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

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

• A dedicated experimental setup was built to simulate BIPV shading conditions. • PV models under partial shading conditions are validates against experiments. • The developed simplified PV model reduces computational efforts preserving accuracy. • The effects of partial shading on cells are analysed by means of detailed modelling. • A dynamic thermal model is introduced to predict the cell temperature in BIPV systems. Building integration of photovoltaic systems is in continuous growth due to the high requirements for building energy efficiency. Some of the integration strategies, however, change the boundary conditions in which the PV systems work. Indeed, when embedded in the façade or in shading devices elements, the effects of partial shading and actual thermal conditions on power production need to be taken into account. In this work, suitable PV models to estimate the performance of such systems and to analyse the effects of partial shading are introduced and validated against measurements. In order to model the whole system, a detailed optical-thermal-electrical model is developed. The electrical model is based on a five parameter PV cells equivalent circuit and it is coupled to a dynamic thermal model and to a specific irradiance calculation method. At the same time, a simplified model is developed to reduce the computational time. A dedicated experimental apparatus, built to reproduce the typical mutual shading conditions that might occur in shading devices, has been used to assess the accuracy of the model predictions – in terms of array voltage, current and cell temperature – and to analyse the effects of mismatching on the shaded cells. The results show that both the detailed and the simplified models predict the electric power production with good accuracies, with daily averaged relative errors between 2% and 10% and with the main deviations occurring during severe mismatching conditions. In such conditions the accuracy of the simulations can be significantly improved using the detailed model and shortening the simulation time-step. Indeed, a model sensitivity analysis has been performed, showing that the detailed model represents adequately the physical response of the PV system to variable environmental conditions, but the results of the simulations are very sensitive to the input data (geometrical tolerances and time-step) during partial shadings. Concerning the thermal model, both stationary and dynamic approaches provide temperature predictions accurate enough for daily power estimations. Nevertheless, the dynamic approach is able to better describe the cell temperature and is necessary for time-steps below the characteristic time of the system. Thus, the detailed optical-thermal-electrical PV model proposed demonstrated to be a valuable tool to investigate the effects of building integration of PV systems, allowing designers to evaluate electrical and thermal effects (e.g. power losses, hot spots). It can also be used for the assessment of simplified models. The simplified model demonstrated to provide comparable results – while requiring less computational effort – respect to the detailed model, thus being suitable to be integrated in long term simulations (i.e. building simulations for early performance evaluation). [ABSTRACT FROM AUTHOR]

Building-integrated photovoltaics (BIPVs) have come to be regarded as a promising technology that reduces the life-cycle costs of building construction and generates energy simultaneously. In this regard, photovoltaic integrated shading devices (PVSDs) constitute an important part of BIPVs and play a role in generating power by transforming the unwanted radiation and in reducing cooling energy consumption. Despite the expansion of the literature in recent years (2016–2017), a comprehensive review exploring the studies on PVSD is still lacking. To fill this research gap, a systematic review of the literature on PVSD was conducted. The current body of knowledge on PVSD is summarized, including aspects such as PVSD types, PV material, orientations, tilt angles, and research approaches. Several noteworthy conclusions are drawn based on the quantitative analysis of 43 journal papers on PVSD. The majority of the studies are South Korea-based (35.9%), followed by China, Greece, and Switzerland. In addition, the focus of the literature has been on the technical approach (76.5%), office building (73.3%), and equator-facing orientation (57.1%). Only 15 types of PVSD have hitherto been studied, with the emphasis on two types: the inclined single panel and horizontal louvres between double layers. Moreover, 21 architectural cases of PVSD in practice are presented and two obstacles to PVSD development are discussed. Suggestions for future study are made, including intensifying the focus on PVSD in countries with the significant solar source, such as Singapore and Australia; diversifying the exploration of multiple PVSD types (instead of only two types); and emphasizing multi-objective optimization studies on PVSD. The review can serve as a quick reference for future research and may find utility in providing an overview of PVSD to both industry practitioners and academicians. [ABSTRACT FROM AUTHOR]

In building integrated photovoltaic (BIPV) systems, PV elements are integrated along with the building which often serves as the exterior weathering skin. PV researchers from various countries have been working for several years to optimize these systems. Sustainable BIPV system has many benefits such as the building itself becomes the PV support structure, and the BIPV components displace the conventional building materials and labor cost, thereby reducing the net installed cost of the PV system and building construction. It also provides on-site generation of electricity and architectural elegance, which increases the market acceptance of the buildings. The BIPV systems can be interfaced with the available utility grid or used as off-grid systems. This paper identifies sustainable building concept in South Asian countries and role of BIPV applications in sustainable building. This article gives review of BIPV applications in South Asian countries. Finally, Barrier and challenges of BIPV system have been discussed and future direction is highlighted. [ABSTRACT FROM AUTHOR]