Solar Savings Calculator Tamil Nadu
Enter your EB bill to see the system size, savings and payback.
Enter amount between ₹2,000 and ₹30,000 • We specialize in 2 kW+ systems
Get your exact numbers
This is a close estimate. Our engineer checks your roof, shade and EB bill and gives you a written quote, with the up to ₹1 lakh subsidy paperwork handled.
Common questions
How accurate is this calculator?
It converts your bill into units using TNEB bi-monthly slab rates, assumes about 1,500 units per kW per year of Tamil Nadu sunshine (about 4 units a day), and uses market-average system prices as of October 2026. Generation varies by season, so treat it as a close estimate; we confirm with a free site visit.
Does this include the subsidy?
Yes. The payback already deducts the subsidy for an eligible Tamil Nadu home: up to ₹1 lakh (₹78,000 PM Surya Ghar + ₹22,000 TN top-up) for 3kW and above. Puducherry homes get up to ₹78,000.
3kW vs 5kW: which do I need?
If your bi-monthly bill is about ₹3,000 - ₹6,000, a 3kW system (12-15 units a day) is usually right. If it is ₹8,000 or more or you run two or more ACs, a 5kW system (20-25 units a day) is recommended. Both get the full ₹1 lakh subsidy.
What is the payback period?
The time it takes for your bill savings to repay the system cost after the subsidy. For homes with AC and bills above ₹4,000 bi-monthly it is typically 3.5 to 4.5 years; smaller bills take 5-6 years. After that, the savings are yours for 20+ years.
How this solar ROI calculator works
Built for Tamil Nadu: TNEB bi-monthly slabs, local sunshine and the 2026 subsidy. Most AC homes break even in about 3.5 to 4.5 years, then enjoy two decades of near-free power, protected from future tariff hikes.
- 1
Your bill becomes units
We reverse the TNEB bi-monthly slabs (free units, then ₹4.50 to ₹11 per unit) to find how many units you really use.
- 2
Units become system size
Each kW of rooftop solar makes about 1,500 units a year in Cuddalore, Villupuram and Puducherry sunshine.
- 3
Size becomes savings and payback
Market-average price minus the up to ₹1 lakh subsidy, divided by your yearly savings, gives the payback.