India solar calculator
Size a rooftop solar system from your electricity bill — kW, panel count, cost after the PM Surya Ghar subsidy, and payback.
Quick answer: At ₹8/kWh and 5.3 peak sun hours, a ₹3,000/month bill needs about 3.3 kW — 6 × 545 W panels on ~12 m². Gross cost is ~₹1,96,200; after the PM Surya Ghar subsidy it lands near ₹1,56,960 net, paying back in ~4.4 years.
Your details
Ballpark, not gospel. Sized at 78% real-world output with the Indian sun-hour average and an indicative 20% subsidy offset — confirm the current PM Surya Ghar slab rates and your DISCOM's net metering rules with a local vendor.
Typical Indian rooftop sizes by monthly bill
| Monthly bill | System size | Panels (545 W) | Net cost after subsidy | Payback |
|---|---|---|---|---|
| ₹2,000 | 2.18 kW | 4 | ₹1,04,640 | 4.4 years |
| ₹3,000 | 3.27 kW | 6 | ₹1,56,960 | 4.4 years |
| ₹6,000 | 6.54 kW | 12 | ₹3,13,920 | 4.4 years |
Computed at ₹8/kWh, 5.3 peak sun hours, ₹60/W installed and a 20% PM Surya Ghar offset. Run your exact bill above.
Questions people actually ask
Straight answers, no fluff. Then run your own numbers above.
How many solar panels do I need for my home in India?
At ₹8/kWh and 5.3 peak sun hours, a ₹3,000/month bill needs about a 3.3 kW system — roughly 6 × 545 W panels covering ~12 m² of shadow-free roof.
What is the PM Surya Ghar subsidy for rooftop solar?
The PM Surya Ghar scheme pays a subsidy directly into your bank account for grid-connected rooftop systems — up to ₹78,000 for 3 kW and above. The calculator applies a 20% effective reduction on gross cost to approximate it.
What does rooftop solar cost in India in 2026?
About ₹60 per watt installed before subsidy. A 1 kW system runs ~₹60,000; a 3 kW system ~₹1,96,200 gross, ~₹1,56,960 net after the 20% subsidy offset.
What is the payback period for solar in India?
Around 4.4 years at current rates. A ₹3,000/month bill saves ₹36,000 a year against a ₹1,56,960 net cost — among the fastest paybacks in the world thanks to high sun hours.
How much roof area does a 3 kW system need in India?
About 12 m² of shadow-free roof for 6 × 545 W panels, at ~2 m² per panel including spacing and maintenance walkways.
Can I sell extra solar power to the grid in India?
Yes — most states offer net metering or gross metering for rooftop systems up to defined capacity limits. Check your state DISCOM's current net metering cap before oversizing.
How much CO₂ does a 3 kW rooftop system avoid?
About 0.7 kg per kWh. A 3.3 kW system generating ~4,900 kWh a year offsets roughly 3.5 tons of CO₂ annually.
Is on-grid or off-grid better for an Indian home?
On-grid with net metering wins on cost where supply is reliable. If your area sees frequent power cuts, pair panels with batteries — size the inverter and bank on the solar system calculator.
Need backup during power cuts? The solar system calculator sizes your inverter and battery bank. Comparing quotes? The solar cost calculator breaks down cost per watt, and the solar ROI calculator maps your payback year by year.