How to Calculate the Right Solar System Size for Your Indian Home

Step 1: Determine Your Monthly Energy Consumption

Review your last 3-6 electricity bills and note the monthly units consumed in kWh. For most Indian homes, monthly consumption ranges from 150 to 600 units.

Step 2: Calculate Daily Consumption

Divide monthly consumption by 30. Example: 300 units per month / 30 days = 10 units per day.

Step 3: Account for Solar Irradiation

India receives 4.5 to 6.5 peak sun hours per day depending on location. Use 5 hours as a conservative national average.

Step 4: Calculate System Size

System Size (kW) = Daily Consumption / Peak Sun Hours. Example: 10 kWh / 5 hours = 2 kW system.

Step 5: Apply System Efficiency Factor

Add 25% for real-world system losses: 2 kW x 1.25 = 2.5 kW, round up to 3 kW.

Quick Reference

• 1BHK (100-200 units/month): 1-2 kW system
• 2BHK (200-350 units/month): 2-3 kW system
• 3BHK (350-500 units/month): 3-5 kW system
• 4BHK / Duplex (500-800 units/month): 5-8 kW system
• Villa / Bungalow (800+ units/month): 8-15 kW system