Micro-Inverter vs. Optimizer vs. String Failures
How different solar topologies fail differently — and what a thermal inspection reveals in each case.
Solar systems with micro-inverters, optimizers, or string inverters all fail in different ways. Thermal inspection reveals each kind — but you have to know what you're looking at.
Micro-inverter failure signatures
A failed Enphase micro-inverter takes its panel offline entirely. The panel runs cool (no current) and the missing production shows up in the monitoring portal as a single panel reporting zero. The fix is a micro-inverter swap, typically warranty-covered for 25 years.
Optimizer failure signatures
A failing SolarEdge optimizer can show up as a hot panel (mismatch losses pushing extra current through one panel), reduced output on a single module, or as a monitoring alarm. Thermal scans catch the partial failures that don't yet trigger the alarm.
String inverter mismatch losses
On older string-inverter systems, a single dirty or shaded panel drags down the entire string. Thermal scans show one panel hot relative to the rest — a clear signal that either the panel needs cleaning or one cell is failing. Either way, the whole string benefits from the fix.