Electricity Production from Renewables Energies

2.8. Exercises

2.8.1. Characteristic of a photovoltaic panel

A photovoltaic panel is formed of two modules, which are connected in parallel. Each of these modules is made up of 24 cells, which are connected in series. The characteristic of a cell is given in Figure 2.70.

a) Draw the current—voltage characteristic (i–v) of such a generator.

b) What is the short-circuit current of the panel?

c) What is the open-circuit voltage of the panel?

d) What is the peak power?

Figure 2.70. Characteristic of the cell

Answers

a) A module is made up of 24 cells in series. The voltage of a module is thus the sum of the cell voltages and the drain current is the maximum current delivered by a cell. We thus have an equivalent generator of 12 V – 2 A.

A panel is made up of two modules, which are connected in parallel. The voltage of a panel is the voltage of a module and the current is the sum of the maximum module currents. We thus have an equivalent generator of 12 V – 4 A (Figure 2.71).

Figure 2.71. Characteristic of the panel

b) The sort-circuit current I_cc of the panel is 4 A (Figure 2.71).

c) The open-circuit voltage V_oc of the panel is 12 V (Figure 2.71).

d) At the Maximum power output point, the voltage V_m is worth 10 V and the current I_m is worth 3.48 A (Figure 2.72). The peak power P ...