Trillion-scale Building-Integrated Photovoltaics (BIPV) Boom! A Comprehensive Overview of Project Plans and Application Design

Building-Integrated Photovoltaics (BIPV) integrates photovoltaic components with building materials, transforming traditional buildings into energy-efficient structures capable of generating electricity, thereby driving a shift from energy consumption to energy conservation and production in the construction industry.

In 2022, the Ministry of Housing and Urban-Rural Development and the National Development and Reform Commission jointly issued the "Implementation Plan for Carbon Peak in the Urban and Rural Construction Field," which explicitly states: Promoting the construction of building-integrated photovoltaics, striving to achieve a photovoltaic coverage rate of 50% for newly built public institution buildings and newly built factory rooftops by 2025. According to calculations by Guotai Junan Securities, the total potential installed capacity of BIPV is approximately 1500-2000GW, corresponding to a market size of 7.5-10 trillion yuan! In today's article, I will detail the design process, application forms, and project return calculation content of BIPV. I have found 5 plans for friends to refer to, helping everyone understand the entire project process.

Table of Contents

1. Practical BIPV Project Plans

2. Four Application Forms of BIPV

3. Design Principles of BIPV Projects

4. BIPV Investment Return Analysis

30601. Practical BIPV Project Plans

I have compiled BIPV project plans and return calculation plans. The following are screenshots of some of the content. If you need to download the complete set of plans, please contact "Low-carbon New Style".

1. BIPV Project Installation Plan

2. BIPV Project Design Plan

3. BIPV Project Technical Plan

4. BIPV Project Return Calculation

5. BIPV Project Case Introduction

30602 Four Application Forms of BIPVWith the rapid development of the construction industry and the ingenuity of architectural designers, the forms of building envelopes are becoming increasingly diverse. As a deeper manifestation of building envelope structures, building-integrated photovoltaics has also appeared in a variety of application forms on buildings. Below are several application forms of BIPV in buildings for your reference.Skylights: Ideal lighting, high power generation efficiency; Curtain walls: Good demonstration effect, diverse forms, beautiful; Sunshades: Both block sunlight and generate electricity to supplement energy; Railings and floors: Make full use of space, simple and convenient installation.

Application of BIPV in Buildings

1. Photovoltaic Glass Curtain WallInstall photovoltaic curtain walls in the interlayer areas of glass curtain walls with sufficient lighting and facade areas that require sunshade design, integrating building decoration, building sunshade, and power generation. Its structural principle is exactly the same as that of glass curtain walls, and the curtain wall form can be made into various forms such as full hidden frame, full bright frame, and semi-hidden frame. The photovoltaic glass curtain wall system can be customized according to the project or the original curtain wall system can be structurally modified; the back of the photovoltaic panel can be lined with different colors to adapt to different architectural styles. The photovoltaic curtain wall integrates power generation, sound insulation, heat insulation, and decoration functions, combining photovoltaic technology with curtain wall technology, representing a new direction in the development of curtain wall technology. It collects, converts, stores, and transforms natural light through solar cells and semiconductor materials, and finally connects to the building's power supply network to provide reliable power support for the building.

Photovoltaic Curtain Wall Node Diagram

2. Photovoltaic Glass SkylightGlass skylights are components of buildings. As the span of buildings becomes larger and larger, the indoor lighting of buildings cannot be met by building curtain walls and windows, so glass skylights need to be set up on large-span roofs for indoor lighting. The innovative design combining photovoltaic glass components and skylights allows green building design to be integrated into the entire construction process. Structurally, a horizontal hidden vertical bright semi-hidden frame design is adopted. For those with fire protection requirements, the fire protection requirements of building roofs must be met. For photovoltaic skylights without fire protection requirements, point-supported glass skylights and aluminum alloy frame glass skylights can be used.

Photovoltaic Skylight Node Diagram

3. Photovoltaic RailingRailings are important protective components of building safety protection facilities. In locations with good orientation and sunlight, using photovoltaic glass instead of common glass and metal can not only meet safety protection needs but also utilize solar power generation, achieving two goals with one action; innovative design combining photovoltaic glass and railings, structurally safe and reliable, perfectly hiding lines and junction boxes for better aesthetics, and simple and convenient construction.

Photovoltaic Railing Node Diagram

4. Photovoltaic AwningPhotovoltaic awnings are one of the most promising forms of building photovoltaic applications in the future, with the following three advantages: At a reasonable installation angle, it is conducive to the photovoltaic components maximizing the reception of solar radiation, improving the efficiency of photoelectric conversion; it can block sunlight from entering the room, which is conducive to controlling and adjusting the indoor temperature, reducing the air conditioning load of buildings, and playing a role in energy saving and emission reduction; photovoltaic components, as a new type of building sunshade component, can save sunshade materials and enrich the building.

Photovoltaic Awning Node Diagram

30603. Design Principles of BIPV ProjectsThe design of a building-integrated photovoltaic system mainly includes the design of the photovoltaic system and the design of the building system. The design of the photovoltaic system is to match the power consumption requirements of the load side based on the specific scene of the site, calculate the appropriate solar component array based on the solar energy resources, temperature, and other environmental factors of the project location, match the corresponding equipment capacity, and achieve the economic rationality of the overall system. The design of the building system is that as part of the building structure, it needs to meet the requirements of use performance, and secondly, it needs to meet the requirements of structural stability, economy, and aesthetics.1. Design Principles of Photovoltaic SystemThe design process of a solar grid-connected power generation system mainly involves electrical engineering, thermal engineering, electrostatic shielding engineering, and mechanical engineering, etc. The key process is to analyze the environmental resource conditions on site, match the power consumption demand, and balance the system. The overall design principle of the system is to determine the most economical system combination on the premise of maximizing power generation. The system configuration design mainly considers two factors: analyzing power consumption demand, environmental resources, and main equipment selection; using professional simulation software for simulation and comparison and verification. Input data mainly includes:

Insolation of the installation location

Insolation of the inclined surface of the array

Ambient temperature parameters

System voltage

Load energy demand

Controller adjustment characteristics and parameters

Characteristic parameters of solar photovoltaic modules

System power reliability and power supply availability

The results parameters calculated by computer simulation methods are mainly:

Tilt angle and azimuth angle of the solar array

Number of solar photovoltaic modules

2. Design steps of solar power generation system
Step 1: List the basic dataGeographical data mainly includes Address, longitude and latitude, altitude, etc. Local meteorological data: mainly includes monthly average total solar radiation, direct radiation and scattered radiation, annual average temperature and highest and lowest temperatures, continuous rainy days, maximum wind speed and special climate conditions such as ice and snow. Generally, the accumulated meteorological data of the past 20 years is selected.Step 2: Calculate daily radiation and array tilt angleMeteorological stations generally only provide horizontal surface total radiation, direct radiation and scattered radiation, which need to be converted into solar radiation on the inclined surface according to the project's tilt angle.Step 3: Estimate the solar arrayUsing the annual average monthly average horizontal surface direct solar radiation and scattered radiation to calculate the monthly total radiation, and then calculate the annual average daily total solar radiation and the power generation of the solar array.Step 4: Determine the power capacity of the solar arrayAccording to the current, voltage and power data of the solar photovoltaic array, and referring to the performance parameters of the host equipment, select the appropriate equipment Model and quantity.3. Design steps of solar power generation system - Design of building structure systemBuilding-integrated photovoltaic systems can be installed on the roofs of industrial plants to replace the original enclosure structure, adding power generation function to the plant roofs. According to the different product structures, the mainstream products are divided into: building solar photovoltaic laminated glass, component type, water diversion rack and metal backplane type.(1) Building solar photovoltaic laminated glass

Building solar photovoltaic laminated glass products integrate solar cells and one or more layers of glass. The structure is composed of two layers of glass on the top and bottom to encapsulate the solar cells, and the glass and solar cells are connected by an internal heat-melting adhesive film. It is the smallest power generation unit that can independently provide DC output. Specifically, it can be divided into two forms according to the combination method of solar cells and glass: lamination to glass with interlayer and direct installation in the cavity of multilayer glass units. The panel material uses double-layer glass. The Model, Size and related parameters of the glass can be customized according to the building requirements. It can be a composite of ordinary tempered glass, ultra-white tempered glass, low-e glass, colored glass and other original sheets, and can also be combined into better-performing single-layer hollow, glued vacuum glass types. The intermediate layer sealing material should be polyvinyl butyral (PVB for short), mainly composed of resin, plasticizer and other materials. It has the characteristics of transparency, heat resistance, cold resistance, moisture resistance, high mechanical strength, and has a 50-year service life with the building.

(2) Integrated component of crystalline silicon photovoltaic and pressed steel plate

The integrated component of crystalline silicon photovoltaic module and roof pressed steel plate mainly includes crystalline silicon solar power generation module, pressed steel plate and their connecting parts, referred to as component-type building-integrated photovoltaic system. Structurally, it can be a complete whole and maintain structural connection characteristics when subjected to external loads. It can be used as the smallest independent power unit. The core photovoltaic roof of this system is mainly composed of purlins, insulation cotton, waterproof breathable membrane, sliding support, pressed steel plate and photovoltaic modules from top to bottom, compatible with the hidden and exposed insulation systems and installation methods of conventional industrial plant purlins. The photovoltaic module uses 2mm tempered glass, front EVA film, high-efficiency monocrystalline Perc cells, polyolefin elastomer encapsulating insulating film (POE for short) and tempered glass. At the same time, the deformation of the battery caused by external force is lower, and the component support structure is changed from the traditional four-point support to a strip support with a span of 30cm, which makes the component force more balanced and greatly reduces the component hidden cracks caused by external force during use, realizing the reliable guarantee of system power generation. The metal roof system uses 0.6mm thick galvanized aluminum zinc steel plate with full-length Model, that is, the whole steel plate from the ridge to the eaves is used without overlapping, which can effectively reduce the risk of leakage caused by overlapping seams. The longitudinal overlapping of the pressed steel plate adopts 360-degree upright lock edge technology to ensure reliable and leak-proof connection between steel plates; in addition, the lock edge gap is also filled with butyl rubber, which can effectively prevent seepage caused by capillary phenomenon.

(3) Water diversion bracket type

The water diversion bracket building-integrated photovoltaic system mainly includes horizontal and longitudinal water diversion channels, conventional solar modules, fixed pressure blocks, rubber strips, edges and other parts, which meet the basic requirements of building water seepage prevention, settlement resistance and expansion and contraction prevention. At the same time, it can resist high wind load, snow load, good lighting performance, good ventilation performance, and can also insulate and heat-proof and waterproof. It is relatively easy in the later operation and maintenance stage. The roof water diversion function mainly relies on the natural drainage of the component surface, and a small part of the water flows to the drainage channel below under the action of pressure difference, and then is discharged through the vertically intersecting drainage channels of the horizontal U-shaped waterproof channel and the longitudinal W-shaped water diversion channel. The short side of the horizontal contact of the component is fixed with a pressure block, and the long side of the longitudinal contact of the component is fixed with a T-shaped rubber strip. The water diversion channel can also play the function of fixing the solar module.(4) Metal backplane typeThe metal backplane type building-integrated photovoltaic system uses galvanized aluminum alloy backplane as the backplane of the solar module to form a lock structure, replacing or covering the roof installation method. Among them, the front of the solar module uses tempered glass, with a front static load of 3600Pa, and the middle composite photovoltaic power generation layer constitutes a non-combustible composite material structure with external dimensions of 2100*1400mm. As shown above, the current building-integrated photovoltaic systems applicable to industrial plant roofs are mainly divided into four categories: building solar photovoltaic laminated glass, integrated component type, water diversion rack and metal backplane type. With the progress of technology, there are already completed cases of various products for research.3060

 

4. BIPV investment return analysis 1. Investment recovery period and rate of returnA simple model is constructed and calculated for the investment economics of typical industrial and commercial BAPV/BIPV photovoltaic roofs. It is assumed that the investor and electricity user of the photovoltaic roof are the same entity, and all photovoltaic power generation is for self-use. Due to the gaps between photovoltaic components in the actual installation of BAPV, the actual effective power generation area will be lower than that of BIPV under the same conditions. We assume that the actual effective power generation area ratio of BIPV is 95%, and that of BAPV is 85%. The project construction period is 0.25 years, and the operation period is 25 years; the power generation efficiency of photovoltaic components decreases by 5% in the first five years, and then linearly decreases at a rate of 0.5%/year, with a total decrease of 14% in 25 years; in terms of subsequent maintenance costs, BAPV is 0.06 yuan/watt·year, and BIPV is 0.04 yuan/watt·year. In addition, the BAPV project needs to replace the color-coated steel roof once after 15 years of operation, with the cost calculated at 300 yuan/㎡; in terms of electricity Price, the average industrial electricity Price of 0.73 yuan/kWh is used. Assuming the installation of a 2000㎡ photovoltaic roof, the estimated power generation in the first year after completion is 298,000 kWh for BAPV and 380,000 kWh for BIPV. If the owner initially chooses to invest entirely with their own funds, the estimated payback period for the BAPV project is 5.87 years, and IRR=15.25%; the estimated payback period for the BIPV project is 5.87 years, and IRR=16.36%; if the owner chooses loan investment, with an annual interest rate of 6% and a loan term of 5 years, the estimated payback period for the BAPV project is 7.32 years, and IRR=34.02%; the estimated payback period for the BIPV project is 7.31 years, and IRR=35.33.2. Impact of surplus grid-connected ratio on investment returnsIf the owner cannot consume all the power generation, or if the photovoltaic investor and the building owner are not the same entity, part or all of the project's power generation needs to be grid-connected and sold. Because the current Price for selling surplus photovoltaic power to the grid is generally lower than the industrial electricity Price, the higher the surplus grid-connected ratio, the lower the return rate of the rooftop photovoltaic project. Assuming that the after-tax Price of surplus photovoltaic power grid-connected is 0.42 yuan/kWh, if the surplus grid-connected ratio is 20%, the payback period of photovoltaic projects with self-funded investment will be extended to 6-7 years; the payback period of photovoltaic projects with loan investment will be extended to about 8 years. If the photovoltaic investor is not the building owner, and chooses to sell all the power generation to the grid, the payback period for self-funded investment in BIPV is about 10 years, and the payback period for loan investment in BIPV projects exceeds 13 years.In other words, the higher the proportion of self-use power generation in industrial and commercial building photovoltaic projects, the better the investment returns.According to the current energy consumption of industrial and commercial buildings in China, the power generation of building photovoltaic projects is still not enough to cover the electricity consumption of the building itself. Taking a typical four-story commercial building in China as an example, with a floor area of 34,300㎡, the monthly electricity consumption is about 1.61 million kWh. Assuming that the roof is renovated with BIPV photovoltaic, the estimated monthly power generation is only about 480,000 kWh. Therefore, the power generation of building photovoltaics can basically be consumed by the building itself, and there is no need to sell it to the grid. It is expected that most building photovoltaic projects will be mainly for self-use in the short term.3. Impact of sunshine duration on the investment return of BIPV projectsThe annual average effective sunshine duration of the photovoltaic project location will directly determine the amount of photovoltaic power generation, which is an important factor affecting the return of photovoltaic roofs. In China, the regions with the longest annual average effective sunshine duration, such as Xinjiang and Tibet, can reach more than 1600 hours, while the shortest, such as Chongqing, is only about 700 hours. Taking the BIPV project as an example, assuming that the local annual average effective sunshine duration is 800 hours, the payback period for self-funded investment is 7.49 years, and the payback period for loan investment is 9.35 years. If the annual average effective sunshine duration is 1300 hours, the payback period for self-funded investment is 4.42 years, and the payback period for loan investment is 5.51 years.4. Impact of construction cost on the investment return of BIPV projectsIn 2021, the average bid Price for distributed photovoltaic EPC projects in China was around 4 yuan/watt, with the highest bid Price in 2021Q4 being 4.75 yuan/W and the lowest being 3.32 yuan/W. From some rooftop distributed photovoltaic projects in February 2022, the unit Price is between 3.42 and 4.95 yuan/W. If the average Price of building photovoltaics in China further decreases to 3 yuan/W in 2025, assuming that the future industrial electricity Price in China remains unchanged, then by 2025, the payback period for self-funded investment in BIPV photovoltaic roof projects can be reduced to 4.67 years, and the internal rate of return is expected to reach more than 20%; the payback period for loan investment in BIPV photovoltaic roof projects is expected to be 5.82 years, and the internal rate of return exceeds 60%.