The quickest way to size a home solar system is to look at the units (kWh) on your electricity bill, not the rupee amount. Tariffs change; your consumption is what the system has to cover.
The rule of thumb
In Telangana and Andhra Pradesh, 1 kW of rooftop solar produces about 120 units a month on average. Generation is higher in summer and lower in the monsoon months.
| Monthly units | Suggested size | Roof space |
|---|---|---|
| Up to 150 | 1–2 kW | 100–200 sq ft |
| 150–300 | 2–3 kW | 200–300 sq ft |
| 300–450 | 3–4 kW | 300–400 sq ft |
| 450–600 | 5 kW | about 500 sq ft |
Things that change the answer
- Shade. Water tanks, trees and neighbouring buildings reduce output. Panels need shade-free roof between 9 am and 4 pm.
- Future load. If you plan to add an AC or an electric vehicle, size for it now.
- Subsidy. The subsidy stops increasing at 3 kW (₹78,000), so going larger is paid for by you, but it still pays back through savings.
Our free site visit checks your bills, roof and shade and gives you an exact size and price in writing.
