Do you know what IAM losses are in a photovoltaic installation?

You probably already know that there are losses due to the lower irradiance reaching the module's surface when it is not optimally oriented.

But, in addition, not all the irradiance that reaches the module's surface actually reaches the photovoltaic cell. Some of it is reflected by the glass that separates the cell from the air.

The parameter that characterizes losses due to reflection is called the incidence angle modifier (or IAM for short in English). The amount reflected and thus the losses depend on the angle of incidence (AOI) between the normal vector of the module and the vector of the solar ray.

Depending on the characteristics of your design, you may encounter losses on total generation ranging from 1% to 5%, potentially reaching up to 10% in extreme cases.

To give you a clearer idea of the impact of this type of loss based on your design characteristics, we have created this heat map where you can observe IAM losses for different inclinations and orientations in Madrid.

At ieco, of course, we already take all these losses into account automatically when making generation calculations. 😉