Building Integrated Photovoltaic Research Articles

A Review on Transparent Electrodes for Flexible Organic Solar Cells

Flexible organic solar cells (FOSCs) represent a promising and rapidly evolving technology, characterized by lightweight construction, cost-effectiveness, and adaptability to various shapes and sizes. These advantages render FOSCs highly suitable for applications in diverse fields, including wearable electronics and building-integrated photovoltaics. The application scope of FOSCs necessitates electrodes with properties such as high optical transmittance, low electrical resistivity, and exceptional mechanical strength, where their selection significantly influences the overall device performance. This review explores several materials, focusing on polymers, carbon nanomaterials, and metal nanowires, highlighting their unique advantages and challenges in FOSC applications. Through this thorough review, we would like to elucidate the relationship between electrode materials and device performance, thereby inspiring further improvements and developments in FOSCs and broadening their application range.

Analysis of energy performance and load matching characteristics of various building integrated photovoltaic (BIPV) systems in office building

Building Integrated Photovoltaic (BIPV) is a key technology for achieving zero-energy buildings by generating electricity and reducing energy consumption. Although many studies have analyzed the impact of BIPV on building energy efficiency, there is a lack of comprehensive comparative analysis of various BIPV systems. This study compared the impact of various BIPV systems on office building energy performance and provided optimal solutions for different climate zones. Simulation models for PV rooftop, PV window, and PV shading systems were developed and validated in EnergyPlus. The energy performance of BIPV systems in different Chinese climates was evaluated using these models. The results show that the PV window and PV shading have the most power generation capability in Beijing, and the PV rooftop has the most power generation capability in Kunming. Energy savings in Kunming are the highest with PV rooftop, PV windows, and PV shading at 111.78 %, 39.36 %, and 44.43 %, respectively. Finally, the study calculated the self-sufficiency rate (SSR) and self-consumption rate (SCR), and their ratio, along with the load matching ratio, were used to assess loading matching. Optimal BIPV schemes were identified for each climate zone, revealing that the PV rooftop combined with the PV shading system achieved the best load matching in Kunming, Guangzhou, Changsha, Beijing, and Harbin, with ratios of 82.00 %, 69.38 %, 70.88 %, 74.78 % and 67.27 %, respectively. These results provide a valuable reference for implementing the BIPV system to achieve zero energy consumption in office buildings under different climatic conditions in China.

Investigation of double-PCM based PV composite wall for power-generation and building insulation: Thermal characteristics and energy consumption prediction

The integration of phase change material (PCM) with building-integrated photovoltaic (BIPV) presents a compelling approach to enhance solar energy utilization and mitigate indoor thermal loads, contributing to energy-efficient and low-carbon building development. Traditional BIPV-PCM structures, however, struggle to balance PV efficiency and thermal insulation, particularly with varying PCM wall positions. To address this situation, this study introduces a novel double-PCM BIPV composite envelope (BIPV-dPCM). An experimentally validated dynamic heat transfer model was developed and used to perform a comparative simulation analysis with three reference systems to quantify the energy-saving potential of the BIPV-dPCM, focusing on PV output and wall insulation effectiveness metrics. Further dimensionless parametric analysis were carried out to investigate the systematic performance of the two PCMs at different relativities. In addition, the coupled working mechanism of the BIPV-dPCM system concerning the power generation performance and thermal insulation performance under transient variations is explored. It was found that the BIPV-dPCM showcases superior thermoelectric coupling performance compared to three alternative enclosures. Incorporating two PCMs significantly enhances electrical exergy efficiency by 11.66 % and thermal exergy efficiency by 1.54 %, surpassing other reference systems. The increase in PCM latent heat ratio has a limited effect on performance gain. Notably, as the PCM thickness ratio exceeds 1, the decline in P value decelerates, for every 0.5 increment in the g, the P value diminishes by merely 0.2 %. The ideal h is identified between 1 and 1.5, with 1.5 being optimal for energy conservation objectives. Additionally, the self-sufficiency coefficient (SSC) of the BIPV-dPCM remains robust, sustaining a range of 55 % to 65 % over prolonged periods. This study offers novel perspectives and serves as a design reference for optimizing building energy systems and enhancing cooling efficiencies in subtropical climates.

Simulation of perovskite solar cell with transparent contacts for solar windows

In recent years, halide-based perovskite solar cells (PSC) have caught worldwide attention since their power conversion efficiency (PCE) has surpassed 25% with low fabrication cost and high scalability. The semi-transparent PSC (ST-PSC) is suitable for building-integrated photovoltaic (BIPV) applications, especially for solar windows. The ST-PSC must demonstrate a reasonable balance between PCE and transparency in the visible region for solar windows, which is inversely proportional to each other. This work studies ST-PSC based on methylammonium lead triiodide (MAPbI3) as solar windows using the General-Purpose Photovoltaic Device Model (GPVDM) and OPAL 2 as the simulation platforms. Parameters such as methylammonium lead triiodide (MAPbI3) thickness, silver (Ag) contact thickness and indium tin oxide (ITO) transparent contact thickness are investigated in relation to the PCE and average visible transmission (AVT). The results demonstrate that the ST-PSC with MAPbI3 thickness of 500 nm and ITO bottom transparent contact of 100 nm leads to PCE of 22.85% and AVT of 11.36%. These parameters represent the best results obtained in this work.

Enhancing Light Utilization Efficiency of Semi‐Transparent Perovskite Solar Cells via Tailored Interfacial Engineering

AbstractSemi‐transparent perovskite solar cells (ST‐PSCs) are promising for their application in building integrated photovoltaics (BIPVs). For BIPVs, a light utilization efficiency (LUE) > 2.5 is required which is multiplication of average visible transmittance (AVT) and power conversion efficiency (PCE). Generally, semitransparency is achieved by reducing film thickness which increases AVT but decreases PCE resulting in lower LUE. Here, an interface engineering strategy is employed on a wide bandgap perovskite thin absorber layer to increase PCE and LUE. The study employs three different alkylamine hydrochlorides molecules with varied alkyl chain length, viz., 2‐chloroethylamine‐hydrochloride, 3‐chloropropylamine‐hydrochloride, and 4‐chlorobutyalamine‐hydrochloride at perovskite/electron transport layer (ETL) interface and investigates their effect on perovskite crystallization. Further, it is demonstrated that 4‐chlorobutyalamine‐hydrochloride can strongly interact with perovskite and suppress non‐radiative recombination facilitating charge transport at the perovskite/ETL interface. Devices post‐treated with 4‐chlorobutyalamine‐hydrochloride interfacial layer, demonstrate a higher LUE of 3.45% (PCE 14.11%) and AVT of ≈25% (400–800 nm), with Voc of 1.23 V. Moreover, the unencapsulated devices retain ≈89% of the initial efficiency after storage for 1500 h under a relative humidity of ≈35–40%. This study provides an efficient approach to improve LUE and stability of ST‐PSCs for the application in energy‐efficient smart windows.

Performance analysis and optimization of insulation layers on a novel building-integrated photovoltaic system

Conventional photovoltaic-thermoelectric generator (PV-TEG) systems are hindered by significant heat transfer losses, which impair power generation throughout the year. Addressing this challenge, a novel PV-MCHP-TEG system is proposed, integrating photovoltaic (PV) cell, microchannel heat pipe (MCHP) array, and thermoelectric generator (TEG) module components with strategically placed insulation layers to facilitate year-round, day-and-night power generation. This study primarily investigates the impact of insulation layers on heat transfer processes, employing a comprehensive analysis and optimization approach. Utilizing Simulink software, the multifaceted influence of insulation layer variables, including locations, thicknesses, and materials, on TEG efficiency across various conditions was examined. Further, a comparative analysis was undertaken to evaluate the dynamic payback period across different modes. The optimization of these insulation parameters revealed that incorporating Polyisocyanurate Foam (PIR) as the insulation material in the optimized PV-MCHP-TEG system achieved an efficiency of 19.32 %, marking a 2.41 % improvement over conventional PV-TEG systems without insulation. Furthermore, the dynamic payback period was reduced to 11.34 years, representing a decrease of 1.05 years compared to conventional PV-TEG systems. These findings underscore the potential of our proposed system to outperform existing solutions by optimizing thermal management through insulation, thereby offering a promising avenue for enhancing photovoltaic-thermoelectric energy conversion.

Functional ventilation building envelope integrated photovoltaic modules and phrase change material in subtropical climate: An in-depth numerical investigation

Most of existing solar ventilation envelope systems adopt a single structure including a glass cover a massive wall, which possesses the drawbacks of low thermal efficiency and poor stability. In recent decades, auxiliary power generation devices, led by photovoltaic (PV), have made epochal achievements in integrated building applications, while the superior thermal regulation capability of thermal storage materials, represented by phrase change materials (PCM), has further helped to improve the thermal environment of buildings, and the above two technologies have demonstrated great energy conservation potential. In order to explore the application and synergistic effect of the above two energy-conservation technologies in passive ventilation envelopes, a novel functional ventilation building envelope (FVBE) integrated with PV panel and PCM is proposed in this paper. A comprehensive exploration of the influence of various key parameters on the thermal performance of the FVBE-PV/PCM system. The electrical and thermal performance of the system is explored based on different seasonal climates. Specifically, effects of thickness as well as the melting temperature of PCM and the air channel width has been provided in this study. Taking the inner wall surface temperature (Tinner_wall), equivalent indoor load (Qload) and electrical efficiency (ηe) as evaluation indexes, the thermal efficiency, electrical performance and the coupling mechanism was assessed. Specifically, the coupling mechanism between the thermal performance and electrical performance of the FVBE-PV/PCM system was analyzed from the perspective of combined heat and power, revealing the functional characteristics of the system. Meanwhile, the article conducted a comparative study on the thermal and electrical performance of a typical building integrated PV (BIPV), FVBE-PV system FVBE-PV/PCM system. In particular, energy and exergy analysis is carried out to characterize the energy utilization of the FVBE-PV/PCM system in different structural systems. The research found that increasing the thickness of both the PCM and air channel leads to lower indoor temperature and heat flux, with different optimal phase transition temperatures for summer and winter. Although the FVBE-PV system exhibited a maximum 3.12 % reduction in power generation efficiency compared to the BIPV system due to increased PV temperature caused by air layer insulation, incorporating PCM can reduce exergy losses by an average of 31.731 % to mitigate this drawback and improve energy efficiency. Additionally, the analysis revealed varying coupling correlations between thermal performance and power generation based on two key parameters. This study could contribute to the functional improvement of the building envelope and simultaneous indoor thermal regulation.

Component-based SHGC determination of BIPV glazing for product comparison

Building-integrated photovoltaic (BIPV) systems are intrinsically designed to generate electricity and to provide at least one building-related function. When BIPV modules act as glazing products in windows, skylights or curtain walls, their ability to control the transmission of solar energy into the building must be characterised by a Solar Heat Gain Coefficient (SHGC) or g value (also known as Total Solar Energy Transmittance – TSET – or “solar factor”). For the comparison of BIPV glazing products consisting of one PV laminate and possibly further, conventional glazing layers separated by gas-filled cavities, the procedures documented in international standards for architectural glazing (e.g. ISO 9050 and EN 410) form a suitable starting point. Easily implemented modifications to these procedures are proposed to take both optical inhomogeneity (if relevant) and extraction of electricity from BIPV glazing units into account. Geometrically complex glazing and shading devices, and light-scattering glazing layers, are outside the scope of the proposed methodology; SHGC determination for obliquely incident solar radiation is also excluded. For these cases, the experimental calorimetric approach documented in [ISO 19467:2017; ISO 19467-2:2021] is recommended.The paper also presents results and conclusions from an implementation exercise and sensitivity study carried out by participants of the IEA-PVPS Task 15 on BIPV. The cell coverage ratio in the PV laminate, the thermal resistance offered by the glazing configuration, the choice of boundary conditions and the effect of extracting electricity were all identified as parameters which significantly affect the SHGC value determined for a given type of BIPV glazing. A practicable approach to accommodate the great variety of dimensions typical for BIPV glazing is also proposed. These findings should pave the way for modifying the existing component-based standards for architectural glazing to take the specific features of BIPV glazing into account.

Enhancing Industrial Buildings’ Performance through Informed Decision Making: A Generative Design for Building-Integrated Photovoltaic and Shading System Optimization

Enhancing Industrial Buildings’ Performance through Informed Decision Making: A Generative Design for Building-Integrated Photovoltaic and Shading System Optimization

Research on the virtual design and implementation of colored glass for BIPV

In this study, we proposed a design and implementation method to display various high-saturation colors of Building Integrated Photovoltaics (BIPV) modules. The color reproduction results were compared and analyzed through simulations, using two methods, physical thickness and reflectance spectrum to reproduce RGB colors of Fraunhofer ISE’s (Germany) color BIPV module, a leading research institute. To achieve colored glass, a single-layer structure of Nb2O5 was simulated on the glass and deposited by the PVD sputtering method. Through this approach, we successfully produced an array of clear color glass. We performed simulations to attain RGB colors through a multi-layer structure model. We investigated the effects of key factors such as material, thickness, and the number of layers (SiO2, Si3N4, Nb2O5, TiO2) on reflectance and color attainment. Finally, assuming a color module deposited with a triple-layer structure of Nb2O5/SiO2/Nb2O5 was installed in a real building, the expected annual power generation was simulated and compared with the normal BIPV module.

Building-Integrated Photovoltaics in Existing Buildings: A Novel PV Roofing System

Among renewable energy generation technologies, photovoltaics has a pivotal role in reaching the EU’s decarbonization goals. In particular, building-integrated photovoltaic (BIPV) systems are attracting increasing interest since they are a fundamental element that allows buildings to abate their CO2 emissions while also performing functions typical of traditional building components, such as sealing against water. In such a context, since one of the main challenges to decarbonizing the building sector lies in the retrofitting of existing buildings, the current paper is focused on the design, development, and testing of a novel roofing BIPV system. The entire research was carried out as part of the Horizon 2020 HEART project. In more detail, the research analyzed the requirements of typical pitched tile roofs, which are currently the most common type in Europe, and developed a universal photovoltaic tile that can be easily and quickly integrated into such a type of roof. The research was also aimed at minimizing the embodied energy of the component and promoting disassembly and recycling at the end of life, fully in line with a circular economy perspective. The adopted design and development processes are described in detail in the present paper, along with the results of several tests performed in the field. In addition, further development prospects of the component, aimed at meeting the integration requirements in historic buildings, are finally presented.

Comparative analysis of steel bar structures of solar canopies composed of hyperbolic paraboloid units using genetic algorithms

Building integrated photovoltaics (BIPV) understood as an integral building component, is becoming more and more popular. In turn, the use of BIPV on curvilinear roofs is an interdisciplinary issue covering geometry, environmental engineering, architecture and construction. The article presents an approach to designing efficient steel bar structures of the modular solar canopies using genetic algorithms and their evaluation. Shaping effective forms of solar roofs was subordinated to the idea “form follows environment” in the original way as the roof form, and thus the shape of the structure depended on the amount of solar energy absorbed by the roof surface. The structures designed on a regular polygon plan were created from three, four, five, or six hyperbolic paraboloid (HP) modules arranged radially. Algorithmic definitions of their forms made it possible to obtain many variants of canopies with the adopted preliminary criteria, as well as to conduct genetic optimization, which helped to obtain the best results. For the best solutions in terms of geometrical forms, structural optimization was carried out due to the structures’ minimum masses. As a comparative criterion of structural effectiveness, a coefficient was used that specified the mass of the considered structure per square meter of the covered area. The proposed shaping method may constitute some guidelines for rational shaping of the steel bar structures with radially arranged modules, in which their effectiveness can be established already at the initial design stage. However, the best optimization results, that is, efficient and aesthetic canopies, can be ecological solutions to be used in practice.

Environmental and economic evaluation of urban building-integrated photovoltaic and electric vehicle system

Facade photovoltaic (FaPV) panels can significantly enhance the capability of building-integrated photovoltaic (BIPV) systems. This study presents a comprehensive analytical framework for optimizing the operation of BIPV and electric vehicle (EV) integrated systems and evaluating their environmental and economic benefits. The Energy-Environmental-Economic (3E) parameters are measured for alternative scenarios, and sensitivity analyses are applied to validate the impacts of changes in major parameters on BIPV-EV system's performance in Xiong'an New Area (XANA). The simulation results demonstrate that BIPV-EV systems can effectively reduce CO2 emissions and electricity costs. Specifically, the installation of FaPV can increase power generation by up to 67.60 % compared to the BIPV system utilizing stand-alone rooftop photovoltaic (RPV). Regarding urban decarbonization, the adoption of BIPV system can reduce CO2 emissions by 41.91 % and 34.99 % in the short- and long-term, respectively. The evaluation of the levelized cost of energy (LCOE) across different scenarios reveal that the configurations of RPV + FaPV (SE)-EV system and RPV + FaPV (SW)-EV system are the most cost-effective options in both the short- and long-term, where BIPV contributes to 48.10 % and 31.90 % of the total electricity generation, respectively. In terms of EV power consumption, the BIPV-EV system can decrease the grid sell ratio by 15.38 % compared to the stand-alone BIPV scenario. Compared to the BIPV system with typical RPV, the appropriate utilization of FaPV can significantly increase the potential of a BIPV system and mitigate the additional electricity demand for EVs. For cities with nascent BIPV and EV markets, the proposed framework can be a strategic tool for urban planners to design BIPV-EV systems, with the objective of enhancing sustainability and energy efficiency.

Machine learning applications for predicting liquid fraction in a PV system with NEPCM and fins

The heat-absorbing and heat-releasing properties of phase-change materials (PCMs) at specific temperatures make them ideal for improving the thermal management of solar systems. Thermal conductivity of PCMs is increased when combined with nanoparticles, leading to significant improvements of their ability to manage and transfer heat efficiently. The objective of this article is to anticipate liquid fraction (LF) with a suitable level of accuracy by utilizing machine learning predictive models in a building-integrated photovoltaic (PV) system. Four different system configurations were proposed, namely PCM without fins, PCM with longitudinal fins, PCM with the additional of nanomaterials and longitudinal fins, and PCM with the additional of nanomaterials and Y-shaped fins. After accomplishing the numerical simulation data, in order to save computational cost and maintain accurate predictions, the following models were chosen to accomplish this objective: linear regression, lasso regression, polynomial regression, and an Auto-Regressive Integrated Moving Average (ARIMA) model. Then, the comparison of them in all cases, using the root mean squared error (RMSE), as well as mean absolute error (MAE). The ARIMA model had superior performance in predicting PCM LF, achieving an RMSE of 0.0149 and an MAE of 0.0093. This technique has been used to predict the LF of the other situations. The results indicated that the case incorporating PCM with the inclusion of nanoparticles and longitudinal fins exhibited the shortest time required to reach the LF value of 1. The approach used in this study reduces the reliability on computationally expensive simulations, which provides a more efficient method for optimizing PV systems. The study also highlights the potential of machine learning to enhance thermal management of PV cells, contributing to more efficient and sustainable energy solutions.

Solar Window Innovations: Enhancing Building Performance through Advanced Technologies

Building-integrated photovoltaic (BIPV) glazing systems with intelligent window technologies enhance building energy efficiency by generating electricity and managing daylighting. This study explores advanced BIPV glazing, focusing on building-integrated concentrating photovoltaic (BICPV) systems. BICPV integrates concentrating optics, such as holographic films, luminescent solar concentrators (LSC), Fresnel lenses, and compound parabolic concentrators (CPCs), with photovoltaic cells. Notable results include achieving 17.9% electrical efficiency using cylindrical holographic optical elements and crystalline silicon cells at a 3.5× concentration ratio. Dielectric CPCs showed 97.7% angular acceptance efficiency in simulations and 94.4% experimentally, increasing short-circuit current and maximum power by 87.0% and 96.6%, respectively, across 0° to 85° incidence angles. Thermochromic hydrogels and thermotropic smart glazing systems demonstrated significant HVAC energy savings. Large-area 1 m2 PNIPAm-based thermotropic window outperformed conventional double glazing in Singapore. The thermotropic parallel slat transparent insulation material (TT PS-TIM) improved energy efficiency by up to 21.5% compared to double glazing in climates like London and Rome. Emerging dynamic glazing technologies combine BIPV with smart functions, balancing transparency and efficiency. Photothermally controlled methylammonium lead iodide PV windows achieved 68% visible light transmission, 11.3% power conversion efficiency, and quick switching in under 3 min. Polymer-dispersed liquid crystal smart windows provided 41–68% visible transmission with self-powered operation.

Study on the Optical Coupling Effect of Building-Integrated Photovoltaic Modules Applied with a Shingled Technology

Building-integrated photovoltaics (BIPV) comprise the integration of a solar power generation system into the exterior design and architectural elements of a building to produce electricity, which allows the building itself to generate electricity. By integrating shingled technology into the photovoltaic module with optimization of the optical effect, the output performance of the module can be increased while securing an aesthetic appeal as an architectural exterior material for the building simultaneously. In this research, we studied enhancing the performance of BIPV modules through an analysis of the optical coupling effect for shingled technology using PSpice simulation. Compared to the efficiency of 0.2 cm string spacing, the optical coupling effect was increased by 33.33%, 46.98%, 67.01%, and 193.49% according to the string spacing of 0.5 cm, 1 cm, 2 cm and 4 cm, respectively. To analyze this increase, we focused on studying the increase in current due to the reflection and re-absorption of light in the back layer of the solar cell as the cause of this output enhancement. Additionally, the coupling effect in accord with different layers showed that using white EVA to reflect the incident light from the top layer resulted in 117.14% and 521.90% enhancements in maximum output power (Pm) loss % compared to the conventional and black backsheet applied PV modules, respectively.

Digitalising BIPV energy simulation: A cross tool investigation

The long-term viability of Building Integrated Photovoltaics (BIPV) as a renewable energy technology has garnered increased attention in recent discussions. However, there is currently a noticeable absence of simulation tools specific to BIPV applications that can cover the whole modelling chain. It remains unclear to what extent existing PV and BIM-based simulation tools can effectively address the complexities of BIPV projects. Therefore, this study aims to assess the process of existing simulation tools for BIPV energy simulation, three standalone PV tools (SAM, PV*SOL premium, and PVsyst), two Building Information Modelling (BIM)-based standalone PV tools (BIMsolar and Solarius PV), two plug-ins in BIM-based tools (INSIGHT for Revit, Ladybug Tools for Grasshopper/Rhinoceros 3D), and one Computer-Aided Design and Drafting (CADD) tool plugin (Skelion for Sketchup). Based on one existing building project with three different types of BIPV-installations, this study explored the capability of these eight tools in modelling/importing building geometry, selecting weather data, setting system layout and array, evaluating the solar resource, estimating energy losses, and assessing energy generation. The simulation results are compared with monitored energy yield data and presented with deviation analysis. Suggestions focus on pointing out the future development directions for BIPV digital simulation. This study offers insights and guidance for digitalising the BIPV performance simulation in the complex building design.

Multi-objective optimization of building integrated photovoltaic windows in office building

Building-Integrated Photovoltaics (BIPV) offer a promising solution to enhance building energy efficiency and reduce building energy consumption. Among the various application of BIPV, BIPV windows stand out as an intriguing and notable example. This paper investigates an office building with BIPV windows in five different climatic cities in China. The study considers four variables, including building orientation (BO), window size (WZ), window visible light transmittance (VLT), and type of PV (TOPV). The objective is to minimize both the annual net electricity cost (ANEC) and the extra investment cost of BIPV windows. To simulate the design variables and objective functions, the jEPlus software is employed. Additionally, the jEPlus + EA software uses the SRC and Morris algorithms for sensitivity analysis of design parameters. The multi-objective problem is addressed using the NSGA-II. By conducting optimization, a set of Pareto optimal solutions were obtained. The results demonstrate that the building with BIPV windows can save a minimum of 6.83 % annual electricity costs. Moreover, the static investment payback period for all cities ranges from 7 to 14 years, indicating the economic feasibility of implementing BIPV windows.

Vertical perovskite solar cell envelope for the circular economy: A case study using life cycle cost analysis in Europe

Recent technological developments make perovskite solar cells (PSCs) particularly suitable for building integrated photovoltaic (BIPV) applications on vertical building envelopes, but the relatively short lifespan of PSCs requires frequent replacement, thereby generating substantial waste. Careful consideration of circularity credentials of this novel technology is therefore essential prior to the extensive implementation of vertical PSCs in building envelopes. This paper provides a circular economy approach for the implementation of PSCs in vertical envelopes and assesses its economic feasibility by life cycle cost analysis in Europe. The process of recycling PSC is developed. The economic performance of PSC envelopes is provided and compared to that of the conventional rigid BIPV system. Uncertainty analysis and sensitivity analysis of economic indicators are then performed to identify the influential parameters. The findings indicate that the PSC envelope has a significant potential for circular BIPV components and that PSCs applied on vertical envelope are economically viable.

Building Integrated Transparent Photovoltaic as a Strategy Towards Net Zero Energy Building in the Tropics

Previous studies have found the potential of Building Integrated Photovoltaic (BIPV) implementation on vertical facades. The implementation was suggested for buildings with a minimum of 45 percent window-to-wall ratio (WWR). This number is quite challenging for tropical buildings where the suggested WWR ranges around 20 to 40 percent. Furthermore, the installation may appear less efficient due to the lower irradiance received on tropical vertical facades. Given the abundance of vertical facades in tropical high-rise buildings, there exists an opportunity to offset power reduction. Therefore, this study aims to determine the feasibility, influencing factors, and approach for installing building-integrated thin film transparent photovoltaics (BITPV) in tropical regions, focusing on energy production. The objective is achieved through a combination of literature review and simulation. Three layout configurations on three different geographical locations, which present a typical classroom module for school buildings, are observed. Treatment is applied based on orientation, WWR, and the cell coverage ratio. The feasibility is shown by at least 23 percent energy substitution promoted by several configurations. East is suggested for classrooms with 1:1 and 3:2 modules, while north is suggested for classrooms with 2:3 modules. For buildings with minimum WWR (20 percent), TPV installation with ≥40 percent cell coverage ratio (on the specified orientation) is suggested to achieve the mixenergy use target. Additionally, this study presents the influencing factors and design approach for BITPV to provide a comprehensive understanding of the subject.