Answer: Solar PV System Installation, Principles & Applications

Working Principle - The Photovoltaic Effect

The photovoltaic effect, discovered by Becquerel in 1839, is the fundamental principle behind solar PV:

1. Photon Absorption: Sunlight (photons) strikes the PV cell made of semiconductor material (silicon)
2. Electron Excitation: Photon energy is transferred to electrons, freeing them from their atomic bonds
3. P-N Junction: The cell has two silicon layers - N-type (excess electrons) and P-type (excess holes), creating an electric field at their junction
4. Charge Separation: The electric field separates freed electrons (negative) and holes (positive)
5. Current Generation: Electrons flow through external circuit as direct current (DC)
6. Conversion: Inverter converts DC to alternating current (AC) for use

System Components

Component	Function
Solar Panels	Convert sunlight to DC electricity (multiple cells in series/parallel)
Inverter	Convert DC to AC; types: string, micro, central
Mounting Structure	Hold panels at optimal angle (fixed or tracking)
Cables & Connectors	DC and AC wiring, MC4 connectors
Net Meter	Measure energy exported to grid (bidirectional)
Battery (optional)	Energy storage for off-grid/hybrid systems
Charge Controller	Regulate battery charging (off-grid systems)

Installation Process

Step 1: Site Assessment

• Evaluate solar irradiance (India average: 5-7 kWh/m²/day)
• Shading analysis - identify shadows from trees, buildings
• Roof assessment - orientation, tilt, structural capacity
• Available area calculation (~10 m²/kW for rooftop)

Step 2: System Design

• Calculate system size based on energy consumption
• Select panel type (mono/poly/thin-film), inverter capacity
• Design array configuration (series strings, parallel)
• Determine optimal tilt (latitude angle) and orientation (south-facing)

Step 3: Installation

• Install mounting structure with proper anchoring
• Mount solar panels securely
• Complete DC wiring with proper polarity
• Install inverter in ventilated, shaded location
• Connect AC output to distribution board
• Install protection devices and earthing

Step 4: Commissioning

• Test all connections and measure output
• Commission net meter with utility (DISCOM)
• Document system parameters

Types of Solar PV Systems

Type	Components	Application
Grid-Tied	Panels + Inverter + Net Meter	Urban rooftops, utility plants
Off-Grid	Panels + Battery + Controller + Inverter	Remote areas without grid
Hybrid	Grid-tied with battery backup	Areas with unreliable grid

Applications of Solar PV Systems

1. Residential Applications

• Rooftop Solar: 1-10 kW systems for homes (PM Surya Ghar Yojana)
• Solar Water Heaters: Hot water for domestic use
• Solar Lighting: Garden lights, security lights

2. Commercial & Industrial

• Commercial Rooftops: Offices, malls, factories (10-500 kW)
• Industrial Power: Captive solar plants for manufacturing
• Solar Parks: Large-scale utility installations (MW-GW)

3. Agricultural Applications

• Solar Pumps: PM-KUSUM scheme for irrigation
• Solar Dryers: Crop drying without fuel
• Agrivoltaics: Dual use - farming under elevated panels

4. Infrastructure

• Street Lighting: Solar LED streetlights
• Traffic Signals: Off-grid traffic management
• Railway Stations: Solarized stations program

5. Special Applications

• Floating Solar: On reservoirs, lakes (reduce evaporation)
• BIPV: Building Integrated PV (facades, windows)
• Space: Satellites, space stations
• Portable: Chargers, camping equipment