Over 20,000 square meters of roofs have been built with more than 30,000 solar panels, making it the world’s largest single-cell solar roof to date. On the 2nd of this month, the photovoltaic power generation project of the Nanjing South Station of the Beijing-Shanghai high-speed railway passed the review of the technical scheme of the secondary access system organized by the State Grid, which means that the preparation for the integration of the solar rooftop energy of the South Station into the power grid is completed and “power generation” will be forthcoming.

At noon on the 5th, the reporter with the staff of the Jiangning District Science and Technology Bureau boarded the roof of the South Railway Station and covered the rooftop with black solar panels, which were very imposing under sunlight. The project responsible for this project is the Zhongdian Electric Solar Energy Research Institute located in Jiangning. The director of the institute, Jia Yangang, introduced that due to the large size of the South Station, this solar roof has become the largest single photovoltaic building integration project in the world so far. Such a large area of ​​solar cells can generate 9.12 million kilowatt-hours of electricity per year. According to 25 years of design work, it is equivalent to saving more than 85,000 tons of raw coal.

After the solar power generation system is connected to the grid, the roof “power plant” is not only used by Nanjing South Railway Station, but also can be used by residents. If calculated by the average electricity usage per household, the daily output of this solar roof can satisfy more than 9,000 households. Household electricity. Moreover, once the station power supply is interrupted, the system can directly supply power within 0.07 seconds.

Jin Hua, deputy director of the Jiangning District Science and Technology Bureau, told reporters that the biggest "innovation" of South Station's solar power supply project is to overcome "shadow" technology. He said that the large roof of Nanjing South Station has a slope, and sunlight will produce shadows. If there is too much shadow, it will affect the efficiency of power generation. If some panels are not exposed to sunlight, it will cause damage to the system.

With the efforts of scientific and technological personnel, a set of "quantitative shadow visual technology" with independent intellectual property rights was created. Scientists and technicians have identified weather data for Nanjing over the past 40 years and formed a database to simulate the location of daily sunshine shadows. A software package was developed to analyze how the pavement can be constructed to minimize shadowing.

Jia Yangang said that the solar roof of the South Station took into account the weather. On cloudy days, this roof has 30% efficiency.

In order to prevent the heavy pressure caused by a large number of metal panels on the station building, the technicians came up with the “composite roofing technology”. Under the premise of ensuring wind resistance and earthquake resistance, only one layer of keel support was used to normalize the roof load. 30 kg/m2 is reduced to about 18 kg/m2.

It is understood that not only Nanjing, Shanghai Hongqiao, Wuhan-Guangzhou high-speed rail Wuhan station and other stations are also using solar roofs. However, the total installed capacity of Hongqiao Station is 6.5 MW, Wuhan Station is 2.2 MW, and Nanjing South Station is 10.67 MW. At present, the solar roof of the Hongqiao station has been connected to the grid. After the roof of the Nanjing South Railway Station has passed the review, the price of the grid will be verified by the price department to be able to generate power on the grid.

“This is the largest and most efficient photovoltaic building integration project in the world,” said Dr. Xu Jinfeng, chief engineer of the Jiangsu Academy of Building Research. In addition to the scale, the efficiency also reflects the leadership of Nanjing's local companies in photovoltaic power generation technology. The South Station project adopted a high-performance solar cell with a conversion rate of 18.5%, which exceeded the industry standard, making the project of demonstration significance and providing technical guidance for the development of photovoltaic building integration in the future.