A rooftop solar system converts sunlight falling on your roof into electricity your building can use. That is the whole idea. Everything else — the components, the paperwork, the sizing arithmetic — exists to make that conversion safe, legal, and worth paying for.
How it works
A grid-connected rooftop system has four functional parts. Modules on the roof produce direct current. An inverter converts that into alternating current your appliances can use. A mounting structure holds the modules at the right angle and survives the wind. A bidirectional meter records what you send back to the grid when you generate more than you consume. There is no battery in most Indian rooftop systems, and that is a deliberate choice rather than an omission.
| Component | Function | Typical service life |
|---|---|---|
| Solar modules | Convert sunlight to DC electricity | 25 years performance warranty |
| Inverter | Convert DC to usable AC, manage the grid connection | 8-12 years |
| Mounting structure | Hold modules at angle, resist wind loading | 25+ years if galvanised |
| DC and AC cabling | Carry power, with protection devices in line | 20-25 years |
| Bidirectional meter | Record import and export separately | Utility owned |
Indicative service lives for typical grid-tied residential and commercial equipment. Actual warranty terms vary by manufacturer and should be confirmed against the specific products quoted to you.
The engineering view
The reason most systems have no battery is that the grid does the job better. When you generate more than you are using, the surplus goes out to the grid and is credited against what you draw later. That is what net metering means in practice. A battery does the same job but costs considerably more and needs replacing well before the modules do, so it earns its place only when you specifically need power during outages.
What this means in Karnataka
In Karnataka a rooftop system is connected under your distribution company — BESCOM in Bengaluru, HESCOM around Hubballi and Dharwad. The capacity you can install is governed by your sanctioned load rather than by how much roof you have, which surprises many first-time buyers. Residential systems also qualify for the central PM Surya Ghar subsidy, which is paid after commissioning rather than deducted from your invoice.
Common mistakes to avoid
Early-stage assumptions that cause problems later:
- Expecting solar to power the house during a grid outage — a standard grid-tied system shuts down for safety
- Sizing to available roof area rather than to the electricity bill
- Assuming a battery is included, or that it is needed
- Overlooking that sanctioned load caps the capacity you can net-meter
- Treating the subsidy as an upfront discount rather than a later reimbursement
What we recommend
Start with twelve months of bills rather than with roof measurements. That tells you what capacity is worth installing. Then check your sanctioned load, and only after both of those does a site survey and equipment discussion become useful.
Common questions
- Will solar run my home during a power cut?
- Not with a standard grid-tied system. It disconnects during an outage so it cannot feed power into lines that may be under repair. Backup during outages requires a hybrid system with storage.
- Do I need to change my existing wiring?
- Usually not. The system connects at your distribution board, and your internal wiring stays as it is. Older installations may need the board itself reviewed.
- How much roof do I need?
- Roughly 90 to 110 sq ft per kW, but usable area after tanks, walkways, and shadow paths is what actually counts.
- What maintenance does it need?
- Periodic cleaning and an annual electrical check. There are no moving parts in the array, so routine upkeep is modest compared with most building equipment.
- Is my roof strong enough?
- Most concrete roofs are. Older buildings and metal-sheet roofs need a structural assessment before mounting, which any competent installer will include in the survey.
Talk to our engineering team for a solar assessment.
We will review your consumption, roof, and site constraints before recommending any capacity.