According to data from the Ministry of Housing and Urban-Rural Development, Chinese generalized building energy consumption accounts for about 30% of the total energy consumption of the whole society. The transition from “energy-consuming cities” to “energy-saving cities” and even “capacity cities” is an important issue in building a low-carbon development of smart cities. According to the “13th Five-Year Plan for Building Energy Efficiency and Green Building Development”, during the “13th Five-Year Plan” period, the applicable area of photovoltaic building integration in Chinese cities is 1.79 billion square meters, and the installed capacity of new PV building applications in cities is more than 10 million kilowatts.

On November 5th, China's first copper indium gallium selenide (CIGS) building photovoltaic integrated (BIPV) technology demonstration building project completed and officially used for power generation. The project is located in Tonghu Science and Technology Innovation Town, Zhongkai High-tech Development Zone, Huizhou, Guangdong province. It is jointly built by the National Energy Group and the private real estate company Country Garden Group.

National Energy Investment Group Co., Ltd. was established in November 2017. It is a merger and restructuring of China Guodian Corporation and Shenhua Group Co., Ltd. It is currently the world's largest coal production, thermal power generation, wind power and coal-to-oil coal chemical company.

“Photovoltaic building integration refers to the integration of solar power products into a building component,” said Tang Yang, deputy director of the National Energy Group's Green Energy and Building Research Center. “Unlike the solar photovoltaic system (BAPV) attached to the building, the battery, as part of the external structure of the building, has both power generation and building materials,” he said.

Copper indium gallium selenide building photovoltaic integrated components

Zhao Jian, Chairman of the National Energy Group China Energy Conservation and Emission Reduction Co., Ltd. introduced that the total construction area of the Wuhu Science and Technology Innovation Town Demonstration Project is about 5,500 square meters. It adopts the core technology of the National Energy Group and independently produces CIGS thin film photovoltaic modules as architectural exterior decoration curtain wall.

Ling Wen, general manager of the National Energy Group and academician of the Chinese Academy of Engineering, told reporters that in addition to the integration of copper indium gallium selenide building photovoltaics, the project has two major technical highlights. The first one is to develop a ventilated photovoltaic wall. The photovoltaic curtain wall and the inner wall form a vertical closed cavity, which solves the problem of fire protection between the building layers. The cavity waste heat recycling is also realized, and the temperature of the photovoltaic module is lowered, and the power generation efficiency is improved. In addition, the photovoltaic curtain wall integrated system adopts the innovative design of the framed curtain wall system and the dry-hanging construction process, with high assembly degree, fast construction speed and reliable safety performance. It has withstood the 14-level typhoon test of “Mangosteen” without any damage.

Ling Wen said that not only in the city, the National Energy Group is also promoting the integration of building photovoltaics in the countryside. For example, combined with the conditions of the plateau pastoral area in Sichuan Aba Tibetan and Qiang Autonomous Prefecture, tailor-made thin-film solar photovoltaic tents were tailored. It is provided free of charge to herders to solve problems such as the difficulty of using electricity during pastoral grazing.

Thin film solar photovoltaic tent.      Image courtesy of the National Energy Group

"BIPV is a market for the photovoltaic industry to transform from a centralized ground station to a distributed generation market." Ling Wen said.

After the demonstration project is put into use, it is estimated that the annual power generation capacity will be 123,000 kWh, which can meet the electricity demand of more than 10% of the building. At present, the National Energy Group has built six entity demonstration projects in five provinces and cities including Beijing, Jiangsu, Guangdong, Hainan and Sichuan. It is expected to be completed by the end of this year and the first half of next year.

In order to further improve the production capacity of CIGS products, China Energy Group China Energy Conservation and Emission Reduction Co., Ltd. has established Chongqing Shenhua Thin Film Solar Technology Co., Ltd., and is constructing a 306MW production line, which is scheduled to be put into operation in 2019.