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Building Integrated Photovoltaic systems can produce a significant portion of the energy demand of urban areas. Despite their potential, they remain a niche technology that architects and project engineers still find esthetically limited. The dark blue or black color of standard photovoltaic panels is considered inappropriate for restoration projects of historic buildings and represents a major constraint on the development of new projects. This work will provide insight into how the use of optic filters can offer new pathways for architectural acceptance of photovoltaic panels. Optic filters selectively reflect or transmit light by interference and can be designed and fabricated using cost-effective and industrially compatible processes. By using in-house developed ray tracing software coupled with TCAD Sentaurus, more than 400 colors were obtained, and their impact on the opto-electrical performance of interdigitated back-contacted solar cells was studied. Results show a maximum efficiency loss of 1.6% absolute at the perpendicular incidence of light on the range of obtained colors when compared with a standard dark blue solar cell. Simulations for different angles of incidence showed that the current reduction on the standard device could be modeled using a cosine relationship. The colored cells, however, deviated significantly from this relationship. We propose that the angular behavior of any cell (colored or standard) could be simulated by modifying the effective irradiance with scaling factors equal to the ratios of the photogenerated current at any angle with respect to the value at normal incidence. We demonstrate that this approach accurately models the effect of the color filter and allows for an easy transition from a bare cell to an encapsulated one. Due to the spectral effect of the filter, we developed both a spectrally resolved optical model and a two-dimensional finite volume transient thermal model. In case of the optical model, we demonstrate an accuracy in the prediction of the reflectance produced by the color with values of mean bias error (MBE) between 2.0% and 3.9%. As for the thermal model, it was validated by first analyzing a standard model under conditions of nominal operating cell temperature and then comparing its results with published scientific literature. Later, we compare its prediction against 2 weeks of measurements. In both cases the thermal model proves an adequate accuracy, yielding differences below 1.5°C with respect to other scientific works and an MBE value of 0.89°C as well as a root-mean-square error value of 2.10°C for the entire measurement period. With the validated models, we studied the effect of the encapsulation on the color perception. We present two options of color filters. The first one produces relatively low reflectance losses and presents relative annual direct current (DC) energy losses of up to 6.4% for Delft, in the Netherlands, and up to 5.9% for Alice Springs in Australia. However, this first option has very poor color brightness. The second studied filter produces highly saturated bright colors. Improving brightness can increase the annual DC relative losses up to 13.7% and 13.5% for Delft and Alice Springs, respectively. Overall, we demonstrate that colored filters based on multilayer optical stacks are a versatile option for coloring cells that allow a good compromise between esthetics and performance.

During the past few years a significant effort has been performed in order to promote the use of renewable energy sources. However, one of the main barriers for a mature commercialization is due to the unpredictability of the renewable power production, mainly in case of wind and solar energy. Unfortunately, electric storage devices are often poorly profitable. Therefore, some more stable renewable energy systems must be designed. In this framework, this paper presents a novel hybrid renewable system consisting of Building Integrated PhotoVoltaic panels and small-scale Wind Turbines and double-stage heat pumps. This combination is very promising since it reduces the typical fluctuations of solar or wind systems, achieving a more stable profile of the overall power production. A detailed dynamic simulation model is developed in TRNSYS environment, including validated models for all the components and a suitable thermoeconomic analysis. A case study is implemented for a hotel building, where the space heating and cooling energy is supplied by an electrically driven reversible air-to-water Heat Pump, supplied by the electricity produced by Building Integrated PhotoVoltaic panels and Wind Turbines. the thermal energy recovered from the HP desuperheater is coupled with the thermal energy produced by a two-stage cascade cycle Heat Pump to produce domestic hot water. Results are presented in terms of hourly, monthly and yearly system performance data as well as by discussing the results of a detailed sensitivity analysis performed to detect the optimum configuration and weather zone of this hybrid renewable system. An analysis of the building envelope features is also performed, according to the nearly zero energy buildings target. Results showed that the combination of photovoltaic and wind technologies allows one to significantly enhance the stability of the renewable power production. Results also show that the use of heat pumps leads to a reduction of the primary energy demand for building space heating/cooling and domestic hot water by 30%. A payback period of about 5.2 years is obtained and the optimum configuration suggests adopting one 20 kW Wind Turbine for the selected case study.

The use of solar photovoltaic has strongly increased in the last decade. A significant part of this growth comes from home owners installing rooftop photovoltaic. Despite this key role, most long-term model-based scenarios do not consider decentralized supply of rooftop photovoltaic but concentrate on utility-scale photovoltaic instead. In this paper, we implement rooftop photovoltaic in the Integrated Assessment Model IMAGE to study its possible role in energy and climate scenarios. We first calculated the global technical and economic potential to derive regional cost-supply curves for rooftop photovoltaic. Next, we have added a new decision in the IMAGE model allowing household investment in rooftop photovoltaic based on the comparison of the whole-sale electricity price with the price of rooftop photovoltaic. The global suitable roof surface area was assessed at 36 billion m2, or 4.7 m2 capita−1, leading to a potential for rooftop photovoltaic of 8.3 PWh y−1, roughly 1.5 times the 2015 global residential electricity demand. In the baseline scenario, adding rooftop photovoltaic could lead to a 80–280% increased share of photovoltaic electricity production in 2050 (i.e. from 6% to 17% in total power production). This increase depends on regional characteristics that are essential to the deployment of rooftop photovoltaic: differences in social-economic and policy factors (capital costs, household income, and electricity prices) are considerably more important than physical factors, such as solar irradiance.

Building integrated photovoltaics (BIPV) coupled with phase change materials (PCM) (BIPV/PCM) provide opportunities for reducing the photovoltaic (PV) panel temperature to increase the overall efficiency of the BIPV, while also transferring the extracted heat for building energy load management. A comprehensive numerical study is conducted to simulate the effects of different BIPV design parameters namely, BIPV height ( H ), air gap between BIPV/PCM and wall ( δ Air ), PCM thickness ( δ PCM ), and air mass flow rate ( m ) on the maximum PV panel temperature, the power production by the PV, and the energy extracted by the air. Optimum BIPV/PCM designs are derived from the studies for three different phase change materials, with the goal of maximizing the total energy from photovoltaics (EPV) and extracted heat (Eair), subject to the constraint of keeping the maximum PV panel temperature to within acceptable values. From the obtained results it is concluded that for the selected range of parameters, the optimum values of δ PCM , H , δ Air and m are, respectively, 0.04 m, 3 m, 0.02 m and 0.18 kg/s for maximizing EPV and 0 m, 3 m, 0.08 m and 0.091 kg/s for maximizing Eair without any constraints.

The present deployment of photovoltaic (PV) panels on the rooftop has been far below its potential. Stakeholders often see the PV as a strong design constraint, isolated from the built environment and not adapted to their requirements. Here, we propose a new design that combines the PV panels with a metal-organic framework basedsorptive thermal battery, which serves as a multi-functional building element and is more actively involved in the indoor environment regulation. The open-loop thermal battery can stock moisture from air with 105 times its volume so that the built environment with high humidity at night is dried to a comfortable and healthy level. The moisture is removed at daytime with unpleasant solar heat, thereby cools the PV panels simultaneously,improving electricity generation by 5%. The benefits of this design can be translated into economic added value to facilitate investment decisions of building-integrated PV projects.

Semi-transparent Building Integrated Photovoltaics provide a fresh approach to the renewable energy sector, combining the potential of energy generation with aesthetically pleasing, multi-functional building components. Employing a range of technologies, they can be integrated into the envelope of the building in different ways, for instance, as a key element of the roofing or façade in urban areas. Energy performance, measured by their ability to produce electrical power, at the same time as delivering thermal and optical efficiencies, is not only impacted by the system properties, but also by a variety of climatic and environmental factors. The analytical framework laid out in this paper can be employed to critically analyse the most efficient solution for a specific location; however, it is not always possible to mitigate energy losses, using commercially available materials. For this reason, a brief overview of new concept devices is provided, outlining the way in which they mitigate energy losses and providing innovative solutions for a sustainable energy future.

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).

This study proposes front colored glass for building integrated photovoltaic (BIPV) systems based on multi-layered derivatives of glass/MoO3/Al2O3 with a process technology developed to realize it. Molybdenum oxide (MoO3) and aluminum oxide (Al2O3) layers are selected as suitable candidates to achieve thin multi-layer color films, owing to the large difference in their refractive indices. We first investigated from a simulation based on wave optics that the glass/MoO3/Al2O3 multi-layer type offers more color design freedom and a cheaper fabrication process when compared to the glass/Al2O3/MoO3 multi-layer type. Based on the simulation, bright blue and green were primarily fabricated on glass. It is further demonstrated that brighter colors, such as yellow and pink, can be achieved secondarily with glass/MoO3/Al2O3/MoO3 due to enhanced multi-interfacial reflections. The fabricated color glasses showed the desired optical properties with a maximum transmittance exceeding 80%. This technology exhibits promising potential in commercial BIPV system applications.

We investigated layered titanium nitride (TiN) and aluminum nitride (AlN) for color glasses in building integrated photovoltaic (BIPV) systems. AlN and TiN are among suitable and cost-effective optical materials to be used as thin multilayer films, owing to the significant difference in their refractive index. To fabricate the structure, we used radio frequency magnetron deposition method to achieve the target thickness uniformly. A simple, fast, and cheap fabrication method is achieved by depositing the multilayer films in a single sputtering chamber. It is demonstrated that a multilayer stack that allows light to be transmitted from a low refractive index layer to a high refractive index layer or vice-versa can effectively create various distinct color reflections for different film thicknesses and multilayer structures. It is investigated from simulation based on wave optics that TiN/AlN multilayer offers better color design freedom and a cheaper fabrication process as compared to AlN/TiN multilayer films. Blue, green, and yellow color glasses with optical transmittance of more than 80% was achieved by indium tin oxide (ITO)-coated glass/TiN/AlN multilayer films. This technology exhibits good potential in commercial BIPV system applications.

Electricity outage is the main challenge facing the residential, commercial and industrial sectors in Nigeria. The country's electricity production is primarily from hydro and thermal sources, yet the available electricity output is far less than the demand. The shortfalls in electricity production and distribution in the residential and commercial sectors are the drive behind the off-grid power generation by individuals and corporate bodies in Nigeria. The off-grid power generation is mainly produced using gasoline/diesel generators which are not environmental friendlies and constitute an increase in the carbon footprint of the country. The use of off-grid power generators, also known as “backup generators” continues to grow, from slightly over 60% in 2002 to more than 80% in 2014, exposing the non-functional power sector in Nigeria. An average of 84% urban household depends on gasoline or diesel-powered generator for electricity supply while the rest live without electricity. This paper's goal is to evaluate the alternative sources that could expedite electricity availability with less carbon footprint. In this study, clean energy - solar photovoltaic (PV cells) utilization prospects were investigated for the common types of residential buildings in Nigeria. Lastly, the prospects of utilizing solar energy in buildings are discussed with their economic and environmental benefits.

Researchers have reported that despite technological development in photovoltaic technology and substantial cost reduction, there is still a narrow interest in architectural photovoltaic applications (APA). Lack of interest is correlated to various bottlenecks, and one of them is a lack of knowledge among architects on the possibilities and approaches to adopt APA. In response to the issues mentioned, the aim of the research presented was collecting qualitative and quantitative information from architects as lessons learned and perceptions in regards to APA. In total, 30 architects with and without experience of using photovoltaics (PV) were invited and interviewed. They were asked about their experience, design and decision-making process with PV, their understanding of integration, and the decisive factors to use APA. The results showed apparent differences between the experiences and perceptions, and they highlighted the lessons learned from realized projects. The analysis of the visual implication of PV integration shows that, to the eyes of architects, integration of PV into architecture does not depend on the PV product used, but instead, that when PV is part of the design concept and design process, the outcome is seen as a meaningful integration.

The optimal diffusion of Building Integrated PhotoVoltaics (BIPV) in cities requires diligent planning to arrange temporal and spatial distribution of energy, while preserving the aesthetics of city landscapes. Benefitting from an increasing quality of 3D models of cities, a comprehensive methodology to estimate potential energy generation from visually-acceptable PV, energy use from buildings, and economically viable micro-grid operation is proposed, by combining validated dynamic energy simulation tools into an open-source computational platform. The platform intends to be useful for urban planners and officials in charge of planning a large-scale BIPV installation into an existing neighborhood: simulations are carried out at the city scale, inclusive of facade potential, shading from vegetation and detailed roof shapes with super-structures. Social acceptability is investigated through a novel visual impact assessment methodology and grid integration solutions are analyzed with reference to their associated costs. Under a conservative scenario, a median of 10 kW hAC-electricity / m2 heated floor area per year is available from BIPV production in Geneva (Switzerland), covering 32 % electricity demand for space heating from heat pumps, or, alternatively, almost 10 times the one for space cooling. Visual impact has demonstrated not to be concurrent to grid integration constraints at the current stage, but rather to contribute to filtering building envelope surface and avoid grid curtailment of excess electricity. In the near future, with an increased grid efficiency, visual impact is expected to become a crucial criterion to limit the integration extent.

High energy efficiency, energy autonomy, and improved living conditions are basic requirements of sustainable buildings. Advanced building envelope structures can provide these requirements. In the present paper, multipurpose facade structure designed as semi-transparent modular building-integrated photovoltaic facade with a forced ventilated cavity and enhanced heat storage capacity, using encapsulated phase change inserts installed on inner glass pane of photovoltaic module and on building envelope, is evaluated. The design of the facade structure, including simultaneous optimization of photovoltaic cell-packing factor, phase change material inserts properties, and heat transfer by convection in air gap, was based on transient modeling. A 60% photovoltaic cell-packing factor enables the highest overall energy efficiency, while phase change material inserts on the inner glass pane of photovoltaic module have no impact on diurnal photovoltaic cell efficiency. However, a phase change material layer installed on the envelope decreases the diurnal heat losses by half at solar radiation of 2200 Wh/m2 day. The energy performance of an optimized modular structure was determined via in-situ experiments; the data were used for developing dynamic approximation models of energy efficiency indicators. It was found that multiple regression models with interactions and past values can predict dynamic responses with sufficient accuracy. Depending on the heating season’s climate conditions, the developed semi-transparent modular building-integrated photovoltaic facade decreases the energy needs 40% to 55% in comparison to the reference facade with solar energy utilization efficiency in the range between 44% and 63%. This proves that such structures can contribute to fulfilling of requirements of sustainable buildings.

Installing renewable energy systems for zero-energy buildings has become increasingly common, building integrated photovoltaic (BIPV) systems, which integrate PV modules into the building envelope, are being widely selected as renewable systems. In particular, owing to the rapid growth of information and communication technology, the requirement for appropriate operation and control of energy systems has become an important issue. To meet these requirements, a computational model is essential, however, some unmeasurable parameters can result in inaccurate results. This work proposes a calibration method for unknown parameters of a well-known BIPV model based on in situ test data measured over eight days, this parameter calibration was conducted via an optimization algorithm. The unknown parameters were set such that the results obtained from the BIPV simulation model are similar to the in situ measurement data. Results of the calibrated model indicated a root mean square error (RMSE) of 3.39 &deg, C and 0.26 kW in the BIPV cell temperature and total power production, respectively, whereas the noncalibrated model, which used typical default values for unknown parameters, showed an RMSE of 6.92 &deg, C and 0.44 kW for the same outputs. This calibration performance was quantified using measuring data from the first four days, the error increased slightly when data from the remaining four days were compared for the model tests.

Building challenges energy production from various sources, since it consumes energy in each stage of its life. The electrical energy in Indonesia is mostly produced by fossil fuel, an unrenewable energy resources has led to negative impacts on the environment. Thus, the availability of this resource is getting less. Fortunately, Indonesia has abundant renewable energy resources, and the use of these resources are still a minimum. This fact is supported by the data that many of Green-certificated buildings in Indonesia failed to take credit for the on-site renewable energy in their assessment. This research presents the proposed case of Universitas Ciputra. A building which was designed with green features and has the potential for on-site renewable energy integration, particularly for solar energy with BIPV as its concept. The aim of this research is to observe efforts made for optimizing electrical energy production from the renewable energy resources, along with the amount of optimum electrical energy generated compared to Greenship standards. The PV panels were integrated to the building facade elements (roof, opaque wall, transparent wall, and shading device), using optimum tilt and orientation angle. The result shows that the application of BIPV concept could substitute for 6–22% of the maximum power demand needed. Thus, the BIPV application on the building roof alone, would already reach the Greenship target for on-site renewable energy tool.

Building integrated photovoltaic (BIPV) is one of the most efficient ways to utilize renewable energy in buildings. However, the stochastic characteristic of PV power generation and load challenges the optimal dispatch of the BIPV. This paper proposes an optimal scheduling strategy of BIPV microgrid considering virtual energy storage (VES), which intends to further improve the operating economy of a BIPV microgrid. Firstly, existing research findings and gaps in this research area were analyzed. Then, the mathematical model of each unit in the system was created, meanwhile, the air conditioner-based VES (ACVES) model and electric water heater-based VES (EWHVES) model are built by exploiting the heat/cold storage capability of building and the electric water heater, respectively. Next, the optimal scheduling model considering the VES is designed. Finally, the optimal scheduling model is solved by CPLEX to obtain the optimal scheduling strategy that reduces the operating cost of the system. Simulation results demonstrate that the proposed strategy can reduce the operating cost of the system. Furthermore, the VES shows the potential to replace the battery energy storage system.

Façade building-integrated photovoltaics is a technology that transforms a passive façade into a distributed, renewable electrical generator by the inclusion of solar cells in the building envelope. Partial shading due to nearby objects is a typical problem for façade building-integrated photovoltaics as it strongly reduces the output power of the installation. Distributed maximum power point tracking by means of embedded converters and a common direct current bus has been proposed to alleviate this issue. However, the bus voltage plays an important role in converter topology selection and overall efficiency, although this is not being covered in literature. Also the influence of the solar cell technology on the output voltage of the module is not studied before, although it strongly influences the converter topology selection and the losses. In this paper, a methodology is described to investigate the influence of the voltage level and solar cell technology by taking conversion losses in the converters and the cabling into account. The methodology is applied to two case study buildings for which four different cell technologies are considered. It is shown that overall high efficiencies are obtained, regardless of the voltage level. However, the loss distribution changes significantly with the voltage. This aspect can be used advantageously to reduce thermal stresses on the embedded converter. Furthermore, the overall system efficiency is typically higher when the voltage step-up is lower.

Building integrated photovoltaics (BIPV) is technology that can significantly increase the share of renewable energy in final energy supply and are one of essential technologies for the nearly zero-energy buildings (nZEB), new build and refurbished. In the article (a) an experimental semitransparent BIPV glazed façade structure with 60% of PV cell coverage is shown; (b) energy efficiency indicators were developed based on identified impact parameters using experimental data; and (c) multi-parametric models of electricity generation, preheating of air for space ventilation, and dynamic thermal insulation features that enable prediction of solar energy utilization in different climate conditions are shown. The modeled efficiency of electricity production of BIPV was in the range between 8% and 9.5% at daily solar radiation above 1500 Wh/day, while low impact of outdoor air temperature and ventilation air flow rate on PV cell cooling was noticed. Between 35% and 75% of daily solar radiation can be utilized by preheating the air for space ventilation, and 4.5% to 7.5% of daily solar radiation can be utilized in the form of heat gains through opaque envelope walls.

Recently, greater research attention has focused on the application of solar power generation technology in building construction to reduce building energy consumption and encourage increased sustainable development. An emerging solar power generation technology is in the use of Building-integrated Photovoltaics (BIPVs), where photovoltaic materials are used to replace conventional building materials. In order to map the development of BIPV technology over time and explore technology paths, this study retrieved a total of 4914 patents dated from 1972 to 2016 from the Derwent Innovations Index patent database. This study applies patent co-citation analysis to map the patent co-citation network in three periods based on Ucinet tool. Evolutional path and three key technology frontiers were identified using Social Network Analysis (SNA) and text clustering. The results of this study provide an informed reference for future researchers in understanding the historical development of BIPV, as an emerging and important solar power generation technology in the built environment. At the same time, big data of patents are analyzed using SNA and text clustering, which overcomes the limitation of previous methods of frontiers study that have depended on expert opinion or peer review., International Journal of Low-Carbon Technologies, 15 (2)

Vertical space bears great potential of solar energy especially for congested urban areas, where photovoltaic (PV) windows in high-rise buildings can contribute to both power generation and daylight harvest. Previous studies on sun-tracking PV windows strayed into the trade-off between tracking performance and mutual shading, failing to achieve the maximum energy generation. Here we first build integrated models which couple the performance of sun-tracking PV windows to the rotation angles. Secondly, one-degree-of-freedom (DOF) and two-DOF sun tracking are mathematically proven to be not able to gain either maximum power generation or non-glare daylighting under reasonable assumptions. Then we derive the optimum rotation angles of the variable-pivot-three-degree-of-freedom (VP-3-DOF) sun-tracking elements and demonstrate that the optimum VP-3-DOF sun tracking can achieve the aforementioned goals. When the restriction of the proposed model is relaxed, the same performance can be achieved by the optimum one-DOF sun tracking with extended PV slats and particular design of cell layout, requiring less complicated mechanical structures. Simulation results of nine global cities show that the annual energy generation and average module efficiency are improved respectively by 27.40% and 19.17% via the optimum VP-3-DOF sun tracking over the conventional perpendicular sun tracking. The proposed optimum sun-tracking methods also reveal better protection against sun glare. The optimum VP-3-DOF sun tracking is also demonstrated to be applicable to horizontal PV windows, as those applied in the sun roof of a glass greenhouse.

Our world is facing an environmental crisis that is driving scientists to research green and smart solutions in terms of the use of renewable energy sources and low polluting technologies. In this framework, photovoltaic (PV) technology is one of the most worthy of interest. Dye-sensitized solar cells (DSSCs) are innovative PV devices known for their encouraging features of low cost and easy fabrication, good response to diffuse light and colour tunability. All these features make DSSCs technology suitable for being applied to the so-called agrovoltaic field, taking into account their dual role of filtering light and supporting energy needs. In this project, we used 40 DSSC Z-series connected modules with the aim of combining the devices’ high conversion efficiency, transparency and robustness in order to test them in a greenhouse. A maximum conversion efficiency of 3.9% on a 221 cm2 active area was achieved with a transparency in the module’s aperture (312.9 cm2) area of 35%. Moreover, different modules were stressed at two different temperature conditions, 60 °C and 85 °C, and under light soaking at the maximum power point, showing a strong and robust stability for 1000 h. We assembled the fabricated modules to form ten panels to filter the light from the roof of the greenhouse. We carried out panel measurements in outdoor and greenhouse environments in both sunny and cloudy conditions to find clear trends in efficiency behaviour. A maximum panel efficiency in outdoor conditions of 3.83% was obtained in clear and sunny sky conditions.

This review study, framed in the Work group 4 “Photovoltaic in built environment” within the COST Action PEARL PV, CA16235, aims to examine applications of integrated and applied photovoltaic technologies on ten landmark buildings characterised by distinctive geometries, highlighting the aesthetics of their architecture and quality of PV integration based on a proposed set of seven criteria. The selected building samples cover a large design diversity related to the quality of PV systems integration into building envelope that could serve as a basis for general guidelines of best architectural and technological practice. After introducing the problem and defining the research methodology, an analysis of ten landmark buildings is presented, as representative models of aesthetics of their architecture, photovoltaic integration and implementation and energy performance. The study concludes with the main characteristics of photovoltaic integration on landmark buildings. The paper is intended to support both engineers and architects in comprehending the convergent development of contemporary architecture and photovoltaic technology, as well as the need for a closer collaboration, sometimes resulting in architectural masterworks that promote the diffusion of photovoltaics to the public. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

This paper assesses the performance of photovoltaic (PV) technologies integrated into buildings in the desert climate and the factors that affect energy yield. Cadmium telluride (CdTe) and standard monocrystalline silicon (c-Si) modules were installed facing south, in the three more common tilt angles used in the Building Applied Photovoltaics (BAPV) and Building Integrated Photovoltaics (BIPV) applications at the Dubai latitude (90°, 25°, and 0°). We monitored the energy production, the temperature of the PV modules, irradiance on each tilt angle, and the meteorological parameters for a full year. We then calculated the performance ratio for the six modules to evaluate the different factors, including temperature and soiling losses, following IEC 61724-1. The 25° modules, usual PV rooftop angle, had the highest and more consistent energy yield throughout the year. Conversely, the energy yield of the 90° modules, typical angle for facades, vertical shading devices, and guardrails, had the lowest yield and showed wide variations. This is expected as the 90° angle is more affected by the seasonal changes of the solar altitude. The soiling losses on these modules were lower than 1%. However, at 0°, the soiling loss was more evident, with an average reduction of 10.79%. The c-Si module at 25° generated the highest normalized energy yield of 402.02 kW h/m2, which was 23.5% more than that of CdTe module with the same tilt angle. The authors would like to acknowledge Dubai Electricity and Water Authority (DEWA) for funding this research, Dr. Sgouris Sgourdis, Director of Research from DEWA R&D, for his valuable inputs, and Dr. Jim John, Ahmad Safieh, Ammar Elnosh, and Omar Albadwawi, members of the DEWA R&D Solar Area, for their support.

Energy flexibility in buildings is gaining momentum with the introduction of new European directives that enable buildings to manage their own energy demand and production, by storing, consuming or selling electricity according to their need. The transition towards a low-carbon energy system, through the promotion of on-site energy production and enhancement of self-consumption, can be supported by building-integrated photovoltaics (BIPV) technologies. This paper investigates the aesthetic and technological integration of hidden coloured PV modules in architecturally sensitive areas that seem to be the best possibility to favour a balance between conservation and energy issues. First, a multidisciplinary methodology for evaluating the aesthetic and technical integration of PV systems in architecturally sensitive area is proposed, referring to the technologies available on the market. Second, the experimental characterisation of the technical performance specific BIPV modules and their comparison with standard modules under standard weather condition are analysed, with the aim of acquiring useful data for comparing the modules’ integration properties and performance. For this purpose, new testbeds have been set up to investigate the aesthetic integration and the energy performances of innovative BIPV products. The paper describes the analyses carried out to define the final configuration of these experimental testbeds. Finally, the experimental characterisation at standard test conditions of two coloured BIPV modules is presented and the experimental design for the outdoor testing is outlined.

Photovoltaic modules integrated into buildings may provide shading to windows, doors and walls to protect against sun rays and at the same time generate ancillary electrical energy. The study develops the methodology for calculating the shadow variation cast by overhangs on doors, windows, carports, and calculates the annual incident energy (beam, diffuse and global energy) on overhangs made up of conventional and bifacial PV modules. The methodology of the present study is different from published articles including software programs. The study starts with shadows on walls cast by a horizontal pole and follows by shadows on walls cast by horizontal plates, inclined pole, inclined plate, and shaded area. The study deals also with overhangs placed one above the other. The calculation of the diffuse radiation involves the calculation of view factors to sky, to ground and between overhangs. In addition, the present study suggests using bifacial PV modules for overhangs and calculates the contribution of the reflective energy (5% and more) from walls and ground to the rear side of the bifacial PV module.

In the future, many modern buildings may rely on solar windows for energy production. Large buildings often have glass facades that have the potential to convert sunlight to electrical power. The standard photovoltaic materials used today are bulky and not transparent, making them poor candidates for solar windows. Transition metal dichalcogenides (TMDCs) and other two-dimensional absorbers are a good alternative because of their unique properties and high transparency at the monolayer and few-layer regime. This work shows the potential for TMDC-based solar windows by simulating the transmission, quantum efficiency, current density, and colour appearance of different solar cell configurations. Different contacts were investigated, along with the influence of contact thickness, to demonstrate colour-neutral solar cells. In addition, four TMDC materials were compared: MoS2, MoSe2, WS2, and WSe2. Colour-neutral solar cells with transparencies of 35 % to 55 % are presented, where a current density of 8.33 mA/cm2 was calculated for a solar cell with a 5-nm absorbing layer of MoSe2. While there are still challenges to overcome in terms of production, our simulations show that it is possible to use TMDCs for colour-neutral solar windows and act as a guideline for further research.

European legislation on building performance and energy efficiency pushes the shift towards minimizing the environmental footprint of buildings. Building-integrated photovoltaics (BIPV) is a promising technology that can accelerate the transition to energy-neutral buildings. Quantifying the potential of BIPV is crucial and one means of obtaining those results is through simulation. The state-of-the-art tools offer either thermal or electrical specialization; in particular, balance of system components (BOS) such as power converters have not been studied in detail within the building simulations BIPV domain. In this paper, a multi-physics model of a BIPV integrated DC/DC converter is developed in the Modelica language, taking into account the thermal and electrical couplings inherent to power electronic systems. The model has been validated using representative outdoor BIPV measurements and a DC/DC converter prototype. It has been found that the proposed model provides reasonable accuracy and outperforms an equivalent power conditioning model in TRNSYS. To demonstrate the model’s functionality, two case studies are performed. First, the temperature-dependence of the converter’s efficiency and losses is quantified and analyzed and, second, the prominent contributors to the converter losses are identified and discussed. ispartof: APPLIED ENERGY vol:240 pages:646-665 status: published

© 2019 by the authors. Since building-integrated photovoltaic (BIPV) modules are typically installed during, not after, the construction phase, BIPVs have a profound impact compared to conventional building-applied photovoltaics on the electrical installation and construction planning of a building. As the cost of BIPV modules decreases over time, the impact of electrical system architecture and converters will become more prevalent in the overall cost of the system. This manuscript provides an overview of potential BIPV electrical architectures. System-level criteria for BIPV installations are established, thus providing a reference framework to compare electrical architectures. To achieve modularity and to minimize engineering costs, module-level DC/DC converters preinstalled in the BIPV module turned out to be the best solution. The second part of this paper establishes converter-level requirements, derived and related to the BIPV system. These include measures to increase the converter fault tolerance for extended availability and to ensure essential safety features. ispartof: Energies vol:12 issue:8 pages:1-20 status: published

A ducted photovoltaic façade (DPV) unit was studied using experimental prototype and simulated in a full scale computational fluid dynamics (CFD) model. The study comes in two parts; this is Part I, as detailed in the title above, and Part II is titled “A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part II CFD Simulation”. The process adopted in the experimental study is replicated in the simulation part. The aim was to optimize the duct width behind the solar cells to allow for a maximum buoyancy-driven cooling for the cells during operation. Duct widths from 5 to 50 cm were tested in a prototype. A duct width of 45 cm had the maximum calculated heat removed from the duct; however, the lowest cell-operating temperature was reported for duct width of 50 cm. It was found that ΔT between ducts’ inlets and outlets range from 5.47 °C to 12.32 °C for duct widths of 5–50 cm, respectively. The ducted system enhanced module efficiency by 12.69% by reducing photovoltaic (PV) temperature by 27 °C from 100 °C to 73 °C. The maximum measured heat recovered from the ducted PV system was 422 W. This is 48.98% from the incident radiation in the test. The total sum of heat recovered and power enhanced by the ducted system was 61.67%.

This paper reviews the present status and outlook of the building integrated photovoltaics (BIPV) market on a global and European scale. In particular, it provides a comprehensive review of the market situation and the future trends for Austria, Cyprus, France, Germany, Italy and the Netherlands until the year 2020. In addition, as education is seen as one of the barriers for BIPV deployment, results of a survey are presented that was conducted among BIPV stakeholders with the aim to identify major knowledge gaps in education and target audiences as well as teaching goals. From that potential courses dedicated to the needs of each target audience related to BIPV can be developed.

This paper investigates the energy and economic profitability of renovating residential buildings in temperate climate through the integration of PV panels on facades. The investigation regards a real multi-storey apartment block, representative of a significant amount of edifices built in Italy in 1950–1990, which often need refurbishment because of obsolescence. This building type is generally well suited to receive a new double-skin facade, supporting both PV and other common cladding materials, while also representing a good compromise in terms of aesthetic quality, cost, weight, durability and ease of maintenance. In order to make general conclusions, a parametric analysis is performed, by virtually changing the orientation, the number of floors and the climatic conditions, and by considering different PV technologies. The results show that for an 8-storey building with the main axis along E-W, the initial investment can be repaid within around nine years, if considering the current fiscal incentives and a 50% self-consumption rate for the electricity produced by the PV modules. The presence of fiscal incentives is essential to make the investment attractive. Better PV efficiencies, lower prices and higher self-consumption rates can enhance the economic profitability, which may generate a significant impact on the retrofit of European multi-storey residential stock. These results can be effectively extended to the PV integration on the facades of new apartment blocks too.

Solar cells using the passivated emitter and rear contact (PERC) structure have become very popular for high eifficiency BIPV modules in the past decade. In this paper, we discuss a method to increase the efficiency of p-type monocrystalline silicon solar cells with equipments suitable for mass production. Using this method,SiOxNy /SiNx film stacks manufactured via PECVD are selected as rear passivation layer. Compared to conventional ALBSF cells, more than 0.6% efficiency gain was obtained. The rear contact pattern is also studied to increase the efficiency further. Most of the standard tools to produce conventional ALBSF solar cells can be utilized in this technology, which provides a cost efficient solution to mass-produce high efficiency BIPV modules.

The working temperature of BIPV modules is high than ground-mounted PV. Based on the theory of material mechanics and thermal stress analysis, the stress distribution of metallization interconnects system for crystalline silicon solar module in BIPV was studied for the first time. The shear stress and normal stress distribution of soldered structure for crystalline silicon solar cell under the thermal field were discussed. And the results show the stress distribution is not simply linear relationship as some results found. But there is a stress concentration at the edge, which was considered as the true reason that caused V-notch at the edge of soldered solar cell. The conclusions we got in this paper provide a theoretical basis for reliability of c-Si BIPV modules.

The Adaptive Solar Facade (ASF) is a modular, highly integrated dynamic building facade.The energetic behavior as well as the architectural expression of the facade can be controlled with high spatio-temporal resolution through individually addressable modules. We present the general design process, the current mechanical design, and simulation results on photovoltaic power production and building energy consumption. We introduce the controller concept and show results on solar tracking as well as user interaction. Lastly, we present our current and planned prototypes., Frontiers of Architectural Research, 5 (2), ISSN:2095-2635, ISSN:2095-2643

This article presents the state of the knowledge on the thermal analysis of double skin facades with integrated photovoltaic (PV) panels called the Building Integrated Photovoltaics (BIPV) in terms of the published studies carried out on these systems. The idea of integration of the PV panels by replacing building elements, increase the prospects of the renewable energy systems. Taking also into account the need to use more renewable energy systems in buildings, the investigation of the BIPV systems to improve their performance is of a great importance. The literature studies are separated into experimental and theoretical for naturally ventilated systems and mechanically ventilated with external means e.g. fan use. It is concluded that most researchers studied the systems with mechanical ventilation rather than the systems with natural ventilation because the latter are more complex in terms of the air flow behaviour in the air duct. Additionally, various researchers proposed Nu number correlations and convective heat transfer correlation under several assumptions and conditions every time, for different range or Ra number which are presented and compared in this paper.

Abtract In 2014, the Singapore government announced plans to increase the adoption of solar power, including by integrating solar PV systems into the urban environment. Careful planning of a neighbourhood at early design stage, which determines the overall urban morphology, is important for effective deployment of solar panels in urban environment. This study performed parametric assessment to understand the relationship between urban morphology and the annual average irradiance on rooftop and facade in Singapore context. It also compares the correlation performance of building irradiance with the two definitions of Sky View Factor (SVF). Among the 10 selected morphology parameters, the correlation analysis shows the correlation performances of both definitions of SVF are the strongest (r = 0.94 to 1). As obtaining the value of SVF is not simple, two multilinear regression predictive models for rooftop and facade irradiance are developed. There is a significant improvement in adjusted R2 of the rooftop irradiance model (R2 = 0.61) when comparing the R2 of other individual parameters (R2 = 0 to 0.36). It is anticipated that the results of this study 1) would be useful for urban planners considering urban PV integration for sustainable cities; and 2) can provide a simpler way to give a rough estimation of SVF, which is commonly used for the parametric studies related to research areas such as urban microclimate and urban renewable energy utilization.

The built environment remains a strategic research and innovation domain in view of the goal of full decarbonization. The priority is the retrofitting of existing buildings as zero-emission to improve their energy efficiency with renewable energy technologies pulling the market with cost-effective strategies. From the first age of photovoltaics (PV) mainly integrated in solar roofs, we rapidly moved towards complete active building skins where all the architectural surfaces are photoactive (Building Integrated Photovoltaics - BIPV). This change of paradigm, where PV replaces a conventional building material, shifted the attention to relate construction choices with energy and cost effectiveness. However, systematic investigations which put into action a cross-disciplinary approach between construction, economic and energy related domains is still missing. This paper provides the detailed assessment of a real multifamily building, taking into account retrofit scenarios for making active the building skin, with the goal to identify the sensitive aspects of the energetic and economic effectiveness of BIPV design options. By assuming a real case study with monitored data, the analysis will consider a breakdown of the main individual parts composing the building envelope, by then combining alternative re-configurations in merged clusters with different energy and construction goals. Results will highlight the correlation between building skin construction strategies and the energy and cost parameters by identifying the cornerstones for enhancing efficiency. The outcomes, related to the total life cost, self-consumption/sufficiency, in combination with different building design options (façade, roof, balconies, surface orientations, etc.), provide a practical insight for researchers and professionals to identify renovation strategies by synergistically exploiting the solar active parts towards lower global costs and higher energy efficiency of the whole building system.

Geometrically equivalent V-trough and compound parabolic concentrators (CPC) were simulated to characterise the variation in optical efficiency using ray tracing modelling with COMSOL Multiphysics. The effect of CPC truncation and V-trough side wall angles were studied. The truncated CPC demonstrated much improved light acceptance outside the designed angle of acceptance when compared to the original CPC design and V-trough-like characteristics past the original design acceptance angles, consequently reducing material consumption for the manufacture of truncated CPC and therefore reduction in the cost of the system. Truncated CPCs showed optical efficiency equal to their full height counterparts, but a lower concentration ratio (4 at full, 3.6 at half and 2.7 at 50 mm height) due to an equivalent reduction of the inlet aperture size. The V-trough had a higher optical concentration ratio over 15–30° angle of incidents (AoI), with the CPC taking over from 30° AoI upwards. Experiments were performed on a 50 mm truncated CPC and a 22° Trough Wall Angle (TWA) V-trough collector under outdoor conditions. Experimentally measured data showed good correlation with ray tracing simulation results. Both experimental and the ray tracing analyses showed the CPC concentrator achieving a 2.4% higher power output compared to the V-trough design.

In this paper, we evaluate passive and active strategies that can be used in solving the heating problems in the residential sector of Northern Cyprus. In doing so, we propose the use of photovoltaics as a shading device (PVSD). PVSD is known to produce clean energy from solar radiation and it also reduces the energy consumed for cooling. We use an empirical method to evaluate the performance of a typical family detached dwelling in Famagusta, Cyprus. The simulation result derived from the study indicates that the strategic use of PVSDs for openings oriented towards the east, west, and south can reduce its energy consumption by almost 50% in three months of the year and cut down up to 400 kWh of energy consumption through the year, thus raising the comfort level of the building by about 20%. It will also generate nearly 2800 W that can provide up to 50% of the electricity demand.

It is generally expected that in the future, photovoltaics will be able to contribute substantially to the mainstream power production, and that through their widespread commercialization, Building-Integrated Photovoltaics (BIPV) systems will become the backbone of the zero-energy building (ZEB) European target for 2020. An outlook on the BIPV market estimated the worldwide installed BIPV capacity during 2016 to nearly 2 GW, confirming the growing trend, increasing by 12.6% compared to 2015, when 1.78 GW were installed [1]. This paper presents the results of the Dem4BIPV project (http://www.dem4bipv.eu/), which has been designed to develop innovative master-level courseware for various European academic institutes focusing on Building-Integrated Photovoltaics (BIPV) in order to bridge the existing knowledge gaps in education of the target audiences (students and professionals in the building sector) as well as to create awareness on the subject. A project survey among BIPV stakeholders showed that lack of education is one of the barriers to BIPV deployment helping at the same time to identify teaching goals and subsequently courses addressing the needs of each target audience related to BIPV. Finally, a full 40 ECTS curriculum on BIPV was developed and is briefly presented in this paper. 209 217

Building integrated photovoltaics (BIPV) has attracted increased commercial interest in recent years due to a growing focus on efficient utilization of land area and local renewable energy generation. Aesthetic aspects must be considered when photovoltaic panels are applied as building elements. Colours can be added by reflecting some of the sunlight that otherwise could have been utilized for electricity generation. Reflectance spectra of commercial solar cell modules have been measured and analysed. Relative efficiency loss caused by the reflected solar radiation energy has been calculated. The calculated losses in efficiency based on measured spectra have been compared to model spectra with colour coordinates corresponding to RAL colours as well as more idealized monochromatic spectra. The analysis shows that the most important colour parameter affecting loss is the lightness. The second most important parameter is the hue of the colour, with green-yellow colours having the lowest loss, and pink colours resulting in the highest loss, when colours with the same lightness are compared. A Colour Performance Index (CPI) given by luminous reflectance divided by relative loss has been proposed as a figure of merit, thus allowing for a useful comparison of colours with different lightness. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Rapid and uncontrolled urbanization is continuously increasing buildings’ energy consumption and greenhouse gas emissions into the atmosphere. In this scenario, solar energy integrated into the built environment can play an important role in optimizing the use of renewable energy sources on urban surfaces. Preliminary solar analyses to map the solar accessibility and solar potential of building surfaces (roofs and façades) should become a common practice among urban planners, architects, and public authorities. This paper presents an approach to support urban actors to assess solar energy potential at the neighborhood scale and to address the use of solar energy by considering overshadowing effects and solar inter-building reflections in accordance with urban morphology and building characteristics. The approach starts with urban analysis and solar irradiation analysis to elaborate solar mapping of façades and roofs. Data processing allows assessment of the solar potential of the whole case study neighborhood of Sluppen in Trondheim (Norway) by localizing the most radiated parts of buildings’ surfaces. Reduction factors defined by a new method are used to estimate the final solar potential considering shadowing caused by the presence of buildings’ architectural elements (e.g., glazed surfaces, balconies, external staircases, projections) and self-shading. Finally, rough estimation of solar energy generation is assessed by providing preliminary recommendations for solar photovoltaic (PV) systems suited to local conditions. Results show that depending on urban morphology and buildings’ shapes, PV systems can cover more than 40% of the total buildings’ energy needs in Trondheim. © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

A seasonal analysis of a long-term dataset produced by an off-grid classroom facility showcasing several solar orientated renewable technologies is presented. The performance of the building’s BIPV and battery storage system is characterised and optimisation strategies are discussed. The building experiences a typical oceanic climate defined by a relatively narrow annual temperature range and a high level of annual precipitation, resulting in significant fluctuation in PV performance throughout the year. On clear days, the battery system reaches capacity quickly and PV power output drops to the base load of the building. This curtailment of solar generation highlights the importance of developing control strategies to optimise system performance. Maximising the performance of the building requires accurate methodologies for predicting PV generation and detailed knowledge of building demand profiles. Significant correlation is observed between the solar irradiance, battery state of charge and PV power output, demonstrating the importance of these variables in any solar forecasting model. Demand profiles are deterministic and follow classroom routine. A baseline accounts for persistent systems such as the building management system that are active throughout the day, with demand peaking during occupancy. This information could be incorporated into scheduling algorithms to optimise performance. Consumption is more aligned with the solar generation profile than typical residential buildings that peak in the evening as levels of solar generation fall. The synergistic effect of buildings with different demand profiles could be a mitigation method to minimise the temporal mismatch between solar generation and consumption.

Worldwide, an increasing number of new buildings have photovoltaics (PV) integrated in the building envelope. In Switzerland, the use of coloured PV façades has become popular due to improved visual acceptance. At the same time, life cycle assessment of buildings becomes increasingly important. While a life cycle inventory for conventional glass-film PV laminates is available, this is not the case for glass-glass laminates, and in particular, coloured front glasses. Only conventional glass-film PV laminates are considered in databases, some of which are partly outdated. Our paper addresses this disparity, by presenting life cycle inventory data gathered from industries producing coloured front glass by digital ceramic printing and manufacturing glass-glass PV laminates. In addition, we applied this data to a hypothetical façade made of multi-coloured glass-glass laminates and its electricity generation in terms of Swiss eco-points, global warming potential, and cumulative energy demand as impact indicators. The results of the latter show that the effect of the digital ceramic printing is negligible (increase of 0.1%), but the additional glass (4% increase) and reduction of electricity yield (20%) are significant in eco-points. The energy pay-back time for a multi-coloured PV façade is 8.1 years, which decreases by 35% to 5.3 years when replacing the glass rain cladding in an existing façade, leaving 25 years for surplus electricity generation.

© 2018 IEEE. Building-Integrated Photovoltaics (BIPV) replace traditional building elements with power generating elements through the use of solar cells. One of the targets for this technology is to place the module-level power converter into the photovoltaic module's frame to achieve an integrated system. Temperature is the most influential parameter for a converter's reliability, its damage caused on the components needs to be studied in detail. In this paper, a reliability comparison based on a four-day mission profile has been made in order to assess the most reliable frame position for this converter to be placed in as all of them possess a different temperature profile. The results show that placing the converter in the lateral bottom of the frame is significantly more reliable than the mid or top position. In addition, a lifetime analysis is performed on the converter's dc-link capacitor in order to demonstrate the required methodology. In future work, this can be extended towards other sensitive components when appropriate lifetime models become available. These lifetime estimations can then be combined to achieve an overall BIPV system lifetime assessment. ispartof: pages:412-417 ispartof: 2018 7TH INTERNATIONAL CONFERENCE ON RENEWABLE ENERGY RESEARCH AND APPLICATIONS (ICRERA) pages:412-417 ispartof: 7th International Conference on Renewable Energy Research and Applications (ICRERA) location:Paris, FRANCE date:14 Oct - 17 Oct 2018 status: published

The increasing demand for nearly zero energy buildings is rapidly contributing to changing the design criteria in architecture and concept of the building envelope. Today, photovoltaics (PV) is one of the most reliable technologies for integration in the built environment, and building-integrated photovoltaics (BIPV) is introducing a different notion of ‘energy integrability’ into practice. The difficulty of undertaking, from the first design stages, a really integrative approach towards energy (PV and building requirements) is today still one of the strongest barriers to the rise of the BIPV market. Likewise, the same uncertainty affects the economic aspects, objects of this paper, since BIPV systems are often evaluated similar to conventional installations. The typical consequence is to neglect their added value such as the multi-functionality of the system and therefore showing limited advantages of BIPV. Scope of this paper, starting from a multi-criteria approach, is to outline a new methodol...

This paper provides an overview of available innovative shape morphing building skins and their design principles. In particular, the proposed review deals with comfort-related issues associated with dynamic solar shading devices, building integration of smart materials, and morphological analyses related to the most recent shape morphing solar skins. In the first part of the paper, an introduction to the typologies of movement in architecture, its concept and application are presented. An explanation of biomimetic principles together with an overview of user’s response to dynamic shading devices is also provided. This is followed by the description of the design principles for shape morphing solar shadings with particular focus on energy and comfort aspects, smart materials and biomimetic principles for efficient movements. A review of most recent developments on the topics of comfort, users’ response and control of dynamic shading devices, is presented and summarized in a comparison table. The main technical and mechanical properties of the most diffused smart materials (Shape Memory Alloys, Shape Memory Polymers and Shape Memory Hybrids) that can be used for innovative shape morphing solar skins are illustrated in detail and compared. Biomimetic principles for efficient movements complete this part of the work. The principles illustrated in the previous part of this paper are then used to critically analyse the most recent examples of building integrated shape morphing shadings.

This paper presents a numerical simulation work on the mechanical behaviors of an ultra-thin double-glazing PV module under static and dynamic load conditions. Three different kinds of PV mounting configurations are investigated respectively to explore their influences on the static and dynamic performance of the studied module. For each kind of mounting configuration, static, modal and modal-based steady-state dynamic analyses are carried out by using the Finite Element Method, respectively. In the static analysis, two kinds of uniform pressure loading conditions with magnitudes of 2400 Pa and 5400 Pa, which are standing for the maximum wind load and snow load respectively according to the Standard of IEC 61215, are applied on the PV modules. After static analyses, modal analyses are performed to obtain the PV modules’ natural frequencies and mode shapes. Based on the results of modal analyses, a steady-state dynamic analysis is conducted to determine the modules’ dynamic responses to the harmonic excitations with an amplitude of 2400 Pa and frequencies ranging from 0 Hz to 100 Hz. The simulation results show that both the deformation and the stresses of three PV system are small in static analysis, but they are quite different in dynamic analysis. The dynamic displacement curves have obvious oscillations near the natural frequencies of PV modules and the amplitudes are large enough to damage the PV modules. The mounting configurations have a significant influence on both the static performance (strength and deformation) and dynamic performance (dynamic characteristics and responses). In conclusion, for this ultra-thin double-glazing PV module, it is not accurate and appropriate for evaluating the safety and stability of the PV module just through the existing static analysis in IEC 61215. The dynamic effects of the loading on PV module also need to be paid attention. Moreover, the mounting configurations should be designed to meet both the static and dynamic requirements.

Dye-sensitized solar cell technology is having an important role in renewable energy research due to its features and low-cost manufacturing processes. Devices based on this technology appear very well suited for integration into glazing systems due to their characteristics of transparency, color tuning and manufacturing directly on glass substrates. Field data of thermal and electrical characteristics of dye-sensitized solar modules (DSM) are important since they can be used as input of building simulation models for the evaluation of their energy saving potential when integrated into buildings. However, still few studies in the literature provide this information. The study presented here aims to contribute to fill this lack providing a thermal and electrical characterization of a DSM in real operating conditions using a method developed in house. This method uses experimental data coming from test boxes exposed outdoor and dynamic simulation to provide thermal transmittance (U-value) and solar heat gain coefficient (SHGC) of a DSM prototype. The device exhibits a U-value of 3.6 W/m2·K, confirmed by an additional measurement carried on in the lab using a heat flux meter, and a SHGC of 0.2, value compliant with literature results. Electrical characterization shows an increase of module power with respect to temperature resulting DSM being suitable for integration in building facades.

This paper presents an integrated bottom-up approach aimed at helping those dealing with strategical analysis of installation of Building Integrated Photo Voltaic (BIPV) to estimate the electricity production potential along with the energy needs of urban buildings at the district scale. On the demand side, hourly energy profiles are generated using dynamic building simulation taking into account actual urban morphologies. On the supply side, electricity generated from the system is predicted considering both the direct and indirect components of solar radiation as well as local climate variables. Python-based Algorithm editor Grasshopper is used to interlink four types of modelling and simulation tools as 1) generation of 3-D model, 2) solar radiation analysis, 3) formatting weather files (TMY data set) and 4) dynamic energy demand. The method has been demonstrated for a cluster of 20 buildings located in the Yasar University in Izmir (Turkey), for which it is found the BIPV system could achieve an annual renewable share of 23%, in line with the Renewable Energy Directive target of 20%. Quantitatively-compared demand and supply information at hourly time step shows that only some energy needs can be met by BIPV, so there is a need for an appropriate matching strategy to better exploit the renewable energy potential.