Classic BIPV Case - Shanghai Jiading Future City Chunxi Collection

Currently, Building-Integrated Photovoltaics (BIPV) has become one of the important methods for sustainable energy use in green low-carbon communities, but it still faces challenges such as unreasonable design and high cost pressure. This article reviews the current research and application status and issues of BIPV in China, taking the Shanghai Jiading Future City Chunxi Collection project as an example. It describes the architectural design features of the project from dimensions such as form and facade, and analyzes key points in the design of photovoltaic integration technology on public building roofs in low-carbon communities from the perspectives of strategy adaptability, photovoltaic roof target value calculation, economy, and aesthetics. In terms of practical application of BIPV, China has introduced many policies in recent years, with various local governments repeatedly issuing 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 review the green building-related policies issued by national ministries and provincial and municipal governments in recent years.

Time	Issuing Authority	Policy Plan	Key Points
2018	Ministry of Housing and Urban-Rural Development	"2018 Work Priorities for Building Energy Efficiency and Technology by the Ministry of Housing and Urban-Rural Development"	Guide regions and cities with conditions to fully implement green building standards for new buildings, expand the mandatory promotion scope of green buildings, and strive to have green buildings account for 40% of new urban buildings by the end of 2018.
2018	Ministry of Housing and Urban-Rural Development	New Version of "Green Building Evaluation Standard"	Revised the green building evaluation standards and reconstructed the technical standard system for green building evaluation. The main evaluation system consists of safety and durability, health and comfort, convenience of life, resource saving, and environmental livability.
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 Issuing the Implementation Plan for Green Building Material Product Certification"	Jointly promote the certification of green building material products. According to regulations, green building materials are certified with graded evaluation from low to high as Level 1, 2, and 3. Certified products will be given priority in government projects.
2020	Ministry of Housing and Urban-Rural Development, National Development and Reform Commission and 7 other departments	"Notice of the National Development and Reform Commission on Issuing the Overall Plan for the Green Life Creation Action"	Propose that by 2022, green building area in newly built urban buildings will account for 70%, the number of star-rated green buildings will continue to increase, the energy efficiency level of existing buildings will continuously improve, residential health levels will steadily enhance, the proportion of prefabricated construction methods will steadily rise, the application of green building materials will further expand, green housing user supervision will be fully promoted, and the public will actively participate in green building creation activities, forming a social atmosphere that advocates green living.
2024	Beijing Municipality	"Interim Measures for the Management of Municipal Reward Funds for Prefabricated Buildings, Green Buildings, and Green Ecological Demonstration Zone Projects in Beijing"	1. Projects meeting Beijing's "Green Building Evaluation Standard" (DB11/T825-2015) or national standards such as "Existing Building Green Renovation Evaluation Standard" (GB/T51141) and "Green Hospital Building Evaluation Standard" (GB/T51153) and obtaining Level 2 or Level 3 green building operation marks will receive reward funds of 50 RMB/square meter and 80 RMB/square meter respectively, with a maximum reward of 8 million RMB per project. 2. Projects that obtained construction planning permits before April 1, 2016, and received Level 2 or Level 3 green building operation marks according to Beijing's "Green Building Evaluation Standard" (DB11/T825-2011) will receive reward funds of 11.25 RMB/square meter and 20 RMB/square meter respectively. 3. Prefabricated building projects that have already received reward funds and then obtain Level 2 or Level 3 green building operation marks will receive additional reward funds of 30 RMB/square meter and 60 RMB/square meter respectively, with a maximum additional reward of 5 million RMB per project.
2024	Shanghai Municipality	"Shanghai Building Energy Efficiency and Green Building Demonstration Project Special Support Measures"	1. For projects meeting green building demonstration standards, Level 2 green building operation mark projects receive a subsidy of 50 RMB per square meter, and Level 3 projects receive 100 RMB per square meter. 2. For projects meeting prefabricated integrated building demonstration standards, AA level projects receive 60 RMB per square meter, and AAA level projects receive 100 RMB per square meter. 3. For ultra-low energy consumption building demonstration projects, a subsidy of 300 RMB per square meter is provided. 4. For renewable energy and building integration demonstration projects, those using solar thermal energy receive 45 RMB per square meter of benefited area; those using shallow geothermal energy receive 55 RMB per square meter of benefited area. 5. The maximum reward for a single demonstration project is 6 million RMB. Subsidy funds for existing building energy-saving renovation demonstration projects shall not exceed 30% of the total investment of the project.
2024	Zhejiang Province	"Implementation Opinions on Deepening the Promotion of New Building Industrialization to Promote Green Building Development in Zhejiang Province" 色建筑发展实施意见》	For new building industrialization projects that have obtained national green building Level 2 (including 2A residential performance certification) and Level 3 (including 3A residential performance certification) marks, financial rewards will be given according to the Ministry of Finance and Ministry of Housing and Urban-Rural Development's "Implementation Opinions on Accelerating the Development of Green Buildings in China" (Cai Jian [2012] No. 167).
2024	Jiangsu Province	"Jiangsu Province Green Building Development Special Fund Management Measures"	Focusing on green building development plans and the Jiangsu Construction 2025 Action Plan, the special fund mainly supports the following aspects: 1. High-quality integrated construction of green urban areas and high-quality green building certification projects; 2. Application of renewable energy building integration, smart buildings, ultra-low energy consumption buildings; 3. Large-scale energy-saving renovation of existing buildings, green renovation of existing buildings, contract energy management; 4. Lean construction, digital construction, green construction, and prefabricated construction and other new construction methods in comprehensive application projects of green buildings; 5. Other projects conducive to promoting high-quality development of green buildings.
2024	Shandong Province	"Shandong Province Provincial Building Energy Efficiency and Green Building Special Fund Management Measures"	Green building demonstration reward standards are: Level 1 - 15 RMB/square meter (building area, same below), Level 2 - 30 RMB/square meter, Level 3 - 50 RMB/square meter, with a maximum of 5 million RMB per single project.

 

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

Project Overview

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 30,086.36 square meters. In the design, the systematic community composition logic of "block - street - street corner - commerce" is adhered to, creating the community's vitality through functional integration, and building future living scenarios based on green low-carbon ecological technology.

The architectural form fully utilizes the staggered sloped roofs to create spacious and sunlit indoor spaces. Under the overall large roof, the building scale is adjusted through the varying heights of the roof; the roof is raised corresponding to the atrium space and lowered at the entrance space, forming abundant high side windows to bring light indoors. The building facade is designed based on the staggered roof to create the main street facade. On the second floor, setback spaces enrich the street-facing facade, making full use of the overhanging eaves and the second-floor setbacks combined with large transparent floor-to-ceiling facades to create a light and dynamic building facade and foster active interactive scenes.

The architectural form and facade constitute the project's architectural foundation, laying a good basis for designing BIPV.

BIPV Insertion

Under local policy requirements, the project must achieve near-zero carbon building standards and the national green building three-star standard, requiring the targeted use of multiple low-carbon design methods to pass the star certification. Integrating photovoltaics into the building is a cost-effective and targeted approach among many design methods. Incorporating photovoltaics to create a BIPV project can bring significant benefits during later operation.

However, adding a photovoltaic system is not simply to meet green building indicators. Under current requirements, the use of rooftop photovoltaics needs to be comprehensively considered from policy response, technical utilization effectiveness, and economic perspectives to form a systematic layout plan. When determining the target rooftop photovoltaic area, it is also necessary to comprehensively consider meteorological data and rooftop solar resource distribution before proceeding with specific calculations.

Economic Analysis of Rooftop Photovoltaics

• Photovoltaic Module Selection

Currently, the more mature photovoltaic modules are crystalline silicon and thin-film. Among them, crystalline silicon holds an absolute market share advantage, while thin-film modules are mainly used for BIPV. The main differences between the two types lie in power generation efficiency, appearance, and weight load. However, both can be customized in color and pattern according to architectural design needs, which may affect power generation to some extent. Since this building is a near-zero energy building, it is calculated that at least 120,000 kWh must be generated annually. Considering appearance, environmental friendliness, and cost, high-efficiency monocrystalline silicon modules are selected.

After calculation, the market roof uses a total of 464 monocrystalline silicon photovoltaic modules, each measuring 1722 mm × 1134 mm × 30 mm, with a maximum power of 396 W, operating voltage of 31.32 V, operating current of 11.37 A, photovoltaic module efficiency not less than 22.3%, and a photovoltaic module area of 906 square meters. This meets about 43% of the rooftop photovoltaic ratio, with a total installed capacity of 165.184 kWp, accounting for more than 4% of the market's total electricity consumption. The photovoltaic module layout diagram is shown below.

• Photovoltaic Component Installation Tilt Angle

Based on the photovoltaic calculation software PVsyst, the impact of different installation tilt angles and azimuths on photovoltaic power generation efficiency in the Shanghai area was analyzed. Considering Shanghai's geographical location and aiming for higher power generation returns, it is recommended that rooftop photovoltaics be installed facing due south, with an optimal horizontal tilt angle range of 20° to 30°, to achieve maximum power generation efficiency.

• Investment Payback Period of Rooftop Photovoltaics

The high initial investment cost and long payback period of BIPV are important factors restricting its development. This project started relatively early, and the calculated payback period is 8 years. However, with technological progress, considering current power generation efficiency and costs, the economic value is more prominent.

The incremental cost calculation of the project is as follows: the photovoltaic part of this project has a capacity of 120 kW, with a unit cost of about 5 yuan/W, totaling an incremental cost of 600,000 yuan. After applying other measures, annual electricity savings can reach 419,000 kWh. Calculated by standard coal consumption, this saves 120.69 tons of standard coal annually, with a carbon reduction of 43.1 tons, indicating good green benefits.

BIPV Aesthetics

After determining the rooftop photovoltaic area and the number of photovoltaic panels, the integration form with the roof needs to be decided. Traditional roofing methods place a large amount of mechanical and electrical equipment, pipelines, and roof penetrations, resulting in a cluttered facade that affects aesthetics. To ensure the overall beauty and coordination of the building, it is required to consider the integration of shading equipment and photovoltaic systems during the design phase. Photovoltaic panels use BIPV, serving as part of the roof structure, emphasizing roof integrity without needing additional maintenance space. To enrich the roof effect, multiple forms such as green roofs, metal roofs, and photovoltaic metal double-layer ventilated insulated roofs are combined to maximize roof integrity and architectural aesthetics. The project photovoltaic panel location diagram is shown below.

Application of the "Light-Storage-Direct-Flexible" System

The project roof space is equipped with 464 monocrystalline silicon photovoltaic glass panels, covering 43% of the entire roof area. To better obtain benefits, the project adopts a grid-connected mode of "self-generation and self-use, surplus electricity fed into the grid." The project will integrate community electricity use to layout renewable energy utilization for the entire community, comprehensively considering resource rational use and configuring the "Light-Storage-Direct-Flexible" system. The project also includes energy storage, with the entire storage system equipped with electrochemical storage batteries and electric vehicle power batteries, achieving distributed energy storage functions. This perfectly combines building energy use and vehicle energy storage needs and has the capability to participate in flexible adjustment of the building's overall electricity use. On the DC distribution side, photovoltaics, electric vehicles, storage batteries, and the municipal grid jointly supply power to lighting, central air conditioning, DC charging piles, etc. This forms a completely closed-loop "Light-Storage-Direct-Flexible" system with intelligent control to achieve effective energy utilization.

Summary

BIPV, as an important approach for the reasonable use of renewable energy in green low-carbon buildings, is the result of a balanced coordination between economy and aesthetics, and is the current development direction advocated for green energy-saving and low-carbon communities. Facing the current difficulties in BIPV design and cost, the Jiading Future City Chunxi Market project has made a series of new explorations in BIPV design and economics, which can serve as a reference for other similar projects.