Shading effect

The activity deals with the investigation of the impact of partial shading on poly-crystalline and mono-crystalline PV modules operation. 
Several experiments consisting of measuring the current–voltage and power–voltage curves of photovoltaic modules of a real PV plant, both unshaded and applying shading profiles, have been carried out in clear sunny days. The experimental analysis can be applied to derive mathematical models for evaluating the power losses under shading conditions influencing PV modules operation.

The role of by-pass diodes is well clarified both in term of I-V characteristic and in term of Maximum Power Point.

Recorded characteristics of mono-crystalline modules, referred to 1000 W/m2 considering different shading profiles: (a) current–voltage, and (b) power–voltage.