"Thin film solar cell technology represents the development direction of photovoltaic technology. For a long time to come, thin film solar cells and crystalline silicon solar cells will coexist, but thin film photovoltaic products will soon expand their share in the market and grow rapidly. Finally, thin film solar cell technology represented by copper, indium, gallium and selenium (CIGS) will become the mainstream of photovoltaic industry." Zhuang Daming, Executive Vice Dean of School of Materials, Tsinghua University, said in an interview with reporters a few days ago.

Recently, the Opinions on Promoting the Application and Industrial Upgrading of Advanced Photovoltaic Technology Products (hereinafter referred to as the Opinions) jointly issued by the three ministries and commissions of the State has aroused heated discussion in the industry. Zhuang Daming believes that the support for thin-film solar energy in the Opinions reflects the national technology orientation. In the future, the market share of thin-film batteries such as copper, indium, gallium and selenium will gradually increase, thus promoting the transformation and upgrading of China's photovoltaic "smart manufacturing" industry.

Thin film technology will lead the industry in the future with lower energy consumption

In the past decade, China's photovoltaic industry has experienced a rapid development period, but also exposed problems such as low-end industrial chain, blind expansion of production capacity and so on. Zhuang Daming believes that for the polycrystalline silicon battery, which currently occupies the mainstream of the market, the photoelectric conversion efficiency of its components is 15-18%, slightly higher than that of the thin film battery. However, from the perspective of its entire life cycle, the polycrystalline silicon battery is characterized by high energy consumption and high pollution in the production process of high purity silicon raw materials. Thin film solar cells represented by copper, indium, gallium and selenium will gradually replace polycrystalline silicon cells and become the mainstream technology direction of photovoltaic development in the future, which has become the consensus of many scholars.

He said that one-sided evaluation of the advantages and disadvantages of solar energy technology based on conversion efficiency is a cognitive misunderstanding in the photovoltaic industry. Different technical routes are applicable to different application scenarios, and need to be evaluated from the perspective of photoelectric conversion efficiency, manufacturing cost, service life, cost performance and sustainable development. For the copper indium gallium selenium battery, the module can achieve a conversion rate of 14% - 16%, which has reached the world leading level. In addition, the service life of copper, indium, gallium and selenium is long. Under the same power, the power generation capacity is also stronger than that of crystalline silicon. In the process of production and manufacturing, it consumes less raw materials, and has more advantages in energy consumption and pollution. Therefore, the national policy is more inclined to support copper, indium, gallium and selenium film technologies.

The policy encourages the leader, and the localization of copper, indium, gallium and selenium is favorable

In the world, there have been many successful cases in the industrialization of thin film technology. First Solar, which is mainly engaged in cadmium telluride thin film batteries, has developed into the largest photovoltaic enterprise in the United States. Solar Frontier in Japan, Hanergy in China and other enterprises mainly focus on copper, indium, gallium and selenium, gallium arsenide and other technical routes. Zhuang Daming believes that copper indium gallium selenium technology has great potential for efficiency improvement and cost reduction. With the expansion of the market, the manufacturing cost may also be cheaper than polysilicon. More importantly, China is rich in indium and gallium resources, and has strong competitiveness in raw material cost and sustainability. Therefore, the localization advantage of copper, indium, gallium and selenium will be very obvious.

Zhuang Daming said that this time, the three ministries and commissions jointly launched a new photovoltaic policy and proposed guiding measures, which reflects the national support for thin film technologies such as copper, indium, gallium and selenium. Among the eight measures in the Opinions, the biggest highlight is to eliminate low-quality production capacity and implement the "leader" plan. This plan is to give appropriate preferential policies to enterprises that have performed well in the R&D and industrialization process of the entire photovoltaic industry, as well as a good demonstration. Zhuang Daming said that this plan is of great significance for encouraging superior production capacity and for enterprises that have really mastered the core technology and production process of thin film solar cells. It is understood that Hanergy has reached the world's leading level in terms of technology by purchasing foreign companies that produce CIGS batteries. The highest conversion rate of its copper, indium, gallium and selenium technology has reached 21%. The "leader" plan is undoubtedly good news for Hanergy.

China's PV industry has a long way to go from technological advantages to scale advantages

Zhuang Daming believes that the use of clean energy such as solar energy, wind energy and tidal energy can greatly promote the sustainable development of society and economy even if it solves 10% - 20% of global electricity consumption. Turning to the industrialization status of thin film technology in China, he said that among domestic thin film solar enterprises, Hanergy has introduced many advanced technologies from abroad, and has done a good job in product performance. The next step is to realize technology localization as soon as possible and continue to reduce costs.

Film enterprises need to "walk on two legs" to improve efficiency and reduce costs, and transform their technological advantages into scale advantages as soon as possible to achieve healthy and rapid development. The issuance of the Opinions has given more support to technology leaders from the state. However, as a market player, enterprises also need to improve cost control and gradually get rid of support. The sound development of the photovoltaic industry requires the joint efforts of the government and enterprises.