Inverters and backup
Backup power, sized properly.
Not every power problem is a solar problem. If what you need is for things to stay on when the grid drops, an inverter and battery may be the whole answer — and it is worth understanding how that differs from a solar installation before buying either.
Two devices people conflate.
A solar inverter converts DC from panels into AC you can use or export to the grid. A backup inverter or UPS charges a battery from the mains and switches over when the supply fails. They solve unrelated problems, and owning one does not give you the other.
This is why an on-grid solar system does not keep your lights on during an outage. It is also why a backup inverter does not reduce your bill: it stores energy you already bought, at a small round-trip loss.
A hybrid solar inverter is the device that does both, and it costs accordingly.
Adding solar to an inverter you own.
Often possible, using a solar charge controller, and worth asking about before replacing working equipment. It reduces what you draw from the grid by charging your existing battery from panels instead of the mains.
What it does not do is make your installation grid-interactive. An ordinary backup inverter cannot export to KSEB, so this route earns no net-metering credit — it lowers consumption rather than turning your meter backwards. For some households that is exactly enough; for others it is a false economy against a proper grid-tied system.
Sizing from load, not from habit.
Add up what must stay running and for how long. That is the whole method, and skipping it is how people end up with a bank that disappoints during a long outage and costs too much for the rest of the year.
Two numbers come out of it: the power the inverter must deliver at once, which sets the inverter rating, and the energy you need over the outage, which sets the battery capacity. They are independent, and a system can be correctly sized on one and badly wrong on the other.
What determines battery life.
Depth and frequency of discharge, far more than calendar age. A battery cycled shallowly and occasionally will outlast an identical one run flat every week. Lithium chemistries generally tolerate many more cycles at a given depth than lead-acid, which is much of what justifies their price.
Heat shortens the life of every chemistry, so installation location is a real design decision in Kerala rather than an afterthought.
Choosing a brand on the right criterion.
Service network before specification sheet. Efficiency and feature differences between reputable manufacturers are usually too small to decide anything; whether a technician can attend a fault in your district, and whether replacement parts exist locally, decides everything.
Delta fits Tier-1 equipment and names the exact make and model in the quote, so you can check the warranty terms and the service presence yourself before committing.
