An on-grid rooftop solar system has four parts that matter: the modules on your roof, the mounting structure holding them, an inverter that converts DC to usable AC, and a bidirectional net meter installed by JdVVNL that measures electricity flowing both ways.
During daylight your home runs on solar. Anything you do not use flows out to the grid and is recorded as an export credit. At night, or when the array cannot keep up, you draw from the grid and those credits offset the import. Your bill settles on the net of the two, which is where the name comes from.
There is no battery in a standard on-grid system. That is a deliberate choice, not a compromise: batteries roughly change the economics of a residential installation and need replacement long before the panels do. For a home in Jodhpur with a reliable JdVVNL supply, the grid is a cheaper and longer-lived store than any battery you would buy.
Worth being clear about, because it surprises people: a standard on-grid system does not run during a power cut. When grid supply drops, the inverter disconnects automatically. This is a mandatory safety feature — it stops your roof from energising a line that a lineman believes is dead. If backup during outages matters to you, that needs a hybrid inverter and a battery, which is a different quote and a different budget.
| Modules | ALMM-listed mono PERC or bifacial panels from Tier-1 manufacturers (Waaree, Tata Power Solar, Adani, Vikram) |
|---|---|
| Mounting structure | Hot-dip galvanised steel, specified to the wind-load class for your site |
| Inverter | Grid-tied string inverter, sized to the array, with MPPT tracking |
| Protection | DC and AC isolators, surge protection device, dedicated earthing |
| Metering | Bidirectional net meter, supplied and installed by JdVVNL |
| Monitoring | Inverter-based generation monitoring, typically via the manufacturer's app |
As a working figure, a residential array needs roughly 80 to 100 sq ft of shade-free roof per kilowatt with standard mono PERC modules. So a 5 kW system typically wants somewhere in the range of 400 to 500 sq ft of genuinely usable area.
The word doing the work there is usable. On a real Jodhpur terrace the following all subtract from the number you measured:
South-facing, unshaded, with a clear run for cabling to the meter is the ideal. Very few roofs are ideal. Tilted or elevated structures can recover a surprising amount of a compromised roof, and on older slabs a non-penetrating ballasted structure avoids drilling into the RCC entirely.
Four things, in roughly this order of impact:
We give a generation estimate after the survey, as a range, with the assumptions written next to it. Anyone giving you a single confident number before seeing your roof is guessing.