Small shadows are often neglected in the prediction of energy producible by photovoltaic systems. This is mostly due to the lack of specific tools available in commercial design software packages, which neither allow realistic drawings nor can account for individual solar cells currents. In this paper the effects of small shadows are accurately analyzed with reference to two special cases, a TV antenna and self-shading. The analysis is based on the interaction between highly specialized and powerful software, AUTOCAD, MATLAB and PSpice, which allow an utmost degree of accuracy.