Common Installation Methods for BIPV (Building-Integrated Photovoltaics)

The concept of BIPV was first proposed by American scholars in the late 1970s. Due to its numerous advantages, including being environmentally friendly, space-saving, and aesthetically pleasing, scholars worldwide have conducted research on BIPV technology. BIPV has evolved from the initial simple stacking of photovoltaic arrays on buildings to a design where the photovoltaic system and building are integrated.Basic Concepts of Building-Integrated PhotovoltaicsBIPV combines existing buildings and solar power generation devices. While performing the functions of traditional buildings, it also generates photovoltaic electricity, providing a portion of power to the load. In addition, for crowded big cities, combining photovoltaic technology with building construction can save a lot of space while achieving photovoltaic power generation. Therefore, building-integrated photovoltaics has significant value and significance for urban use.Classification of Building-Integrated PhotovoltaicsFrom the perspective of the integration of photovoltaic power generation technology and buildings, building-integrated photovoltaics can be divided into two types: (1) Photovoltaic power generation equipment as an additional system of the building. This type usually uses existing buildings as a basis and adds photovoltaic power generation equipment to the building's surface. In the early stages of building-integrated photovoltaic technology, this type was more common. The advantages of this type of building-integrated photovoltaics are easy modification, lower investment, and convenient construction; however, its disadvantages are also obvious. After the renovation, the appearance of the building is usually not in harmony with the architectural design style, resulting in poor aesthetics and making it difficult to achieve ideal results. (2) Photovoltaic power generation equipment integrated with the building. In this type, photovoltaic components are usually part of the building. During the entire design process, photovoltaic components and buildings are considered simultaneously, construction and installation are also carried out simultaneously, realizing a perfect combination of photovoltaic power generation equipment and buildings. It has both power generation and building equipment functions.Application of Building-Integrated PhotovoltaicsBIPV systems can have different operating modes, capable of both grid-connected and off-grid operation. When connected to the grid, excess electricity generated can be fed into the grid; conversely, when electricity generation is insufficient, electricity from the grid is used. For standalone BIPV systems, these are usually suitable for remote areas such as grasslands and deserts where grid access is difficult. At the same time, when solar radiation conditions are good, the surplus electricity produced by the BIPV system can be stored using specialized energy storage devices for use when the light is poor, achieving self-sufficiency.Installation Methods of Building-Integrated PhotovoltaicsPhotovoltaic components can be assembled into customer-required styles, partially or wholly replacing building components. The installation style is determined by several factors, including the performance of the selected photovoltaic components, the architectural design of the building, and the climatic conditions of the project location. Among these, the performance of photovoltaic components plays a decisive role in the entire design process. Currently, the installation methods of building-integrated photovoltaics mainly include the following:Awning-Style Photovoltaic Power Generation SystemFigure 1 shows an awning-style photovoltaic power generation system. The photovoltaic panels in this system are primarily installed as shading facilities. The solar panels provide a good shading and heat insulation effect, effectively reducing air conditioning energy consumption, saving energy, and resulting in a more aesthetically pleasing building appearance compared to general awnings.

Figure 1 Awning-Style Photovoltaic Power Generation System

Tile Photovoltaic Power Generation SystemFigure 2 shows a tile photovoltaic power generation system. As shown in Figure 2, the solar roof tiles of the tile photovoltaic power generation system are different from the conventional distributed grid-connected roof design. The tile photovoltaic power generation system perfectly combines the roof and solar energy. Replacing conventional tiles with solar tiles to create a sloped roof, achieves a perfect combination of design and aesthetics in the field of photovoltaic power generation. However, the disadvantage is that the cost of solar tiles is higher than that of ordinary solar panels, which does not yield better economic returns.

Figure 2 Tile Photovoltaic Power Generation System

Between-Window Photovoltaic SystemFigure 3 shows a between-window photovoltaic system. This system can automatically adjust indoor ventilation, humidity, and temperature according to seasonal changes and external environmental differences while providing electricity. Compared with ordinary tempered glass tops, the between-window photovoltaic system provides more convenient functions and makes full use of building space resources.

Figure 3 Between-Window Photovoltaic System

Wall-Mounted Photovoltaic Power Generation SystemFigure 4 shows a wall-mounted photovoltaic power generation system. As can be seen from Figure 4, the wall-mounted photovoltaic power generation system installs photovoltaic panels directly on the exterior wall of the building. This unique external mounting photovoltaic power generation system makes construction and maintenance simpler. Since the solar system is installed on the exterior wall of the building, the solar cells absorb the external radiation light of the building and generate electricity. This part of the radiation light was originally absorbed by the building surface; therefore, it effectively reduces the radiation energy absorbed by the building, and effectively reduces the indoor temperature level, especially in summer.

Figure 4 Wall-Mounted Photovoltaic Power Generation System

Louver-Style Photovoltaic Power Generation SystemFigure 5 shows a louver-style photovoltaic power generation system. The heat of this photovoltaic building is transferred through the thermal conductivity of the building envelope and the radiation of the windows, which plays an important role in improving the thermal comfort performance of indoor spaces in summer. Unlike other wall-mounted photovoltaics, the adjustable angle of the louver allows the building to maximize light energy utilization and make full use of building space.

Figure 5 Louver-Style Photovoltaic Power Generation System

Skylight Photovoltaic SystemFigure 6 shows a skylight photovoltaic system. The skylights of this system are usually located in the lobbies of buildings, usually in the lobbies of iconic buildings in China, such as museums and science and technology museums. If semi-transparent double-glazed photovoltaic panels are modified or added, it can make more effective use of the building's skylight space while also taking into account lighting needs, and can also showcase the modern atmosphere for these science and technology venues.

Figure 6 Skylight Photovoltaic System

Specific CasesFigure 7 shows Shanghai Hongqiao Station. A photovoltaic power station system was added during the construction process. As shown in Figure 7, the photovoltaic power station system is integrated with the building itself. Photovoltaic power generation devices are installed on the top and part of the facade of Hongqiao Station, with a total capacity of up to 6.5MW.

Figure 7 Shanghai Hongqiao Station

Figure 8 Dubai Bird Island Solar Photovoltaic

In Figure 8, we see Dubai's fashionable photovoltaic system. The roof is not just a roof, but a small power plant. Glass is no longer just glass; it has become a structural wall. The openness of this traditional architecture is not transformative, but creative. He is an architect who focuses on performance, humanity, and narrow-mindedness. Harmonizing aesthetics and lifestyle.Future Research and Development FocusMost of the energy consumed in buildings is used for temperature regulation. Currently, there are some examples of passive solar houses used for heating, but these buildings are relatively expensive and difficult to promote. Active solar houses are even more expensive, making them less valuable to promote. Therefore, future research on solar houses must combine renewable energy with conventional energy. In the implementation of the plan, different schemes can be coordinated according to the functions of the rooms in the building, which can effectively reduce the initial investment of photovoltaic power stations used for building energy supply and improve the operability of the entire scheme. The control and regulation technology of air temperature inside the building should be applied as intelligently as possible, following nature to meet the needs of human health and comfortable life. The purpose of air temperature control and regulation technology should be to minimize the so-called artificial environment. On the premise of using active energy supply to ensure the comfort of living in the building, the active function technology and passive energy supply technology should be combined as much as possible to optimize the cost-effectiveness of solar buildings.SummaryBIPV combines existing buildings and solar power generation devices. Based on the functions of traditional buildings, it adds solar photovoltaic power generation, which can be used to provide electricity for indoor buildings. Photovoltaic building integration is not a simple stacking of photovoltaic power generation systems and buildings, but an organic combination of the two, achieving a 1+1>2 effect.