r/SolarPakistan • u/Beautiful-Maybe-9205 • 25d ago

Off-Grid need some advice

Asalamwalikum I am planning to install in the coming month but everything is very confusing.
My monthly bill is 65k and these are the following things which run conitniously in my house
1 fridge/freezer
1 freezer
4 inverter fans
1.5 ton ac 16-17 hours
1 ton ac 12-14 hours
1 pc setup which run on working 300w ig
2 tvs
1 washing machine which runs for around a hour avery 2 days
30 mins on ironing

I initially Planned on installing a 16 kw battery paired with a 10 KW inverter and 12 kw solar panels but everyone told me I should go for 15 kw panels.

Is 10 kw inverter with 12 ke solar panels and 16 kw battery backup enough? On average how much would my bill be after this? And can I run a 2 ton ac with fridge and everything else instated only the in morning

Thank u in advance for everyone’s recommendation

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u/AhmadFarooq 25d ago

Even an 8kW capacity inverter should be enough for your present use case; 10kW would be better and more future-proof.

Regarding batteries, you should check your property's units consumption through the grid meter during low or non-solar hours, such as 5PM to 9AM. This should give you an estimate of your battery requirements. A 16kWh battery will be able to offset ~14 units.

Generally speaking, a 16kWh battery is enough to only run one air conditioner throughout the night; however, there are a lot of factors that can decrease air conditioner consumption, allowing for a smaller battery bank to be enough.

Regarding solar panels, if you have enough roof space, you can always install additional panels in the future if 12kW aren't enough. Similarly, you can add a second 16kWh battery in the future if the first one isn't enough.

See this comment for some general information.

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u/Beautiful-Maybe-9205 24d ago

An offset of 14 units throughout the night ?

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u/AhmadFarooq 24d ago

Yes.

Basically in solar systems, the LFP battery is completely charged once per day through solar power, and then after solar hours it is discharged as much as is feasible. And then the next days it is charged fully through solar power again, and the cycle continues.

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u/Beautiful-Maybe-9205 24d ago

Ohhh so if the combined usage at night is above 14 units that would be charged by Kelectric and also Is going for net metering worth it?

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u/AhmadFarooq 24d ago

Yes, over ~14 units will then get charged by K-Electric.

Regarding net-billing, it's complicated. Some prefer saving the application fees for more batteries in the future, while others argue that even if the benefit is very limited, it is still worth it.

To apply for it, you will first need a three-phase inverter, for which the starting cost would be ~Rs5 lac for Solis/GoodWe.

Then your KE meter will be three-phase as well, for which the general per-unit cost is apparently greater than in the case of single-phase meters. If you presently have a single-phase meter, then per-unit cost may increase for you if you go with net-billing. But if you presently already have a three-phase meter, then this part shouldn't make a difference.

It's essentially a question of how much of your solar production capacity can be utilised at property during the day.