On‑grid vs hybrid inverter

Short answer: choose on-grid if the main goal is a lower electricity bill and the grid is reliable. Choose hybrid if the customer also wants power during cuts and would otherwise buy a separate inverter and battery.

The key difference: what happens in a power cut

An on-grid inverter shuts down as soon as the grid fails. This is called anti-islanding and it is a safety requirement: it stops the solar system feeding power into a line that electricity workers may be repairing. So with an on-grid system, the home has no solar power during a cut, even at noon.

A hybrid inverter has a battery input and a separate backup output. When the grid fails, it disconnects from the grid safely and keeps the backup loads running from the battery and the panels. Polycab's hybrid inverters switch over in under 4 ms, fast enough that computers and Wi-Fi routers don't restart.

Side by side

When on‑grid is enough

• The area has few and short power cuts.
• The home already has a conventional inverter and battery for backup.
• The customer wants the lowest cost per unit of solar and the full subsidy.

When hybrid makes sense

• Cuts are frequent or long, as in many towns and villages across Bihar and Jharkhand.
• The customer is about to buy or replace a conventional inverter and battery anyway: a hybrid does both jobs.
• There are critical loads: a fridge, medical equipment, work-from-home, a shop's billing system.
• A shop or clinic wants to reduce diesel generator use. Polycab hybrids have a generator input.

Sizing the battery

One Polycab 5.12 kWh LFP battery has 5 kWh of usable energy. As a rough guide, before inverter losses:

• about 500 W of essential load (fans, lights, fridge, Wi-Fi) for around 10 hours
• about 1 kW for around 5 hours

Batteries can be added in parallel, up to 30 units (150 kWh). Most homes start with one battery and add a second if cuts run long. The inverter warranty is longest with a Polycab battery: 10 years for the single phase hybrid and 8 years for the three phase.

Subsidy and net metering with a hybrid

The PM Surya Ghar subsidy is calculated on the solar panel capacity, so a hybrid system with DCR panels can still qualify. The battery itself isn't subsidised. Meter arrangements for hybrid systems vary by DISCOM, so get the set-up approved in writing by NBPDCL, SBPDCL, JBVNL or your DISCOM before installation.

Scheme rules and DISCOM procedures change. Check the latest guidelines on the PM Surya Ghar portal and with your DISCOM before you install. This guide is general information, not legal or financial advice.