Comparing microinverters and string inverters
Microinverters and string inverters are two common approaches to converting DC power from solar panels into AC power. Each method has different performance, cost, and maintenance characteristics.
String inverters
- One central inverter handles a series (string) of panels.
- Cost-effective and simpler for large, uniform arrays with consistent exposure.
- Under partial shading or mismatched panels, the whole string’s output can be limited.
Microinverters
- Small inverters are installed at each panel, converting DC to AC at the source.
- Each panel operates independently, so shading or panel mismatch affects only the shaded panel.
- Enable detailed per-panel monitoring and can increase production in shaded or complex roof layouts.
Power optimizers
- An intermediate solution that pairs panel-level optimization with a central inverter.
- They mitigate mismatch losses while keeping the central inverter model.
Key trade-offs
- Cost: Microinverters and optimizers add upfront cost compared to string inverters but can improve yield and simplify panel-level maintenance.
- Reliability: Central inverters are easier to service, while microinverters spread electronics across the array; however, modern microinverters have strong reliability records and long warranties.
- Design flexibility: Microinverters are ideal for arrays with varying orientations and shade; string inverters work well for uniform arrays.
Choosing the right option depends on roof complexity, shading, budget, and preferences for monitoring and redundancy.