Short answerA 3 kW on-grid system in Telangana costs about ₹1.85–2.1 lakh, gets the maximum ₹78,000 subsidy, produces 360–420 units a month, needs around 300 sq ft of roof, and typically pays for itself in four to five years.
Why 3 kW is the most popular size
It is the smallest size that gets the full ₹78,000 subsidy, and its output matches the use of a typical 2–3 BHK home with one AC. Going bigger saves more but gets no extra subsidy; going smaller leaves subsidy money unclaimed.
The numbers
| Panels | 6 × 545 W or 7 × 450 W DCR modules |
| Inverter | 3 kW grid-tied with Wi-Fi monitoring |
| Roof area | About 300 sq ft, shadow-free |
| Generation | 12–14 units/day, 360–420 units/month |
| Monthly saving | ₹2,800 – ₹3,500 for most homes |
| Price before subsidy | ₹1,85,000 – ₹2,10,000 |
| Subsidy | ₹78,000 |
| Payback | About 4–5 years |
Who should pick a bigger system
If your bill is regularly above ₹4,500, you run two or more ACs, or you plan an EV, consider 4–5 kW. The extra kilowatts cost about ₹60,000 each with no subsidy, but at higher slab tariffs they still pay back in five to six years.
Who should pick hybrid
If evening power cuts are common in your area, a 3 kW hybrid with batteries keeps fans, lights, fridge and Wi-Fi running. See on-grid vs hybrid.
Frequently asked questions
How many units does a 3 kW system generate per day?
About 12–14 units on a clear day in Telangana, averaging 360–420 units a month across the year.
Can a 3 kW system run an AC?
Yes. A 1.5-ton inverter AC uses about 1–1.4 units an hour. A 3 kW system easily covers daytime AC use plus fans, fridge and lights, with net metering covering evenings.
How much roof space does 3 kW need?
About 300 sq ft of shadow-free roof, using six to seven panels of 450–550 W.