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Solar Rooftop Savings Calculator

Estimate rooftop solar system size, PM Surya Ghar subsidy, net installation cost, annual savings, and payback period for Indian homes.

Key termsSolar kWInstalled rooftop solar capacity; a 1 kW system typically needs about 100 sq ft of shade-free roof area.Payback periodTime required for savings to recover the upfront investment cost.

Adjust inputs

INR
500100000
INR/kWh
220
sq ft
1005000

فارمولا وضاحت

System kW = min(monthly units / 120, rooftop area / 100); payback = net cost / annual savings

A 1 kW rooftop system needs roughly 100 sq ft and generates about 4 kWh per day. The calculator sizes the plant by electricity demand and available roof area.

Step-by-Step Example

  1. 1Convert monthly bill into monthly electricity units using tariff per kWh.
  2. 2Estimate required system size using 4 kWh/day generation per kW.
  3. 3Limit system size by available roof area and estimate installation cost at INR 65,000 per kW.
  4. 4Apply central subsidy estimate, calculate annual generation, bill savings, and payback period.

Reference

Benchmark Table

Compare common scenarios quickly. Scroll horizontally on smaller screens.

Reference 1
System size
1 kW
Roof area
100 sq ft
Annual generation
About 1,460 kWh
Best suited for
Small household load
Reference 2
System size
2 kW
Roof area
200 sq ft
Annual generation
About 2,920 kWh
Best suited for
Moderate bill reduction
Reference 3
System size
3 kW
Roof area
300 sq ft
Annual generation
About 4,380 kWh
Best suited for
Common subsidized home setup
Reference 4
System size
5 kW
Roof area
500 sq ft
Annual generation
About 7,300 kWh
Best suited for
Larger independent home

عام سوالات

A practical thumb rule is about 100 sq ft per 1 kW of rooftop solar capacity, depending on panel type and layout.

Recommended system size

5.21 kW

Details