BIPV Classic Case - Shanghai Jiading Future City Chunxi Collection

Currently, Building Integrated Photovoltaics (BIPV) has become one of the important methods for sustainable energy utilization in green and low-carbon communities, but it still faces the problems of unreasonable design and high cost pressure. This article reviews the research and application status and problems of BIPV in China. Taking the Shanghai Jiading Future City Chunxi Collection project as an example, it describes the architectural design characteristics of the project from the dimensions of form and facade, and analyzes the strategy adaptability, photovoltaic roof target value calculation, economy and aesthetics. Key points for the technical design of integrated rooftop photovoltaics in supporting public buildings in low-carbon communities. At the level of practical application of BIPV, China has successively introduced many policies in recent years, and various places have also repeatedly introduced relevant targeted policies. Especially since this year, adding photovoltaics to buildings has basically become standard, which has promoted the development of the photovoltaic industry. Below, we will look at the relevant green building policies issued by national ministries and commissions and various provinces and cities in recent years.

Time	Issuer	Policy Planning	Key Points
2018	Ministry of Housing and Urban-Rural Development	Key Points of the Ministry of Housing and Urban-Rural Development on Building Energy Conservation and Technology in 2018	Guide areas and cities with the conditions to fully implement green building standards for new buildings, expand the scope of mandatory promotion of green buildings, and strive to achieve 40% of green buildings in new urban buildings by the end of 2018
2018	Ministry of Housing and Urban-Rural Development	New version of "Green Building Evaluation Standard"	The green building evaluation standard has been revised, and a green building evaluation technical standard system has been rebuilt. The main evaluation system consists of safety and durability, health and comfort, living convenience, resource saving, and environmental suitability.
2019	General Office of the State Administration for Market Regulation, General Office of the Ministry of Housing and Urban-Rural Development, General Office of the Ministry of Industry and Information Technology	"Notice on Printing and Distributing the Implementation Plan for Green Building Materials Product Certification"	Jointly promote the certification of green building materials products. According to regulations, green building materials products are subject to graded evaluation and certification, which are divided into one, two, and three stars from low to high. Certified products will be given priority for government projects.
2020	Ministry of Housing and Urban-Rural Development, National Development and Reform Commission and other 7 departments	《关于印发 〈绿色生活创建行动总体方案〉的通知》	Proposed that by 2022, the proportion of green building area in new urban buildings in that year will reach 70%, the number of star-rated green buildings will continue to increase, the energy efficiency level of existing buildings will continue to increase, the health level of residential buildings will continue to improve, the proportion of prefabricated construction methods will steadily increase, the application of green building materials will be further expanded, and green housing users Supervision will be fully promoted, and the people will actively participate in green building creation activities, forming a social atmosphere that advocates green and green living.
2024	Beijing	《北京市装配式建筑、绿色建筑、绿色生态示范区项目市级奖励资金管理暂行办法》	1. Projects that meet Beijing’s "Green Building Evaluation Standard" (DB11/T825-2015) or national special standards such as "Existing Building Green Renovation Evaluation Standard" (GB/T51141) and "Green Hospital Building Evaluation Standard" (GB/T51153) and obtain two-star and three-star green building operation labels will be given a reward of 50 yuan/square meter and 80 yuan/square meter respectively, and the maximum reward for a single project will not exceed 8 million yuan. 2. Projects that obtained construction project planning permits before April 1, 2016 and obtained green building two-star and three-star operation labels in accordance with Beijing’s "Green Building Evaluation Standard" (DB11/T825-2011) will be given 11.25 yuan/square meter and 20 yuan/square meter respectively. reward funds. 3. Prefabricated building projects that have already enjoyed reward funds and have obtained two-star and three-star green building operation labels will be given an additional reward of 30 yuan/square meter and 60 yuan/square meter respectively, and the maximum additional reward fund for a single project will not exceed 5 million yuan.
2024	Shanghai	《上海市建筑节能和绿色建筑示范项目专 项扶持办法》	1. For projects that meet the green building demonstration, two-star green building operation label projects will be subsidized 50 yuan per square meter, and three-star green building operation label projects will be subsidized 100 yuan per square meter. 2. For projects that meet the assembled monolithic building demonstration, AA level will be subsidized 60 yuan per square meter, and AAA level will be subsidized 100 yuan per square meter. 3. Projects that meet the ultra-low energy consumption building demonstration will be subsidized 300 yuan per square meter. 4. For projects that meet the demonstration of renewable energy and building integration, those using solar thermal energy will be subsidized 45 yuan per square meter of benefiting area; those using shallow geothermal energy will be subsidized 55 yuan per square meter of benefiting area. 5. The maximum reward for a single demonstration project is 6 million yuan, and the subsidy funds for existing building energy-saving renovation demonstration projects shall not exceed 30% of the total investment of the project.
2024	Zhejiang Province	《浙江省深化推进新型建筑工业化促进绿 色建筑发展实施意见》	New building industrialization projects that have obtained the national green building two-star (including 2A residential performance certification) and three-star (including 3A residential performance certification) labels shall be subject to the "Implementation Opinions on Accelerating the Development of Green Buildings in China" (Cai Jian [2012] No. 167) of the Ministry of Finance and the Ministry of Housing and Urban-Rural Development. ) provides financial rewards.
2024	Jiangsu Province	《江苏省绿色建筑发展专项资金管理办法》	Focusing on the green building development plan and the Jiangsu Construction 2025 Action Outline, the special fund will focus on supporting the following aspects: 1. High-quality integrated construction of green urban areas, high-quality green building label projects; 2. Integrated application of renewable energy buildings, smart buildings, and ultra-low energy consumption buildings; 3. Existing building large-scale energy-saving renovation, existing building green renovation, contract energy management; 4. Lean construction, digital construction, green construction and assembled construction and other new construction methods in green building comprehensive integration application projects; 5. Other projects that are conducive to promoting the high-quality development of green buildings.
2024	Shandong Province	《山东省省级建筑节能与绿色建筑专项资金管理办法》	The green building demonstration reward standard is: 15 yuan/square meter (construction area, the same below) for one-star, 30 yuan/square meter for two-star, and 50 yuan/square meter for three-star, and the maximum for a single project is 5 million yuan.

 

Shanghai is one of the most economically developed cities in China and also a region with abundant solar energy. Shanghai has also issued a series of incentive policies for BIPV, and many excellent BIPV project cases have emerged, such as the World Top Scientists Forum venue, Digital Jianghai "Vertical Factory", etc.

Project Overview

The Shanghai Jiading Future City Chunxi Market is located at the southeast corner of the intersection of Hezuo Road and Yunyi Road in the core area of Jiading New City, as shown in the figure below. The total above-ground construction area is 30086.36 square meters. The design adheres to the systematic community composition logic of "block - street - corner - commerce", creates a community atmosphere through functional integration, and builds future life scenarios based on green, low-carbon ecological technologies.

The architectural form makes full use of the staggered slopes to form a high and sunny indoor space. Under the overall large roof, the building scale is adjusted through the height difference of the roof. The roof is raised corresponding to the atrium space and lowered corresponding to the entrance space, forming rich high clerestory windows to introduce light into the interior. The building facade is based on the staggered roof to create the facade of the main street. Recessed platforms are set on the second floor to enrich the street facade, and the overhanging eaves are fully utilized, and the recessed platforms on the second floor and the large-area floor-to-ceiling transparent facade are used to create a light and flexible building facade and create positive interactive scenes.

The architectural form and facade constitute the architectural heritage of the project, laying a good foundation for the design of BIPV.

BIPV insertion

Under the requirements of local policies, the project must meet the standards of near-zero carbon buildings and national three-star green buildings, which requires the project to use a variety of targeted low-carbon design techniques in order to pass the star rating standards. Inserting photovoltaics into buildings is one of the most cost-effective and targeted methods among many design methods. Inserting photovoltaics to create a BIPV project can bring many benefits in the later operation process.

However, the addition of photovoltaic systems is not simply to complete green building indicators. Under the current requirements, the application of roof photovoltaics needs to be comprehensively considered from the perspectives of policy response, technical utilization effect, and economy, and form a systematic layout plan. When determining the target value of roof photovoltaic area, it is also necessary to comprehensively consider meteorological data, roof light resource distribution before performing specific calculations.

Economic analysis of roof photovoltaics

• Photovoltaic module selection

The more mature photovoltaic modules are currently crystalline silicon and thin film, among which crystalline silicon has an absolute advantage in market share, and thin film modules are mainly used for BIPV; the main differences between the two types of modules are in power generation efficiency, appearance, and weight load, etc., but both can be customized in color and pattern according to architectural design needs, which will affect the power generation power to a certain extent. Since this building is a near-zero energy consumption building, it is estimated that at least 120,000 kW·h of electricity needs to be generated annually. Considering the requirements of appearance, greenness, and price, high-efficiency monocrystalline silicon modules are selected.

After calculation, a total of 464 monocrystalline silicon photovoltaic modules are used on the roof of the market, with dimensions of 1722 mm×1134 mm×30 mm, a maximum power of 396 W, a working voltage of 31.32 V, and a working current of 11.37 A. The efficiency of the photovoltaic modules is no less than 22.3%, the area of the photovoltaic modules is 906 square meters, which meets the roof photovoltaic ratio of about 43%, and the total installed capacity is 165.184 kWp, accounting for more than 4% of the total power consumption of the market. A schematic diagram of the photovoltaic module layout is shown below.

• Photovoltaic component installation angle

Based on the photovoltaic calculation software PVsyst, analyze the impact of different installation tilt angles and azimuth angles of photovoltaics on photovoltaic power generation efficiency in Shanghai. According to the geographical location of Shanghai, considering higher power generation benefits, it is recommended that the roof photovoltaics be installed facing south, and the optimal horizontal tilt angle range is 20°～ 30°, which can achieve the maximum power generation efficiency.

• Investment recovery period of roof photovoltaics

The high initial investment cost and long investment recovery period of BIPV are important reasons restricting the development of BIPV projects. This project was earlier, and of course, the calculated investment recovery period is 8 years, but with the progress of technology, the economic value is more prominent from the perspective of current power generation efficiency and cost.

The incremental cost of the project is calculated as follows. The photovoltaic part of this project uses 120kW, and the unit cost is about 5 yuan/W, with a total incremental cost of 600,000 yuan. After the comprehensive application of other measures, 419,000 kW·h of electricity can be saved annually. Calculated by standard coal consumption, a total of 120.69 t of standard coal can be saved annually, and the carbon reduction is 43.1 t, which has good green benefits.

BIPV aesthetics

After determining the roof photovoltaic area and the number of photovoltaic panels, it is necessary to determine the combination form with the roof. The traditional roof practice is that a large number of mechanical and electrical equipment pipelines and roof outlets are placed, which makes the plane and elevation facade more cluttered and affects its aesthetics. In order to ensure the overall beauty and coordination of the building, it is required to consider the combination of shielding equipment and photovoltaic systems in the design stage. The photovoltaic panels adopt BIPV, and the photovoltaic panels are used as part of the roof structure, emphasizing the integrity of the roof and without the need to add additional maintenance space. At the same time, in order to increase the rich effect of the roof, a variety of forms such as planting roof, metal roof, and photovoltaic metal double-layer ventilated and insulated roof are combined to maximize the overall and architectural aesthetic requirements of the roof. A schematic diagram of the location of the photovoltaic panels of the project is shown in the figure below.

Application of "PV-ESS-DC" system

The project's roof space is equipped with 464 monocrystalline silicon photovoltaic glass, accounting for 43% of the entire roof area. In order to better obtain benefits, the project adopts a grid-connected mode of "self-generation for self-use, and surplus electricity to the grid". The project will combine community electricity consumption to make a renewable energy utilization layout for the entire community, comprehensively consider the rational use of resources, and configure a "PV-ESS-DC" system. The project is also equipped with energy storage. The entire energy storage system is equipped with electrochemical energy storage batteries and electric vehicle power batteries, realizing distributed energy storage functions, perfectly combining the energy storage needs of building energy consumption and automobile energy consumption, and has the ability to participate in the flexible regulation of the overall building electricity consumption. At the DC power distribution end, photovoltaics, electric vehicles, energy storage batteries, and the municipal power grid jointly supply power to lighting, central air conditioning, DC charging piles, etc. This forms a completely closed-loop "PV-ESS-DC" system and is intelligently controlled to achieve effective energy utilization.

Summary

As an important way for green and low-carbon buildings to rationally utilize renewable energy, BIPV is the result of a balanced coordination of economy and aesthetics, and it is also the development direction of the current advocacy of green energy conservation and low-carbon communities. Facing the current difficulties of BIPV in design and cost, the Jiading Future City Chunxi Market project has made a new exploration in the design and economy of BIPV, which can be used as a reference for other similar projects.