Is There A Significant Efficiency Difference In Inverter Types?

Efficiency Differences Between Inverter Types

Efficiency differences between string and microinverters are significant, particularly in systems with high roof shading or irregular panel layouts. Microinverters convert DC power from individual panels to AC power, allowing each panel to operate independently and maximizing energy production. In contrast, string inverters convert DC power from an entire string of panels to AC power, which can lead to reduced efficiency in shaded or mismatched systems. For example, a system with 50% shading can see a 10-20% reduction in efficiency with a string inverter, compared to only a 2-5% reduction with microinverters.

Efficiency Comparison and Typical Numbers

Typical efficiency ratings for string inverters range from 95-98%, while microinverters can achieve efficiencies of 98-99%. This may not seem like a significant difference, but it can add up over time, especially in larger systems. For example, a 10 kW system with 95% efficiency would produce 9.5 kW of AC power, while a 10 kW system with 98% efficiency would produce 9.8 kW of AC power, a difference of 300 watts or approximately $450 per year in electricity savings.