Topology · after 9 Feb 2026

Hybrid: sun by day, lithium by night, grid as the spare tyre.

Net-billing killed the “export your way out of the bill” story. The house product is PV sized to daytime load plus at least 5 kWh LFP on a hybrid IP65 box.

USUALLY WRONG FOR HOMES

On-grid

Cheapest PKR/kW. Exports under net-billing at ~Rs 8–13. Zero output in a blackout unless you add a backup interface. Right for offices with a generator, wrong for homes that need fans at 2 a.m.

ZARKAAR DEFAULT

Hybrid

PV charges the house and the battery. Grid covers monsoon weeks. Essential loads on the backup port: lights, fans, fridge, router, one inverter AC if the bank allows. 640–650 W N-type + 5.12 kWh LFP is the 2026 stack.

WHEN THE FEEDER IS THEATRE

Off-grid

No DISCO file. Double the battery, generator inlet, and discipline. Only when the feeder is theatre.

Priority loads on the backup bus

Never put the whole DB on backup unless the inverter and battery were sized for it. Split: backup (LED, fans, fridge, internet, maybe 1 AC) vs non-backup (geyser, extra AC, workshop welder).

After SRO 251, oversizing PV “for the green meter” is a bad trade. Put that money in a second LFP pack if nights are the problem.

Compare capex in the hybrid calculator On-grid page Off-grid page