BIPV (Building-integrated Photovoltaics): It means that photovoltaic modules not only realize the function of photovoltaic power generation but also undertake the functions of building components and building materials. They are designed and constructed simultaneously with the main body of the building and integrated into the building. It is currently the focus of the development of photovoltaic buildings.

The Main Manifestations and Application Scenarios of BIPV

At present, BIPV products can be divided into two forms according to their manifestations: building material type and component type. The "building material type" BIPV integration is more complete, integrating photovoltaic cells completely into building materials, and there may be little difference in appearance from traditional building materials (as shown on the left in Figure 1); while the "component type" BIPV is more inclined to standardized products and is easier to distinguish from traditional building materials in appearance (as shown on the right in Figure 1).

Figure 1. The Manifestations of BIPV

Application Scenarios

Building Roofs

The BIPV roof can be further divided into ordinary roofs and daylighting roofs. Ordinary roofs are generally applied to industrial buildings and have no requirements for the light transmittance of the roof. They are mainly used to replace traditional metal roofs or colored steel tile roofs. Therefore, crystalline silicon photovoltaic cells can be used, with low investment costs and good economic efficiency. At the same time, due to the good sealing and waterproof performance of BIPV equipment, it extends the service life of the roof from the side. Currently, the expected service life of roof BIPV projects can reach more than 50 years.

Building Facades

Considering the problem of daylighting efficiency, currently the BIPV facade is mainly applied to the south facade of buildings (in the Northern Hemisphere). Since most buildings, especially high-rise office buildings, have a large demand for daylighting on the facade, opaque crystalline silicon panel photovoltaic modules cannot be used, and light-transmitting thin-film photovoltaic modules must be used. While the cost of the modules is high, the theoretical energy conversion rate is low. Compared with the roof, the building facade often undertakes more functions, and the installation area ratio of its photovoltaic modules is significantly lower. Compared with the theoretical maximum coverage ratio of 60% to 70% for the roof, the coverage ratio of traditional photovoltaic exterior walls is generally only about 40%, and the coverage ratio of photovoltaic curtain walls is slightly higher, but only about 60%. At the same time, installing light-transmitting BIPV requires the overall demolition and reconstruction of the building facade, which is costly and difficult, and it is not easy to transform general buildings.

Figure 2. The Classification of BIPV Application Scenarios

The Development History and Current Status

The Development History

In 2021, photovoltaic power generation entered the parity stage. With the further decrease in the cost of photovoltaic power generation, it is more favorable to promote BIPV on a large scale. With technological upgrades, the cost of photovoltaic power generation will further decrease and is expected to become the cheapest energy source. Since then, the development of photovoltaics has advanced from being "subsidy-driven" to "demand-driven", entering the parity stage, gradually getting rid of its dependence on financial subsidies, achieving market-oriented and competitive development, and the industry's supporting policies have been continuously improved. The National Energy Administration has clearly stated that in the future, the non-hydropower renewable energy consumption responsibility weight will be used as the basis for the annual installed capacity scale of each province. Except for household photovoltaics, other projects can voluntarily participate in market-oriented transactions to form the on-grid electricity price. The market-oriented electricity price environment will help the development of distributed photovoltaics represented by BIPV, which is conducive to integrating resources for intensive development and promoting healthy competition in the industry.

Figure 3. The Development History of BIPV

The Current Development Status

1) BIPV is still in the initial stage of application

The market operation mechanism has not been perfected, and there are many pain points in the promotion process. For the construction party, the investment is large, the payback period is long, and the construction standards are not clear, which is likely to lead to problems such as inability to pass the inspection; for the user, they need to bear a certain usage cost, and based on considerations of economic benefits and the stability of their own business operations, they may reduce their enthusiasm for use; for the operator, the operation and maintenance cycle is long, they are more sensitive to the stability of the enterprise, and it is easy to have conflicts of interest with the property owner.

2) Currently, whether it is the building material type or the component type of BIPV, there is still a lack of a national standard system

In the past few years, the BIPV industry has still been in the initial stage of development, and there is no accurate and unified concept of "optoelectric buildings" yet. The formulation of relevant standard systems for BIPV in the construction industry is not perfect, mainly relying on internal industry discussions and local plans. This has also led to a lack of a unified standard system with national standards as the main body. Overall, it still takes time to establish a dedicated standard system for BIPV, and in the near future, BIPV will still mainly follow the standards of conventional building materials.

Future Developments and Testing Requirements

As consumers' awareness of green buildings and sustainable development continues to increase, the demand for BIPV products will also continue to grow. Especially in the industrial and commercial fields, users pay more attention to investment returns and energy conservation and emission reduction effects, and BIPV has become an ideal choice for them. The industry chain of building-integrated photovoltaics (BIPV) has been developed and improved, and there is broad prospects for future market economic development. Driven by multiple factors such as technological innovation, policy support, market demand growth, and cross-border cooperation, the BIPV industry will ushering in a broader space for development.

As a component of buildings, BIPV needs to meet the safety requirements of the building structure, including wind resistance, earthquake resistance, fire resistance, and other performances. Therefore, BIPV products need to pass relevant structural safety tests to ensure that their combination with the building is firm and reliable. As a solution provider, Yanzhi Testing provides a complete set of mature BIPV testing equipment for different application scenarios. For specific solutions, please feel free to consult.