Overview Of The Photovoltaic Power System

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Overview Of The Photovoltaic Power System

• The IEEE 7th Technical Exchange Meeting
• April 18-19, 2000

• Mohammed A. Al-Jofaish
• Saudi Aramco/Consulting Services Department

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Presentations Outline

• Photovoltaic (PV) Theory
• PV Systems Components
• Design Strategy Considerations
• Applications
• Advantages Disadvantages
• Summary

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Photovoltaic Theory

n-Silicon
- - - - - - - - - -


p-Silicon
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PV Systems Components

• Solar Array
• Storage Batteries
• Charge Controller (Regulator)
• Inverter (For AC Systems Only)

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Photovoltaic System
PV Array
Charge Controller
Battery
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PV Systems Components
Charge Controller
Battery Bank
Photovoltaic Array
Inverter (AC loads)
Load
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Design Strategy PV Array

• Type Selection
• Sizing
• Climate Geographical Location Considerations

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Design Strategy PV Array Types
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Design Strategy PV Array Sizing

• De-rating Factors
• Aging 20
• Dirt Accumulation 20
• Future Growth 10
• Recharging Period 4 days
• System Voltage
• Load Profile

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Design StrategyPV Array Climate Geographical
Location

• Solar Insolation (Radiation)
• Effective Sun Hours
• Array Orientation
• Direction (Toward South)
• Tilt Angle
• Fixed Angle (Latitude 10 Degrees)
• Adjustable (Sun Tracking)

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Sun Insolation
5.0 kW/m2/day
5.0
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Photovoltaic Arrays Field
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Photovoltaic Arrays Field
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Photovoltaic Arrays Field
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Design Strategy Storage Battery

• Type Selection
• Sizing
• Environment Considerations

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Design Strategy Storage BatteryType Selection
(cyclic application)

• Tubular Plate Lead-Acid
• Pocket Plate Nickel-Cadmium

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Design Strategy Storage BatterySizing

• System Voltage
• Load Profile
• Backup Time (Autonomy) 7 days
• De-rating Factors Lead-Acid Ni-Cad
• Aging 25 10
• Temp. Compensation 19 14
• Design 10 10

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Design Strategy Storage BatteryEnvironment
Considerations

• No Temperature Control ? Temp. Compensation
• Outdoor Battery Enclosure
• Shade Requirement

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Design Strategy Charge Regulator

• Type Selection
• Single Stage
• Multistage
• Sizing (Array Rated Currents)
• Temperature Compensation
• Lead-Acid -5mV/oC/cell
• Ni-Cad -3mV/oC/cell
• Low Voltage Disconnect
• Lead-Acid 1.85V/cell
• Ni-Cad 1.15V/cell

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Applications

• Cathodic Protection Systems
• Telecommunications Systems
• SCADA Systems
• Offshore Platforms
• Highway Lighting
• Remote Homes
• Irrigation Water Pumping

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Advantages

• Reliable
• No Fuels
• Low Maintenance
• Long-term Savings
• No Pollution
• No Noise

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Disadvantages

• High Initial Cost (3-10 times)
• Specialized Maintenance
• Batteries
• Power Conditioning Equipment
• Large Space

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Summary

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

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THE END
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QUESTIONS ?