1. Choose calculation method
Tip: 1 BHK typically consumes ~150 units/month (1 kW).
3 BHK: Consumes ~350–450 units/month (3 kW).
Optimal System Sizing
3 kW
Generates ~360 units / month
Total panels required:6 panels (540W)
Shadow-free roof space:~255 sq ft
PM Surya Ghar central subsidy:₹78,000
How this is calculated
Calculations are based on 540W to 550W Tier-1 ALMM monocrystalline modules (dimensions ~2.27m x 1.13m = ~27 sq ft per panel). Accounting for spacing between rows to avoid self-shading, approximately 85 to 100 sq ft is required per 1 kW of installed rooftop solar.
Frequently asked questions
How many solar panels do I need for a 3 kW system?+
With modern high-wattage 540W to 550W mono PERC or TOPCon bifacial modules, a 3 kW solar array requires only 6 solar panels.
How much shadow-free rooftop space is required per kW of solar?+
In India, each 1 kW of rooftop solar capacity requires approximately 80 to 100 square feet (7.5 to 9.5 square meters) of unobstructed, shadow-free roof area facing south or south-west.
Can solar panels be installed on a metal sheet or tiled roof?+
Yes. Installers use specialized anodized aluminium clamping brackets for trapezoidal metal sheets and standing seams without puncturing the roof. For tiled roofs, stainless steel tile roof hooks are mounted underneath the tiles.
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