Do String Inverters Work Well in Shaded Areas?

String Inverter Limitations

String inverters are not ideal for installations with multiple panels in shaded areas. When one panel is shaded, the entire string’s output voltage and current drop, which can lead to reduced efficiency and even complete shutdown. This is because string inverters are designed to operate at a fixed voltage and current level, and can’t adjust to variations in string output.

Shading and String Inverter Performance

In a typical string inverter system, a shaded panel can cause the entire string’s voltage to drop by up to 20%. This can result in a significant reduction in power output, potentially leading to a system shutdown. To mitigate this issue, array designers often use bypass diodes to isolate shaded panels and prevent the entire string from being affected. However, this approach can also lead to increased heat generation and reduced system efficiency.

Micro-Inverter Alternatives

Micro-inverters, on the other hand, are designed to handle variable voltage and current inputs from individual panels, making them more suitable for shaded areas. Each micro-inverter is connected to a single panel, allowing it to operate independently of the others. This design enables micro-inverters to maintain optimal performance even in shaded conditions, making them a more reliable choice for solar installations with multiple panels in shaded areas.