As advanced, the device developed to have a practical approach to the above described topics consists on three main components: a variable light source, a load simulator and a set of monocrystalline solar cells. In addition to these main components, the kit is completed by a solarimeter and two general purpose electrical multimeters. Any elementary spreadsheet software is can be used for data analysis and graphic representations.

The light source is constituted by fifteen identical wells containing an incandescent lamp. The lamps are connected to the mains by a box, including corresponding fifteen switches and a feeding power selector. Each well is designed to allocate a 2V monocrystalline cell at the top (Figure 5). Every cell is illuminated by the lamp at the bottom, being the value of irradiance at the top of the well determined by the solarimeter prior the experiment.

Fig. 5 Main box structure and views of cells arrangement in the proposed device

Using the load simulator, the characteristic curve of each cell is drawn once irradiance is known. The load simulator is a potentiometer connected to the positive and negative poles of the cell [5]. The corresponding cell voltage and current are measured for different values of potentiometer resistance ranging from the short circuit to the open circuit situations. The table of experimental I-V pairs allows the graphical representation of characteristic curve for each value of irradiance. All the cells have free terminals that can be further interconnected by the use of available cables according to a selected series-parallel configuration. Once cells are interconnected, the corresponding lamps are switch-on and the curve of the complete generator can be obtained.

The curves for shaded cells in modules can be studied after simultaneous load simulation on cells (series or parallel connected) placed on wells with their corresponding lamps switched-off or regulated to a lower electrical feeding.