The Influence of Shadow on PV Power Generation

According to the calculation, the tiny shade of trees and wires in the photovoltaic system can reduce the power generation of the power station by about 20-30%! At present, the construction of photovoltaic power stations for rural households and industrial and commercial roofs has become a popular trend. The power generation capacity of photovoltaic power stations directly affects the final income, and shadow  is one of the very common problems affecting the power generation capacity.

Under certain conditions, some cells in the photovoltaic system will be blocked by other surrounding objects, resulting in local shadows, which will cause some cells to heat and produce the so-called "hot spot" phenomenon. If the shadow effect does not eliminate but exists for a long time, when the hot spot effect reaches a certain degree, the solder joint on the module melts and destroys the grid line, resulting in the scrapping of the whole solar cell module. Obviously, shielding seriously affects the service life of junction box and battery board, and seriously affects the power generation and reduces the income of the owner.

Common photovoltaic shadow occlusion sources

Wire and guardrail  

Although the construction scope of photovoltaic power station is fixed, the environment around the power station is diverse. Even a very professional system design company will ignore the invisible shielding between wires and power station guardrails.

Fixed building  

There are two kinds of buildings here: first, the buildings that have existed before the construction of the power station; Second, buildings built the day after tomorrow.

Plants near photovoltaic power plants

When the photovoltaic power station was built, there were no plants nearby, but later, new plants grew up, which played a role in shielding the power station.

Bird droppings and dust

Photovoltaic modules are often built on the roof and ground. For photovoltaic power stations placed outdoors, it is easier to attract dust. When the modules are covered with a layer of dust, don't underestimate this layer of dust, it also has a great impact on the power generation of photovoltaic modules. Moreover, photovoltaic modules will also become a place for birds to "play", and bird feces and scattered bird feathers become regular visitors on photovoltaic modules.

How to avoid photovoltaic shadow occlusion

  1. Pay attention to shadow analysis before power station construction

Before the construction of the photovoltaic power station, we must do a good job in the preliminary investigation to determine whether there will be shielding around the high-voltage lines, railings, vegetation and existing buildings (the planned buildings should also be expected earlier). We should find ways to eliminate the shielding and change the installation position. In the survey and installation, the growth year of plants shall be fully considered, and whether the shade and branches and leaves cause shelter shall be considered. If there is shelter, it can be cut off..

  1. Clean the surface of photovoltaic modules

Shadow shielding is mainly due to the influence of bird droppings, dust, tree shade, etc. first, we can choose an appropriate position to install photovoltaic modules, and try not to install modules in the place with shielding. When it is inevitable, choosing an appropriate module placement method can reduce the influence of shadow. In daily operation and maintenance, pay attention to the cleaning of photovoltaic modules and timely clean up dust and other foreign matters.

  1. Multi channel MPPT inverteris selected

Considering the system itself, the implementation of multi-channel MPPT will reduce the influence of shadow occlusion. For example, the micro inverter photovoltaic system is a fully parallel design circuit, and each component has an independent MPPT, which can realize the maximum power output, so that the shadow, dust and leaves can partially block the battery panel, and there is no short board effect, which eliminates the mismatch caused by different component shielding, orientation and angle, and greatly improves the power generation. However, based on this kind of system, each solar panel is equipped with inverter, and the cost is also relatively high. It can only be said that according to the site conditions and basic calculations, if the cost budget allows, the use of this system can avoid the restrictions on the site and bring higher power generation efficiency and benefits, it is a good choice.

It is easy to build a photovoltaic power station, but the shielding problem should not be underestimated. In order for the photovoltaic power station to achieve the expected income, these shielding problems should be paid attention to early. Only in this way, the photovoltaic power station is not a "vase" in the user's home and truly becomes the "cash cow" of the user.

To learn more, just pay attention to the official website of SOLARPARTS. As the best off-grid solar manufacturer, our solar panel series products adopt efficient single crystal cells with a conversion rate of up to 23%! Below is the contact information of SOLARPARTS, looking forward to your consultation!

Phone: +86-13923729619         Fax: +86-755-28720791

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Email address: Philip@isolarparts.com

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