This paper provides theoretical studies of photovoltaic and modeling techniques using equivalent electric circuits. The use of equivalent circuits makes it possible to investigate the characteristics of a PV cell. The method used here is implemented in orcad pspice program. The same modeling technique is also applicable for modeling a PV module. Details are also given of methods of measuring the panel parameters Rs Isc, and Is . Several techniques are described to create new components (PV), in the orcad-pspice simulator library that can be directly called by their equivalent circuits.