2. New and Renewable Energy Sources Photovoltaic Panel (PV) Panel And Wind Energy

3. The Solar Energy The Photovoltaic Panel is no more than an energy transducer. It has an ability to generate electric energy from solar energy. It is one of the renewable energy sources. It is cheap, clean and available. The most important property to be considered, is that “it has a non-linear internal resistance”. This property is shown in the figure below:

4. From the graph above, I sc = 2.65 A and V oc = 21.3 V At the maximum power point, I mp = 2.5 A and V mp = 17.3 V P mp = 2.5 x 17.3 = 43.25 W The optimal resistance for operation = V mp / I mp = 17.3/2.5 = 6.9 ohms The optimal resistance is the ratio of voltage to current determined from the maximum power point. At this point, the load resistance is equal to the solar panel internal resistance.

5. Standard sunlight conditions on a clear day are assumed to be 1000 watts of solar energy per square meter (1000 W/m 2 ). This is sometimes called "one sun," or a "peak sun." Less than one sun will reduce the current output of the module by a proportional amount. For example, if only one-half sun (500 W/m 2 ) is available, the amount of output current is roughly cut in half. Thus, the brightness affects the current output only.

6. Axis Formats (Scales) There are three common axis formats: Rectilinear: Two linear axes Semi-log: One log axis Log-log: Two log axes Length (km) 1 km10 km Log scale: 1 km Length (km) Linear scale:

7. Example on Maximum Power Transfer Theorem (Q27 ch9) For the network in Fig. determine the value of R for maximum power to R.

8. Example on Millman’sTheorem (Q33 ch9) Using Millman’s theorem, find the current through and voltage across the resistor R L in Fig

9. Example on Substitution Theorem (Q36 ch9) Using the substitution theorem, draw three equivalent branches for the branch a-b of the network in Fig.

10. Example on Reciprocity Theorem (Q39 ch9) For the network in Fig.,Is the reciprocity theorem satisfied?