Assessing Self-shading Benefits of Twisting Towers

Over the last number of decades, tall building geometries have been shifting from rectangular boxes towards shapes that are defined through geometrical transformations such as twisting. While, from an aesthetical point of view, these twisting geometries make tall buildings appear contemporary and iconic, from an environmental point of view, however, the benefits are not as straightforward. They may vary significantly based on climatic loads and urban conditions, among others. This study aims to assess the self-shading benefits of twisting geometries by finding a correlation between floor-to-floor rotation and façade solar irradiation across climates, primarily focusing on hot ones, where self-shading is used as a passive solar design strategy. The study analysed three types of irradiation studies: Cumulative Annual Irradiation, Cumulative Harmful Irradiation during Cooling Design Day, and lastly, Solar Irradiation Self-Shading Balance. The latter compares beneficial and harmful solar irradiation during Hot and Cold Degree Days to quantify the impact of floor-to-floor rotation on optical and thermal performance. The study explored hundreds of possible scenarios across different climates and various floor-to-floor rotation angles, revealing a variety of positive, negative, and neutral situations. The study recommends careful examination of environmental conditions via a combination of multiple irradiation studies, particularly in the case of a smooth façade scenario

Dynamic Visualization of Optical and Energy Yield Co-Simulation of New Generation BIPV Envelope in Early Design Phase Using Custom Ray Tracing Algorithm in Python

With the aim of improving and supporting design process of BIPV, new tools and methodology is developed to co-simulate both electricity yield and daylighting performance of complex 2nd and 3rd generation BIPV envelope. Methodology is based on opto-electrical simulation using custom non-sequential ray tracing algorithm written in Python under the Rhinoceros 3D platform to analyse optical geometric scattering and light trapping capabilities of macro-structured BIPV system and absorption of PV cells. Algorithm defines set of rules for light photon propagation through different media calculating light and energy distribution for every bounce. This paper explains how this methodology is used in design workflow where architect and designers have an opportunity to obtain a direct feedback and dynamic visualization of performances of new generation BIPV systems and to explore innovative active-passive solar envelope concepts by finding balance of transparency, shading, daylighting and energy yield during Early Design Phase (EDP). Furthermore, it is shown how having interactive simulation representation of performances during EDP can improve overall performance of design solutions by using parametric meta-model to allow creation of multi-dimensional design search space and support multi-criteria decision-making in EDP in order to exploit best of both designer creativity and computation approach

Knowledge based expert system tool for optimization of the complex glass BIPV system panel layout on the cable net structural skin

Nowadays, digital tools in architectural performance-based design have become almost inevitable in creation of Nearly Zero Energy Buildings (nZEB). Rising the number of performances to be included in the building simulation, rise also the need for optimization of building geometry and performances. Current optimization techniques, mostly developed as black-box models, offer great features and target detailed design phase, but they do not provide enough user control during the optimization process. This paper, however, presents knowledge-based expert system with user-interactive features, integrated within Rhinoceros 3D environment, that guide optimization in early design phase. Single criteria optimization of energy generation potential has been done to show and evaluate the effectiveness of the process in qualitative and quantitative manner. One typology of complex Building Integrated Photovoltaics (BIPV) components was chosen as a case study to demonstrate and evaluate potential of the early design phase optimization of paneling considering aesthetical criteria. Results indicate the software is capable to support architects by providing crucial information, allowing them to optimize overall performance while keeping integrity of the design decision-making

Coloured BIPV : Market, Research and Development

In the building sector, net-zero energy performance targets and reduction of CO2 emissions are the main drivers for building integrated photovoltaics. Recent market studies [10,18,19] show the history and perspective of the global market in the BIPV sector and calculate a global compound annual growth rate of ~ 40 % from 2009 up to 2020. In Europe, the BIPV market is in a transition. The past decades of a slowly emerging BIPV market have been characterized by the original dominant value of BIPV: a building that communicates an image of sustainability and innovation. Payback time or "return on investment" have not been the major parameters in the decision process for applying BIPV. This is changing now. In most European countries, the new regulations on energy performance in buildings (derived from the European Energy Performance of Buildings Directive and the Directive on energy efficiency) have been translated in national regulations/laws, stating that all new (and freshly refurbished) buildings of the EU member states should be nearly zero energy buildings (nZEBs) by 2020. Thus, the time for the regulations to become mandatory is very near. It is expected that the energy performance regulations are now taking over as the main driving factor for the BIPV market and that should have huge consequences in removing the difference between a conventional building component and a BIPV component both in aesthetical and construction terms. This has led to intensified research and development aiming to create BIPV products that come in a variety of colours and sizes, while at the same time being as close as possible to existing building components, to its requirements and how it is considered by the construction industry. The given market overview of state-of-the-art coloured BIPV products clearly reveals that for all parts of a BIPV module (glass, polymers, PV-active layers), there are technical solutions available for colouring. Pilot projects utilizing coloured BIPV products have been built in numerous (mainly European) cities clearly demonstrating the maturity of these solutions. The key aspect that has been slowing down the progress of implementation of these aesthetically appealing and technically sophisticated new products into a wider market are the costs. In this respect, a lot of effort has been made to improve and optimize the relationship between colour and efficiency/power generation of BIPV elements. The results of the past and on-going innovative research and intensified fundamental considerations are also summarized in this report. Besides the colour perception of the coloured BIPV elements under solar irradiation which is essential for the acceptance of the exterior appearance of a building, also transparency and inside visual comfort of BIPV – windows and façade elements are essential for the users and inhabitants.Competitive Industrialized Photovoltaic Roofin