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Electricity Backup for AC

EINSTEIN

TF Premier
VIP Lounge
I am looking to upgrade my inverter+battery need your suggestions.
Currently having a square wave inverter & 300Ah battery. Electricity consumption in summer is high, six two ton ACs along with other appliances. Power cuts are very frequent, sometimes 4-5 hours in a day. I want a backup system that can run two ACs and rest of the house for 5+ hours which also doesn’t shut down immediately in case the load is high at the time of power cut. Also want to add solar panels if suitable or at least have the option to add later.
Please help me out.
 

NOOBY

TF Ace
VIP Lounge
I am not sure if any Invertor is capable of supplying power for 6 two ton ACs (or 2) for 5+ hours

you need to get generator for such high requirement..
 

anupamsinha

TF Buzz
VIP Lounge
You have not provided the power that these ACs need. Assuming it to be inverter AC. In that case I think 15 KVA would suffice.A 6 KVA would had been ok for around 2 hours of backup time. If going in for a lower capacity inverter then keep in mind In case of non inverter AC you would need a higher capacity inverter as the starting current without be very high.

Also in you scenario of possible and feasible a generator might be better. As inverter would need a lot of time to charge back in case of power cuts that last 5-6 hours.
 

EINSTEIN

TF Premier
VIP Lounge
As inverter would need a lot of time to charge back in case of power cuts that last 5-6 hours.
Power cuts are not continuous but in monsoon they cut power whenever it rains😑
You have not provided the power that these ACs need. Assuming it to be inverter AC.
These are LG Dual Inverter ACs don’t know the power requirements I can give you the model no if that helps.
 

EINSTEIN

TF Premier
VIP Lounge
You need generator - not invertor for such backup
Also in you scenario of possible and feasible a generator might be better. As inverter would need a lot of time to charge back in case of power cuts that last 5-6 hours.
I have no idea about generators. What I have seen online is that they require a lot of maintenance plus aren’t eco friendly.
I think inverter is also feasible as people are able to run whole house off of solar panels that also includes battery and inverter.
 

D7162

TF Ace
VIP Lounge
I have no idea about generators. What I have seen online is that they require a lot of maintenance plus aren’t eco friendly.
I think inverter is also feasible as people are able to run whole house off of solar panels that also includes battery and inverter.
You will need smaller ones - that wont required much maintenance. If you consider battery replacement cost with inverter, gen wont be that high - although running cost will be high as you will have to run it on petrol or diesel


You cant run your home just on solar panels during power outage.
 

hks789

TF Ace
VIP Lounge
Offgrid solar systems for your requirements may not be financially profitable.
You will need quite a few batteries and a powerful inverter. The maintenance cost is higher for battery-operated systems, and you need to replace them after their rated cycle life.

You can have a combination of an on-grid solar system and a generator system for a reduced electricity bill and uninterrupted power.

To calculate and design the system.
Check your peak load and usage history for the past 1-2 years.
Feel free to ask if you have any specific questions.

I used to have a monthly consumption of 400 units, and I installed a 4 KW ongrid system 2 years back.
It produces around 4600 units a year in Kollam, Kerala.
I have a 200 AH home inverter backup for uninterrupted power (not for AC).

Production varies according to the location and surroundings.
Screenshot_20230510_154456_SolisCloud.jpg
 
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hks789

TF Ace
VIP Lounge
during rain solar wont work
It does work. I am living in Kerala, where we have intermittent rain throughout the year. Production will be comparably lower, but it will still produce a fair amount. Please check the above graph.

Regardless of whether it is summer or monsoon season, you cannot directly use solar power. Solar won't consistently provide enough wattage; the system will take rest from the grid or battery all the time.

Exceptions are there if you have nonstop rain for multiple days.

But what I noticed is that even in the monsoon, the rains are mostly intermittent and provide fair sunlight throughout the month.
 

D7162

TF Ace
VIP Lounge
It does work. I am living in Kerala, where we have intermittent rain throughout the year. Production will be comparably lower, but it will still produce a fair amount. Please check the above graph.

Regardless of whether it is summer or monsoon season, you cannot directly use solar power. Solar won't consistently provide enough wattage; the system will take rest from the grid or battery all the time.

Exceptions are there if you have nonstop rain for multiple days.

But what I noticed is that even in the monsoon, the rains are mostly intermittent and provide fair sunlight throughout the month.
For us in Gujarat, During rains so much cloudy atmosphere is there and if you just rely only on solar, it will be useless in that case.
 

hks789

TF Ace
VIP Lounge
@hks789 thanks for the insights
How much did your setup cost?
And if I go with just inverter and battery right now can I add solar panels later?
Nope. Inverters are different for home, ongrid, offgrid, hybrid etc.
Read and explore more about these different systems and design the system after that.

For me
The total cost was around 2.75 L.
4kw monoperc Waaree 445w x 9
Solis 4K 3-phase inverter

Home inverter: This is independent of the other system.
Luminous Zelio 1100
Exide 200 AH
 

Copycat

TF Ace
VIP Lounge
There are 2 parts to this question
1) Firstly, you need to calculate the capacity of the inverter. So you will have to consider the load with all compressors running and most importantly the load at the time of startup. Your sanctioned load (from the electricity department) would be a good starting point but you will still need to calculate
2) Once you have established that, then you need to pick an inverter and see the number of batteries it uses. You then calculate the AH rating of the batteries that you need in order to give you the desired backup time

There are several additional complications
a) The inverter may or may not need an external charger
b) Charging will take a long time
c) You will need proper load values and power factor values for all your equipment to calculate correctly
d) SMF batteries will be too expensive. So you will likely need to go for tubular batteries. That means you will have to take into account proper ventilation

Just as a rough guess I would say you need a 20 KVA inverter (for 6 ACs) which is about 2.5 lakh. That will need about 30 batteries. So about 3-3.5L for the batteries (assuming tubular). Far higher in case of SMF. You can expect to throw out the SMF batteries after 2-4 years while tubular may give you 8-10 years if maintained properly.
For 2 ACs plus other equipment you will likely need between 6-10KVA and between 16-30 batteries

Some reading for you:
 
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