At a time when rising electricity prices and environmental concerns have driven the need for alternative energy sources, Solar power has established itself as an excellent way of harnessing sunlight into energy.
However, switching to solar doesn’t always guarantee favourable results even with a high-quality setup. That’s because we often ignore small obstacles during installation that later affect systems efficiency.
Shading is one of the most prominent issues faced by solar panels. Even a partial shadow over one solar module can reduce the output of the whole PV system. But how does shading cause such a drastic effect and how to prevent it?
Well if you are wondering the same then you are at the right place. Keep reading this guide for optimizing PV system performance by minimizing shading losses.
A solar panel system consists of solar panels and an inverter. Whenever sunlight reaches the surface of a PV module, the solar panel converts this into DC (direct current) power and the inverter changes this DC into AC (alternative current) power for running appliances at your home or business. But when sunlight doesn’t reach the solar cells due to shading or other obstacle, it reduces the output of the entire solar system. This loss of power is known as shading loss.
Shading can happen due to numerous reasons varying as per the season and the structure of your home or building. The two main types of shading include:
- Static Shading: Trees, buildings, poles, antennas, or terrains surrounding the solar system installation site
- Dynamic Shading: Clouds, dust, snow, and debris from falling leaves or bird droppings.
Other than that, solar shading can happen due to self-shading from parallel solar panels, soiling, panel placement, etc.
Therefore, choosing a certified solar company in Gold Coast will ensure your solar system remains free from shading loss.
Most solar PV systems installed at home or small-scale businesses consist of 6 to 30 solar panels, depending on the module capacity. Generally, these panels are divided on the voltage requirement of the inverter and connected parallel in a series of ‘strings’ of PV modules.
Therefore, if a shadow from a tree or other object covers one panel, it reduces the output of all the connected panels within this string to practically zero.
You can imagine strings as water pipes and constant power as the water flowing through the pipes. So when the shadow blocks the power flow, like a clog in pipes, it prevents the unshaded panels from delivering their peak outcome.
Moreover, shading of just one cell in the panel can flatten the output of the entire module and eventually affect the whole system.
While considering solar panel packages, it’s essential to discuss different solar designs that can mitigate solar panel shadings. Some of the crucial ways to reduce shading loss include:
One of the simplest ways to prevent solar shading is by selecting an optimal location with minimal shading and maximum solar availability. Usually, a solar panel installer will help you to locate the appropriate placement site through mapping tools. Also, they ensure that the installation site has no trees that will obstruct the panel throughout its lifespan.
As we know, a shaded solar panel can affect the efficiency of the entire string. However, it will not hinder the performance of parallel strings.
So if your solar installer can analyze and group the shaded panels on a separate string and the unshaded modules on another, you can enjoy the maximum solar output.
Bypass diodes are devices used in solar panels isolating the specific shaded solar cells by rerouting the solar power to flow around that shaded cell. But this method is expensive, so only three bypass diodes are used in a PV module by grouping the solar cells in three solar strings.
These are the devices that installers attach at the back of each panel to deliver optimum output, even with shading issues. It mainly includes the devices that help tackle partial shading concerns, such as power optimizers and micro-inverters.
- Power optimizers with maximum power point tracking (MPPT) capability help with static and dynamic shading by adjusting the output power and voltage to maintain full solar power.
- Similarly, Micro inverters with separate MPPT are attracted to each panel, helping to convert their output from DC to AC separately. This way, each module will deliver maximum efficiency.
Shading in solar panels can affect the performance and output of the system significantly. That’s why it’s crucial to get a basic understanding of the shading effects and the ways to tackle this issue.
We hope all the points discussed in this guide have given you a better understanding of optimizing PV system performance and minimizing shading loss.