Analysis on the advantages and development advanta

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Analysis on the advantages and advantages of thin film battery development recently, it was learned from some people in the photovoltaic industry that the domestic photovoltaic industry will gradually recover this year, and the photovoltaic industry will improve in the second half of this year and next year at the latest. It was revealed that in fact, many factories have reopened

At the end of last year, the Ministry of Finance and the Ministry of housing and urban rural development issued the notice on 2012, weight: About 500kg, main technical indicators: the 12th annual solar photovoltaic building application demonstration project (hereinafter referred to as the notice), proposing that for building materials and other photoelectric integration projects closely integrated with the height of buildings, the subsidy standard this year is tentatively set at 9 yuan/watt, an increase of 3 yuan over last year. For the utilization forms generally combined with buildings, The subsidy standard is tentatively set at 7.5 yuan/watt

"thin film cells are very useful in the field of BIPV (photovoltaic building integration). In terms of characteristics, thin film cells are more convenient to install on buildings." Xu Zhengxiang, director of the Institute of optoelectronic technology at Beijing Jiaotong University, said

Xu Zheng believes that crystalline silicon cells have high conversion efficiency and are suitable for large-scale photovoltaic power stations, but the technical characteristics of thin-film cells are more suitable for construction, so there is more space in the field of BIPV. "Don't set thin films against crystalline silicon. In the future, they will coexist rather than replace." Xu Zheng said

at present, crystalline silicon technology is the mainstream in the photovoltaic industry, accounting for a high proportion. The development of thin films has a wavy process. At the beginning, when silicon materials were relatively expensive, many people invested in thin-film batteries. Recently, with the decline of silicon materials, people have different views on thin-film batteries. Now the cost of crystalline silicon battery is very close to that of thin-film battery, which has been reduced to 6 yuan/watt, but the conversion efficiency is much higher than that of thin-film battery

there are many development advantages in the future

how to measure the capacity of dynamometer of Jinan testing machine in a short time? The inner crystalline silicon battery will still dominate, but in the long run, the development prospect of sensor film is far higher than that of crystalline silicon

"at present, the efficiency of crystalline silicon can reach 17%-18%, the ultimate efficiency of a single cell is 29%, and the current laboratory can achieve 25%, so the room for improving the efficiency of crystalline silicon is limited. Theoretically, the ultimate efficiency of thin film is the same as that of crystalline silicon, which can reach 29%, while the current efficiency is only about 10%, that is to say, there is still much room for improving the conversion efficiency of thin film." Zhao Lei told China Energy News

concise believes that conversion efficiency is not equal to power generation, "The conversion efficiency of photovoltaic cells generally refers to the efficiency under standard conditions. Under standard conditions, the conversion efficiency of thin film is lower than that of crystalline silicon. However, reports in many industries show that in practical application, the power generation of thin film cells with the same capacity in a year is higher than that of crystalline silicon. Our experiments in Dongguan found that the power generation of thin film cells with the same wattage is 8%-10% higher than that of crystalline silicon."

however, in addition to the conversion efficiency, thin-film technology is still questioned by some industry insiders. Some industry insiders believe that thin-film batteries have large attenuation, large floor area and high technology cost. In this regard, it is succinctly pointed out that the product characteristics of thin films are that the attenuation is large at the beginning, but after 600 hours, the attenuation is relatively stable, which is similar to that of crystalline silicon batteries. "Generally, thin-film battery manufacturers take the attenuation into account before leaving the factory. For example, a battery of 130 watts is generally sold at 100 watts, and the attenuation is deducted in advance."

concisely attributed the high cost of thin-film technology to the fact that thin-film battery equipment mainly depended on imports. Concise believes that after the equipment is localized, "the thin-film battery industry chain is very short, and one workshop can complete it. In order to achieve parity in the future, the advantages of thin-film are obvious. In the future, the power generation cost of thin-film can reach 0.3 US dollars/watt, less than 3 yuan."

however, the large floor area is a barrier that thin-film cells can't get around. For the construction of large-scale photovoltaic power stations, the biggest disadvantage of thin-film cells is the large floor area. Relevant data show that the photovoltaic cell module with an efficiency of 14% has a rated output of 140 watts per square meter under standard sunlight. Based on this calculation, to achieve the same capacity, the floor area of the thin-film battery is inversely proportional to its conversion efficiency

"technically, if we want to improve the conversion efficiency of thin-film batteries to 12%, or even further to 15% and 16%, then the cost will be greatly reduced, but this is very difficult." Zhao Lei said, however, with the development of technology, crystalline silicon will be replaced by thin film in the long run. Due to the low pollution, low energy consumption and higher power generation of thin film technology, "what crystalline silicon can do in the future, thin film can do, but what thin film can do can't do."

bipv application should meet the needs of building materials

at present, it is unrealistic for thin-film batteries to replace crystalline silicon batteries, but as experts say, the advantages of thin-film batteries are more obvious in the field of BIPV. Concise believes that even if analysts point out that it is a rooftop solar photovoltaic system, whether users choose crystalline silicon or thin-film cells mainly depends on policy changes, "It is generally believed that crystalline silicon is mainly used on roofs. However, due to policy changes in some countries, many roofs use thin films. Germany adopts the policy of encouraging more power generation, and users make money by generating and selling electricity, so they choose crystalline silicon more; but Australia encourages self-use, and the government subsidizes each household within 1500 watts. Beyond this range, there is no subsidy, so users tend to use low-cost thin-film batteries."

for "building materials and other photoelectric integration projects closely combined with the height of buildings", thin-film batteries are less sensitive to the installation angle and have stronger adaptability to architectural design requirements, so they also have more advantages. Xu Zheng pointed out that the thin-film battery should really meet the needs of building materials and meet the installation and design specifications of building materials, such as safety, fire resistance and other requirements, before it can be installed on buildings. At present, some building photovoltaic specifications have been drafted

"it turns out that many architects and designers don't realize the use of thin-film batteries in architecture. How to integrate thin-film batteries into design and architecture is not only for those who make batteries, but also for those who make architecture. Those who make thin-film should be combined with those who make building materials and design, which is a process of mutual learning." Xu Zheng said

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