Changsha has a glass curtain wall that will generate electricity

Looking from afar, the Zhongjian Fifth-Block Building in Jingwanzi, Changsha is like a window shutter. When you approach it, most of the windows are equipped with a tilted solar panel. The China Construction Fifth Board Building uses the independently developed “Zhongjian” brand shutter-type amorphous silicon photovoltaic wall, and the 2,500 square meters of power curtain wall and photovoltaic roof put the glass coat on the building, creating a truly energy-efficient building.

According to Cui Yanjun, Technical Department Manager of China Construction 5th Building Energy Technology Co., Ltd., the building's shutter-type amorphous silicon photovoltaic wall consists of front and rear glass sheets, solar cell glass components and aluminum alloy keels. The solar cell glass module receives solar energy and converts it into direct current power to complete the first process of power generation. The DC power is then integrated into the inverter on the roof by the built-in transmission line in the keel. The inverter is the core of the entire system and is responsible for converting the DC power generated by the glass components into usable AC power for the entire building.

"The photovoltaic curtain wall system was completed in 2008 and it has won 17 national patents and it cost more than 6 million yuan.

According to Cai Yanjun, the city's photovoltaic wall has already existed. The cost of traditional photovoltaic curtain wall construction is about 3.5 times that of ordinary glass curtain walls. The cost of the "Zhongjian" brand shutter-type amorphous silicon photovoltaic wall is only 60% of that of traditional photovoltaic curtain walls. It can generate 80,000 kilowatt-hours of electricity each year to meet one-third of the building's electricity consumption. Every day, every square meter, it saves 0.7 kilograms of standard coal. It overcomes the defects of poor heat insulation, low power generation, and no light transmission of traditional photovoltaic curtain walls, meets the requirements of energy saving, heat preservation, and lighting, and realizes the integration of photovoltaic power generation and architecture. At present, the power generated by this curtain wall has been connected to the Changsha power grid.

The solar photovoltaic glass curtain wall used in the China Construction Fifth Building has solar photovoltaic cells distributed in a louver shape. The power generation efficiency is double that of the vertical layout, which solves the solar incident angle problem and achieves the best photoelectric conversion efficiency. The light transmittance of the louvered solar cells reaches 90%, and the sunlight is collected to the maximum. While optimizing the power generation effect, light pollution caused by reflections is reduced, and the heat island effect is weakened. The amorphous silicon panels used are nearly half as cheap as crystalline silicon panels. The curtain wall can not only generate electricity, but also transform buildings from energy consumption to production energy, and can completely replace the decorative effect of the external walls.

The hot summer in Changsha greatly increased the city's electricity load. Energy consumption is huge, pollution emissions increase; but it also contains opportunities for energy saving and emission reduction. Photovoltaics in urban buildings can use urban solar energy resources and convert power-consumption buildings into power generation buildings. In 2008, the China Construction Fifth Board Building was awarded the national “Eleventh Five-Year Plan” for demonstration of renewable energy building applications. It is currently the largest demonstration project of amorphous silicon solar photovoltaic wall in China and is also a representative of the optoelectronic integrated building in Changsha.