Shadowing Effects on Photovoltaics

Impact of Shadowing on Photovoltaic Systems

Despite the efficiency and relatively low cost that Photovoltaic (PV) systems are known to provide, they are vulnerable to a number of factors which may harm them. Such critical parameter is shadowing which impacts the efficiency of power generation by photovoltaic modules in its straight forward manner. They include situations where trees, structures or even clouds may for example cast shadow on the surface area containing the solar panel thus denying the solar panel direct access to sunlight. This leads to decrease in dry bubble condition and thus less heat is being received from the sunlight and therefore less electric production.

Although the results present shadows as fading power generation, its effects are more profound than simply that. The above harm affects the overall output of the PV systems in a more generalized form. For example, just one shaded cell in a module will invariably lead to energy losses because cells in most panels are connected in series. This can lead to hotspot formation where the shaded cell along dissipates power instead of producing and this over time can destroy the module in question. Thus, knowledge and control of the shadowing impacts is vital for improving the efficiency of PV systems.

Causes and Types of Shadowing

There are diverse environmental and man-made factors that cause shadowing. Common sources include:

Trees and Vegetation: Increased tree growth can have a considerable impact on shading of PV arrays mostly in late morning and early evening.

Buildings: Other factors such as buildings around it especially within urban areas will at some time of the day or year block the rays of the sun.

Cloud Cover: Basically, due to relative movement of clouds, one part of the solar farm will be shaded while the other part receives light intermittently.

Shadowing can be classified into several types, each with distinct characteristics:

Static Shadowing: Occurring from fixed objects such as erect structures and trees. Fortunately this type is somewhat controllable and can be determined in advance during the design process.

Dynamic Shadowing: Consequences produced by temporary occasions, for example, moving clouds or swaying tree branches. This is less predictable and thus solutions have to be adjusted in one way or the other to fit the new conditions.

Self-Shadowing: Frequently develops in the area of the panels themselves with low interpanel spacing and improper tilting. Elimination of self-shadowing is an aspect of layout design that should be well done.

SUNGO's Solutions and Optimization Measures

Shadows have a detrimental effect on the output of photovoltaic (PV) systems through the obstruction of sunlight which induces power loss and damage to the solar cells. One additional layer of obstruction on one cell type may lower the whole panel’s production due to the cell’s series alignment. To reduce these effects, it is necessary to perform site visits in several phases of the design process. Such as determining seasonal sun trajectories and potential blockages through the use of solar pathfinders to reduce shade efficiency prior to installation.

New technologies are undeniably influential in improving performance in shaded areas. Bypass diodes allow the current to conduct around its obstruction, which in this case, are the shaded cells while micro inverters permits each panel to operate independently so that in areas where there are shadowed panels, the total output of the system is not compromised. Other strategies include routine cleaning and maintenance such as cutting that improve the overall efficiency of the system. Also, technologies like half-cell and shingled-cell designs make it easier for PVs to capture more light while solar tracking systems increase energy yield, moving with the sun throughout the day. Most importantly, by employing appropriate design and innovative mechanisms to manage and reduce shading difficulties, there is enhanced performance and durability of PV systems so as to harness maximum solar energy benefits.

Application of SUNGO's iOPT 800W Optimizer

There are devices such as SUNGO’s iOPT 800W Optimizer that go a long way towards lessening the String shading effect. Inside the power optimizers, there are five main operations which are as follows; there is an attempt to make every module in a PV system to work at its MPP. When shading takes place, the output is equalized by the interactive control of each panel in the device to minimize power loss.

And this is where the iOPT 800W Optimizer, for example, has certain benefits. It operates by controlling for voltage and currents thus delivering optimal power even under shadowing conditions. Research work has demonstrated that when such power optimizers are applied it is quite possible to enhance the efficiency and dependability of PV systems, in particular in partially shaded operations.

Case Analysis: Handling and Improvement of Shadowing Issues

A couple of examples are provided below showing how shadowing is effectively resolved if the problem is detected in time. For example, a utility scale power PV plant had its performance reduced by novelty trees shading some of the panels. I was able to increase the performance of the system by using SUNGO’s iOPT 800W power optimizers and changing the panel configuration.

Another case was an urban PV system which was affected by shadowing problem due to nearby buildings. Proper use of shading devices and frequent maintenance greatly reduced shadow impacts and improved power generation capacity considerably.

These cases clearly explain why shadowing concerns must be addressed as soon as they are identified. If the causes are spotted and dealt with immediately, the PV system owners can ensure that maximum power is being produced and that the system’s life span is being utilized to the fullest.

All in all, therefore, shadowing presents a real threat to the effectiveness of photovoltaic systems. Nevertheless, if these problems are addressed with proper solutions like, enhancing the layouts, using shading devices and high technologies including SUNGO’s iOPT 800W Optimizer the above problems can actually be solved. For the optimal performance of PV systems and most importantly to have the systems impact the environment positively and return an optimal value to the investors, constant maintenance and timely preventive measures should be observed.