Building-integrated photovoltaics (BIPV) | Building truly green buildings

Under the national overall strategic requirements for the "dual carbon" goals, from the government to families, from industry to enterprises, all shoulder the important task of reducing carbon emissions. The huge number of buildings will become an important carrier for reducing carbon emissions. The country has also seen the potential contained therein and is actively promoting the reduction of carbon emissions from buildings.

Under the "dual carbon" goal, with the green recovery of China's economy, the development of the building energy efficiency market has accelerated. Energy-efficient buildings, marked by green buildings, near-zero energy consumption, and ultra-low energy consumption, have begun to shift from energy consumption to the substantive stage of zero-carbon, low-carbon, and ultra-low-carbon buildings or parks. Relevant departments at all levels have gradually become active forces in promoting photovoltaic applications in urban and rural areas.

From the national to the local level, building-integrated photovoltaics (BIPV) is booming.

 

Building-integrated photovoltaics (BIPV) is one of the most effective solutions for building green buildings and has received unprecedented attention since last year. During this year's Two Sessions, the All-China Federation of Industry and Commerce and energy giants submitted their proposals through various channels, calling for the promotion of green buildings and building-integrated photovoltaics (BIPV), including suggestions to increase policy support, provide differentiated electricity price subsidies, further improve national or industry standards, and encourage various provinces and cities to carry out pilot city construction of BIPV.

On December 10 last year, Ren Yuzhi, deputy director of the New Energy Department of the National Energy Administration, said that the National Development and Reform Commission and the National Energy Administration are currently calculating the targets for photovoltaic power generation during the 14th Five-Year Plan and the 15th Five-Year Plan periods. Judging from the current development situation, the demand for photovoltaic power generation during the 14th Five-Year Plan period will be much higher than that during the 13th Five-Year Plan period. To this end, it is necessary to further mobilize the enthusiasm of photovoltaic manufacturing enterprises, photovoltaic power generation enterprises, and other entities. While ensuring the basic income of projects, gradually and orderly promote the participation of new photovoltaic power generation in electricity market transactions, promote the construction of new generation power systems, ensure the access and consumption of large-scale photovoltaic power generation, and the introduction of mandatory national standards for the installation of photovoltaics on buildings.

Not long ago, the Ministry of Housing and Urban-Rural Development and 15 other departments jointly issued opinions on strengthening green and low-carbon construction in county towns, proposing to "reduce the proportion of traditional fossil energy in building energy consumption by improving the proportion of photovoltaic roofs for newly built factories and public buildings and implementing building-integrated photovoltaic development."

National and provincial and municipal governments have intensively introduced relevant policies to encourage the transformation of green buildings.

 

Previously, many places, including Beijing, Tianjin, Shanghai, Chongqing, Inner Mongolia, and Zhejiang, have issued relevant policies on BIPV for the next three to five years. Promoting the large-scale market application and high-quality development of BIPV has been put on the agenda.

Shandong, Fujian, Shaanxi, and Guangdong provinces have recently successively issued notices on the pilot work of promoting distributed photovoltaic power generation in entire counties. In early June, Lian Weiliang, deputy director of the National Development and Reform Commission, also held a symposium and investigation in Shandong Province, specifically listening to opinions and suggestions from relevant parties on the pilot work of promoting the large-scale development of distributed photovoltaic power generation in entire counties.

Among them, Shaanxi Province proposed that various cities should, in accordance with requirements, classify and sort out the number and scale of natural person distributed (household) and non-natural person distributed photovoltaic projects in various counties (districts); organize investigations and assessments of the construction conditions such as the types of rooftops (factories, commerce, and farmers), load-bearing capacity, surrounding obstructions, and grid access. At the same time, various cities should establish special teams, select 2-3 counties (districts) to propose municipal distributed photovoltaic whole-county promotion work plans, and submit the pilot work to the Shaanxi Development and Reform Commission before June 21.

In the document, Fujian Province made it clear that the development and reform commissions of relevant prefecture-level cities should, based on local solar radiation resource conditions and household photovoltaic construction conditions, organize the counties (cities, districts) under their jurisdiction to carry out household photovoltaic whole-county concentrated promotion pilot application work, prioritizing support for areas with good solar radiation resources, and the annual total radiation should generally reach 1250 kWh/㎡.

The BIPV power generation tile project in the Beijing sub-center will be fully completed in 2024.

 

BIPV has a market space of trillions of yuan.

 

Among the two main application modes of photovoltaic power generation, distributed photovoltaic power generation has developed rapidly in recent years. For a country like China with vast territory, different levels of economic development, and uneven resource distribution, the development of distributed photovoltaic power generation is more practical.

Currently, centralized power stations are mostly distributed in the western regions rich in water and coal resources, while distributed power stations are distributed in the central and eastern regions with more developed industry and commerce and social economy.

Attaching photovoltaic modules to traditional roof tiles, this method does not change the building structure, and this is BAPV.

 

In the past, most distributed photovoltaic projects used the BAPV form (ordinary photovoltaic modules, which refer to solar photovoltaic power generation systems attached to buildings, also known as "installed" solar photovoltaic buildings. Its main function is power generation, which does not conflict with the functions of buildings and does not damage or weaken the functions of existing buildings). Due to its large area, the matching beauty of the building is affected, so a new building-integrated photovoltaic (BIPV) form (building material photovoltaic modules) is proposed. By integrating photovoltaic modules and buildings, it becomes an inseparable building component and replaces some building materials.

BIPV, or building-integrated photovoltaics, is a solar photovoltaic power generation system that is designed, constructed, and installed simultaneously with the building and perfectly integrated with the building, also known as "component-type" and "building material-type" solar photovoltaic buildings. As part of the external structure of the building, it has both power generation function and building component and building material functions, which can enhance the aesthetics of the building and perfectly integrate with the building.

It has both power generation function and building component and building material functions, this integration with the building is BIPV.

 

In fact, BIPV was proposed many years ago, but it has not been greatly developed. Now, as more and more enterprises integrate photovoltaic modules and building materials, it has become the focus of attention from all walks of life.

As a new type of building form, BIPV has various application forms and can be used in a series of scenarios such as photovoltaic tiles, skylights, external window shading, and awnings, and has huge development potential. In recent years, the construction of distributed photovoltaic power stations using vacant commercial rooftops has become a unanimous choice for more and more business owners.

Traditional commercial distributed photovoltaic power station construction mainly focuses on installing photovoltaic component products on building rooftops. According to statistics from the China Photovoltaic Industry Association, in current distributed photovoltaic projects, the proportion of photovoltaics + buildings has reached 80%.

According to data from the National Bureau of Statistics and calculations by the China Academy of Building Research, China currently has about 80 billion square meters of existing buildings, and the market currently adds nearly 100 million square meters of skylight tile roof area each year. Once it moves toward large-scale application, BIPV will be a market of nearly one trillion yuan.

An important application form of BIPV—photovoltaic curtain walls

 

BIPV may become the future standard configuration for green buildings

 

Ju Xiaolei, director of the Solar Energy Building Technology Research Institute of China Architecture Design & Research Group Co., Ltd., pointed out: "In design, BIPV can achieve different building energy-saving effects (heat preservation and insulation/ventilated roofs, shading, natural lighting, adjusting indoor lighting/shading, reducing wall temperature) by selecting different installation locations for photovoltaic components (parallel/shade board installation on the roof, skylights/windows, combined installation with building exterior decorative curtain walls/walls) and combining the characteristics of the building itself (whether it is translucent, the degree of translucency, the heat generation of the working state component backplane). Its passive energy-saving benefits can exceed the benefits brought by power generation."

Regarding the application of BIPV in future buildings, Wang Zhidong, chief engineer of photoelectric buildings at the China Academy of Building Research, believes that modern buildings pursue green, environmental protection, and energy saving, and photovoltaics happen to meet this concept.

With the development and progress of photovoltaic materials, photovoltaics and buildings have moved from integration to fusion, and buildings will also move from passively accepting photovoltaics to actively embracing photovoltaics. The future development direction of buildings is energy-efficient and low-carbon buildings. The energy consumption of buildings can be offset by the energy they produce themselves, or even produce more energy than they consume. This requires not only the roof to generate electricity, but also the walls to generate electricity, and BIPV happens to meet these needs. BIPV is the only way for zero-energy passive buildings and will also be the common building form of future buildings.