Rooftop Solar Savings Calculator (2026)
See how much a rooftop solar system would cost and save you, including the PM Surya Ghar central subsidy. Enter your monthly units and roof area to get a system size, net cost after subsidy, monthly savings and payback period.
Assumptions
Year-by-Year Savings Projection
| Year | Annual savings | Cumulative savings | Net position | Status |
|---|
Assumes electricity tariffs rise ~5% a year and panel output degrades ~0.7% a year, so the flat headline figures above are on the conservative side. Net position = cumulative savings minus your net system cost after subsidy.
How does it work?
- You enter your average monthly bill — we work back to your consumption in units.
- We recommend a system size in kW that offsets that consumption, limited by your roof at 100 sq ft per kW.
- We apply the 2026 PM Surya Ghar scale: ₹30K for 1 kW, ₹60K for 2 kW, ₹78K for 3 kW and above.
- Yearly generation assumed at 4 kWh per kW per day — a realistic India average across seasons.
- Savings = yearly generation × your ₹/unit. Payback = net cost ÷ yearly savings.
The year-by-year table above is the careful version of the same sum: it adds ~5% a year of tariff inflation and ~0.7% a year of panel degradation, which these flat figures ignore.
More solar tools on TheDiscomBill
Solar Panel Size Calculator (2026) — how many kW and panels your ACs and load need, plus roof area. · Solar Battery Backup Calculator (2026) — size a LiFePO4 or lead-acid bank to ride through power cuts.
Estimates use India-average generation (~4 units per kW per day) and the PM Surya Ghar residential central subsidy (₹30,000/kW up to 2 kW, ₹18,000 for the 3rd kW, capped at ₹78,000). Actual generation, cost and state subsidy vary with location, roof orientation, shading and your DISCOM's net-metering policy. Treat this as a planning guide and get a quote from an empanelled vendor on the National Portal ↗.