Solar 101
How solar and batteries actually work — in plain language
No jargon, no sales pitch. Here’s how solar, inverters and battery storage work, what subsidies you can claim in Tamil Nadu, and how it all gets paid for.
How it works
How solar works — the short version
How solar panels work
- Sunlight hits the panels on your roof and creates DC electricity.
- An inverter converts that DC into the AC electricity your home actually uses.
- Your home runs on that power first, before touching the grid.
- Anything extra goes to a battery (if you have one) or back to the grid.
- At night, you draw from the battery or the grid as needed.
How batteries fit in
A battery stores the surplus your panels make during the day so you can use it in the evening — and keeps your essential circuits running during a power cut. Without a battery, a standard grid-tied system shuts off during an outage for safety.
System types
System types — on-grid, off-grid & hybrid
These three words describe how your system relates to the grid and to batteries — and the choice changes both your cost and what happens during a power cut. Here’s the plain-language version.
On-grid
Connected to the TANGEDCO grid, with no batteries. It’s the cheapest option, works with net metering, and gives the fastest payback. The one catch: it shuts off during a power cut for safety, so it won’t run your home during an outage. Best for homes with a reliable grid supply that don’t need backup.
Off-grid
Runs entirely on solar plus battery storage, with no grid connection at all. You get full independence, which is useful where the grid is absent or unreliable — but batteries add real cost and eventually need replacing. Best for remote sites.
Hybrid
Grid plus batteries. It powers your home and exports surplus by day, and keeps your essential circuits running during a cut. It costs more than on-grid, but for homes with frequent outages it’s usually the sweet spot.
| System | Grid connection | Battery | Backup during power cut | Relative cost |
|---|---|---|---|---|
| On-grid | Yes | No | No | Lowest |
| Off-grid | No | Yes | Yes (full) | Highest |
| Hybrid | Yes | Yes | Yes (essentials) | Medium–high |
How to choose
It comes down to three questions — how reliable is your grid, do you need backup during outages, and what’s your budget and payback priority? There’s no single best system, only the best fit. For most Madurai homes with a workable grid, on-grid is the best value; where cuts are frequent, hybrid is usually the pick; off-grid only where the grid genuinely isn’t an option. Not sure which suits you? We’ll tell you honestly after a quick look at your home and bill.
Subsidies & incentives
Rooftop solar subsidies in Tamil Nadu
- PM Surya Ghar (central): Central Financial Assistance up to ₹78,000 for a residential system (≥3 kW).
- Net metering (TANGEDCO): export credits offset the units you draw from the grid.
Scheme amounts can change — we confirm the current figures and your eligibility at the time of your quote.
PM Surya Ghar: Muft Bijli Yojana
The big one for homeowners is PM Surya Ghar: Muft Bijli Yojana, a central government scheme that pays a direct subsidy towards a home rooftop solar system and credits it to your bank account after installation.
Indicative amounts (per current government guidelines — we verify before every claim):
| System size | Indicative central subsidy |
|---|---|
| Up to 2 kW | ₹30,000 per kW |
| Additional (2–3 kW) | ₹18,000 per kW |
| Above 3 kW | Capped |
| Typical 3 kW home | Up to ₹78,000 |
Who qualifies: an Indian homeowner with your own roof, a valid TANGEDCO connection, a roof with decent sun, and no rooftop solar subsidy claimed before. Criteria are set by the government and can change. We register you on the national portal, file the claim, and handle the net metering — you don’t touch the paperwork.
TANGEDCO net metering
Your bidirectional meter records both what you export and what you import; exports are credited against imports each billing cycle. We manage the DISCOM (TANGEDCO) application and net-meter installation.
DISCOM (TANGEDCO) application, National Portal subsidy claim, net-meter installation and DISCOM approval — all managed as part of your install, not an extra service.
Finance
What you actually pay
Going solar is an up-front cost that pays you back for 25 years. We’ll give you a clear, itemised quote with the estimated subsidy already worked in, so you can see the real net number before you decide. Financing / EMI options: to confirm — we’ll only list what we actually offer.
Curious what a system runs to around here? Try the savings calculator.
Warranty
Warranties — backed for the long run
Panels and inverters carry manufacturer warranties — typically long on panels and solid on inverters — and we add our own workmanship cover on the install itself. Exact terms depend on the brand and model you choose; we’ll put them in writing in your quote.Specific year figures: to confirm against final product list.
FAQ
Subsidies, finance & ownership
Is rooftop solar worth it in Tamil Nadu?
For most homes with a decent roof and a real monthly bill, yes. Tamil Nadu gets plenty of sun, grid tariffs keep climbing, and the PM Surya Ghar subsidy brings the up-front cost down. A well-sized system usually pays for itself within a few years and then delivers largely free power for two decades.
How much does a system cost after the subsidy?
It depends on your roof and your usage, so we won’t throw a single number at you. After the PM Surya Ghar subsidy, a typical 3 kW home system is a good deal cheaper than it looks up front. We give a fixed, written quote after a free survey.
Which areas do you cover?
Madurai and across Tamil Nadu. Our base is in Vandiyur, Madurai.
How long does an installation take?
A typical home system goes up in two to four days once materials arrive. The subsidy and net-metering approvals run in the background while that happens.
What makes Quadbiz different?
We don’t outsource. The team that quotes your job installs it and stands behind it — and we handle all the government paperwork ourselves.
Do I need a battery?
Not necessarily. If you mainly want to cut your bill and your grid is reliable, a grid-tied system without a battery gives the fastest payback. If power cuts are frequent or you want backup, a battery (with a hybrid inverter) is worth it.
What happens during a power cut?
A standard grid-tied system switches off for safety. A system with a battery keeps your essential loads running.
After specifics on a particular panel, battery or inverter? See the Products page.
Want to know what you’d actually save?
Answer a few quick questions about your home and your bill. We’ll show you a real, subsidy-adjusted estimate — no phone call needed to see the number.
Get my estimateReady to see your number?
Free quote, no obligation — serving Madurai and across Tamil Nadu. We’ll get back to you within one business day.