Read units before rupees
Bills combine energy charges, fixed charges, taxes and adjustments. Use monthly kWh where possible, note seasonal air-conditioning or heating, and include known changes such as an EV. Do not assume every rupee on the bill disappears after solar.
Turn the estimate into a site question
Ask the installer to show module placement, shade through the day, maintenance access, structural considerations and inverter selection. Grid-connected solar normally needs appropriate protection and shuts down during a grid outage unless a suitable backup arrangement is designed. Battery backup is a separate scope and cost decision; see on-grid, off-grid and hybrid systems.
Keep kW and kWh separate
kW describes power capacity; kWh describes energy over time. Module DC capacity and inverter AC rating are different specifications. Annual generation is an estimate affected by weather, orientation, shade and losses, not a guaranteed monthly supply. Have the installer explain the assumptions behind any production promise in the quotation.
1, 2, 3 or 5 kW: the same decision side by side
| System | Monthly use it is planned for | Indicative installed cost | Central CFA limit | UP top-up limit |
|---|---|---|---|---|
| 1 kW | About 100 units | ₹65,000–₹75,000 | ₹30,000 | ₹15,000 |
| 2 kW | About 200 units | ₹1,10,000–₹1,30,000 | ₹60,000 | ₹30,000 |
| 3 kW | About 300 units | ₹1,50,000–₹1,80,000 | ₹78,000 | ₹30,000 |
| 5 kW | About 500 units | ₹2,40,000–₹2,80,000 | ₹78,000 | ₹30,000 |
Built from SolarKhoj's own records: the planning baseline of 100 units per kW per month, the mid-2026 market cost range (secondary source, checked 3 October 2026) and scheme limits checked 6 October 2026. A 5 kW system costs more but receives the same scheme support as 3 kW, so choose by usage and roof, not by the subsidy columns. The UP column applies only to eligible Uttar Pradesh applications. Subsidy needs eligibility and arrives after you pay; read the subsidy limits and compare any quote with the calculator's cost table.
Bring these to a sizing conversation
| Check | What to clarify |
|---|---|
| Recent bills | Monthly units and seasonal changes |
| Roof context | Shade, usable area, access and ownership |
| Connection | DISCOM, sanctioned load and metering route |
A useful definition
- kW / kWh
- kW is power capacity. kWh is energy used or generated over time.
Quick answers
How many units does a 1 kW, 3 kW or 5 kW system produce?
SolarKhoj's planning baseline for Uttar Pradesh and Delhi NCR is about 100 units (kWh) per kW per month. That gives roughly 100 units a month from 1 kW, 300 from 3 kW and 500 from 5 kW, or about 3.3, 9.9 and 16.4 units a day on average. It is a research estimate, not a measured yield for your roof: shade, orientation, season, dust and system losses change the real figure.
How many solar panels does a 5 kW system need?
Divide the system's DC capacity in watts by the module wattage written in the quote. For example, 5 kW is 5,000 W; with 540 W modules that is 5,000 ÷ 540 ≈ 9.3, so a design would use 10 modules (5.4 kW DC). Higher-wattage modules mean fewer panels for the same capacity. Check the module count × wattage and the inverter rating in writing.
How much roof space does 1 kW of solar need?
About 10 square metres of shade-free roof per kW, according to UPNEDA's scheme information and the MNRE consumer FAQ, so a 3 kW system needs roughly 30 square metres. The real figure depends on module wattage, layout, walkways and shade, so ask the installer to mark the actual panel layout on your roof before you compare quotes.
A common question
Should I choose a larger system just for subsidy?
Choose around your requirement and connection constraints. The household central CFA has a capacity cap; more panels do not mean proportionately more support.
Sources for this guide
MNRE
Residential CFA operational guidelines · §§5–6
Standard rates, household/GHS eligibility, DCR and payment process. PDF, 57 pages.
Checked: Rules can changeUPNEDA / MNRE
Rooftop technical specifications
Module, inverter, structure, protection and metering scope to discuss with the installer.
Checked: Rules can changeUPNEDA
PM Surya Ghar scheme information · 1 August 2024
About 10 sq m of shade-free roof space per 1 kW; the MNRE consumer FAQ gives the same figure and notes it varies with module efficiency and placement.
Checked: Official source