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Solar powered air conditioner

snabil

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Joined
Oct 2, 2021
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Hello,

I am new here, but I have been researching this topic for several months now without being able to determine whether or not it is possible. So, kindy bear with me.
Here is what I am trying to do:

I have a 12250 BTU (1166W) split unit air conditioner and I would like to run it on solar energy. The system will be off-grid, and will not be used to power anything else.
The Air conditoner specs:
* Voltage: 240V AC single phase
* Normal operating current: 4.8A (at maximum cooling settings)
* Startup current: 32A (less than 1 second)
I verified these values with current clamp tool.

My idea is to use the following components:

Solar Panel:
2 x Sungold 100W panels with controller

Battery:
1 x TalentCell Rechargeable 12V 100Ah deep cycle battery (LiFePO4)

Inverter:
1 x 12V DC / 240V AC 3000W modified Sine wave

I live in Egypt where the sun is abundant, so connecting the 2 solar panels in parallel would give me charging current of around 10A for 10 hours per in winter and 12 ours in summer. If my calculations are correct (hopefully), I assume that the battery can charged from 20% - 90% in 10 hours taking into consideration the solar panel and charger efficiencies.
When the battery is fully charged, I believe I can run the air conditioner for 12 hours at least (assuming 5A normal current and 240V)

I would really be grateful if you could provide me some guidance, and please correct me if I am doing something wrong.

Thanks
Sandra
 
5A x 240V = 1200 Watts of power. Your battery capacity is 12 V x 100Ah = 1200 Wh. So, ideally, you could only run your air conditioner for 1 hour, at best and likely far less.
 
There do exist mini split air conditioners which have a built in MPPT charge controller and will accept direct input from solar panels. So, during the day, your solar panels would run the air conditioner with supplemental power from the grid.
 
Can you show how you determined your battery could power the air conditioner for 12 hours? @turbo6bar is correct that it will last less than 1 hour. Not anywhere near 12 hours. This assumes the A/C is running at maximum continuously for the hour. If it only runs 30 minutes per hour then you might get closer to 2 hours of usage (probably more like 90 minutes or so).

Since your A/C uses 1200W at max cooling settings you might want to consider getting about 1500W-1800W of solar panels. Then while the sun is out the solar power would run the A/C all by itself and charge the battery. The battery would only be needed to run the A/C when the sun is down. But you definitely need more batteries if you need to run it more than an hour in the evening.

Also note that a single 12V 100Ah battery is incapable of running a 3000W inverter. You really should be considering a 24V setup. A couple of 24V batteries in parallel would be able to handle the inverter much better.
 
Looks to me as if he {you} is only doing the math based on Amps, not power. Need to add in the voltage differential and then it becomes clear why the proposed setup is not adequate.

Also needs to account for that startup power 240v x 32A = 7680W. Maybe as simple as adding a soft-start and re-measuring the surge.
 
Looks to me as if he {you} is only doing the math based on Amps, not power.
Both turbo6bar and I did the math on watts (power), not amps. And we both made it quite clear that the system isn't adequate.
 
Right, the answering posts were correct and helpful, but didn't explicitly point out what the OP got wrong. I was just trying to make that clear to the OP.
 
Right, the answering posts were correct and helpful, but didn't explicitly point out what the OP got wrong
The only reply should have been along this line:

"2 x 100w panels are not sufficient for any type of air conditioner"
 
The only reply should have been along this line:

"2 x 100w panels are not sufficient for any type of air conditioner"
But the AC only takes 4.8 amps and two 100watt panels can make 13 amps?
 
But the AC only takes 4.8 amps and two 100watt panels can make 13 amps?
Watts goes in is watts comes out! Not amps in- amps out and the probability of 2 100w panels achieving that for any time is unlikely.
 
But the AC only takes 4.8 amps and two 100watt panels can make 13 amps?
It’s 4.8A at 240V. That’s 1152W. You can’t get 1152W from 200W of solar panels no matter how many amps they make. Comparing amps without voltage doesn’t work unless you already know both amperages are for the same voltage.
 
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Not enough panels or battery.
You have to remember that during the day the panels need to supply enough energy to run the AC and charge the battery.
 
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