How Solar Power Systems Work: A Beginner's Guide for Homes & Businesses

The Basics: How Solar PV Works

Photovoltaic (PV) solar panels convert sunlight into DC electricity using semiconductor cells. A solar inverter converts this DC output into the AC power your appliances use. Any surplus generation can be fed back to the grid (net metering) or stored in batteries.

The Four Key Components

• Solar Panels: Monocrystalline (higher efficiency, smaller footprint) or Polycrystalline (lower cost). Rated in Watts peak (Wp).
• Solar Inverter: String inverter for standard rooftops, microinverters for shaded or complex roofs, hybrid inverter for battery integration.
• Mounting Structure: Rooftop (RCC, metal sheet, tin) or ground-mounted. Must withstand wind loads per IS 875.
• Balance of System (BOS): DC and AC cables, combiner boxes, earthing, surge protection, and net metering equipment.

On-Grid vs Off-Grid vs Hybrid

• On-Grid: Connected to utility grid. No battery. Lowest cost. Export surplus via net metering. Power cuts = system shuts down.
• Off-Grid: Fully battery-dependent. No grid connection. Ideal for remote locations. Higher cost.
• Hybrid: Grid-connected with battery backup. Best of both — backup during cuts and net metering when grid is up.

Sizing Your System

Divide your monthly kWh consumption by the average peak sun hours in your city (Mumbai ≈ 5h, Delhi ≈ 5.5h, Chennai ≈ 5.5h). Example: 300 kWh/month ÷ (5h × 30 days) = 2kW system required. Add 20% buffer for losses.

Payback & Savings

A 3kW rooftop system in India generates roughly 360–420 kWh/month and saves ₹3,000–₹4,000/month at ₹8–10/kWh. With subsidies under PM Surya Ghar Muft Bijli Yojana, payback periods have dropped to 3–4 years on a 25-year panel life.