Photovoltaic glass has been widely used in recent years with the development of the global photovoltaic industry. The main application areas of photovoltaic glass are cover glass for crystalline silicon photovoltaic module packaging, as well as cover plates and back glass for a small number of double glass components. At present, the cover glass for crystalline silicon photovoltaic modules is made of white embossed glass or ultra-white embossed glass coated with anti-reflection film.

The production of ultra-white embossed glass is a calendering process. The calendering method uses a calender to form a molten glass from the kiln and then enters the annealing kiln for annealing. The upper roller of the calender is a light roller with a certain roughness, and the lower roller is an embossing roller with various pattern structures. After molding, a corresponding flower structure is formed on the glass, and an appropriate flower angle can be increased. The incident light traverses the energy of the flower surface twice, thereby increasing the transmittance. Generally, the content of ferric oxide in the composition is not more than 0.015%. Due to its low iron content, the solar light transmission is much higher than that of ordinary glass, and the sensory is also more "white". Therefore, it is commonly called "ultra-white glass" in the industry. ".

The higher the transmittance of ultra-white embossed glass, the higher the photoelectric conversion rate of the module and the more power generation. Therefore, the ultra-white embossed glass with high solar transmittance is especially favored by photovoltaic system and photovoltaic module manufacturers. Through the efforts of glass enterprises at home and abroad, the effective transmittance of sunlight for ultra-white embossed glass produced by various companies is not much different, and it is concentrated in the range of about 91%, further improving the characteristics of ultra-white embossed glass. The means to enhance the solar transmittance has been very limited.

Therefore, plating an anti-reflection film on the surface of ultra-white embossed glass is an effective means to improve the effective transmittance of photovoltaic glass. Generally, this method can make the effective transmittance of sunlight more than 93.5%, which is generally uncoated. The transmittance of ultra-white embossed glass is increased by about 2.5%, and the conversion efficiency of photovoltaic modules can be increased by about 2%. This technology is highly controversial in the initial stage of promotion. The main reason is that the components in the desert, hot and humid environment, after the anti-reflection film wear and peeling failure, it is easy to form dirty shading and lead to a decrease in component output power. However, with the continuous maturity of coating technology, such problems have been basically solved, and the coated glass components can maintain the same output power as the uncoated glass components even after the anti-reflective film wear failure in the desert area. Currently, coated glass has been widely adopted by component manufacturers.

Capacity and technology transfer to China

In view of the globalization characteristics of the photovoltaic industry, the development of the domestic photovoltaic glass industry is inseparable from the development of the foreign photovoltaic glass industry, showing a trend of change. Before 2006, due to the low threshold and demand for photovoltaic glass, coupled with the extremely severe international economic situation, domestic glass enterprises invested no one. In the international arena, St. Gobain, Pilkington, Asahi Glass, and Banzizi have basically monopolized the market, resulting in the domestic PV module factory relying entirely on imported ultra-white embossed glass to make the cover plate. The import price was maintained at around 80 yuan/m2. Driven by high profits, domestic rolling glass production technology has been restarted and developed. Domestic glass manufacturers have invested in the construction of ultra-white embossed glass production lines, and the production capacity has been rapidly improved. At the same time, foreign companies are considering resources and costs. In the face of the rapid expansion of China's production capacity and the initial decline in product efficiency, there is almost no expansion plan in foreign countries, and the transfer of production capacity and technology to China began.

From 2006 to 2013, the production of domestic PV modules was mainly based on exports. 2013 is a watershed in the transformation of the supply and demand pattern of the photovoltaic industry. Under the pressure of double reverse and overcapacity in Europe and the United States, expanding the internal demand for photovoltaic products and increasing the domestic PV installation capacity have become the main driving direction of domestic policies. The state has launched a series of policy support to stimulate domestic demand, and the domestic PV application market has developed rapidly, making up for the slowdown in the growth of the overseas PV market, which has brought huge impact to the PV industry.

In less than ten years, the domestic photovoltaic glass industry has developed from relying on import development to fierce competition in the domestic industry. Overcapacity has led to prices continuing to decline and entering a low-profit stage. The scale of enterprise development has become a consensus, and there is no competition for importing similar products from abroad. Advantages, Asahi Glass, Guardian and other foreign glass companies have quit the photovoltaic glass market. At present, according to incomplete statistics, three kiln furnaces of Saint-Gobain, Interfloat and Ducatt in Europe are still in production, and the kiln capacity is small kiln within 300d/t. Some large glass companies in China have begun to go out, such as Xinyi Glass in Malaysia, and CNBM is preparing to build a plant in Nigeria. According to statistics, in January 2016, the export volume of China's photovoltaic glass to Japan, the United States, Europe and other international markets was 129,900 tons, accounting for about one-third of the total production, and increased by 7.74% compared with last year. If the photovoltaic glass exported from the component form is included, the export will far exceed this ratio. Compared with exports, China's PV glass imports in January 2016 were only 934 tons, which is still less than the domestic production of kiln one day. China is the world's number one photovoltaic glass producing country is an indisputable fact.

Market supply and layout

Since 2006, China's large glass companies such as Xinyi and Follett have been involved in the production of ultra-white embossed glass. The production capacity has increased from 7,820 tons/day at the end of 2010 to 22,850 tons/day at the end of 2015, with an average annual growth rate of 38.4%. In 2011, the growth rate was fast, with a growth rate of 63.4%; the concentration of the top five PV glass markets gradually increased, reaching 68.8% at the end of 2015; the average single kiln scale increased from 232 tons/day in 2010 to 448 tons/day at the end of 2015. The largest ultra-white embossed photovoltaic glass production kiln capacity reaches 900 tons / day. At the same time, the unit manufacturing cost has been declining, the product energy consumption has been further reduced, and the environmental protection equipment level of the production line has been further improved. New products and technologies such as anti-reflective coating, high-transparent glass, and a kiln multi-line have been developed, and the comprehensive yield has been achieved. 68%, the global market share reached 93%, has become the world's major photovoltaic glass supply market.

At present, domestic super white embossing original film production enterprises are mainly distributed in North China, East China and South China according to regions, with 23 production enterprises. The main enterprises in North China are: Tianjin Xinyi Glass, Shaanxi Rainbow Group, Henan Ancai High-tech, Tuo Rixin Energy, Jinxin Solar, etc. The main enterprises in East China are: Zhejiang Fu Laite Photovoltaic Glass, Wuhu Xinyi Glass, AVIC Sanxin, Dongguan CSG, China Building Materials, New City Energy, Wujiang CSG, etc., South China has annexed glass photovoltaic glass, Xinfuxing, etc. Among them, the large-scale enterprises include Xinyi Glass, Zhejiang Follett, Henan Ancai, Shaanxi Rainbow and other enterprises. The total number of kiln is more than 1000 tons / day.

There are more than 40 enterprises producing anti-reflection film glass for solar photovoltaic modules in China, which are distributed in Jiangsu, Zhejiang, Anhui, Henan, Shaanxi, Fujian, Tianjin and other provinces. According to the type of production and processing of enterprises, they are mainly divided into two categories:

The company has both ultra-white embossed glass original film production line and anti-reflection film glass production line and tempering line, such as Wuhu Xinyi Photovoltaic, AVIC Sanxin Solar Photovoltaic Glass, Wujiang CSG Solar Glass, Follett Photovoltaic Glass, Henan Ancai High-Tech, Enterprises such as Shaanxi Rainbow Group, such enterprises are large in scale.

The company does not have a glass original film production line, and purchases ultra-white embossed glass for smearing and tempering, such as Changzhou Amarton Co., Ltd., Jiangsu Xiuqiang Glass Technology Co., Ltd., Changzhou Huamei Photovoltaic Materials Co., Ltd., Suzhou Taiyue, etc. Such enterprises have different scales of large, medium and small.

According to the “2015~2016 China PV Industry Annual Report” issued by the China Photovoltaic Industry Association, the utilization rate of photovoltaic glass capacity has been improved, but a large amount of production capacity is still idle. By the end of 2015, there were 36 ultra-white embossed photovoltaic glass production enterprises, including 17 in-production enterprises, and the ultra-white-rolled glass kiln that has been put into production (excluding ordinary embossing) has 76 production lines of 76 kiln, and the production capacity is 22,850 tons / day.

At the same time, the report also pointed out that the growth rate of total photovoltaic glass production capacity has slowed down, and the production capacity has increased compared with the same period of last year. As of the end of December 2015, the new kiln has put into operation 10 production lines of 2 kiln, with an additional capacity of 1400 tons/day, a decrease of 66.4% compared with the same period of last year. In the production capacity of 32 kiln 102 production lines, the production capacity is 14,340 tons / day, an increase of 9% over the same period last year.

Demand has a slowdown

Photovoltaic glass has gradually grown with the development of the photovoltaic industry. In 2015, the global installed capacity of new photovoltaic power generation was about 53GW, of which China's new photovoltaic power generation installed capacity was about 15GW, an increase of over 40% year-on-year, accounting for a quarter of the world's new installed capacity. the above. At present, the main application of photovoltaic glass is uncoated ultra-white embossed glass and ultra-white embossed glass coated with anti-reflection film (AR). China has become the world's largest producer of ultra-white embossed glass, 93% of the world's The crystalline silicon photovoltaic module uses photovoltaic glass produced in China.

In 2015, the overall domestic PV glass market was in good trend. From the fourth quarter onwards, it was affected by factors such as the rush of PV power plants. The orders of PV glass companies were sufficient, and the inventory pressure of manufacturers was temporarily reduced. At the end of the year, the tight supply of photovoltaic glass was partially increased.

From the end of 2015, AR coating glass orders are very sufficient, manufacturers' production plans are full, some manufacturers to control their own orders, control the original off-chip sales, in the case of insufficient supply of the original film, the company actively communicates with customers, and strive to cash the AR coating The rise in glass, some corporate prices rose to 33 yuan / m2. With the igniting and normal production of photovoltaic glass manufacturers such as Fujian Xinfuxing, Hefei Rainbow and Far East Optoelectronics, the tightness of the original film procurement will be gradually eased. On the whole, some manufacturers have reduced the external sales of the original film and have not had a major impact on the original film market. With the end of the rushing market, the overcapacity of photovoltaic glass in the later period is still the main problem that the photovoltaic glass industry will face. It should be noted that in the spot checks of the AQSIQ in recent years, there are always different types of PV modules for PV modules in different enterprises that do not meet the standards. Enterprises should fully consider the brand and quality when purchasing.

Future trends

With the ups and downs of the photovoltaic industry, photovoltaic glass production enterprises have experienced the phenomenon of large price changes and the process of industrial upgrading and transformation, and there has been a phenomenon of “two concentration”, that is, production area concentration and large-scale concentration. However, from the scale of the kiln, the average single kiln scale increased from 232 tons/day in 2010 to 448 tons/day at the end of 2015, and the maximum ultra-white embossed photovoltaic glass production kiln capacity reached 900 tons/day, and will become the mainstream; The unit manufacturing cost has been declining, the product energy consumption has been further reduced, the environmental protection equipment level of the production line has continued to increase, and the industrial concentration has been further improved. In 2015, due to the overall trend of the domestic PV glass market, from the third and fourth quarters, due to the impact of photovoltaic power plant grabbing and other factors, photovoltaic glass appeared to be in short supply. After the Spring Festival, the price of ultra-white embossed glass production and coated glass showed a slight increase. . At the same time, with the ignition of new kiln such as Fujian Xinfuxing and Far East Optoelectronics, the kiln of AVIC Sanxin, Wuhu Xinyi Photovoltaic, Jinxin Glass and other kiln are ready to be ignited during the year, and the demand for PV glass will gradually ease. In the future, overcapacity and cost control will remain the problems that domestic PV glass companies need to face.

With the rapid development of the photovoltaic industry, the photoelectric conversion efficiency has experienced a rapid increase in the early stage. As it has gradually approached the theoretical limit value, the research and development speed of breakthrough technology has entered a stable period. In this case, the influence of other factors on the power generation efficiency and power generation of the components is gradually becoming prominent. According to the "2015~2016 China PV Industry Annual Report" issued by China Photovoltaic Industry Association, photovoltaic glass with anti-ash, dustproof, anti-pollution and easy-cleaning features has become one of the focuses of the industry recently. Relevant data show that in areas with large pollution or sandstorm, the surface dust and dirt of photovoltaic modules greatly reduce the average power generation efficiency of photovoltaics. Frequent maintenance and cleaning of power plants in the late stage not only leads to the increase of late-stage loss of photovoltaic power generation projects in China, but also affects the use of components. life.

In short, the challenges and opportunities of the photovoltaic glass industry coexist. Only through technological improvement, cost reduction and continuous innovation can we achieve healthy, stable and sustainable development.

Source: Glass mesh