Handling Shading Issues: Microinverters vs String Inverters
Overview
- Microinverters are small devices attached to individual solar panels, converting direct current (DC) to alternating current (AC) at each panel. This setup allows each panel to operate independently, minimizing the impact of shading on overall system efficiency.
- String Inverters connect solar panels in a series (“strings”) and convert the collective DC power to AC. However, when one panel is shaded, it can reduce the performance of the entire string.
Microinverters and Shading
- Advantages: Microinverters are ideal for systems with frequent or unpredictable shading. Each panel operates independently, ensuring that if one is shaded, the rest continue to produce energy at full capacity.
- Example: In California, homes using microinverters experienced a 5-10% increase in energy output compared to traditional string inverter systems, particularly in shaded conditions.
String Inverters and Shading
- Limitation: The performance of a string inverter system can be severely impacted by shading on a single panel. This is often referred to as the “Christmas light effect,” where one underperforming panel can drag down the entire string’s output.
- Mitigation Strategies: While string inverters struggle with shading, they can be effective in fully exposed installations like ground mounts. Additionally, oversizing the inverter and designing the array with care can help mitigate some shading effects.
Comparison Summary
| Feature | Microinverters | String Inverters |
|---|---|---|
| Shading Impact | Each panel operates independently, minimizing impact. | Performance reduced by the most shaded panel in a string. |
| Cost | Generally more expensive than string inverters | Less expensive upfront compared to microinverters |
| Suitability | Ideal for complex roof layouts or frequent shading | Suitable for ground mounts and systems without shading |
In summary, microinverters outperform string inverters in handling shading by ensuring each panel operates at its maximum potential regardless of shading conditions. However, they are more expensive upfront. String inverters are cost-effective but are best suited for installations without significant shading issues.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-microinverters-handle-shading-issues-compared-to-string-inverters/
