As the core of the entire photovoltaic industry chain, solar cells are currently mainly divided into three types: monocrystalline silicon, polycrystalline silicon and thin film technologies represented by amorphous silicon.
Standard PV modules are made from monocrystalline and polycrystalline silicon. 50% of the cost of making a component is the cost of the processed silicon wafer. In 1980, Imanzur Sachs of the Massachusetts Institute of Technology invented the technology of growing string ribbon crystals (US Patent No. 4,661,200), which made it possible to produce continuous thin strips of polycrystalline silicon wafers, eliminating the need to cut silicon rods before. The resulting waste and huge expense, and the reduction in production costs made wider application of solar technology more feasible, and the solar panel industry has since taken off.
Silicon is currently the most ideal solar cell material, and more than 85% of solar cell components are made of crystalline silicon. Crystalline silicon mainly includes polycrystalline silicon and monocrystalline silicon, and polycrystalline silicon is the raw material for processing monocrystalline silicon. With the rapid development of information technology and solar energy industry, the global demand for polysilicon has grown rapidly, the market supply is in short supply, and the price has risen sharply. In 2005, the global polysilicon production was 30,200t, which was highly concentrated in 7 companies in the United States, Japan and Germany. Among them, the consumption of semiconductor integrated circuits was 20,100t, and the production of solar cells was 10,100t. At present, the global polysilicon gap for manufacturing solar cells is 24%, and Shortages in the global market will continue for years to come.
But by the end of 2008 there was no longer a shortage of polysilicon. Frost & Sullivan predicts that the global solar photovoltaic market revenue in 2005 was 6.49 billion US dollars, and it is estimated that in 2012 it will exceed 16 billion US dollars. This high growth rate will come from a large demand for polysilicon. It is estimated that the demand for silicon raw materials in 2004 reached nearly 2.6 × 104t. In 2005, silicon wafer production increased by nearly 7%. However, this growth still cannot meet the market demand. In 2006 the shortage of raw materials reached a dangerous point affecting the production of solar panels, which in turn affected the development of the solar industry. However, things are changing. According to Frost & Sullivan analysis, by the end of 2008 the supply of polysilicon has caught up with demand.
On the demand side, demand from the semiconductor industry is expected to grow steadily at a single-digit rate. The demand for solar-grade polysilicon reached more than 50% of the total demand for high-purity silicon in 2008-2009.
In mid-June 2008, after Hemlock Semiconductor, the world’s leading manufacturer of polysilicon materials, announced that it would more than double the production capacity of its multi-product silicon production facility in Michigan, USA, other multi-product silicon producers also It has been announced to the outside world one after another that the related devices will be expanded and transformed. After this round of capacity expansion, the global shortage of multi-product silicon materials will be effectively improved, which will help alleviate the pain of silicon material shortages suffered by the solar photovoltaic industry in recent years. It is said that Holmrock’s new plant has a production capacity of about 9,900t per year. After reaching production at the end of 2008, the company’s total production capacity of polysilicon materials has increased to 2.1×104t per year.
Frost & Sullivan, a world-renowned consulting firm, said that in addition to Holmrock Semiconductor, the other five largest silicon material manufacturers in the world include Germany’s Wacker, REC Silicon, MEMC Electronic Materials, and Japan’s Tokuyama Chemical. company and Mitsubishi Corporation. In order to meet the needs of customers, these companies are currently implementing expansion projects. In addition, in China, North America and Europe, some companies have also poured into this industry with huge sums of money because they are optimistic about the market prospects of polysilicon materials.
Norwegian Renewable Energy (REC) announced at the end of June 2008 that it would invest US$77 million to expand the existing silicon wafer capacity at its Heroya production plant by about 100MW. The expansion was completed in 2009 and started production in the first quarter of 2010. By 2012, the production capacity of silicon wafers will reach 740MW, cells will reach 550MW, and modules will reach 590MW.
Some experts predict that after this round of expansion, the global polysilicon production capacity will increase from 4.5 × 104t per year in 2006 to 2 × 105t per year in 2011, and the state of insufficient supply and demand will be improved.
Innovation in production technology may affect the supply and demand of polysilicon materials, such as thin-film solar elements market may grow rapidly, and the production of such elements does not require polysilicon materials. The new technology, developed by veteran solar cell maker Kyocera, reduces the silicon content in solar panels, thereby reducing consumption of polysilicon, an expensive raw material.
In addition, changes in government subsidy policies for solar cell consumers are also an influencing factor. At present, more than half of the world’s solar photovoltaic cells are produced in Germany, and the German government has determined that the amount of subsidies for solar cell users will be reduced by 16% in the next two years.