Almost everyone who calls us about solar asks the same first question, and it is the wrong one. They ask how many panels they need. The question that actually decides your bill, your subsidy and whether the lights stay on during a cut is a different one: on-grid, off-grid or hybrid?
Here is the honest comparison, including where each one is weakest.
The short version
| Feature | On-grid | Off-grid | Hybrid |
|---|---|---|---|
| Battery | None | Large bank | Smaller bank |
| Works in a power cut | No | Yes | Yes |
| Exports to KSEB | Yes | No | Yes |
| Government subsidy | Yes | No | Usually not |
| Cost for 3kW | From ₹2,10,000 | Considerably more | In between |
| Best for | Homes with a decent supply | Places with no supply at all | Frequent, long cuts |
On-grid: the default, and usually the right one
An on-grid system has no battery. The panels feed your house, and whatever you do not use goes out to the KSEB grid through a net meter. At night you draw from the grid as normal, and you are billed on the net.
This is the only one that gets the subsidy. PM Surya Ghar covers on-grid rooftop systems, and that alone moves the sums considerably — a 3kW system is eligible for ₹78,000 back. If your supply is reasonably stable, an on-grid system will pay for itself faster than either alternative.
Its weakness is the one that surprises people. An on-grid system shuts down during a power cut. Not because of a fault — by design. If the grid is down, a lineman may be working on it, and a rooftop system pushing power back into a dead line is a serious hazard. So the inverter disconnects. On a bright afternoon during an outage, your panels sit there producing nothing.
If nobody has explained that to you before quoting, ask why.
Who it suits
Homes and shops with a supply that mostly works, where the goal is to cut the bill rather than to survive outages. In most of Alappuzha, Kottayam and Ernakulam that describes the majority of houses.
Off-grid: only when there is genuinely no supply
An off-grid system has no connection to KSEB at all. Everything runs from panels and a battery bank sized to carry the property through the night and through a run of cloudy days.
That last part is what makes it expensive. In Kerala the sizing is not set by your average day — it is set by the monsoon, when you can get a week with very little useful sun. A battery bank big enough to ride that out is a large part of the total cost, and batteries are the part that needs replacing first.
No subsidy applies, because the scheme is built around grid-connected rooftop systems.
Who it suits
Genuinely unelectrified sites. A pump house on a plot with no line, a farm shed, a plot being built on before the connection arrives, a remote installation where bringing a line in would cost more than the solar. If a KSEB connection is available at reasonable cost, off-grid is almost always the wrong answer.
Hybrid: the honest middle, at a price
A hybrid system is grid-connected and has a battery. In normal running it behaves like on-grid — powering the house, exporting the surplus. When the grid goes down it disconnects safely and keeps running the circuits you chose, drawing on the battery and continuing to charge from the panels.
That is the arrangement most people picture when they imagine solar. It costs more than on-grid because of the battery and the more capable inverter, and the subsidy position is generally less favourable than a straightforward on-grid system.
One thing worth understanding: hybrid does not mean the whole house stays live. You choose which circuits are backed up — lights, fans, the fridge, the router, maybe one AC — and those are wired to a backup distribution board. Trying to back up everything, air conditioning included, needs a battery bank that pushes the cost towards off-grid territory.
Who it suits
Properties where cuts are frequent or long enough to matter: clinics, small businesses, homes with someone working from home, anywhere in the low-lying belt where a monsoon fault can take a day to clear.
The question we actually ask on a site visit
Not “how many panels” but: what are you trying to fix?
- “My bill is too high” → on-grid. Take the subsidy, keep it simple.
- “The power keeps going and I have already got an inverter” → often on-grid solar alongside your existing inverter, which is cheaper than a hybrid conversion and keeps the subsidy.
- “The power keeps going and I have no inverter” → hybrid is worth pricing against on-grid plus a separate inverter and battery. Sometimes the split system wins, sometimes it does not.
- “There is no supply here at all” → off-grid, and expect the battery to be the biggest line on the quote.
What we do not do
We do not quote a system size from a phone call. Kerala roofs are rarely simple — shade from a coconut palm at four in the afternoon can cost you a meaningful share of a string’s output, and that does not show up on a satellite image.
Every quote starts from your last twelve months of KSEB bills and a survey of the actual roof: orientation, shading through the day, the condition of the structure, and where the inverter and meter can sensibly go.
Send us a photo of your latest bill and we will tell you which of the three suits you before anyone comes out. If the honest answer is that solar does not pay for you yet, we will say that too.
