China’s conventional energy reserves are far below the world average, only about 10% of the world’s total reserves. With the gradual exhaustion of conventional energy and the increasingly prominent environmental problems, the country must gradually change the energy consumption structure and vigorously develop new energy represented by solar energy. Among various new energy sources, solar energy is abundant in reserves, and hardly produces any pollution during development and utilization. It is the most ideal alternative energy for mankind and has great potential for development and utilization.
There are two main ways to develop and utilize solar energy: one is the photothermal utilization of solar energy, which is mainly represented by the application of solar water heaters; the other is the photovoltaic utilization of solar energy, which is mainly represented by the application of solar photovoltaic power generation. Both of these two methods have the advantages of non-polluting, sustainable and flexible application methods, and they are the focus of the development of new energy and renewable energy in countries around the world. As far as solar photovoltaic power generation is concerned, according to the forecast of the International Energy Agency (JRC), by 2030, renewable energy will account for more than 30% of the total energy structure, and the proportion of solar photovoltaic power generation in the world’s total electricity supply will also be reach more than 10%; by 2040, renewable energy will account for more than 50% of the energy structure, and solar photovoltaic power generation will account for more than 20% of the total electricity; by the end of the 21st century, renewable energy will account for 80% of the energy structure. % or more, and solar photovoltaic power generation will account for more than 60%.
(1) Development status of solar photovoltaic power generation in the world
With the support of governments around the world, the solar photovoltaic power generation industry has developed rapidly in recent years. Affected by the global solar photovoltaic market demand, solar cell production has grown the most rapidly. In 2008, the global solar cell production was 6.85GW, which increased to 10.66GW in 2009, and reached 20.5GW in 2010, almost doubling from 2009. The output of polysilicon is also increasing year by year. In 2009, the output of polysilicon was 110,000 tons, and in 2010, the output of polysilicon reached 160,000 tons. In the 1960s, the first photovoltaic modules for ground applications were priced at US$1,500/W, and then the price of PV modules gradually dropped to US$300/W. Due to factors such as technological progress and the expansion of production scale, the price of photovoltaic modules has been continuously reduced, especially since the 21st century, the production cost of photovoltaic modules has dropped significantly. In 2000, the price of PV modules was $4.5/W; in 2010, it dropped to $1.7/W.
Since 2007, the world photovoltaic market has shown an explosive growth trend. In 2007, the world’s cumulative installed photovoltaic capacity was 12.3GW; by 2010, the cumulative installed photovoltaic capacity reached 39.6GW, with an average annual growth rate of more than 50% in the past five years.
In 2011, due to the rapid decline in the price of photovoltaic modules and other costs, the installed capacity of the year increased significantly. According to the statistics of the European Photovoltaic Industry Association, in 2011, the world’s newly installed capacity was 27.7GW, and the cumulative installed capacity was 67.4GW. In 2012, the world’s newly installed photovoltaic capacity was 30.5GW. According to the statistics of “2013 China Photovoltaic Industry Development Report”, Germany accounted for 24.5% of the global photovoltaic market share in 2012, Italy and the United States accounted for 10.6% and 10.3% respectively, Japan accounted for 6.5%, and China increased to 14.5%. This shows that China has begun to gradually move towards the center of the photovoltaic market. After 2013, the world photovoltaic market will enter a new period of stable growth.
(2) Development status of solar photovoltaic power generation in China
China began research on solar cells in 1958, produced the first solar cell with practical value in 1959, and successfully applied solar cells to artificial satellites for the first time in 1971. After continuous efforts, the conversion efficiency of solar cells produced in China has also been continuously improved. At present, the laboratory efficiency of monocrystalline silicon solar cells has reached 25%, and the mass production efficiency is 16%~18%; the mass production efficiency of polycrystalline silicon solar cells has also reached 15%~17%. Since the successful application of solar cells in the 1970s, China’s solar photovoltaic power generation technology has made great progress, and its application fields have continued to expand. an area.
In the mid-to-late 1980s, China’s solar cell production capacity reached 45MW, and the photovoltaic industry was initially formed. After entering the 1990s, China’s solar photovoltaic industry has developed steadily, and the output has increased year by year. In particular, the “Bright Project” and “Transmitting Electricity to the Township” project launched in recent years have greatly promoted the development of the photovoltaic industry. Since 2002, it has developed rapidly with an annual growth rate of more than 100% for many consecutive years. In 2006, China’s solar cell output accounted for 17.1% of the world’s total, ranking third in the world. In 2007, China’s solar cell output reached 1.088GW, accounting for 27.2% of the world’s total output, surpassing Germany and Japan for the first time and becoming the world’s largest producer of solar cells. Since then, in 2008, 2009 and 2010, China’s solar cell output remained the world’s largest for three consecutive years. In 2010, the solar cell output was about 10GW, accounting for 50% of the global total. As the main representative of the new energy industry, the photovoltaic industry has developed rapidly in China and has grown into a pivotal force in the international new energy market. China has also become a major producer of photovoltaic products in the world.
The development of China’s photovoltaic power generation market is relatively slow, far behind the growth of solar cell production. In the 1970s, the application of solar cells on the ground was very limited, and then with the initial formation of the photovoltaic industry, the application on the ground began to develop, and the photovoltaic market gradually expanded. In 1996, the cumulative installed capacity of photovoltaic power generation in China was only 1.0MW. By the end of 2010, the cumulative installed capacity of photovoltaic power generation reached 893MW, and its share in the world increased from 0.2% at the end of 1996 to 2.2%. Table 1.
With the continuous improvement of solar photovoltaic power generation technology, its application scale and field are also expanding, from the original only used in remote areas and special power-consuming occasions, to urban grid-connected systems and large photovoltaic power plants. The proportion of solar photovoltaic grid-connected power generation applications is increasing, and it has become the main market for solar photovoltaic power generation applications since the 21st century. China’s photovoltaic power generation is mainly used in remote and powerless areas. The grid-connected photovoltaic power generation started relatively late, but it has also developed rapidly in recent years. As of 2010, China’s photovoltaic grid-connected installed capacity reached 240MW. Figure 1 shows the statistics of the installed capacity of photovoltaic systems in China over the years by the National Energy Administration. In 2010, China added 500MW of installed capacity, mainly used in large-scale grid-connected photovoltaic power plants and solar photovoltaic building integration.
In 2012, the annual installed capacity of photovoltaic power generation in China was 4.5GW, an increase of 66% compared with 2011. By the end of 2012, the installed capacity of photovoltaic power generation in China had jumped to the third place in the world.
(3) Development plan of solar photovoltaic power generation in China
China has formulated a series of policies to encourage the development of solar photovoltaic power generation. On August 31, 2007, the “Medium and Long-Term Development Plan for Renewable Energy” was released, which clearly stated that the proportion of renewable energy in China’s energy consumption will be gradually increased, reaching 10% in 2010, and is expected to reach about 15% by 2020. Among them, the cumulative solar photovoltaic power generation is 1600MW. The solar energy industry has been included in the national strategic emerging industry and will be given key support.
In order to promote the formation of China’s solar photovoltaic power generation market, in 2009, the state successively issued policies such as the “Interim Measures for the Management of Financial Subsidy Funds for Solar Photovoltaic Building Applications” and “Notice on the Implementation of the Golden Sun Demonstration Project”, which provided the basis for China’s solar roof and photovoltaic power generation. Grants for construction projects. In addition, two batches of large-scale photovoltaic grid-connected power station concession bidding projects have been launched successively, and a number of grid-connected photovoltaic power stations have been built in western regions with advantageous solar energy resources. In order to continue to promote the large-scale development of the solar photovoltaic power generation industry, on August 1, 2011, the state issued the “Notice on Improving the On-grid Tariff Policy for Solar Photovoltaic Power Generation” to unify the on-grid tariff of solar power generation. This policy has brought new hope to the market application of solar photovoltaic power generation, increased the enthusiasm of Chinese photovoltaic enterprises, and further promoted the development of solar photovoltaic power generation.
At the beginning of 2012, the Ministry of Industry and Information Technology formulated the “Twelfth Five-Year” Development Plan for Solar Photovoltaic Industry, which clearly put forward the development direction of China’s solar photovoltaic industry from four aspects: economic goals, technical goals, innovation goals and power generation cost goals. Among them, the cost target of photovoltaic power generation is that by 2015, the cost of photovoltaic modules will be reduced to 7,000 yuan/kW, the cost of photovoltaic systems will be reduced to 13,000 yuan/kW, the cost of power generation will be reduced to 0.8 yuan/kWh, and the power distribution side will achieve “grid parity”. Make photovoltaic power generation have a certain economic competitiveness; by 2020, the cost of photovoltaic modules will drop to 5,000 yuan/kW, the cost of photovoltaic systems will drop to 10,000 yuan/kW, and the cost of power generation will drop to 0.6 yuan/kWh. ”, to achieve effective competition in major electricity markets. High cost has always been the main obstacle affecting the large-scale application of solar photovoltaic power generation. Reducing the power generation cost of photovoltaic systems will further expand the application field of photovoltaic power generation. In addition to large-scale grid-connected photovoltaic power plants, small and medium-sized photovoltaic power generation systems such as distributed photovoltaic power generation and building-integrated photovoltaic power generation will also become the emerging driving force for the growth of China’s photovoltaic power generation market demand. This is extremely beneficial to the orderly development of China’s overall photovoltaic industry.
In the “Twelfth Five-Year Plan for the Development of Solar Power Generation”, the National Energy Administration proposed that 20GW of solar photovoltaic installed capacity will be added during the “Twelfth Five-Year Plan” period, and distributed photovoltaic power generation should be vigorously developed. The “Notice of Demonstration Zones for Large-scale Application of Power Generation” further proposes a requirement that the installed capacity of distributed power generation in each province should not exceed 500MW during the “Twelfth Five-Year Plan” period, and encourages provinces to support distributed photovoltaic power generation in an appropriate manner on the basis of the national subsidy policy. Demonstration area construction. State Grid has also given corresponding policy support to this, providing convenience in terms of approval procedures and Internet access. Due to the state’s policy support, subsidies for photovoltaic power generation have been increased, such as the on-grid price of photovoltaic power generation is still maintained at 1 yuan/kWh, and subsidies are provided for self-generated self-consumption and surplus power on-grid, which has beneficially promoted the development of China’s photovoltaic application market. The steady and rapid implementation of projects such as “Photovoltaic Building Integration” and “Golden Sun Project” proves that China’s photovoltaic power generation has entered a new stage of development.
(4) Problems faced by solar photovoltaic power generation
At present, the main reason that restricts the large-scale development of solar photovoltaic power generation is still the cost. In recent years, with the sharp drop in the price of polysilicon materials and the improvement of solar cell production technology and efficiency, the cost of photovoltaic power generation has dropped significantly, but it is still much higher than the cost of conventional power generation. Compared with developed countries, China’s solar photovoltaic power generation still has a big gap. There are still many problems in the development of China’s photovoltaic industry.
① There is a gap between the research and industrialization level of photovoltaic technology compared with foreign countries. The solar cells developed in China, such as monocrystalline silicon and polycrystalline silicon cells, are 5% lower than the world’s advanced level in laboratory conversion efficiency, and 2% to 3% lower in commercial cells. There are very few enterprises in China that really have industrial scale and master core technology. The production of solar cells requires high-purity polysilicon, but China’s current refining technology is relatively backward. Compared with foreign levels, the refining purity of Chinese polysilicon is lower, but the energy consumption is 2~3 times higher, and the environmental pollution is serious. Therefore, more than 90% of the high-purity polysilicon of solar cells manufactured in China can only be imported, which directly affects the production and product cost of solar cells, resulting in higher cost of photovoltaic power generation.
②The solar photovoltaic equipment is backward, and the localization of special raw materials is not high. About 1/3 of China’s photovoltaic equipment relies on imports, and the performance indicators and reliability of some equipment still need to be improved. Such as polysilicon casting furnace, wire cutting machine ingot breaking machine, etc. need to be imported. PEVCD hydrogenated silicon deposition equipment, screen printing machine, cell sorting machine, series welding machine and other performance can not meet the needs of modern production, need to introduce a full set. Almost all the key equipment of China’s new large-scale solar cell production lines are imported, and the localization matching rate is very low, and the core key technologies still need to be researched and breakthroughs.
③Silicon materials are basically imported, while most of the photovoltaic products produced in China are sold abroad, that is, “two ends are outside”, and the market is highly dependent on foreign markets. In addition, the fierce market competition is also a fact that cannot be ignored.
At present, from the perspective of the global photovoltaic market, it is in a situation of oversupply, and it is difficult to change in the short term. At present, China’s solar photovoltaic applications are still very imperfect in terms of technical standards, management procedures, and quality monitoring systems, including photovoltaic product quality inspection and certification systems. and management methods, unified photovoltaic system design specifications, photovoltaic system operation, maintenance and management specifications. There is a lack of perfect technical standards and management requirements for the integration of solar photovoltaic power generation into the grid. The operation mechanism for distributed power generation to be connected to the grid has not been established, and a reasonable on-grid electricity price mechanism has not been formed. There is no unified technical standard for the photovoltaic building integration system. These problems hinder the development of photovoltaic grid-connected power generation.
(5) Prospects of solar photovoltaic power generation
Solar photovoltaic power generation is the most promising power generation technology in the 21st century, and it is also an important form of solar energy utilization. The World Energy Organization predicts that in 2020, the world’s solar photovoltaic power generation will account for 1% of the total power generation, and in 2040, it will account for more than 20% of the total power generation.
The development of solar photovoltaic power generation can not only solve the problem of depletion of fossil energy, but also an important way to protect the ecological environment and control pollution. Fossil energy will emit a large amount of pollutants during the combustion process. For example, the carbon emission of coal-fired power is 796.7g/kWh, the carbon emission of oil-fired power generation is 525g/kWh, the carbon emission of gas-fired power generation is 377g/kWh, and the carbon emission of solar photovoltaic The carbon emission of power generation is 33~50g/kWh, which is only 1/20~1/10 of the carbon emission of fossil energy power generation. It is a good clean and low-carbon energy. The development potential of solar photovoltaic power generation in China is huge, and it will gradually become the mainstream form of energy utilization.