Solar panels rarely deliver their full rated wattage. Tested under ideal Standard Test Conditions (STC), real-world factors like heat, angle, and atmosphere reduce output. Expect 60%-75% efficiency in normal use, meaning a 100W panel may produce 60-75W in the field.
From our monitoring data, 70–80% appears to be the normal operating band for real-world solar panels, while 90%+ output looks more like a "perfect conditions" event rather than something you should expect daily—or even weekly.