Guides · August 2, 2026
The right system size comes down to two things: how much electricity you use, and how much usable roof area you have. As a rough starting point, 1kW of rooftop solar generates roughly 120 units of electricity per month in the Lucknow region, depending on shading and panel orientation.
A simple way to estimate: take your average monthly electricity bill, divide by your per-unit tariff (roughly ₹7/unit for most domestic connections in UP) to get your monthly unit consumption, then divide that by 120 to get an approximate kW requirement. Our homepage subsidy calculator does this math for you instantly.
Roof space is the other constraint — a standard 1kW system needs roughly 80–100 sq. ft. of shadow-free roof area. If your roof is smaller than your ideal system size, we'll help you prioritize the highest-value capacity that still fits.
These are estimates only — every property is different, which is why we always recommend a free physical site survey before finalizing system size and subsidy numbers.