Application of thin-film solar cells in photovoltaic building integration

As a developing country, China's energy consumption is growing at an alarming rate year by year. As buildings are large energy consumers (building energy consumption in developed countries generally accounts for more than 1/3 of the country's total energy consumption), their energy-saving benefits become particularly important. The construction industry has proposed the concept of "21st century architecture", that is, buildings generate energy themselves, and solar photovoltaic building integration (BIPV) has become a hot spot in the 21st century architecture and photovoltaic technology market.

Photovoltaic building integration is an important application of thin-film solar cells. It combines the functions of solar cell power generation and building exterior walls. Solar cell modules are installed on buildings, making them dual-purpose for both power generation and replacement of building materials. Whether from the perspective of architecture, technology or economy, solar photovoltaic building integration has many advantages: saving solar cell support structure, replacing roofs, walls, windows and other building materials; saving solar cell installation costs; effectively utilizing the surface area of ​​the building without occupying additional land; providing shade, reducing the building's exterior temperature and increasing the building's beauty; combining solar energy with buildings so that the building can have its own power supply.

The construction industry has begun to use thin-film solar cells as a source of electricity for photovoltaic buildings, because it can both generate electricity and reduce carbon dioxide emissions, making the advantages of solar photovoltaic buildings more obvious, which is determined by the basic characteristics of thin-film batteries.

First, thin-film batteries have a good cost-performance ratio and are relatively low in cost. The room for cost reduction of crystalline silicon solar cells is very limited, while thin-film solar cells not only have a large room for cost reduction, but also have a conversion efficiency close to that of crystalline silicon. The production cost of thin-film batteries is less than $1 per watt, making it possible to lay photovoltaic modules on large areas of buildings, and they are widely favored by the construction industry.

Secondly, thin-film batteries have good weak light performance and are relatively less affected by temperature and environment. Even under the influence of severe weather such as wind, sand, rain and snow, they have stable power generation performance. On average, they can generate 15% more electricity than crystalline silicon each year.

Photovoltaic modules used in buildings will inevitably be blocked by external environment such as tree shade, chimney, dust, clouds and other objects. For crystalline silicon solar cells, a small blockage can cause a large power loss, resulting in excessive module temperature, which can seriously burn out the module and even cause a major fire; however, the current density of thin-film batteries is small, so that the power loss caused by shadow is small, and the system is safer, more reliable and more adaptable. In comparison, thin-film batteries are more in line with the material selection requirements of photovoltaic buildings.

Finally, from the perspective of architectural aesthetics, thin-film battery modules are uniformly transparent, have good external and internal viewing effects, have a good overall appearance, and are easier to integrate with buildings. Thin-film battery cells can be processed into dot-shaped, cloth-shaped, etc. by laser to achieve different light transmission effects, and the color and shape of the battery cells can also be adjusted to meet the aesthetic design of different buildings.

At present, photovoltaic building integrated (BIPV) application systems are booming not only in Europe, the United States, Japan and other places, but also in China, more and more BIPV demonstration and application systems are showing strong vitality. For example, in the Micro-row Building in Dezhou, Shandong, the amorphous silicon thin-film solar panels laid in the building are produced and provided by Puro New Energy (Bengbu) Co., Ltd. As the main venue of China's Sun Valley, it not only has a unique artistic shape, but also truly embodies the concept of energy conservation and environmental protection. At present, the Sun Valley Micro-row Building is the world's largest solar office building, with an overall energy-saving efficiency of up to 88%, which can save 2,640 tons of standard coal, 6.6 million kilowatt-hours of electricity, and reduce pollutant emissions by 8,672.4 tons each year.

As environmental pollution becomes increasingly serious, vigorously developing photovoltaic building integration is a new trend in the future. In this regard, thin-film solar cells will gradually replace some building materials and perfectly integrate with buildings, so that buildings can have their own power supply and reduce carbon dioxide emissions, playing a pivotal role.

Bai Huihui: Graduated from South-Central University for Nationalities with a major in journalism, and now works in the news department of Pure New Energy.