Semitransparent Photovoltaics Research Articles

Smart and Solar Greenhouse Covers: Recent Developments and Future Perspectives

The examination of recent developments and future perspectives on smart and solar greenhouse covers is significant for commercial agriculture given that traditional greenhouse relied on external energy sources and fossil fuels to facilitate lighting, heating and forced cooling. The aim of this review article was to examine smart and solar materials covering greenhouse. However, the scope was limited to intelligent PhotoVoltaic (PV) systems, optimization of some material properties including smart covers, heat loading and the use of Internet of Things (IoT) to reduce the cost of operating greenhouse. As such, the following thematic areas were expounded in the research; intelligent PV systems, optimization of the Power Conversion Efficiency (PCE), Panel Generator Factor (PGF) and other material properties, heat loading future outlook and perspectives. The intelligent PV section focused on next-generation IoT and Artificial Neural Networks (ANN) systems for greenhouse automation while the optimization of material parameters emphasized quantum dots, semi-transparent organic solar cells, Pb-based and Pb-based PVs and three dimensional (3D) printing. The evaluation translated to better understanding of the future outlook of the energy-independent greenhouse. Greenhouse fitted with transparent PV roofs are a sustainable alternative given that the energy generated was 100% renewable and economical. Conservative estimates further indicated that the replacement of conventional sources of energy with solar would translate to 40–60% energy cost savings. The economic savings were demonstrated by the Levelized cost of energy. A key constraint regarded the limited commercialization of emerging innovations, including transparent and semitransparent PV modules made of Pb-quantum dots, and amorphous tungsten oxide (WO3) films, with desirable electrochromic properties such as reversible color changes. In addition to intelligent energy harvesting, smart IoT-based materials embedded with thermal, humidity, and water sensors improved thermal regulation, frost mitigation and prevention, and the management of pests and disease. In turn, this translated to lower post-harvest losses and better yields and revenues.

Carrier transport and performance limit of semi-transparent photovoltaics: CuIn1−xGaxSe2 as a case study

Semi-transparent photovoltaic devices for building integrated applications have the potential to provide simultaneous power generation and natural light penetration. CuIn1−xGaxSe2 has been established as a mature technology for thin-film photovoltaics; however, its potential for Semi-Transparent Photovoltaics (STPV) is yet to be explored. In this paper, we present its carrier transport physics explaining the trend seen in recently published experiments. STPV requires deposition of films of only a few hundred nanometers to make them transparent and manifests several unique properties compared to a conventional thin-film solar cell. Our analysis shows that the short-circuit current, Jsc, is dominated by carriers generated in the depletion region, making it nearly independent of bulk and back-surface recombination. The bulk recombination, which limits the open-circuit voltage Voc, appears to be higher than usual and attributable to numerous grain boundaries. When the absorber layer is reduced below 500 nm, grain size reduces, resulting in more grain boundaries and higher resistance. This produces an inverse relationship between series resistance and absorber thickness. We also present a thickness-dependent model of shunt resistance showing its impact in these ultra-thin devices. For various scenarios of bulk and interface recombinations, shunt and series resistances, AVT, and composition of CuIn1−xGaxSe2, we project the efficiency limit, which—for most practical cases—is found to be ≤10% for AVT≥25%.

Experimental and numerical study on the annual performance of semi-transparent photovoltaic glazing in different climate zones

Semi-transparent photovoltaic (STPV) glazing can beautify the architectural appearance, generate power in-place. However, few researches study the climate adaptability of monocrystalline silicon STPV glazing. For the STPV glazing system, this paper develops a multi-physics model including the solar radiation, optical, electrical, and thermal models to analyze its overall performance. The model is validated by experiment. The performance of the STPV glazing system with different solar cell coverage ratios (R) in various climate zones of China (Guangzhou, Changsha, Kunming, Lhasa, and Beijing) is also studied. Among the five cities, the energy output of the STPV glazing system is proportional to the R value, and all follow approximately the same trend as the incident solar radiation. However, the geographic latitude has a greater impact on the electrical performance of the STPV glazing system than solar radiation. The thermal performance is primarily affected by the ambient temperature. The STPV glazing system performs well in the temperate area, with low cooling demand and high annual energy output. Compared with the traditional single clear glazing, the overall performance of the STPV glazing system is better, especially when the large solar cell coverage ratio. This paper provides a research basis for application in different climate zones.

Wide Bandgap Polymer with Narrow Photon Harvesting in Visible Light Range Enables Efficient Semitransparent Organic Photovoltaics

AbstractWide bandgap polymer D18 with narrow photon harvesting in visible light range and small molecule N3 with near‐infrared photon harvesting are adopted for building semitransparent organic photovoltaics (OPVs). To find out the optimal D18:N3 weight ratio for semitransparent OPVs, series of opaque OPVs are built with a varied D18:N3 weight ratio. The power conversion efficiency (PCE) and fill factor can be maintained over 16% and 77% in the D18:N3 (0.7:1.6, wt/wt) based opaque OPVs, respectively. The average visible transmittance (AVT) of the corresponding blend films can be achieved over 50%, demonstrating the great potential in fabricating efficient semitransparent OPVs. The semitransparent OPVs based on D18:N3 (0.7:1.6, wt/wt) are fabricated by using 1 nm Au/(10, 15, 20 nm) Ag as cathode. The thickness of Ag layers is varied to balance the optical properties and electrical properties of semitransparent top electrode. The semitransparent OPVs with 10 nm Ag achieve the highest light utilization efficiency of 2.90% with a PCE of 12.91% and an AVT of 22.49%, which should be among the best performance of reported semitransparent OPVs. This work demonstrates that the wide bandgap polymer donor with narrow photon harvesting in visible light range has great potential in preparing efficient semitransparent OPVs.

Comprehensive investigation on the luminous and energy-saving performance of the double-skin ventilated window integrated with CdTe cells

The PV double-skin windows, as an advancing BIPV technology, possess great potential in developing low-energy consumption buildings. However, the Semi-Transparent PV glasses change the indoor illuminance and spectral distribution. Therefore, quantifying the indoor luminous environment and comprehensively evaluating the luminous and energy-saving performance are of great significance to the promotion of PV double-skin windows. In this work, the thermal-electrical-daylight experiment of a double-skin ventilated window integrated with CdTe cells was conducted. Based on the measured spectral data of the CdTe glasses, the color properties and the daylighting performance were predicted. Then, the overall energy performance of the proposed window was simulated using the validated thermoelectric model. Finally, the comparison between the proposed window and some PV windows in the reported literature was performed. The main results were: (1) The SHGCs of the investigated window in winter and summer were 0.28 and 0.11, respectively. Its U-value and daylight factor were 2.05 W/m2K and 0.6%, respectively. (2) CdTe glass could improve indoor luminous performance and lead to a reduction of annual energy consumption. (3) Compared with the reported PV windows, the CdTe-DSV window could meet seasonal thermal demand while providing better color properties.

Concentrating PhotoVoltaic glazing (CoPVG) system: Modelling and simulation of smart building façade

This paper presents an innovative Concentrating Glazing system to be adopted in smart building façades: The Concentrating Photovoltaic Glazing system (CoPVG). The device consists of a double-glazing panel integrating a series of concentrating lenses. A thin layer of PV cells is then placed at the lenses' focus. The peculiar lens design can produce, by using the Total Internal Reflection (TIR), a seasonal effect with more light entering the building at low incidence angles (i.e. in the winter months) and higher electricity production at high incidence angles (i.e. in the summer months). To investigate this device's performance, a suitable dynamic simulation tool has been developed in MATLAB environment. Furthermore, to investigate active (electric energy production) and passive (building insulation and solar gains variations) effects related to the building integrated devices, the developed CoPVG simulation tool is implemented in a building energy performance simulation one (DETECt). To show the potential of the innovative device, a case study relative to a multi-floor office building integrating the innovative CoPVG prototype is investigated. Conventional and semi-transparent PV windows are also investigated for comparative purposes. By using the novel façade system, interesting energy savings ranging from 30 to 60 % for the investigated weather zones can be obtained.

Review on the progress of building-applied/integrated photovoltaic system.

Integration of photovoltaic (PV) technologies with building envelopes started in the early 1990 to meet the building energy demand and shave the peak electrical load. The PV technologies can be either attached or integrated with the envelopes termed as building-attached (BA)/building-integrated (BI) PV system. The BAPV/BIPV system applications are categorized under the building envelope roof and facades as PV-roof, PV-skin facade, PV-Trombe wall, PV claddings, and louvers. This review covers various factors that affect the design and performance of the BAPV/BIPV system applications. The factors identified are air gap, ventilation rate, a tilt angle of PV shading devices, adjacent shading, semitransparent PV (STPV) glazing design, cell coverage ratio (CCR), transmittance, window to wall ratio (WWR), and glazing orientation. Furthermore, the results of the possible factors are compared to building locations. This review article will be beneficial for researchers in designing the BAPV/BIPV system and provides future research possibilities.

Expanded Phase Distribution in Low Average Layer‐Number 2D Perovskite Films: Toward Efficient Semitransparent Solar Cells

AbstractThe application of low average layer‐number (〈n〉 ≤ 2) 2D perovskites in semitransparent photovoltaics (ST‐PVs) has been hindered by their strong exciton binding energy and high electrical anisotropy. Here, the phase distribution is expanded fully and orderly to enable efficient charge transport in 2D (NMA)2(MA)Pb2I7 (NMA: 1‐naphthylmethylammonium, MA: CH3NH3+) perovskite films by regulating the sedimentation dynamics of organic cation‐based colloids. Ammonium chloride is synergistically introduced to enhance the phase separation further and construct a favorable out‐of‐plane orientation. The wide and graded phase distribution well aligns the energy level to facilitate charge transfer. As a result, the first application of an average 〈n〉 = 2 2D perovskite is implemented in ST‐PVs with visible power conversion efficiency (PCE) of 7.52% and high average visible transmittance (AVT) of 40.5%. This study offers a new candidate and an effective strategy for efficient and stable ST‐PVs and is relevant to other perovskite optoelectronic devices.

Design, Development, and Characterization of Low Distortion Advanced Semitransparent Photovoltaic Glass for Buildings Applications

Aesthetic appearance of building-integrated photovoltaic (BIPV) products, such as semitransparent PV (STPV) glass, is crucial for their widespread adoption and contribution to the net-zero energy building (NZEB) goal. However, the visual distortion significantly limits the aesthetics of STPV glass. In this study, we investigate the distortion effect of transparent periodic-micropattern-based thin-film PV (PMPV) panels available in the market. To minimize the visual distortion of such PMPV glass panel types, we design and develop an aperiodic micropattern-based PV (APMP) glass that significantly reduces visual distortion. The developed APMP glass demonstrates a haze ratio of 3.7% compared to the 10.7% of PMPV glass. Furthermore, the developed AMPV glass shows an average visible transmittance (AVT) of 58.3% which is around 1.3 times higher than that of AMPV glass (43.8%). Finally, the measured CIELAB values (L* = 43.2, a* = −1.55, b* = −2.86.) indicate that our developed AMPV glass possesses excellent color neutrality, which makes them suitable for commercial applications. Based on the characterization results, this study will have a significant impact on the areas of smart window glasses that can play a vital role in developing a sustainable environment and enhancing the aesthetical appearance of net-zero energy buildings (NZEB).

Bifacial Color‐Tunable Transparent Photovoltaics for Application as Building‐Integrated Photovoltaics

Transparent photovoltaics (TPVs) have attracted enormous attention due to their potential to be applied as building‐integrated photovoltaics (BIPV). Transparent and semitransparent photovoltaics have achieved a high level of efficiency, but there are still a number of issues that limit their application, such as their device size, lack of stability, and transmittance in the visible wavelength region. The excellent color implementation of a bifacial color‐tunable (BCT) TPV by tuning the indium tin oxide (ITO) thickness is demonstrated. The BCT TPV has a bifacial factor of 97.2% while maintaining an average visible transmittance (AVT) of 41.6%. The use of a 16 cm2 large‐scale TPV device using a dry plasma fabrication process is also demonstrated. This dry process enables large‐scale device production and ensures long‐term device stability. The efficiency improvement with various background colors (blue 14%, red 25%, and white 35%) without any additional installation on the device is also confirmed. The BCT TPV is a promising candidate for BIPV applications due to its wide range of color tunability and excellent double‐sided photovoltaic operation, even under an indoor artificial light.

Semi-Transparent Organic Photovoltaics Applied as Greenhouse Shade for Spring and Summer Tomato Production in Arid Climate

Recognizing the growing interest in the application of organic photovoltaics (OPVs) with greenhouse crop production systems, in this study we used flexible, roll-to-roll printed, semi-transparent OPV arrays as a roof shade for a greenhouse hydroponic tomato production system during a spring and summer production season in the arid southwestern U.S. The wavelength-selective OPV arrays were installed in a contiguous area on a section of the greenhouse roof, decreasing the transmittance of all solar radiation wavelengths and photosynthetically active radiation (PAR) wavelengths (400–700 nm) to the OPV-shaded area by approximately 40% and 37%, respectively. Microclimate conditions and tomato crop growth and yield parameters were measured in both the OPV-shaded (‘OPV’) and non-OPV-shaded (‘Control’) sections of the greenhouse. The OPV shade stabilized the canopy temperature during midday periods with the highest solar radiation intensities, performing the function of a conventional shading method. Although delayed fruit development and ripening in the OPV section resulted in lower total yields compared to the Control section (24.6 kg m−2 and 27.7 kg m−2, respectively), after the fourth (of 10 total) harvests, the average weekly yield, fruit number, and fruit mass were not significantly different between the treatment (OPV-shaded) and control group. Light use efficiency (LUE), defined as the ratio of total fruit yield to accumulated PAR received by the plant canopy, was nearly twice as high as the Control section, with 21.4 g of fruit per mole of PAR for plants in the OPV-covered section compared to 10.1 g in the Control section. Overall, this study demonstrated that the use of semi-transparent OPVs as a seasonal shade element for greenhouse production in a high-light region is feasible. However, a higher transmission of PAR and greater OPV device efficiency and durability could make OPV shades more economically viable, providing a desirable solution for co-located greenhouse crop production and renewable energy generation in hot and high-light intensity regions.

Analysis of the Viability of a Photovoltaic Greenhouse with Semi-Transparent Amorphous Silicon (a-Si) Glass

For decades, society has been changing towards an energy mix that enhances the use of renewable sources and a more distributed generation of energy. The agricultural sector is included in this trend, which is why several studies are currently being carried out focused on the use of solar energy in greenhouses. This article aims to demonstrate the viability of a greenhouse that integrates, as a novelty, semi-transparent amorphous silicon photovoltaic (PV) glass (a-Si), covering the entire roof surface and the main sides of the greenhouse. The designed prototype is formed by a simple rectangular structure 12 m long and 2.5 m wide, with a monopitch roof, oriented to the southwest, and with a 35° inclination. The greenhouse is divided into two contiguous equal sections, each with an area of 15 m2, and physically separated by an interior partition transparent wall. The surface enclosure of one of the sections is made of conventional glass, and the one of the other, of PV glass. How the presence of semitransparent PV glass influences the growth of horticultural crops has been studied, finding that it slightly reduces the production of vegetal mass and accelerates the apical growth mechanism of heliophilic plants. However, from a statistical point of view, this influence is negligible, so it is concluded that the studied technology is viable for horticultural production. The energy balance carried out indicates that the energy produced by the PV system is greater than the energy consumed by the greenhouse, which shows that the greenhouse is completely viable and self-sufficient for sites with the adequate solar resource.

Photoelectric response characteristics of a novel translucent one-dimensional MAPbI<sub>3</sub>·DMF single crystal material

<p indent=0mm>Organic halide perovskites have broad application prospects in photoelectric detector due to their excellent photoelectric properties. Moreover, there has been growing interest in applying halide perovskites to semitransparent photovoltaics to achieve the highest combination of transparency and efficiency. In this paper, we aimed to prepare high-performance materials which are suitable for translucent optoelectronic devices using new preparation methods and explore the potential properties of these materials. We successfully synthesize a type of translucent linear MAPbI₃·DMF single crystal material with controllable size and good stability in atmospheric environment using the anti-solvent method. Toluene, which is often used as one of the surfactants to control the morphology of the perovskite films, was used as an anti-solvent in this paper. The growth of the one-dimensional (1D) single crystal wires was regulated by the control of the adsorbed toluene molecular at the interface, promoting the [PbI₆]⁴⁻octahedral unit in the precursor to assemble into a chain structure along the 1D direction. In addition, we could control the width and length of the single crystal wires via a slow cooling process. The width can reach tens of microns, and the length of the single crystal wires can be the centimeter level. The crystal structure of the transparent wire was analyzed using single crystal X-ray diffraction (XRD). The material exhibited a good 1D chain structure with an infinitely extended single edge-sharing octahedral lead halide chain {PbI₃}⁻ surrounded by CH₃NH₃⁺ (MA) and <italic>N</italic>,<italic>N</italic>-dimethylformamide (DMF). Through XRD characterization of the crystal structure after keeping the material at room temperature in air (~25°C, humidity ~40%) for a long time, we found that the single-crystal wire showed good stability in air. In addition, <italic>in situ </italic>heating XRD and <italic>in situ</italic> heating transmission electron microscopy (TEM) analyses showed that the morphology and crystal structure of the semi-transparent perovskite remained stable at 90°C, indicating that this material has good thermal stability. Further, an ultraviolet-visible absorption spectroscopy test showed that this material could absorb photons at <sc>300–800 nm,</sc> indicating that the obtained single crystal wire could absorb both ultraviolet and visible light. The material also exhibited a strong transmission effect for photons with wavelengths ranging from 500 to <sc>784 nm,</sc> indicating that the material has the semi-transparent property. According to the absorption spectrum, the transparency was calculated, and it was found that the transparency of single crystal materials increased in the range of more than <sc>500 nm,</sc> further implying that they have excellent translucence properties. Photoluminescence (PL) spectrum test showed that the single crystal material could emit <sc>~780 nm</sc> of fluorescence under laser irradiations of 409 and <sc>633 nm.</sc> Furthermore, using the Tauc plot method, we determined that this material has a bandgap of <sc>~1.58 eV,</sc> which is consistent with the PL test. In addition, this material shows good responsivity <sc>(7.13 A W^–1)</sc> with a response time of <sc>9.95 ms,</sc> making it suitable for photodetector applications. The good stability and photoelectric properties make this linear single crystal material an ideal candidate for the core absorbent layer of semi-transparent photodetector devices. This research work is expected to provide a reference for the development of transparent perovskite materials with high stability and good photoelectric properties.

An optimization approach to photovoltaic building integration towards low energy buildings in different climate zones

Building integrated photovoltaic systems (BIPVs) focusing on windows, such as semi-transparent photovoltaic (STPV) or PV shading devices (PVSD), are proposed as efficient approaches to the production of electricity and the improvement of building energy performance. However, glass replacement with advanced PV concepts needs thorough energy and environmental assessment, since it took more than a millennium to produce transparent window glass of high visibility. Despite the many published studies in relation to the performance of each technology, there are limited comparative investigations of the proposed PV integration options and the most appropriate integration solutions for different climatic regions. Here, we report, for the first time, on the energy performance of four BIPVs that control solar radiation through windows and their effect on the built environment for three different climatic zones. The evaluation was done through TRNSYS simulations and calculation of representative indexes associated with thermal and visual comfort. A BIPV-flexibility index, given as a ratio of self-sufficiency to self-consumption, is proposed as a figure of merit for the assessment of each BIPV technology’s electricity production and its effect on building energy performance. The findings clearly show that BIPVs could substantially contribute to the transition to zero energy buildings due to their passive energy benefits (up to 43% savings) in addition to their electricity production. Opaque module, PV shadings and PV windows optimize the BIPV-flexibility index (up to 0.57) for cold, moderate and hot climates, with acceptable indoor thermal (up to 54% of time) and visual (up to 83% of time) comfort.

Regioregular narrow bandgap copolymer with strong aggregation ability for high-performance semitransparent photovoltaics

Semitransparent organic solar cell (ST-OSC) has developed into one of the most promising direction for the actual application of OSCs. Balancing high power conversion efficiency (PCE) and high average visible transmittance (AVT) is the greatest challenge in this field currently, which mainly due to the shortage of appropriate materials, especially the high-performance narrow bandgap (NBG) donor materials. In this work, we demonstrated a synergetic strategy to design a new type of NBG polymer by combining main chain extension and side chain engineering, which aimed to down-shift the highest occupied molecular orbital energy level, red-shift the absorption edge and enhance the regioregularity and crystallinity of the polymer donor. Compared with the state-of-the-art NBG donor of PTB7-Th, the newly designed polymer-based traditional device presents the significant improvement of photovoltaic performances. More importantly, a new breakthrough for ST-OSC with more balanced PCE of 11.0% and AVT of 35% has been successfully obtained, indicating the suitability of the reported NBG polymer for the exploration of high-performance ST-OSCs.

Outdoor comparison of two organic photovoltaic panels: The effect of solar incidence angles and incident irradiance

This study investigated the effect solar incidence angles and irradiance intensity on two commercially available semi-transparent organic photovoltaics panels. The results of electrical measurements taken for the panels at different solar incidence angles and in sunny and overcast conditions is presented. This data is compared to diurnal data of the same panels on a frame at 30° tilt facing south.It was found that the panels behaved very differently under different solar incidence angles and irradiance conditions. Panel A had high absorption from the underside of the panel, whereas panel B did not. Panel A efficiency and fill factor values were highest under lower irradiance and panel B efficiency was highest under higher irradiance.In sunny conditions, panel A efficiencies and fill factors increased with increasing solar incidence angles, indicating a higher absorption of the panel in lower irradiance. Panel B fill factor reduced, efficiency remained constant and % transmittance reduced with increased solar incidence angles, indicating reflected irradiance increased with increasing θ.Diurnal measurements showed that for both panels, efficiency and fill factor were higher in the morning compared to the afternoon with the same incident irradiance levels, indicating an overnight recovery phenomenon.

Energy partitioning and spatial variability of air temperature, VPD and radiation in a greenhouse tunnel shaded by semitransparent organic PV modules

A study related to the application of organic photovoltaic (OPV) modules in greenhouses is presented. It considers the impact of nonhomogeneous shading by semitransparent OPV modules, placed on the cover of a greenhouse tunnel housing a tomato crop, on energy partitioning and the spatial variability of radiation, air temperature and vapour pressure deficit (VPD) within the tunnel. Experiments were conducted in two similar tunnels covered by a diffuse polyethylene sheet. Flexible semitransparent strips of OPV modules were placed on 37% of the roof area of one tunnel, creating an approximately 23% nonhomogeneous shading, while the other tunnel, homogeneously shaded by a 25% black shading net, served as a control greenhouse. The results show that on cloudy days (high diffuse radiation), spatial variability of radiation in the OPV tunnel was smaller than on sunny days (low diffuse radiation). Conversely, variability in air temperature and VPD did not change much with the change in diffuse radiation. Except when diffuse radiation was high, no significant difference in the energy partitioning between nonhomogeneous shading by OPVs and homogeneous shading was observed. Most of the net radiation in the tunnels was converted into latent heat. With a high solar elevation angle, the spatial variability of radiation within the tunnel was higher than with a low solar elevation angle. Additional experiments are needed to determine the best arrangement of semitransparent OPV modules on the roof, without resulting in any significant increase in spatial variability. Agronomic aspects of plant growth under the OPV modules are briefly presented.

Semi‐Transparent Organic Photovoltaics: Sequential Deposition of Donor and Acceptor Provides High‐Performance Semitransparent Organic Photovoltaics Having a Pseudo p–i–n Active Layer Structure (Adv. Energy Mater. 13/2021)

In article number 2003576, Kung-Hwa Wei and co-workers demonstrate that semi-transparent organic photovoltaics with a sequential deposited (SD) active layer—individually deposited polymer donor layer and a small-molecule acceptor layer—forming pseudo p–i–n structures have larger power conversion efficiency and transmittance values than those for the devices with bulk heterojunction (BHJ) structures, and the enhancements for SD versus BHJ devices increase with the decreasing active layer thickness.

Organic photovoltaic water reservoir covers – dual purpose land use, renewable electricity and water conservation

ABSTRACT This paper presents a novel water reservoir cover using semi-transparent Organic Photovoltaics (OPV), that addresses water, energy and land shortages in addition to water quality improvements, by creating a dual-purpose usage of land resources by both generating electricity and reducing evaporation, whilst at the same time preserving or enhancing water quality. A simulation of the effect of the OPV cover on water temperature and evaporation is presented, as well as a discussion on the different variables influencing its viability. The filtering out of parts of the IR spectrum and 400–550 nm parts of the spectrum reduced both water temperatures and evaporation, which could thereby improve water quality.

Angular loss of window integrated thin film semi-transparent photovoltaic module

When photovoltaic modules are installed in the static window or façade, the solar radiation hardly falls perpendicularly on it. The deviation of radiation from perpendicular incidence incurred an additional loss of energy in photovoltaic systems known as an angular loss. This paper presents an assessment of the angular loss for the semi-transparent photovoltaic (STPV) module used in a vertical window system. All four geographical orientations have been considered in the analysis. Evaluation of angular loss with module transparency is one of the prime objective and contribution of this research. The analysis has been carried out using measured module characteristics and ‘EnergyPlus’ simulation software. In the study, the angular loss has found to be as high as 8.7% in the considered latitude. The analysis indicates that the angular loss becomes prominent for an angle of incidence (AOI) above 70°. With STPV module transparency, the angular loss has been found to vary by around 25%.