Solar Photovoltaic (PV) System
Definition; Solar Photovoltaic (PV) System is a renewable energy technology that converts solar energy directly into electrical energy using semiconductor materials like silicon through the photovoltaic effect.
Principle – Photovoltaic Effect; The photovoltaic effect is the phenomenon in which electrons are ejected from a material (typically silicon) when it is exposed to sunlight, creating an electric current.
🌞 Sunlight → Electron Excitation → DC Electricity
Components of Solar PV System
Component | Function |
Solar Panel / PV Module | Converts sunlight into DC electricity |
Charge Controller | Regulates voltage and current from panels to batteries |
Battery (optional) | Stores DC electricity for later use |
Inverter | Converts DC electricity to AC for home/industrial use |
Mounting Structure | Holds PV modules at optimal angle |
Cables & Junction Box | Connects and protects the system components |
Types of Solar PV Systems
Type | Description | Key Feature |
Off-Grid System | Not connected to utility grid | Requires battery storage |
Grid-Tied System | Connected to main electricity grid | No batteries needed |
Hybrid System | Combines solar, battery & grid | Ensures power even during outages |
Building Integrated PV (BIPV) | Integrated into building façade or rooftop | Aesthetic and space-saving |
Working of a Solar PV System
- Sunlight falls on the solar panels.
- Panels generate DC electricity via the photovoltaic effect.
- If connected to an inverter, the DC is converted to AC.
- AC power is used to run appliances, and excess can be stored (off-grid) or exported to the grid (grid-tied).
Types of PV Technologies
Type | Material | Efficiency | Remarks |
Monocrystalline Silicon | Single crystal silicon | 18–22% | High efficiency, costly |
Polycrystalline Silicon | Multiple crystals | 15–17% | Moderate cost |
Thin Film (CdTe, a-Si) | Amorphous or layered | 10–12% | Flexible, lightweight |
Perovskite Solar Cells | Hybrid organic-inorganic | 20%+ (lab) | Emerging tech |
Applications of Solar PV Systems
Domestic Applications
- Lighting, fans, TVs, refrigerators
- Solar rooftop systems (subsidized in India)
- Solar water pumping for irrigation
Commercial/Industrial
- Office lighting and backup
- Telecom towers and data centers
- Cold storage, grain dryers
Agricultural Applications
Application | Description |
Solar Water Pumps | For irrigation and drinking water in remote areas |
Solar Electric Fencing | To protect crops from wild animals |
Solar Dryers | Drying agricultural produce efficiently |
Solar Milk Chillers | For preserving milk in rural dairy farms |
Solar Cold Storage | To store fruits and vegetables with minimal loss |
Public Utilities
- Street lights
- Traffic signals
- Remote weather stations
- Railway signaling
Remote Areas and Defense
- Border areas, forest posts
- Disaster relief and refugee camps
Advantages of Solar PV Systems
- Abundant and Free solar energy
- Environmentally friendly, zero emissions
- Modular and scalable: Add more panels as needed
- Low maintenance
- Suitable for off-grid and grid-connected systems
- Ideal for remote agricultural use
Limitations
- High initial installation cost
- Output depends on weather/sunlight
- Efficiency limited to 15–22% in common panels
- Battery storage can be expensive and has limited life
- Requires space and orientation for best performance
Performance Parameters
Parameter | Typical Value |
Panel Efficiency | 15–22% |
Temperature Coefficient | -0.3 to -0.5%/°C |
Life of PV Module | 25+ years |
Inverter Life | 10–15 years |
Battery Life | 3–7 years (if used) |
Government Initiatives in India
- PM-KUSUM Scheme – Solar pumps for farmers
- Rooftop Solar Programme (MNRE)
- Subsidy schemes for residential and institutional users
- National Solar Mission – Target of 100 GW solar capacity
Recent Advancements
- Bifacial solar panels – Capture sunlight from both sides
- Floating solar PV – Installed on water bodies
- Tracking systems – Panels move with sun for max output
- Perovskite and Organic PV cells – High efficiency, flexible
Solar PV vs Solar Thermal
Feature | Solar PV | Solar Thermal |
Output | Electricity | Heat |
Use | Lights, appliances | Water heating, space heating |
Efficiency | 15–22% | 30–70% |
Cost | High upfront | Low to moderate |
Technology | Semiconductor | Heat collectors |
