Inverter, generator, or solar — which backup actually makes sense

People usually ask this the day after a bad cut, which is the wrong time to decide — you're optimising for yesterday's problem, not your actual pattern. Worth checking your district's recent listing history first, since the right answer depends heavily on how often and how long your area actually loses power.

An inverter with a couple of batteries is the right call for most homes seeing frequent short-to-medium cuts — an hour to half a day. It's silent, needs no fuel, and covers lights, fans, a router and charging without fuss. The tradeoff is capacity: run an AC or a water heater off one and you'll drain it fast, so it's really a comfort-and-connectivity solution, not a way to ride out a cut in full comfort.

A petrol or diesel generator earns its keep when cuts are long (many hours to a full day) and you genuinely need heavier loads — a fridge, a pump, maybe an AC. The tradeoffs are real too: noise, fuel to store and refill, and upkeep on a machine that mostly sits idle. It's the right tool for genuinely unreliable areas, not for an occasional evening cut.

Solar with battery storage is the only option here that also lowers your day-to-day bill rather than just sitting in reserve, which is why it's worth serious thought if your cuts are frequent enough that you'd otherwise be running an inverter or generator constantly. The upfront cost is the real barrier, and sizing it wrong either wastes money or leaves you short exactly when you need it — that's what the solar sizing calculator on this site is for, using your actual monthly units rather than a generic guess.

If you're genuinely unsure, an inverter is the low-regret starting point for most households — it's the cheapest to get wrong and the easiest to add solar or a generator alongside later if your situation changes.

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Match the backup to the outage you actually get

Before spending anything, write down the last five outages you remember: how long each lasted, what time of day, and what you genuinely missed. Most Tamil Nadu households discover the honest answer is "fans, lights, phone charging and the Wi-Fi router, for two to four hours in the afternoon". That is a small inverter problem, not a generator problem.

Inverter with battery

Best for short and medium outages and for fans, lights, TV, router and a laptop. A 900 VA to 1500 VA unit with a single tubular battery covers a typical household load for several hours. It is silent, needs no fuel and starts instantly. It will not run an air conditioner or a borewell motor unless you buy a much larger and much more expensive system. Batteries are consumable: expect three to five years from a tubular lead-acid battery, less if you routinely deep-discharge it, and top up distilled water on schedule.

Diesel or petrol generator

Best where outages run long or where you must run a motor, a shop refrigerator or commercial equipment. It is loud, needs fuel on hand, needs ventilation and needs periodic running to stay reliable. Never run one indoors, in a closed garage or in a stairwell — carbon monoxide from a generator kills people every year. For a normal home with occasional four-hour cuts, it is over-buying.

Rooftop solar

Solar is a bill-reduction investment, not by itself a backup. A standard grid-tied system shuts down during an outage for the safety of line workers, so it gives you nothing during a cut unless you add a hybrid inverter and battery storage. The real argument for it in Tamil Nadu is net metering against the higher tariff slabs: if your bimonthly consumption sits in the 600-unit-plus range, the payback maths gets attractive. Estimate your slab position with the bill calculator first.

A simple recommendation