Performance ratio of photovoltaic installations in France: Comparison between inverters and micro-inverters

The efficiency of a photovoltaic installation is determined by its performance ratio (PR). This ratio depends on many parameters including orientation, inclination, shading, losses in cables, and number and performance of panels. The topology of the installation is also of great importance. Indeed, the number and location of the converter(s) can also have a significant impact on the PR. This is why choices between a central inverter, string inverters or micro-inverters must be made so as not to degrade the PR. In the scientific literature, it is stated that a photovoltaic installation equipped with a central inverter has a PR of 70–80%. For micro-inverters in theory, it should be higher. The objective of this publication is to compare the PR of installations equipped with a central inverter and string inverters with the PR of those using micro-inverters, based on a statistical study grouping together 200 private installations spread throughout metropolitan France. For a better comparison, 100 installations will use a central inverter or string inverters and 100 other installations will use micro-inverters. For each installation, the data will be averaged over the longest possible periods.