Project | Proactive Thinking—Building-Integrated Photovoltaic Design for the Permanent Venue of the World Top Scientists Forum

01.

Project Background

Building Integrated Photovoltaics

 

Building-integrated photovoltaics (BIPV) is a technology that integrates solar photovoltaic power generation systems directly into the building envelope. Specifically, it installs photovoltaic components on the surfaces of the building's roof, walls, and awnings, etc., not only providing electricity but also serving as a functional part of the building structure, replacing some traditional building materials such as tiles and glass curtain walls.

/ Photovoltaic Roof /

/ Photovoltaic Facade /

 

/ Photovoltaic Carport /

BIPV technology has three main characteristics: First, it is energy-efficient and environmentally friendly. BIPV can effectively utilize solar energy resources, reduce reliance on traditional energy, and lower the building's energy consumption and carbon emissions; second, it is aesthetically pleasing and practical. Photovoltaic components, as part of the building materials, not only provide electricity but also blend with the building's appearance, enhancing its aesthetics; third, it has economic benefits. Most of the electricity generated by the BIPV system is consumed by the power-consuming equipment within the building, and the surplus electricity can be fed into the grid, achieving self-sufficiency in energy and grid-connected power generation.

General Code for Building Energy Efficiency and Renewable Energy Utilization

Implementation Opinions on Promoting the Application of Renewable Energy in Newly Built Buildings in This City

 

In order to actively promote the rapid development of the building-integrated photovoltaic application field, China has introduced a series of policies and regulations, such as the "General Code for Building Energy Efficiency and Renewable Energy Utilization" issued by the Ministry of Housing and Urban-Rural Development in October 2021. Shanghai's "Implementation Opinions on Promoting the Application of Renewable Energy in Newly Built Buildings in This City" requires that "new public buildings, residential buildings, and public utility plants whose construction drawings are submitted for review after March 1, 2023, shall comply with these opinions (see table below)." These policies aim to encourage and support the integration and application of photovoltaic technology in buildings to promote green and sustainable energy utilization.

Table of Area Ratio for Rooftop Solar Photovoltaic Installation

 

Given the policy-driven promotion requirements for photovoltaic applications and the positive impact of photovoltaics on economic development and environmental protection, building-integrated photovoltaics has become an inevitable trend in the development of the construction industry. Although photovoltaic applications still face some challenges in construction technology, for architects, photovoltaics are also a new form of design expression and means. Architects should take a proactive stance and actively adapt to this transformation. This article takes the World Top Scientists Forum permanent venue project as an example to comprehensively introduce our exploration in the application of building-integrated photovoltaics.

 

 

02.

Project Overview

Building Integrated Photovoltaics

 

The World Top Scientists Forum permanent venue project is the first project in the Lingang World Top Scientists Community. Positioned as a "world-class major frontier scientific source in the new era," it serves as the permanent venue for the World Top Scientists Forum. The project has a total construction area of 223,827 square meters, with its main functions being a comprehensive complex for the Top Scientists Forum conference center, as well as an accompanying theater, library, science exhibition hall, and hotel. The entire building unfolds like double wings towards the city, with undulating photovoltaic roofs seamlessly integrated with the building, expressing the beautiful vision of "spreading the wings of the future and gathering the light of technology."

/ Front Semi-Bird's-Eye View /

 

Wings of Science, Connecting the City

The entire building is arranged in north-south sections, with the conference center to the north and the hotel and apartment hotel to the south. The design integrates and streamlines the city's spatial relationships, emphasizing the combination of natural and humanistic environments. Unlike the cold and negative stereotypes of previous conference centers, it aims to create a vibrant venue.

/ Functional Analysis Diagram /

 

The design introduces vehicular access to the second-floor platform, opening up the ground floor space to introduce pedestrian traffic. It combines rich functional spaces to create an organic spatial sequence and connects with the park to the south; the stepped setbacks of the hotel's annex building continue the wing design concept, forming a reciprocal landscape dialogue with the planned park to the south.

/ Morphology Generation Analysis Diagram /

 

Green and Low-Carbon, Throughout

The dual-carbon goals are China's commitment to the international community, and "Science for the common destiny of mankind" is the eternal theme of the World Top Scientists Forum. From the beginning of the design, the design team considered the building's energy consumption control, such as the building's shape factor, window-wall ratio calculation, and external shading in different orientations.

/ Green Building Analysis Diagram /

 

Through calculations and analyses of the design scheme's comfort, energy consumption, and lighting, a harmonious and unified building facade with constantly changing orientations was formed. By comprehensively using climate-responsive design, high-performance enclosures, high-efficiency electromechanical systems, and integrated photovoltaic design, the building has become Shanghai's first public building project to pass the ultra-low energy consumption scheme review. Among them, the integrated photovoltaic design is one of the highlights of this project's achievement of ultra-low energy consumption buildings.

/ Elevation /

/ Photovoltaic Roof Bird's-Eye View /

 

 

03.

Architects' Knowledge Reserve on Building-Integrated Photovoltaics

Building Integrated Photovoltaics

 

Before undertaking photovoltaic design, architects need to have a certain understanding of building-integrated photovoltaics, including the impact of solar radiation on photovoltaic panels and the possible application methods of BIPV in buildings.

 

Solar Radiation and Photovoltaic Panel Installation

Given the characteristics of solar radiation, the optimal tilt angle for photovoltaic panel installation is crucial. The optimal tilt angle can improve the energy output efficiency of the photovoltaic panels, thereby improving the efficiency of the solar power generation system. For large-scale photovoltaic panel deployment, determining the optimal installation angle is essential.

/ Diagram (Source: Internet) /

 

The calculation of photovoltaic panel paving density is also a meticulous and complex task. It not only needs to consider the angle optimization of photovoltaic panels but also needs to take into account the reduction of shading effects to maximize light reception. In urban environments, implementing photovoltaic projects cannot enjoy unlimited spatial intervals like desert areas, so it is necessary to balance the ratio of light intensity and the area that can be paved.

 

Through comprehensive analysis, the aim is to maximize system efficiency. This process often involves economic considerations, namely a comparative analysis of investment costs and power generation returns, which is the basis for determining the overall paving strategy. Based on these principles, designers can innovatively derive various design schemes to create building photovoltaics that are both efficient and aesthetically pleasing.

 

Application Methods of BIPV in Buildings

Generally, there are two main ways to apply photovoltaic arrays in buildings:

The Combination of Photovoltaics and Buildings This is the most common approach, primarily integrating photovoltaic arrays with building roofs, walls, etc., such as photovoltaic roofs and photovoltaic curtain walls. This method does not occupy space outside the building, making it the most widespread and optimal installation method for photovoltaic power generation systems in cities. ^[1] For example, the metal roof of the exhibition hall on the north side of the project features photovoltaic panels installed on brackets.

Integration of Photovoltaics with Architecture This is an advanced form of BIPV, where photovoltaic components must not only meet the basic requirements of photovoltaic power generation but also serve as building components, such as waterproofing, insulation, and load-bearing. ^[2] The skylight atrium roof of the hotel annex on the south side of the project uses this integrated approach, with photovoltaic panels serving as both the atrium's glass roof and the exterior curtain wall.

Photovoltaic Design for the North Side Exhibition Hall Metal Roof

Photovoltaic Design for the South Side Hotel Annex

 

 

04.

Specific Applications of Photovoltaic Integration in the Project

Building Integrated Photovoltaics

 

The Dingke project underwent multiple design optimizations and iterations, evolving from an initial design without photovoltaics to a final design incorporating building-integrated photovoltaics upon completion. Ultimately, the project's photovoltaics are primarily applied to the building roof and atrium skylights. Throughout the design process, the architects collaborated closely with green building and BIM professionals, integrating photovoltaics as a core design concept, carefully considering both efficiency and compatibility with the architectural design.

 

Combination of Photovoltaics and Roof

The project's unique roof structure is derived from its wing-like architectural form, directly influencing the layout of the photovoltaic panels. It's important to note that architectural forms may be adjusted during the design process, necessitating corresponding adjustments to the photovoltaic system layout. This highlights the importance of architects considering the integration of architectural form and photovoltaic systems, ensuring harmony between the two.

/ Design Renderings /

 

The undulating photovoltaic form of the conference center roof requires optimization under the guidance of the design concept, combined with BIM design. To achieve the architect's design concept of 'soaring wings,' the design team used parametric technology to simulate and compare different roof undulations, including linear roofs and hyperbolic curved roofs.

Linear Roof

Hyperbolic Curved Roof

 

Considering the sun's angle of incidence and architectural needs, the design integrates the theater's staggered roof, ensuring air circulation for roof equipment. Parametric design simulates the optimal light angle to maximize power generation, and considering shading factors, monocrystalline silicon thin-film components are selected to avoid light spots damaging the components.

/ Rhino + Grasshopper Assisted Integrated Design of Photovoltaic Building Structure (Drawing: Liu Wen) /

 

Adhering to the 'wing' design concept, the photovoltaic components adopt a modular layout strategy. Each photovoltaic panel is installed at a 15° angle, creating an orderly, layered, and dynamically beautiful feather-like array structure.

/ Completed Project Photos /

 

The gaps between the unit panels provide good ventilation for roof equipment. This modular photovoltaic design also significantly reduces costs. The main steel beam structure of the photovoltaic rack under the irregular shape is completed using Rhino single-line positioning and Revit Dynamo parametric solid model conversion, achieving efficient and batch interaction of data formats between diverse heterogeneous models.

/ Summary of Integrated Design Process for Photovoltaic Building Structure (Drawing: Liu Wen) /

 

Photovoltaic Selection

Material selection involved several considerations. First, material color. The initial design used light-colored materials, but this resulted in significantly lower photovoltaic conversion efficiency. We were unwilling to sacrifice the functionality of the photovoltaic system for aesthetics alone. We then evaluated several dark-colored materials, including dark gray, blue, and purplish-red. To balance function and aesthetics, we ultimately chose dark gray.

Light-Colored Photovoltaic Design

Dark Gray Photovoltaic Design

 

In this project, the conference center roof uses cadmium telluride thin-film components (85W per unit), with modules measuring 1.2 x 3.6 meters, totaling 2690 modules. Each module connects 6 cadmium telluride thin-film components in parallel, for a total of 16140 components, with a total installed capacity of 2000 kW.

/ Photovoltaic Component Installation Diagram /

 

Another aspect of architectural photovoltaic design to mention is the design of the edge portions of the photovoltaic panels. Since the roof is not a regular square, the edge portions of the parametrically generated photovoltaic panels are not complete rectangles. Therefore, other materials are needed to simulate the effect of photovoltaic panels to achieve overall aesthetic unity. Initially, we tried using the glass material from the photovoltaic panels to create "fake photovoltaics," but this proved too costly. We then used aluminum panels, adjusting the color and gloss to make them virtually indistinguishable from the photovoltaic panels.

/ "Fake Photovoltaics" in the Exterior Design /

 

In the architectural design, we further considered the balance between architectural aesthetics and energy efficiency. After deciding on dark gray photovoltaic panels, we adjusted the architectural design accordingly, including the color of the facade glass and the overall facade color scheme. This involved significant revisions to ensure the building's exterior harmonized with the color of the photovoltaic panels, resulting in the current architectural effect. This demonstrates the close relationship and mutual compromise between function and aesthetics throughout the design process.

/ Coordination and Unity of Photovoltaic and Facade Design /

 

Combination of Photovoltaics and Atrium Skylights

The hotel annex uses a sloped photovoltaic glass roof design in conjunction with the skylight shape, improving natural lighting and ventilation in the deep annex. The angle between the roof and the horizontal plane balances power generation efficiency and indoor spatial feel. Through simulation and comparison of various light transmittance values, a 40% light transmittance photovoltaic glass was ultimately selected, balancing power generation with indoor lighting needs. Solar roof panels were custom-designed according to the architectural plan, with a usable roof area of approximately 2100 square meters and an installed capacity of approximately 230 kW. The skylight glass uses triple-glazed, double-cavity tempered ultra-white glass, with battery chips embedded in the interlayer of the outer double glazing, effectively absorbing solar radiation. ^[3] It also provides heat insulation, reducing the air conditioning load. The sloped photovoltaic glass roof design achieves the optimal balance between indoor transparency and shading, creating a comfortable indoor space.

/ Hotel Indoor Photovoltaic Glass Roof /

 

The Role of BIM Technology in the Project

BIM technology played a vital role in achieving the photovoltaic integration of this project. We used parameterization to guide the implementation of non-linear design results, achieving a visualization of the construction process guided by "physical objects".

The photovoltaic brackets and the main steel structure were deepened simultaneously, guiding the construction of the roof structure system with the concept of integrated construction of steel structure units.

The roof secondary structure layout scheme was fully considered, fully coordinating the construction relationship between the roof structure and roof equipment.

Deepening of the prefabricated installation scheme for the photovoltaic panel secondary structure bracket, reducing the amount of on-site welding work.

/ Multi-professional Integrated Implementation of Photovoltaic Roof System (Drawing: Liu Wen) /

 

Multi-professional Collaboration of Photovoltaic Roof ——Apart from the topmost photovoltaic roof, the large roof of the conference center is very complex, involving multiple disciplines and multi-dimensional specialties, such as photovoltaic columns and the main structure, roof-top wells and pipelines, drainage ditches, etc. When multiple variables are adjusted together, it is difficult to achieve rapid coordination. However, BIM 3D technology can clearly and completely reflect the spatial relationships between these components, even the contradictory relationships in construction methods, in a very short time. Finally, the project underwent multiple rounds of checks and design optimization through the 3D model. ^[4] achieving integrated implementation of the photovoltaic roof.

/ BIM Structural Model under Roof Photovoltaics (Drawing: Liu Wen) /

 

Model Quality Control ——The facade model has always accompanied the design process, updating the model prior to the drawings. The model is used to control the quality of the facade drawings, especially for the non-linear folded surface modeling of the hotel annex. By outputting the unfolded facade through the model, it is convenient for the curtain wall professionals to carry out the layout and detailing of each panel.

BIM Model

Unfolded Drawing

Curtain Wall Detailing Drawing

/ Positive Drawing Based on BIM Model (Drawing: Liu Wen) /

 

Therefore, the professional deepening design and output of deepening drawings based on the BIM model have improved the quality of the drawings, solved the difficulties in construction, optimized various construction technical schemes, and helped the World Top Scientists Forum Permanent Site project to proceed efficiently and with high quality.

/ Roof Photovoltaics Shining under the Setting Sun /

 

 

05.

Conclusion

Building Integrated Photovoltaics

 

The successful application of photovoltaic integration technology in the World Top Scientists Forum Permanent Site project demonstrates its advantages in aesthetics, structural safety, environmental protection, and economic benefits. As an international exchange platform, the BIPV technology adopted by this project will undoubtedly attract global attention and become a model for learning and reference. This successful case not only sets an example for the development of building-integrated photovoltaic technology in China, but also promotes domestic and international exchanges and cooperation in the fields of green buildings and renewable energy utilization.

From the perspective of architects, photovoltaic integrated design is guided by overall design, using photovoltaics as building elements, aiming to explore their rich expressiveness and application potential. This includes adopting appropriate design methods according to different spatial effects, and comprehensively considering the integrated location and materials of the photovoltaic structure to achieve maximum power generation. In actual projects, architects constantly explore and transform research results into design methodologies to provide guidance for photovoltaic integration applications. It is hoped that more architects will increase their acceptance of photovoltaic building integration, actively innovate, and better integrate it into building design.

With the continuous progress of new energy technologies and the increasing demand for energy saving, emission reduction, and green environmental protection in cities, building-integrated photovoltaic technology will be more widely applied. Its market size is expected to gradually expand, becoming a key component of the digitalization and intelligence of modern buildings, committed to creating a more beautiful, comfortable, and environmentally friendly building environment.

 

 

Photographed by: Three Thousand Images

 

References

1. Liang Xiangying. Design and Research of Energy-saving Building System Based on Solar Photovoltaic Technology [J]. Applied Energy Technology. 2009(2):6-9.

2. Hao Bin, Li Xianhui. Discussion on Solar Photovoltaic Building Integration [J]. Construction Technology, 2009, 20(10):32-34.

3. Yan Yan, Sun Bin, Shen Weiwei, et al. Design Strategies and Technical Paths for Large-scale Ultra-low Energy Consumption Public Buildings—Shanghai Free Trade Zone Lingang New Area PDC1-0401 Unit H01-01 Plot Project [J]. Green Building, 2022, 14(2):8-11. DOI:10.3969/j.issn.1004-1672.2022.02.004.

4. Yu Liang. Application Research of BIM in Building-Integrated Photovoltaic Design—Taking the World Top Scientists Forum Permanent Site Project as an Example [J]. Contemporary Architecture, 2024(6):142-144

 

 

Project Information

 

Project Name | World Top Scientists Forum Venue

Construction Unit | Shanghai Noah Port Exhibition Co., Ltd.

Construction Location | Intersection of Haigang Avenue and Huanhu South Third Road, Lingang New Area, Shanghai Free Trade Zone

Building Area | 224,000 square meters

Completion Time | 2022

Design Unit | Hua Jian Group Shanghai Architectural Design & Research Institute Co., Ltd.

Conference Center Interior Design | Hua Jian Group Shanghai Modern Architectural Decoration and Environmental Design Research Institute Co., Ltd.

Landscape Design | Shanghai Institute of Landscape Architecture Design & Research Co., Ltd.

Floodlighting Design | LEOX Lighting (Shanghai) Co., Ltd.

Construction Unit | Shanghai Construction Group Co., Ltd.

 

 

Huajian Group Shanghai Architectural Design and Research Institute Co., Ltd. Project Team

 

Chief Designer | Su Chang, Tan Chunhui, Wang Wenxiao

Project Manager | Ni Jingbo, Tan Chunhui

Architectural Design | Zuo Lei, Chen Di, Gong Xinlei, Tian Xinxin, Gong Zhenqiang, Gan Lu, Chen Zhaoming, Gao Linian, Zhu Heng, Fang Lei, Yan Yang, Li Ni, Ding Dishu, Shu Yi, Zong Tao, Zhong Haocheng, Feng Feng, Shen Yifei

Structural Design | Li Yaming, Liu Hongxin, Jia Shui Zhong, Zhang Zhenlei, Pan Fachao, Zhang Yifang, Sun Qiu Zhi, Huang Bo, Huang Yi

MEP Engineering | Wang Hai Liang, He Jiangbo, Zhou Haishan, Li Kai, Zhang Gaohan, Wei Liang, Yu Zhengqing, Wu Meiling, Wang Miao, Ma Mengcao, Zhou Saiqun, Chen Zeran, Li Tong, Cao Jing, Tu Ju, Li Hanchao, Sheng Liang, Sun Yuzhi, Wu Minyi, Deng Qing, Qu Di, He Le

Curtain Wall Engineering | Li Haiming, Ma Ruifeng, Zhu Taixi, Zhang Hai, Li Fang

Ultra-Low Energy Consumption/Green Building Special Project | Yan Yan, Sun Bin, Shen Weiwei, Xu Yue, Chen Jiale, Hou Mengtian, Shen Qishan

BIM Engineering | Wang Wanping, Liu Wen, Wu Fanfan, Zhu Guangxiang, Du Ming