2. The IEEE 7 th Technical Exchange Meeting April 18-19, 2000 Overview Of The Photovoltaic Power System Mohammed A. Al-Jofaish Saudi Aramco/Consulting Services Department

3. Presentation’s Outline u Photovoltaic (PV) Theory u PV System’s Components u Design Strategy & Considerations u Applications u Advantages & Disadvantages u Summary

4. Photovoltaic Theory Photovoltaic Theory p-Silicon n-Silicon + + + + + + + + + - - - - -

5. PV System’s Components u Solar Array u Storage Batteries u Charge Controller (Regulator) u Inverter (For AC Systems Only)

6. Photovoltaic System Battery PV Array Charge Controller

7. PV System’s Components Load Photovoltaic Array Battery Bank Inverter (AC loads) Charge Controller

8. Design Strategy PV Array: u Type Selection u Sizing u Climate & Geographical Location Considerations

9. Design Strategy PV Array Types:

10. Design Strategy PV Array Sizing: u De-rating Factors X Aging 20% X Dirt Accumulation 20% X Future Growth 10% u Recharging Period 4 days u System Voltage u Load Profile

11. Design Strategy PV Array Climate & Geographical Location: u Solar Insolation (Radiation) u Effective Sun Hours u Array Orientation X Direction (Toward South) X Tilt Angle l Fixed Angle (Latitude + 10 Degrees) l Adjustable (Sun Tracking)

12. Sun Insolation 5.0 kW/m 2 /day 5.0

13. Photovoltaic Arrays Field

16. Design Strategy Storage Battery: u Type Selection u Sizing u Environment Considerations

17. Design Strategy Storage Battery: Type Selection (cyclic application) u Tubular Plate Lead-Acid u Pocket Plate Nickel-Cadmium

18. u System Voltage u Load Profile u Backup Time (Autonomy) 7 days u De-rating Factors Lead-Acid Ni-Cad Aging 25% 10% Temp. Compensation19%14% Design10%10% Design Strategy Storage Battery: Sizing

19. u No Temperature Control  Temp. Compensation u Outdoor Battery Enclosure u Shade Requirement Design Strategy Storage Battery: Environment Considerations

20. Design Strategy Charge Regulator: u Type Selection X Single Stage X Multistage u Sizing (Array Rated Currents) u Temperature Compensation X Lead-Acid-5mV/ o C/cell X Ni-Cad-3mV/ o C/cell u Low Voltage Disconnect X Lead-Acid1.85V/cell X Ni-Cad1.15V/cell

21. Applications u Cathodic Protection Systems u Telecommunications Systems u SCADA Systems u Offshore Platforms u Highway Lighting u Remote Homes u Irrigation Water Pumping

22. Advantages u Reliable u No Fuels u Low Maintenance u Long-term Savings u No Pollution u No Noise $ $ $

23. Disadvantages u High Initial Cost (3-10 times) u Specialized Maintenance X Batteries X Power Conditioning Equipment u Large Space $ $ $ $ $ $

24. Summary Despite the disadvantages of the photovoltaic power, there are many applications where the PV is the only choice that is economically justifiable.

25. THE END

26. QUESTIONS ?