With the rapid development of science and technology, photovoltaic power generation technology has been widely used at home and abroad. Its application forms are diverse, and its application sites are widely distributed, mainly used in large ground photovoltaic power stations, roofs of residential and commercial buildings, building photovoltaic building integration, photovoltaic street lamps, etc. In these places, buildings, shade, chimneys, dust, clouds, etc. will inevitably block solar cell modules. Therefore, people are concerned about how much this kind of situation affects the power generation efficiency of solar cells, and how to solve it?

In practical applications, solar cells are generally composed of multiple battery modules in series or in parallel to obtain the desired voltage or current. In order to achieve high photoelectric conversion efficiency, each cell in the battery module must have similar characteristics. In the process of use, one or a group of batteries may not match, such as cracks, internal connection failure or shading, which may cause its characteristics to be out of tune with the whole. Under reasonable lighting conditions, the shielded photovoltaic cells in a series branch will change from power generation unit to power consumption unit. The shielded photovoltaic cells will not only contribute to the output of the module, but also consume the power generated by other cells. At this time, they will generate heat, which is the hot spot effect.

Compared with crystalline silicon, the film thickness of amorphous silicon thin film battery module on the whole module is relatively uniform, the current of multiple sub-cells is well matched, and there will be no crack or hidden crack of crystalline silicon module. The amorphous silicon photovoltaic module made by excellent production process and strict quality control system will almost not have the problem of internal link failure of each sub-cell in the thin film module. In addition, for crystalline silicon solar cells, small shielding can cause large power loss, resulting in excessive module temperature, serious burning of the module, and even major fire; However, the current density of the amorphous silicon thin film battery is small, and shadow shading will also have an impact on the thin film battery, but the impact is much smaller than that of the crystalline silicon battery.

For the hot spot effect of thin film photovoltaic products, the International Electrotechnical Commission has formulated strict certification test standards, and the products must withstand the hot spot effect test under extremely harsh conditions. After the hot spot durability test of the thin film PV module, the appearance inspection shall be carried out first, and any crack, bubble or delamination shall be recorded or photographed. If serious appearance defects specified in the standard are found, such as broken, cracked, bent, irregular or damaged external surface; If any film layer in the effective working area of the module has more than 10% of the area of a battery, visible corrosion, continuous bubbles or peeling between the edge of the module and any part of the circuit, and the mechanical integrity is lost, which affects the installation or operation of the module, it is considered as unqualified. If there are appearance defects but not the serious appearance defects mentioned above, such as: any film layer in the effective working area of the module has gaps and visible corrosion, and the output wire has visible corrosion, take photos for record; If there is no impact on other subsequent test experiments, the thin-film PV module is considered to have passed the hot spot effect test. If there is impact, another two modules are selected for the hot spot effect test again. In addition, the attenuation of the maximum output power of the module under standard test conditions shall not exceed 5% before the test; The insulation resistance shall meet the same requirements of the initial test.

The common way to solve the problem of hot spot effect is to connect a diode in parallel on the module. Normally, this diode does not affect the normal operation of the module. When the battery in the module is blocked, the diode is on to avoid overheating and damage of the blocked battery.

Customers can rest assured that at present, many domestic film module manufacturers, including Pule New Energy, have passed the most authoritative and rigorous certification of product working performance and safety performance in the world. It should be noted that during the design, construction and grid-connected use of the photovoltaic power station, the impact of shading on the photovoltaic power station and the photovoltaic system should be fully considered, and the photovoltaic power station should be reasonably arranged and the maximum power control technology should be adopted to minimize the impact of shading on the photovoltaic system.