Can String Inverters Compromise Energy Production With Shaded Panels?

Shading Impact on String Inverters

String inverters can suffer from reduced efficiency when panels are shaded, as they operate on a principle of “worst-case scenario” – the inverter assumes the entire string is performing at the lowest output. For example, if one panel is shaded by 20%, the entire string output may be reduced by around 10-15%. This is because the inverter prioritizes system stability and reliability over maximum energy production.

Microinverters as a Solution

Microinverters, on the other hand, are designed to optimize energy production at the panel level, making them more suitable for installations with shading issues. By converting DC power to AC at each panel, microinverters can isolate the impact of shading to a single panel, allowing other panels to continue producing at maximum capacity. This is particularly beneficial for systems with a high number of panels, where shading is more likely to occur.

System Design Considerations

When designing a solar system with potential shading issues, it’s essential to consider the placement of panels and the type of inverter used. Using microinverters can help mitigate the effects of shading, but it may also increase the overall system cost. In some cases, a combination of string and microinverters, known as a “hybrid” system, may offer a compromise between cost and performance. By carefully evaluating the shading patterns and system requirements, solar designers can create efficient and effective systems that maximize energy production and minimize the impact of shading.