What is Shading and Effects on Solar Panels
In 2021, solar energy provided around 4.4% of the world’s total energy. Compare that to 2020, when it was 3.3%. As per the Ember Climate report, solar energy made up 11.5% of all renewable energy sources. In the global shift to sustainable energy sources, solar energy has become a key performer. However, shade may seriously reduce the efficiency of solar panels. In this section, we will let you know the difficulties caused by shade as well as the creative technical fixes used to lessen its negative effects on solar panel performance.
What is Shading?
Shading is a challenge for solar panels because if even one part of the panel is shaded, it can stop the whole panel from producing power.
When one part is shaded, it affects the whole group of cells or modules, making them produce less power. The extra power from the unshaded parts goes to the shaded part, but special diodes called bypass diodes help to keep the shaded part separate.
How Does Solar Panel Shading Work?
Traditionally, solar panels are set up in groups called ‘strings.’ Imagine these strings like a chain of holiday lights – if one bulb goes out, the whole string can be affected. Similarly, if a tree or chimney shades one panel in a string, all the other panels connected to it will also lose power. This happens because the panels are linked in a way that the output is only as strong as the weakest panel in the group. If even one part is shaded, it’s like turning off a switch, and the whole string loses power. So, shading just one part of a panel can make the entire group lose power.
What Factors Can Cause Solar Shading
When setting up a Solar PV System, it’s important to think about different types of shading. Shading comes in various forms and can be different for each home. At Deege Solar, we categorize shading into two types: Dynamic and Static. Surprising, right? Shading can be pretty advanced!
Dynamic Shading is temporary and includes things like shadows from moving clouds, falling leaves, snow, bird droppings, and even dust. On the other hand, Static Shading is more predictable, caused by things like nearby trees, satellite dishes, buildings, or chimneys. This type of shading can be planned for in advance because it’s caused by existing obstacles.
Solar Panel Shading Solutions
The Shading Conundrum
When outside objects prevent sunlight from reaching the surface of solar panels, shading happens. Trees, buildings, neighbouring structures, or even dust and dirt deposition on the panel surface can be responsible for this. Shading reduces the total amount of sunlight that the panels absorb, which lowers their energy production. According to experts, shade can lead homeowners to lose up to 40% of the potential output of their solar PV installation. And it’s not because there is shadowing throughout the entire panel. A simple 10% shade on a photovoltaic panel can cause a 50% reduction in efficiency, as per reports.
Conventional Bypass Diode Systems
Using bypass diode technology is one traditional way of coping with shading issues. Using this method, solar panels are divided into many strings, each of which has a bypass diode. The bypass diode works to avoid damaging the cells in the shadowed area of the panel, allowing the remaining portion of the panel to operate at maximum efficiency. In the junction box of the solar panel, bypass diodes are often connected in parallel with groups of solar cells. They serve the purpose of allowing current to bypass the defective or shaded cells, which would otherwise lead to overheating and deterioration. This method works well for partial shading, but it becomes problematic when a major portion of the panel is shaded. The quantity of energy generated will be 10% less with bypass diodes than under ideal circumstances when the solar panels are not shadowed.
Maximum Power Point Tracking (MPPT)
The Maximum Power Point Tracking (MPPT) algorithm is a feature of charge controllers that is utilized to collect the most power that can be extracted from photovoltaic modules under specific situations. The maximum power point of a photovoltaic module is the voltage at which it can generate maximum power. Maximum Power Point Tracking (MPPT) connection is a crucial component in modern solar inverters. Even in situations when there is continuous shade, this technology constantly modifies the solar panel’s operating settings to maximize electricity extraction. MPPT makes sure that the panels run as efficiently as possible by continuously adjusting the voltage and current levels.
Microinverters and DC Optimizers
Modern techniques to handle shading concerns at every panel level include microinverters and DC optimizers. Every panel has a microinverter suited to convert DC power to AC power right at the source. On the other side, before the DC output from each panel reaches the inverter, DC optimizers adjust it. The effects of shading on the overall performance of the system can be reduced by both techniques.
Intelligent Panel Design
We can plan and design PV systems around obstacles through software design. The panel arrangement is designed to optimize shade to the maximum level achievable. The solar professionals are well-versed in creating solar systems that are resistant to shadows. Modern panel designs include elements that reduce the impact of shade. For example, some panels include bypass diodes installed at the cell level, which allows for more accurate control over areas that are darkened. Moreover, multi-busbar panels reduce power loss in shaded areas, increasing the overall efficiency of the system.
Combined Use of Energy Storage
Batteries and other energy storage devices can be used in conjunction with shading solutions to store extra energy during times of high solar radiation and provide it when shade occurs. This ensures a more steady flow of energy, especially in areas with some shadow.
Advanced Monitoring and Analytics
Real-time performance data on individual panels is provided through sophisticated monitoring systems. In addition to optimizing the overall efficiency of the solar power system, this allows for the timely diagnosis of shading concerns and targeted maintenance projects.
Even though shade makes it tough to capture solar energy, the solar industry has shown incredible creativity in coming up with ways to overcome it. To optimize solar panel efficiency even in shadowed conditions, the industry is coming up with innovations, ranging from traditional bypass diode systems to microinverters, smart panel designs, and sophisticated monitoring. As solar energy adoption continues to soar, these shading solutions will play an indispensable role in ensuring the reliability and effectiveness of solar power systems worldwide.