Open assumptions
How we calculate.
Every number comes from the assumptions below. We'd rather under-promise: real systems usually do a little better than our estimates.
| Assumption | Value | Why / source |
|---|---|---|
| Solar generation | 1500 units per kW per year | A cautious figure for Jaipur. Real-world results range from 1,450 to 1,650 depending on tilt, shade and cleaning. |
| Panel ageing | 0.5% less output each year | Typical for modern panels with a 25-year warranty. |
| Tariff increase | 3% per year | Used for 25-year savings. Rates were unchanged for 2026-27, so this is an assumption. |
| JVVNL home tariff | ₹4.75 / 6.50 / 7.35 / 7.65 / 7.95 per unit by slab | Slabs: 0–50, 51–150, 151–300, 301–500, 500+. Plus a fuel surcharge (₹0.40) and a regulatory surcharge (₹0.70–1.00). Fixed charges and duty are left out because solar doesn’t remove them. |
| Surplus export | ₹3.26 per unit | RERC rate for net-metering surplus (Oct 2025). |
| Central subsidy | ₹30k/kW to 2 kW, ₹18k for 3rd kW, max ₹78k | PM Surya Ghar Muft Bijli Yojana. |
| Rajasthan subsidy | ₹17,000 | 150-unit Nishulk Bijli Yojana, for eligible JVVNL home consumers, minimum 1.1 kW. |
| Loan rate | 5.75% per year | PM Surya Ghar collateral-free loans (repo + 0.5%). Bank rates vary. |
| CO₂ | 0.716 kg per unit; 21 kg per tree per year | CEA grid emission factor. |
| Roof area | 100 sq ft per kW | Shade-free area, using 550 W panels. |
Our price list used in calculators
| Up to 2 kW | ₹86,000 / kW |
| 2 – 3 kW | ₹70,000 / kW |
| 3 – 4 kW | ₹66,000 / kW |
| 4 – 5 kW | ₹63,000 / kW |
| 5 – 10 kW | ₹60,000 / kW |
| 10 – above | ₹56,000 / kW |
Estimates only. Government subsidy rules and tariffs can change. Last reviewed November 2026. Your final quote comes after a free site survey.