Solar Rooftop

A correctly sized 3 kW system generating around 360 units a month typically eliminates 70 to 90% of a household bill. For a family paying ₹4,000 a month, that is roughly ₹36,000 a year. Against a post-subsidy cost of about ₹1.2 to ₹1.5 lakh, payback lands between three and four years, with the system warranted for twenty-five.

Not individually, in most cases, since the roof is common area owned by the society. What does work is a society-level installation for common loads — lifts, pumps, corridor and basement lighting — which reduces everyone's maintenance charge. This requires a resolution from the RWA or association. It is increasingly common in NCR societies and the economics are usually strong because common-area consumption is steady and predictable.

Generation falls on overcast days and is nil at night. A grid-connected system without batteries simply draws from the grid at those times, and net metering credits your daytime surplus against it. Batteries are only necessary if you want backup during outages. They add substantially to cost and have a shorter life than the panels, so most households skip them unless supply is genuinely unreliable.

Very little. Panels need cleaning every two to four weeks in the dusty NCR months, since accumulated dust can reduce output by 15 to 25%. Beyond that, an annual check of connections and inverter performance. The inverter is the component most likely to need replacement, typically after ten to fifteen years, against a panel life of twenty-five.

Less well. Because Indian tariffs are progressive, the savings come from avoiding the expensive upper slabs. A household consuming under 150 units a month is mostly in the cheapest slab, so the value of each unit generated is low and payback stretches well beyond five years. As a rough threshold, a monthly bill above ₹2,500 is where rooftop solar starts to make clear financial sense.

The system transfers with the property and is generally treated as a value-adding fixture, though the net metering connection must be transferred into the new owner's name with the DISCOM. Buyers increasingly price it in, particularly where the subsidy has already been claimed and the payback period is largely behind them.