When it comes to PV modules, all know that it is the core part in Solar system. And its function is to transform solar power into electricity power and send the transmitted power to the storage batter for storage, or to promote the loading to work. Types and quality directly influence revenue of the power station. When deciding installing the solar power station, we should learn about the PV modules in detail and no carelessness is allowed.
Here the PV module types and some common problems are listed to make all know about PV module more deeply in detail.
PV module types
Monocrystalline silicon cell
Photoelectric conversion efficiency of crystalline silicon solar cell is about 15%, even to 24%, the maximum level. And this is the highest photoelectric conversion efficiency among all types of solar cells. But its producing cost is so high that it hasn’t been widely used. As monocrystalline silicon generally applies tempered glass and water repellent resin to seal and package, then it’s sturdy and durable, with a usage life span of 15 years to 25 years.
Polycrystalline silicon cell
Producing techniques of polycrystalline silicon solar cell is similar to that of monocrystalline silicon solar cell. However, photoelectric conversion efficiency of polycrystalline silicon is less about 12% (The highest photoelectric conversion efficiency of polycrystalline silicon is 14%, listed by SHARP from Japan on July 1st 2004). In terms of production cost, the cost of polycrystalline silicon cell is cheaper than that of the monocrystalline silicon cell because the material for production of the former is simple and can save power consumption. Its total production cost is relatively low and thus is widely developed. In addition, life span of polycrystalline silicon cell is shorter than that of the monocrystalline silicon cell. But in terms of the performance-cost ratio, the monocrystalline silicon is a little bit better.
Amorphous silicon cell
Amorphous silicon cell is a new type of thin film solar cell born in 1976. Its production method is quite different from that of the monocrystalline silicon and polycrystalline silicon cell. Techniques in its production process is greatly simplified. The consumption of silicon material is much less and power consumption is lower. Its main advantage is that it can generate power even in weak power condition. But the main problems of amorphous silicon cell is that its photovoltaic conversion efficiency is relatively low, about 10% of an international level. Moreover, it’s not stable enough and the conversion frequency will reduce as time passes by.
Recommended first-line brands of PV modules
The distributed residential PV power station installed by us all use high quality PV modules produced by first-line manufacturers. The usage life span can be as long as 25 years. The EPC total package price is about 8 Yuan/W.
a. Do PV modules need to be frequently cleaned?
Many users think that the PV modules need to be cleaned upon being used for a period of time. Actually this is not absolutely right. There is self-cleaning effect on the PV modules surface, and rainwater will help get rid of dust on the surface regularly. Frequent cleaning of the PV modules will not help improve the power generation capacity greatly at all, but will result in waste of water resources. The PV modules need to be checked and maintained regularly. Some obvious sewage which can’t be easily flew away by rainwater such as bird droppings need to be cleaned.
b. How about attenuation rate of the PV modules?
Attenuation rate of the PV modules refers to the ratio of output power to nominal power under the standard testing conditions (AM1.5; modules’ temperature:25°C; irradiance: 1000W/m2) upon running of the PV modules for a period of time. According to national standards: attenuation rate of the monocrystalline modules in the first year will be no more than 3%; that of the polycrystalline modules in the first year will be no more than 2.5% and less than 0.7% every year hereafter, with a power generation rate of no less than 80% within 25 years.
c. Does the aberration of the PV modules affect power generation rate and life span?
Different colors of PV modules will affect the whole appearance and users may not accept that psychologically. But simple aberration of the PV modules will not affect the power generation rate and life span. The main factors affecting power generation capacity is some mechanical damage such as hidden cracks. Aberration is simply some technic problems and will not affect power generation rate and life span of the PV modules.