores design strategies for complete electrical systems and the constructional integration of BIPV modules within building envelopes.
• Another review is dedicated solely to perovskite technology and gives a summary of this technology, but, because it was performed in 2020, it does not capture the latest technological advancements related to perovskite PV cell production and applications [49].

The existing reviews on building-integrated photovoltaic (BIPV) systems cover various topics, primarily focusing on technology, methodology, and design. Some address specific advancements, such as bifacial and semi-transparent systems, digital twin technologies, and innovative materials like perovskites. Others examine BIPV windows and double-skin façades and their potential for energy efficiency. Broader reviews synthesize case studies across climates, highlighting policy impacts, with colder regions benefiting from incentives despite low solar gains, while hot desert regions face challenges like interior heat gains.

Specific reviews explore esthetic and design aspects, such as the module layout and façade integration, while others use modeling tools to evaluate the solar potential at larger scales. Bibliometric studies reveal research trends and evolving themes. Despite these contributions, a gap remains in understanding climate-specific BIPV performance and its adaptability across diverse conditions.

This review addresses this gap by evaluating BIPV performance in various climates, integrating technological, policy, and climatic insights. It aims to propose region-specific strategies for the optimization of BIPV adoption, supporting sustainable energy solutions tailored to local conditions. Key research questions include identifying emerging technologies (e.g., semi-transparent PV, perovskites), assessing climate-specific challenges, and understanding why façade PV adoption lags behind that of rooftop systems.

3. Literature Review

To ensure novelty, this review focuses on studies from the period of 2023–2024, using keywords such as “BIPV façade”, “double-skin façade”, “solar software”, and “FBIPV”. Articles were sourced from the WOS, ScienceDirect, SCOPUS, and Google Scholar databases. Studies irrelevant to climatic performance, such as those on rooftop PV, acoustics, or regulatory aspects, were excluded. This approach captured advancements in efficiency, materials, and integration methods, providing a foundation for sustainable BIPV implementation across climates. As Figure 2 shows, the main research keywords were compiled from selected article keywords using a free online word cloud generator. The most frequently appearing keywords included BIPV, solar energy, energy performance, integrated building photovoltaic systems, energy performance, and efficiency. These keywords indicate a strong focus on integrating photovoltaic technology into buildings for energy generation, enhancing sustainability, and optimizing energy efficiency in buildings.

Figure 2. The main research keywords (compiled from selected article keywords with a free online word cloud generator).

The most cited research papers from the earlier 2019–2022 period, according to the Web of Science (WOS) database, are studies investigating solar-active applications on building façades in various climatic conditions. These studies recommend specific façade orientations to optimize heating, cooling, and electricity generation depending on the geographic location [50]. Another study examines the integration of solar thermal and photovoltaic (PV) collectors into building façades to reduce energy consumption across five European locations, highlighting the interplay between the solar energy supply and heating or cooling demand [51]. Solar energy and shading have also been explored in warm climates as strategies to reduce the cooling energy requirements [29].

Research on the mounting and location of solar façades still needs to be completed. One study presents a method for the optimization of the geometric layout of façade-mounted PV arrays, considering the finite height of façades and identifying the optimal tilt angle and number of panels to maximize solar radiation while avoiding shading issues [52]. Another study discuss the design processes for façade PV systems, including selecting suitable panels and developing software to simulate PV energy production and building energy consumption [53].

Innovative architectural designs for solar façades have also been proposed. These include kinetic photovoltaic systems that adjust to the optimal tilt angles for maximum energy generation [54,55] and façade-based BIPV designs optimized for yields within available façade areas [56]. Additionally, studies explore the potential for passive energy solutions, such as integrating solar panels into walls and window canopies, which offer easier maintenance and reduced installation costs compared to rooftop systems [57].

Recent studies (2023 onward) adopt a more comprehensive approach, exploring aspects such as economic viability, design optimization, technological advancements, and methodologies for BIPV placement, often supported by case studies. Many studies integrate multiple dimensions—for instance, analyzing economic feasibility alongside strategies to enhance it, proposing methodologies to estimate solar gains, and simultaneously developing techniques to optimize PV panel placement. These studies can be categorized into overlapping but distinct thematic areas.

• Climatic Adaptation and Optimization: Research on orientation and tilt optimization for solar façades to balance heating, cooling, and electricity generation across various climate zones.
• Building Integration and Design Strategies: Studies on the integration of PV systems into innovative building designs, such as semi-transparent façades, multi-skin façades, and kinetic systems.
• Material and Technological Innovations: The development of novel PV technologies, including bifacial and third-generation panels and façade-integrated materials, enhancing the efficiency and esthetics.
• Energy Performance and Multifunctionality: The analysis of PV façades providing multifunctional benefits, such as electricity and heat generation or passive cooling.
• Economic Feasibility and Social Acceptance: Evaluations of cost-effectiveness, energy savings, and esthetic appeal to enhance the public and market acceptance of BIPV systems.
• Simulation and Predictive Models: The application of modeling tools to optimize PV configurations and predict energy outputs under different conditions.
• Environmental Impact and Sustainability: The exploration of BIPV’s contributions to net-zero energy goals and greenhouse gas emission reductions.
• Architectural and Urban Potential: Research highlighting the potential to maximize façade surfaces, especially in urban areas, where façade-mounted systems can outperform rooftop installations in electricity generation due to larger surface areas.

These categories reflect the multifaceted nature of solar PV research, although dividing the studies into exclusive categories is challenging due to their interdisciplinary focus. Table 1 provides a simplified categorization of the selected articles: case studies (24 papers), design optimization (4), economic factors (6), methodological developments (12), and technology-focused research (28). Some articles fit specifically into these categories and are discussed separately.

Table 1. Selected research papers and their summaries.

Reference, Year	Topics Covered	Country	Category
[33], 2023	This review examines the role of BIPV technology in advancing net-zero energy buildings (NZEBs). It emphasizes critical parameters, including the area-to-volume (A/V) ratio, window-to-wall ratio (WWR), and solar heat gain coefficient (SHGC), in achieving NZEB standards. The benefits of integrating BIPV with building-integrated solar thermal (BIST) systems are highlighted, alongside the challenges posed by limitations such as the omission of indoor conditions and insufficient energy monitoring. The findings underscore the significant contribution of BIPV to enhancing energy efficiency and achieving carbon neutrality.	International (Singapore, Brazil, Italy, Switzerland, Japan, Greece)	Case study
[58], 2025	This study investigates the window-to-wall ratios (WWRs) of glass façades with five different transparency levels in four distinct climate zones and suggests the optimal ratios.	Iran	Case study
[59], 2024	A study on Mediterranean single-family homes examines how the building typology, orientation, and BIPV integration optimize energy efficiency, leveraging high solar potential to enhance sustainability.	Cyprus	Case study
[60], 2024	BIPV often faces challenges like suboptimal orientation, limited ventilation, and additional losses in colored modules. To study these factors, a BIPV curtain wall façade test site was constructed and monitored for a year at the Technical University of Denmark.	Roskilde, Denmark	Case study
[61], 2024	This study advances the field by conducting a cost–benefit analysis of established BIPV case studies located in Southern Switzerland.	Switzerland	Case study
[62], 2024	This study examines the integration of a BIPV/T façade with a direct-expansion heat pump system for applications in severe cold climates.	Harbin, China	Case study
[63], 2024	This study evaluates the potential of PV systems to improve the energy self-sufficiency of small-scale, low-rise apartment buildings, using a case study based on the Republic of Korea’s Zero-Energy Building Certification System.	Korea	Case study
[64], 2024	This study applies the method to a database of 233 actual buildings in Switzerland, a leading country with a 10% BIPV rate, focusing on PV installations documented between 1997 and 2023.	Switzerland	Case study
[65], 2024	This research focuses on identifying the ideal orientation for the integration of PV into tropical building façades. The study involved conducting experiments, simulations, and modeling to assess the energy output of BIPV systems and to forecast the indoor daylighting effects in a scaled building model. A 105 Wp monocrystalline silicon PV system was positioned on the model, facing each cardinal direction, with the location of the study being Bandung, Indonesia.	Indonesia	Case study
[66], 2024	This case study explores the integration of BIPV in a cultural heritage building in Norway, focusing on the balance between preserving architectural value and enhancing energy efficiency.	Norway	Case study
[67], 2024	This paper discusses a case study on the design of a solar façade incorporating solar thermophotovoltaics (STPVs) and wavelength-selective thermophotovoltaics (TPVs) in a high-rise residential building located in Tehran, Iran, a semi-arid region. The design process included energy-saving and cost–benefit analyses, using simulation tools such as EnergyPlus within Rhino, along with the Ladybug and Honeybee plugins.	Tehran, Iran	Case study
[68], 2024	This study was conducted using large-area commercial modules under real operational conditions over an extended period. It provides an analysis based on precise data from a set of organic panels laminated in glass, installed vertically as part of a pioneering project in Latin America.	Latin America	Case study
[69], 2024	This study examines and compares the energy-saving potential of four transparent wall configurations for buildings, namely basic glass, façades, basic glass integrated with photovoltaics, and façades integrated with photovoltaics, across varying ambient temperatures, wind speeds, and solar radiation levels.	Egypt	Case study
[70], 2023	This study evaluates a BIPV thermal (BIPV/T) system, which generates both thermal and electrical energy to improve the efficiency. The performance of BIPV and BIPV/T systems is compared in the cold climate of Tabriz, Iran.	Tabriz, Iran	Case study
[71], 2023	This study sought to assess the solar potential of building façades across different urban forms, with a focus on Adelaide as a case study.	Australia	Case study
[72], 2023	This study explores the potential for the large-scale installation of BIPV modules on the façades of commercial buildings in Tokyo. The findings suggest that BIPV could meet 15–48% of the city’s annual electricity demand by 2050. While enhancing PV power generation, large-scale BIPV could present challenges such as reduced asset utilization and the need for increased flexibility, offering important insights for policymakers.	Tokyo, Japan	Case study
[73], 2023	This study uses Seoul, the most populous region in South Korea, as a reference model to analyze third-generation PV panels.	Korea	Case study
[74], 2023	This study assesses the feasibility of integrating grid-connected rooftop and façade BIPV systems for residential buildings on an academic campus, considering factors like the built area and energy consumption. The results demonstrate that low-rise residential buildings can boost energy production by up to 62.5% through façade BIPV systems. The proposed system achieves net-zero energy building potential, with a nominal PV capacity of 5.6 MW, generating 7182 MWh annually.	West Bengal, India	Case study
[75], 2023	This study monitored a roof-integrated PV system in South Korea over 2.5 years, analyzing the power generation, solar irradiance, and system temperature. The findings indicate a direct correlation between the monthly power generation and solar irradiance. The internal module temperatures exceeded both the roof and module rear temperatures, with a minimal effect on the roof temperature but a significant impact on the power conversion efficiency, ranging from a maximum of 11.42% to a minimum of 5.24%. Effective temperature control is essential in optimizing PV systems’ performance.	Gyeongsan, South Korea	Case study
[76], 2024	This study develops and presents a multidimensional assessment tool informed by the experiences and lessons learned from implemented BIPV projects.	International	Case study, economy
[72], 2023	This study develops a model to estimate the hourly PV potential of building surfaces at a regional scale, applied to the commercial building stock in Tokyo, Japan. The analysis reveals that, by 2050, the PV power generated could meet 15–48% of the annual electricity demand of the building stock, depending on the extent to which the PV potential of building surfaces, particularly façades, is utilized.	Japan	Case study, modeling
[77], 2023	This study developed an integrated framework to assess the urban-scale photovoltaic (PV) potential for rooftops and façades at a high spatiotemporal resolution, with a focus on Beijing. The results show that the façade PV power generation (18.07 TWh/y) was 239% higher than the rooftop PV yield, demonstrating the framework’s superior accuracy compared to simplified models. These findings offer valuable insights for policies aimed at optimizing PV integration in dense urban areas.	Beijing, China	Case study, research
[78], 2023	This study evaluates building-integrated PV/T technologies in low-carbon, zero-energy buildings through a demo building with PV/T walls. Using a validated simulation approach, it found significant clean electricity and heat generation, optimized energy storage, and reduced cooling and heating loads. The optimal azimuth for energy efficiency was 45 degrees, although dust accumulation reduced the overall benefits. A simulation method was proposed by coupling PV/T wall models with the TRNSYS software for accurate building modeling.	Hot summer/cold winter	Case study/research
[79], 2023	This study examines the effect of the panel orientation on PV system performance, particularly under partial shading in urban areas. Simulations and tests reveal that landscape-oriented panels produce up to 1010 Wh more power than portrait-oriented ones. The findings suggest the optimal PV module design and placement, especially in arid and densely populated regions.	Ben Guerir, Morocco	Design optimization
[80], 2023	This study compares conventional, BIPV, and BIPV/T double façades, examining the effect of the cavity depth between the PV system and the façade. Simulations using DesignBuilder and EnergyPlus revealed that conventional double façades had lower heating demands but higher cooling requirements. Increasing the cavity depth resulted in higher heating loads and reduced cooling loads, with an optimal cavity depth of 0.97 m for improved energy efficiency.	Nicosia, Cyprus	Design optimization
[81], 2023	This study explores the integration of PV shading systems in office buildings to manage cooling, heating, and lighting energy use. Using a decision support methodology, it analyzes variables like the shading surface area, angle, energy output, embodied carbon, and costs. The findings suggest that, despite Mono-Si PV’s higher energy efficiency, Poly-Si PV offers a better balance between the cost and embodied carbon.	İstanbul	Design optimization, MCDM TOPSIS
[82], 2023	This study explores how optimizing the window size, orientation, and shading strategies can mitigate the cooling energy demand in sub-Saharan African cities. Using IDA-ICE simulations, it finds that window-to-wall ratios (WWR) > 70% increase the cooling demands, especially on eastern and western façades. Internal blinds improve the thermal comfort but increase the artificial lighting needs, while PV panel integration reduces the cooling energy and provides additional electricity. The study offers insights for the design of energy-efficient buildings in hot climates.	Niamey in Niger, Nairobi, Sub-Saharan Africa	Design optimization
[83], 2023	This paper examines the impact of mixed orientations in building-integrated photovoltaics (BIPV) on the PV output power forecasting accuracy for a system in Trondheim, Norway. The study finds that incorporating mixed orientations in the prediction models reduces the RMSE forecast error by 34%. These results highlight the significance of accurate forecasting for effective energy management in BIPV systems, especially in urban zero-emission buildings.	Trondheim, Norway	Design optimization, forecast
[84], 2024	Several BIPV scenarios were evaluated, with the most effective demonstrating economic viability through a payback period of 14–18 years and internal rates of return (IRR) ranging from 5.3% to 5.9%. These findings highlight the economic and environmental advantages of integrating BIPV in building renovations.	Not relevant	Economics
[85], 2023	This paper examines the potential of BIPV in addressing the growing energy demands due to urbanization in India. It highlights the role of BIPV in densely populated cities and compares its economic feasibility with that of traditional rooftop PV modules. The study also explores how BIPV can contribute to India’s clean energy and climate change mitigation objectives.	India	Economics
[86], 2023	This study examines solar data and the energy potential for semi-transparent BIPV systems in Hong Kong. BIPV façades with large window-to-wall ratios can significantly reduce the need for electric lighting and cooling while generating energy. The research highlights the promise of BIPV for entire building skins, with peak irradiance and illuminance data supporting substantial energy benefits.	Hong Kong	Economics
[87], 2023	This study explores a holistic solar energy system combined with a ground-sourced heat pump for residential buildings, integrating various photovoltaic plant orientations and hydrogen-based energy storage. Analyzing five cities, a 20-floor building requires 550–1550 kWp of PV capacity. The results show overall energy and exergy efficiencies of 18.76% and 10.49% in Ottawa and self-sufficiency with BIPV façades and rooftop PV in Istanbul.	Miami, USA Los Angeles, USA Istanbul, Turkey Ottawa, Canada Frankfurt, Germany	Economics
[88], 2023	This study assesses various photovoltaic (PV) systems—building-attached PV (BAPV), building-integrated PV (BIPV), and BIPV–thermal (BIPV/T)—for a community of two residential and two nonresidential buildings. It finds that the community achieved a 139% net energy balance, with 33.2% energy self-sufficiency and 76.7% self-consumption of solar power. The payback period for the initial investment, analyzed through carbon credit trading, ranged from 9 to 17 years.	Daejeon, South Korea, at a latitude of 36.381° and longitude of 127.359°	Economics
[89], 2023	This study explores various building-integrated passive solar energy technologies by comparing six scenarios, including PV and BIPV glazing windows, façades, and double-skin façades. The results show that the BIPV model reduced the indoor temperatures by up to 1.3 °C. The double-skin façade reduced the annual heating energy consumption by 17%, while the PV glazing façade reduced the cooling energy demand by over 21%. Additionally, significant reductions in CO2 emissions and energy costs were observed, demonstrating the effectiveness of these technologies.	Tehran, Iran	Economics
[90], 2024	This paper provides an overview of various coloring technologies used in BIPV modules, outlining their functionality, challenges, and benefits. It also reviews the current market for colored PV products, including considerations of pricing and power output.	Switzerland	Esthetics
[91], 2023	This study evaluates building-integrated photovoltaics (BIPV) in the refurbishing of 1960s Spanish office buildings. The TRNSYS software shows that transparent BIPV reduces the energy demand by 6.9% and the overall energy balance by 21%, with opaque BIPV achieving a 38.3% reduction. Despite reduced daylight autonomy, the technology’s potential is underscored, emphasizing electricity pricing’s role in BIPV promotion. A building simulation of transparent BIPV was performed.	Palma de Mallorca (Spain)	Methodology
[92], 2023	This study presents a comprehensive digital methodology for the parametric design of urban residential buildings in Morocco’s Mediterranean semi-arid climate, focusing on the early design phase. It examines the morphological parameters of the buildings, including the typology, spacing, urban grid orientation, and window-to-wall ratio.	Morrocco	Methodology
[93], 2025	This study introduces an autonomous design framework for the deployment of building-integrated photovoltaics (BIPV). The framework utilizes 3D modeling and parametric design tools such as Grasshopper, enabling the efficient integration of BIPV into building structures. The approach incorporates life cycle assessment (LCA) to evaluate the environmental impacts, helping to optimize the design process by balancing energy production with sustainability considerations. This method aims to streamline the deployment of BIPV, offering a comprehensive solution for the design of energy-efficient, environmentally friendly buildings.	Not relevant	Methodology
[94], 2025	This study employs a convolutional neural network (CNN) for 3D modeling to evaluate the potential of building-integrated photovoltaics (BIPV) at medium and large urban scales. By leveraging a CNN, the model can efficiently analyze complex urban environments and predict the optimal integration of BIPV systems. This approach allows for more accurate assessments of the energy generation potential, considering factors such as the building geometry, orientation, and surrounding infrastructure, enabling more informed decision-making for sustainable urban planning.	Not relevant	Methodology
[95], 2024	This study explores machine learning-driven optimization for building-integrated photovoltaic (BIPV) envelope design, enhancing the energy performance, esthetics, and architectural integration. By analyzing factors like the orientation, shading, and material properties, the approach maximizes the efficiency, sustainability, and cost-effectiveness in urban developments.	Not relevant	Methodology
[96], 2024	This study introduces SolarSAM, a novel BIPV evaluation method that leverages satellite imagery, deep learning techniques, and advanced data analytics to optimize energy performance and system integration in urban environments.	Not relevant	Methodology
[97], 2024	This study presents the large-scale prediction of solar irradiation, shading impacts, and energy generation on building façades using urban morphological indicators, employing a machine learning approach to enhance the accuracy and optimize the energy performance in diverse urban environments.	Not relevant	Methodology
[98], 2024	This article presents an advanced multi-criteria assessment (MCA) framework for the evaluation of the suitability of urban surfaces for solar energy deployment. It broadens the traditional focus on economic, environmental, and technological factors by incorporating social, political, legal, health, safety, cultural, and psychological aspects, offering a comprehensive evaluation of PV applications in urban settings.	Not relevant	Methodology
[99], 2024	The study introduces a hybrid approach that combines physical model-based solar radiation calculation with machine learning techniques for city-wide building solar radiation potential (SRP) analysis. The approach accounts for the urban morphology, land cover, and meteorological factors, leading to the classification of local climate zones (LCZs). This methodology offers an innovative way to assess the solar radiation potential in urban environments, enhancing the precision of solar energy assessments.	Not relevant	Methodology
[100], 2024	This study introduces a comprehensive simulation framework designed to model, assess, and optimize the performance and reliability of BIPV systems in various environments.	Not relevant	Methodology
[101], 2024	In this study, a parametric method is proposed to assess the solar energy potential of buildings, considering factors such as the orientation, shading, and environmental conditions.	Not relevant	Methodology
[102], 2024	This paper introduces BIM-AITIZATION, a novel approach combining photogrammetry and deep learning to improve BIPV decarbonization and energy prediction. By integrating BIM data and AI techniques, the method enhances the prediction accuracy and automates the process. Extensive experiments show that this approach outperforms existing BIPV software, successfully generalizing new building data, as demonstrated through a case study.	Not relevant	Methodology
[103], 2023	Efficient control is crucial for optimal HVAC-connected BIPV/T system performance. This paper uses the Varennes library as a case study to examine how model predictive control (MPC) enhances the operation of air-based BIPV/T systems. The study finds that MPC can significantly increase the helpful heat output, reduce PV overheating, and lower the building energy consumption by 40%, with the potential for excess heat supply to nearby buildings.	Canada, Montreal	Methodology, case study
[104], 2023	This study proposes a multi-objective optimization framework for photovoltaic-integrated shading devices (PVSDs) in building-integrated photovoltaics (BIPV). It focuses on maximizing the PV potential, minimizing the area, and ensuring an adequate sunshade duration. The GIS-based analysis explores different PVSD planning scenarios, finding that optimized rotating PVSDs can generate significant electricity and provide effective shading, aiding solar farming in urban environments and promoting renewable energy use.	Hong Kong	Methodology, optimization, GIS
[105], 2023	This paper presents a detailed numerical modeling approach to evaluate the impact of BIPV-DSF on indoor visual conditions, energy consumption, and overall building performance in an office module, using a typical climate in the United Kingdom.	UK	Modeling
[69], 2024	This study investigates the energy-saving potential of four transparent wall configurations, including basic glass and photovoltaic-integrated façades, using a 3D heat transfer and electrical model. Simulations under Egypt’s summer conditions reveal that photovoltaic-integrated façades generate approximately 394 Wh/m2 of daily electrical energy and reduce the electricity consumption by up to 79.3% compared to basic glass walls. The study incorporates computational fluid dynamics (CFD) simulations to assess the thermal performance.	Egypt, summer	Research, energy effectiveness
[106], 2023	This review examines the development of BIPV/T systems in Middle Eastern and North African countries, comparing them with other regions. It covers the technologies, heat transfer media, energy storage, and installation locations. The study assesses the current modeling techniques and trends, noting the use of batteries and phase change materials for storage. It emphasizes the need for thorough economic and environmental evaluations to advance the field.	Middle Eastern and North African countries	Comparative review
[107], 2024	This study examines the temperature performance of pigment-based colored BIPV modules within a ventilated façade. It explores the potential of incorporating BIPV modules into building envelopes to enhance their energy efficiency while preserving their esthetic design.	Bolzano, Italy	Technology
[108], 2024	In this study, solar PV vacuum glazing (SVG) is proposed as a promising alternative to traditional external insulation layers in buildings, offering superior thermal insulation, incombustible properties, and potential for enhanced energy efficiency.	Hong Kong and Hunan, China	Technology
[109], 2024	The study highlights that integrating glazing-integrated photovoltaic (GIPV) with radiative coatings can help to create nearly zero-energy buildings, achieving significant energy savings of 34.9%.	UAE	Technology
[110], 2023	The study proposes a photovoltaic/thermal heat pump system (BIPV/T-HP) integrated into the building façade to address heat loss during winter, when the system’s heat output is insufficient and the low-temperature water fails to meet the building’s heating requirements.	Henan and Beijing, China	Technology
[110], 2023	This study presents a façade-mounted photovoltaic/thermal heat pump (BIPV/T-HP) system designed to enhance space heating in high-rise buildings during winter. Increasing the flow velocity reduces the mean outlet water temperature while extending the heat pump’s operational hours and boosting its heating capacity. However, higher temperature thresholds elevate the water temperature and increase the heat loss, leading to a decrease in the heat pump’s output.	Beijing, China	Technology
[110], 2023	This study introduces a hybrid CdTe-PCM PV glass module (CdTe-PCMG) for building windows, validated through a mathematical optical–electrical–thermal model. Testing reveals that PCM enhances the electrical output and indoor comfort. Optimal performance was achieved with a 3.5 cm PCM layer and a 22–24 °C phase change range. Annual predictions suggest that the module best suits areas with abundant solar radiation or mild climates.	Hefei, China	Technology
[73], 2023	This study assesses the technical and economic performance of a window-integrated PV system in a residential building in Seoul. Type B panels generated the highest annual electricity, while type C achieved the highest electricity per unit area. The economic performance improved with higher electricity consumption and a southern orientation, demonstrating the potential of window-integrated PV systems for net-zero-energy buildings.	South Korea	Technology
[111], 2023	The paper discusses an innovative, highly efficient BIPV system, specifically designed as PV panes with rotating bifacial modules that can be attached to the building. It also reviews sun capture technologies.	Italy	Technology
[112], 2024	This study introduces an eco-friendly passive cooling technique using an evaporative porous clay material to enhance the efficiency of building-integrated photovoltaic (BIPV) systems. Experimental results show that this approach reduces the PV module temperature by up to 19.1 °C and improves the system’s efficiency by 9.8%. The technique also significantly lowers the building’s thermal load, outperforming phase change material (PCM) in terms of cooling effects.	Alexandria, Egypt	Technology
[113], 2023	This study introduces a multifunctional PV/T window to improve building-integrated photovoltaics’ (BIPV) performance by recovering heat for winter warmth and for hot water in other seasons. Mathematical and sensitivity analyses show that the optimal slope and orientation angles, combined with low-iron glass, significantly reduce the energy consumption and CO2 emissions in four cities in the Yangtze River region. The new system lowers the annual operation costs and enhances the energy efficiency. This study developed and validated a mathematical model for the proposed window, which was then integrated into the TRNSYS platform to evaluate its electrical and thermal performance. The EnergyPlus software was used to assess its daylighting performance.	Yangtze River region, China Shanghai, Nanjing, Wuhan and Chongqing	Technology, methodology
[114], 2023	This study compares the thermal performance of ventilated building-integrated semi-transparent photovoltaic (BiSPV) and building-integrated opaque photovoltaic (BiOPV) Trombe walls in cold climates. The results indicate that BiSPV Trombe walls are more efficient in heating, achieving room temperatures that are 15 °C higher than those of BiOPV walls, while BiOPV walls offer better indoor thermal comfort. The indoor temperature can be adjusted by modifying the PV modules’ packing factor, the airflow rate, and the wall thickness.	Montreal, Canada	Technology
[115], 2023	This study examines the impact of dew-induced soiling on PV modules and introduces an automated water-based cleaning system. Experiments in Islamabad, Pakistan, show significant soiling losses at various tilt angles, with the new system improving the power recovery and cooling effects. The cleaning process reduces the PV module temperatures and proves economically feasible for domestic and commercial applications.	Islamabad, Pakistan	Technology
[116], 2024	This study explores reversible radiative cooling–photovoltaic (RRC-PV) modules to optimize energy harvesting in buildings with limited façade areas. The modules generate electricity during the day and provide cooling at night. Tests in Shenzhen showed electrical efficiencies of 11.4–13.0% and highlighted superior cooling performance when used as rooftop awnings, emphasizing the need to evaluate the radiative cooling potential based on sky exposure.	Shenzhen, China	Technology
[117], 2023	This study presents a novel lightweight crystalline silicon PV module to overcome the limitations of traditional silicon and thin-film PV modules. The proposed PV roof, tested on various substrates, increases the building cooling load but delivers notable energy-saving benefits. Asphalt substrates perform the best, while the lightweight PV roof on a TPO substrate is the most sensitive to the thickness and wind speed. The findings suggest that adjusting the substrate thickness and wind speed can improve the energy yield and reduce CO2 emissions.	Zhenjiang, China	Technology
[118], 2023	This study introduces innovative single- and dual-inlet ventilation PV curtain wall systems (SVPV and DVPV) to mitigate PV overheating and improve buildings’ energy efficiency. Compared to non-ventilated systems, these solutions achieve significant annual energy savings of 28.07% and 26.72%, utilizing exhaust air for cooling in summer and heating in winter, respectively. The findings highlight the effectiveness of these systems and their potential for widespread adoption.	Hefei, China	Technology
[119], 2023	This study compares the power generation performance of angle-adjustable PV blinds with fixed BIPV systems, focusing on the effects of self-shading. Both experimental and simulation analyses indicate that PV blinds, particularly those set at a 30° angle, enable significant power reductions due to shading. Even with monthly angle adjustments for optimization, PV blinds perform less efficiently than fixed BIPV systems.	South Korea	Technology
[120], 2023	This study presents an innovative PV/thermal (PV/T) hybrid panel design using heat pipe technology to supply hot water and electricity for homes in Sydney. Initial tests demonstrate that the system can reach hot water temperatures of up to 50 °C in summer and 30 °C in winter, providing 3.7–5.2 MJ/m2 daily. The energy efficiency of this PV/T design is more than four times greater than that of conventional PV panels, highlighting its feasibility for residential applications.	Sydney, Australia	Technology
[121], 2023	This study evaluates the environmental and economic viability of textile envelope-integrated flexible photovoltaic (TE-FPV) systems used as sunshades for a teaching building at Politecnico di Milano. Life cycle assessment (LCA) and life cycle cost analysis (LCCA) indicate that TE-FPV systems are economically advantageous, generate clean energy, and provide societal benefits. Their successful deployment in Bergen, Norway suggests that these systems could be widely adopted across Europe.	Italy, Netherlands, Norway	Technology
[122], 2023	This study presents a partitioned design approach for vacuum-integrated photovoltaic (VPV) curtain walls to balance their various functions. The optimal design was determined by dividing the curtain wall into sections for daylight, views, and spandrels, using software simulations. The results demonstrated notable improvements in daylight utilization, net-zero energy ratios, and surplus electricity production, providing a novel strategy for energy-efficient building designs.	Changsha, China	Technology, design optimization
[123], 2023	This study proposes a curved solar balcony with a flexible PV/T system to generate electricity and hot water. Verified in Hefei, China, the results show that the curved system outperforms the flat one in non-heating seasons, with a higher electrical yield and heat gain, especially when facing south.	Hefei, China	Technology, design
[2], 2025	This work aimed to develop a multifunctional window (MFW) that maximizes solar spectrum utilization while significantly improving the thermal efficiency and overall performance of BIPV windows in building applications.		Technology
[36], 2023	This paper reviews BIPV façade technologies, focusing on PV windows’ performance and demonstrating 37.18% average energy savings. It discusses optimizations for PV shading and double-skin façades, highlighting the potential of smart PV windows and switchable building envelopes to improve the energy efficiency across seasons.	Range of latitudes: 12.4~51°	Technology
[124], 2023	This study investigates the effect of multi-skin façade (MSF) designs integrated with photovoltaic (PV) systems on the thermal performance and energy production in office buildings. The analysis of triangular and rectangular pyramid configurations reveals that PV-integrated MSF systems can lower the cooling and heating demands while significantly boosting power generation compared to traditional vertical PV setups. The optimal design, particularly the rectangular pyramid, results in up to 49.4% higher energy output than in the base case.	Korea, 36.35° N, 127.38° E	Technology, design optimization
[125], 2023	This study examines the effects of South Korea’s new renewable energy policies, with a focus on building-integrated photovoltaics (BIPV). It presents a novel bidirectional reflectance photovoltaic (BRPV) system that improves the energy generation efficiency and minimizes the solar heat gain. When applied to a school building, BRPV increased its energy independence rate from 34.1% to 65.8%, as determined through model-based simulations.	South Korea	Technology, method
[126], 2023	This study introduces a new approach to zero-energy buildings, integrating an all-oriented façade with a photovoltaic–sky radiative cooling system (PV-RSC). The model, featuring PV modules on the south wall and a cooling system on the north wall, demonstrates that the PV-RSC system provides average electrical and cooling power of 7.7 W and 130–220 W, respectively, improving the cooling efficiency during summer. The numerical model, developed using typical meteorological data from Beijing, evaluates the system’s cooling performance.	Beijing, China	Technology, design optimization
[116], 2024	This study introduces an energy-efficient photovoltaic–phase change material (PV-PCM) window. During the day, the system converts solar radiation into electricity, while excess heat from internal sources and sunlight is stored in the PCM layer. At night, the stored heat is released from the PCM. Unlike traditional PV windows with integrated PCMs, this design uses sealed, modular PCM units, allowing for easier adjustment or removal to optimize the performance based on changing weather conditions.	Shenzhen, China	Technology
[122], 2023	The large-scale implementation of BIPV presents challenges to the stable operation of the utility grid, primarily due to the variability and intermittency of solar radiation. This study introduces a smart photovoltaic (SPV) window and an operational control strategy to mitigate these challenges, enhancing both the building energy efficiency and grid compatibility.	Hunan, China	Technology
[127], 2024	A micro-CPV system is designed to be incorporated as a semi-transparent glazing element, enabling diffuse irradiance to illuminate the building’s interior while concentrating direct irradiance onto the photovoltaic cells. In a typical residential setting, a 1 m2 aperture area system can generate an annual electricity output of 229 kWh/year.	Barcelona, Spain	Technology
[128], 2024	The study introduces an innovative PV curtain wall system with exhaust ventilation, integrated with ASHP units (EVPV-HP) for outdoor air treatment. This system effectively combines PV cooling, supply air reheating, and heat recovery from both the PV façade and exhaust air.	Anhui, China	Technology

The distribution of research related to specific climatic conditions and economic circumstances among regions is as follows: international and transcontinental (3); European (12), in which Switzerland (3) and Italy (3) dominate; the Middle East (13); Eastern countries (34), in which China (17) and South Korea (8) clearly dominate; Africa (4); North America (3); South America (2); and Australia (2).

4. Discussion: Key Barriers to the Widespread Adoption of BIPV Systems

BIPV systems offer a promising solution for sustainable energy generation in urban environments, yet their widespread adoption faces significant challenges. Recent studies’ main findings reveal critical barriers, such as economic viability, social acceptance, mechanical stability, thermal performance, and regulatory compliance. While BIPV systems provide unique advantages, such as enhanced energy efficiency and integration into building envelopes, their implementation could be improved by considering longer payback compared to rooftop PV systems, esthetic concerns, and complex design requirements.

This section identifies and discusses five key barriers to the widespread adoption of BIPV systems. These barriers include economic viability, where more extended payback periods compared to rooftop PV systems hinder the investment appeal; social acceptance, as esthetic concerns often conflict with architectural and community preferences; mechanical resistance and stability, which impose stringent structural requirements that are unique to façade integration; thermal performance limitations, particularly the heat-related efficiency losses in specific integration methods; and regulatory challenges, with façade-mounted PV systems needing to meet strict construction product standards. Understanding these barriers is crucial in developing strategies to promote BIPV adoption and enhance its role in sustainable energy transitions.

Barrier 1—economic viability and payback period. Solar PV panels are primarily used in power plants or when integrated into buildings. They are universally placed on building roofs since this results in the shortest payback times. According to the study by Li and Liu [129], flat-installed PVs on roofs have a payback period of 6.16 years. In contrast, the most effective BIPV scenarios demonstrate economic viability with a payback period of 14–18 years and internal rates of return (IRR) between 5.3% and 5.9% [84], or, as reported in other recent research, 13–17 years [61]. By inclining the panels [130], it is possible to shorten this gap, but rooftop PV panels remain the most economically viable option. In places beyond a 60° latitude, the inclination on façades is close to optimal, but the shading becomes a significant issue because of the low sun horizon. There is one more bonus for façade panels in cold climates—installing panels on façades eliminates the need for maintenance during the winter season to clear snow from the panels and also avoids the potential increase in roof loads due to snow drift. Although the payback time is longer, the lifetime of façade-mounted PV is longer than that of rooftop-mounted PV because of the lower solar radiance and less exposure to rain, snow, and dust [131]. Some studies report that solar plant cells do not reach the expected 20–25 years and last only 10–12 years because of intense exploitation and other factors [132].

Barrier 2—social acceptance or visual appearance. Social acceptance and visual appearance present significant challenges in the widespread adoption of solar façade technologies. Public and professional perceptions of building-integrated photovoltaics (BIPV) are often influenced by these installations’ visual impacts on building esthetics and urban landscapes. While BIPV systems contribute to sustainable energy goals, their appearance—particularly in urban areas—may not always align with traditional architectural styles [133] or the esthetic expectations of communities [134,135]. To address these concerns, manufacturers have developed customizable options regarding color, texture, transparency, and materials [136]. However, while such customization can improve their visual integration and potentially increase their social acceptance, it may also reduce the efficiency of PV systems and raise the installation costs. Balancing the functional performance of solar façades with esthetic demands thus remains a complex issue, as any compromise in energy efficiency or economic feasibility could further impact public acceptance and slow the adoption of sustainable building technologies.

Barrier 3—ensuring mechanical resistance and stability. This is a critical requirement for BIPV systems due to their dual role as energy generators and integral components of a building’s envelope. Unlike PV panels installed in open fields, BIPV systems must comply with stricter structural standards to limit deflections that could compromise the building’s integrity and safety. For example, façade-integrated PV panels must withstand wind loads, thermal expansion, and vibrations while maintaining their functionality. Additionally, BIPV panels are subject to stringent watertightness standards to prevent leaks that could damage the building’s interior. At the same time, they need to allow for easy access to essential components—such as cable junction boxes, inverters, and connectors—for regular maintenance, inspection, and testing. For instance, roof-integrated PV systems often incorporate modular designs or accessible mounting systems to facilitate quick replacement or repairs without compromising the roof’s waterproofing. Barrier 4—decreased output performance as temperatures rise [137]. This is beneficial in facilitating airflow and cooling over the rear surface of the PV. However, specific integration methods, such as fully sealed double-glazed transparent curtain walls, do not allow for this, resulting in a performance loss of 5% to 10% that must be accepted [138]. Alternatively, integration methods like rain screens do not pose such drawbacks. In these systems, the panels are mounted with an offset from the façade onto the lattice substructure, creating an intermediate ventilated space. The integration method also depends on the type of PV.

Barrier 5—construction product requirements. PV panels are typically installed on rooftops using ground-mounted systems, where the panels are mounted on frames, concrete blocks, or poles optimized for large solar farms. These systems are built with low-cost, standard components and are easily assembled and scalable. They do not serve additional building functions, making them ideal for retrofit applications. Structurally, they only require an assessment of the increased roof load from the weight and ballast of the panels. However, when any object is permanently incorporated into a building, affecting its performance, it becomes a construction product, subject to national building codes. In Europe, these requirements are governed by Directive 305/2011, and similar regulations exist in other regions to ensure the safety, health, and environmental protection of construction products. For example, watertightness is typically achieved using sealants and gaskets. When panels are attached to a façade using structural sealants or frames, they are classified as structural sealant glazing systems and must meet the basic requirements outlined in ETAG 002.

BIPV continues to face challenges that hinder its broader market adoption. While the costs gradually decrease, high initial expenses remain a significant obstacle to investment and widespread uptake. Supportive policies are still essential for BIPV to achieve more significant usage within the construction sector.

5. Findings

This section examines the key findings on building-integrated photovoltaic (BIPV) systems, emphasizing their performance, environmental impacts, and technological advancements. While photovoltaic innovations have made remarkable progress over the past 10–15 years—transforming building-integrated applications through improved efficiency, functionality, and esthetic integration—many of these advancements fall outside the specific timeframe of this review. Semi-transparent photovoltaic (STPV) panels, which gained momentum between 2015 and 2020, now offer improved power conversion efficiency and daylighting benefits. Perovskite solar cells, emerging as a promising technology after 2012, have seen rapid advancements, particularly from 2022 onward, with breakthroughs in stability, scalability, and tandem configurations, pushing them closer to large-scale commercial deployment. Vacuum-insulated BIPV technologies, particularly suited for cold climates, have seen notable progress in integration and thermal performance since 2015.

The regions leading these technologies include Europe, North America, and parts of Asia, particularly China, Japan, and South Korea. Europe has been at the forefront of the integration of semi-transparent and vacuum-insulated BIPV technologies, driven by stringent energy regulations and a focus on sustainable building designs. North America, especially the United States, has been a hub for perovskite solar cell research, with significant contributions to scalability and commercialization. Meanwhile, China leads in the large-scale production and deployment of photovoltaic innovations, leveraging its strong manufacturing capabilities and ambitious renewable energy goals.

5.1. Longevity and Life Cycle Assessment

Solar PV panels have a lifespan of about 25–30 years, which is, on average, 40% lower than the design working life of common structures [39]. Moreover, photovoltaic systems not only experience an annual decrease in performance due to degradation but also require maintenance. Certain components, such as inverters, which are external to the PV module itself, may need repair or replacement due to their shorter life expectancy of approximately 15 years. This means that PV panels come with embodied carbon emissions and only offset the environmental impact through operational carbon savings. In addition, with the global strive for net zero and electrical grid decarbonization, the margin of accepted emissions becomes smaller yearly, as do the environmental benefits of PV panels.

5.2. Climate Zone Impact: Orientation and Angle of Solar Panels

The optimal tilt angle for photovoltaic (PV) panels varies based on the geographic location, the precise latitude, and the desired seasonality of energy production. For locations in the northern hemisphere, the optimal tilt angle is often recommended to be close to the latitude angle of the site for year-round performance. For example, at a northern latitude of 60° (Canada, Norway, Sweden), a tilt angle close to 60° is generally considered optimal. This angle maximizes the annual energy capture by aligning the panel perpendicularly to the average solar path over the year.

The optimal tilt angle may be adjusted for applications prioritizing seasonal performance. For instance, in winter, increasing the tilt angle by 10–15° beyond the latitude angle allows for higher energy capture when the sun is lower in the sky. Conversely, in summer months, a tilt angle 10–15° below the latitude angle can optimize the performance when the sun is higher.

Equatorial regions’ optimal angle is typically low or close to horizontal to maximize the exposure to direct sunlight throughout the year. Near the poles, where sunlight is minimal in winter, adjustments are less impactful, but steeper tilt angles are generally used to capture low-angle sunlight.

Cloud cover affects the number of hours of brightness while using solar energy, which is particularly relevant in cold climates with limited solar energy usage. Cloudy conditions result in diffused light, causing surfaces in all directions, including those opposite to the sun, to contribute similarly to the solar energy yield.

In façade-integrated PV systems, however, panels are often installed at a fixed 90-degree angle relative to the ground, which presents unique challenges in optimizing the solar gain. While such vertical installations may capture less direct sunlight compared to optimally tilted panels, they have the advantage of an extensive surface area on façades, particularly in mid- to high-rise buildings. This allows for a more comprehensive collection area and potential energy generation, which can be significant despite the lower irradiance at such angles. Advanced modeling and orientation techniques for façade-integrated PV systems continue to improve the energy capture and efficiency, even under these suboptimal tilt conditions, underscoring the potential of façade PV to contribute meaningfully to building energy requirements.

5.3. Solar Façade Classification and Technologies in Recent Literature

Solar façades are classified into opaque and transparent/semi-transparent types, with the former designed to reject or absorb solar heat. At the same time, the latter can integrate photovoltaic (PV) and/or thermal solar systems [30,139].

PV modules can be integrated into buildings through various technical arrangements, including roofs, façades, and sun screening, each aiming to improve the power efficiency and reduce air conditioning use [140].

The main types of PV cells include single-crystal, multi-crystalline silicon, amorphous, and thin films, each with different semiconductor materials and manufacturing methods [141]. Over the past decade, perovskite solar cells have achieved significant efficiency improvements, reaching over 25% in laboratory settings and comparable to traditional silicon-based cells. One of the key advantages of perovskite cells is their flexibility, which allows them to be applied to various substrates, including flexible films, and integrated into building materials such as window glass [142] and façades, a potential breakthrough for BIPV applications. Their low-temperature, solution-based manufacturing process reduces the production costs and energy input, making them an attractive option for large-scale deployment. However, perovskite cells face challenges, particularly with stability and long-term durability [143], as they can degrade under exposure to moisture, heat, and UV light [144]. Researchers are actively exploring methods to improve their stability, such as encapsulation techniques and hybrid materials, aiming to make perovskites commercially viable for widespread use [145,146]. The potential for perovskite–silicon tandem cells, which combine perovskites with silicon to overcome the single-junction efficiency limits, is also a promising area of research, with prototypes demonstrating efficiencies of over 30% [147].

5.4. Esthetics

The color, texture, and surface gloss of colored photovoltaics significantly impact their esthetic quality, and angular sensitivity experiments have been conducted to provide architectural design guidelines for façade-integrated photovoltaics [148].

6. Conclusions

6.1. Economic Viability

Solar PV panels are predominantly used on rooftops due to the shorter payback periods compared to façade installations. Rooftop PV systems achieve economic viability with payback times as low as 8–10 years on average for residential buildings and 6–9 years for commercial and industrial buildings [149,150], while, in industrial PV systems with 100% self-consumption, a payback time of less than 4 years can be achieved [151]. Façade-integrated BIPV systems often require 13–18 years to break even [84,152]. However, façade systems benefit from extended operational lifespans due to reduced exposure to environmental degradation. In cold climates, façade panels offer additional advantages, such as snow-free operation and reduced maintenance costs.

6.2. Social Acceptance and Esthetics

Public perception remains a critical barrier to BIPV adoption. While color, texture, and transparency customization options have improved the visual integration of solar façades, these enhancements often reduce the efficiency and increase the costs. Balancing esthetics with energy performance and affordability is necessary to enhance their social acceptance and accelerate the adoption of façade PV technologies.

6.3. Mechanical and Thermal Stability

BIPV systems face stringent mechanical resistance and watertightness requirements, particularly for façade applications. These panels must meet the dual criteria of structural stability and maintainability. Thermal performance is another challenge, as façade installations can suffer from efficiency losses of up to 10% due to limited ventilation. Improved integration designs, such as ventilated rain screens, can mitigate these losses.

6.4. Longevity and Life Cycle Impacts

While PV systems have a projected lifespan of 25–30 years, operational factors such as degradation and maintenance requirements reduce their effectiveness over time. Façade systems, with their lower exposure to environmental stressors, can last longer than rooftop PVs. However, embodied carbon emissions and the increasing demand for low-carbon construction materials emphasize the need for comprehensive life cycle assessments.

6.5. Climate-Specific Considerations

The performance of solar façades is highly influenced by the climatic zone. In northern latitudes, façade-mounted panels with steep angles optimize solar capture and mitigate snow accumulation, but are challenged by shading issues. In contrast, tilt and orientation adjustments are crucial in maximizing their performance in equatorial and temperate regions. Additionally, the effect of diffused light under cloudy conditions remains an underexplored phenomenon. To enhance the performance, particularly for non-ideal installations such as vertical façades, advanced modeling and simulation tools are vital.

6.6. Technological Innovations

Emerging technologies like perovskite solar cells and tandem solar cells show significant potential for BIPV applications but face challenges related to technical maturity and market readiness. Perovskite solar cells have achieved over 25% efficiency in lab settings but suffer from stability issues, moisture sensitivity, and toxic lead content. Efforts to address these include improved encapsulation and lead-free formulations, although scalability and cost reduction remain key hurdles. Tandem solar cells, particularly perovskite–silicon hybrids, offer efficiencies above 30%, but the manufacturing complexity, material compatibility, and high production costs limit their commercial viability. Overcoming these challenges through continued research and industry collaboration is critical for their widespread adoption in BIPV systems.

6.7. Esthetic Design Implications

The esthetic quality of façade-integrated PV systems is increasingly emphasized. Color, surface gloss, and texture are key in architectural integration. Ongoing research into angular sensitivity and design guidelines aims to balance esthetics with energy efficiency, facilitating wider adoption. The potential for customizable PV panel designs and the integration of innovative materials may allow for more flexible and visually appealing solutions, addressing both esthetic and functional needs.

6.8. Policy and Market Implications

Supportive policy frameworks and incentives are crucial in improving the economic feasibility of BIPV systems. Strong incentives in colder regions demonstrate how policy can offset lower solar potential and drive adoption. Broader market strategies must address barriers such as high upfront costs and regulatory requirements to enable the more widespread deployment of solar façade technologies. The current policies on electricity tariffs, which often support solar energy production, cannot directly support BIPV systems. These policies typically provide incentives or subsidies for solar power generation in general, without distinguishing between traditional rooftop PV and building-integrated photovoltaic (BIPV) systems. As a result, while BIPV systems can benefit from such policies, they do not receive specific support tailored to their unique costs and integration challenges. Therefore, for BIPV systems to become more economically viable, additional targeted policy measures that address their higher initial costs, as well as incentives for building integration, would be necessary.