Noobie ? Airconditioner

[Johann]

I am new and I do not have any VP setup yet. So links would be very welcomed for things that I need or things I need to read.

Here is my thought what I like to do.
I would like to run a 550 watt window air-conditioner unit.
I checked into prices for 250W panels which I believe that I need to have 3 to 4 of them to get enough power for the compressor to start. If I could run it day time only that would be a plus and I understand that it may take to much power to run at night on battery power.
I seen where they make a battery powered window unit, but the price is outrages.
This would be a off grid system.

Could anyone advise me what I would need to do this.
What inverter would be ok to use for this that is not to expensive. Talking about inverters.....years back I bought a 12 volt 1800watt inverter that I used many times already for back-up by hooking it up to my car battery. Would this inverter work for the window unit?

Thank you.

[Naptown]

is grid power available?

[Johann]

is grid power available?

Yes, it is.

[Naptown]

Then why would you want to take this off grid and pay 5-10 times what it would cost you to run it on grid power.
Off grid electricity when you add it all up (particularly batteries and their replacements) is a losing proposition when grid power is available.
For what you will spend on the off grid to do this you could get twice the power from a grid tie system.

[Sunking]

Yes, it is.

Then th every last thing you want to do is take it off-grid.

[Johann]

Eventually I like to get solar panels and I thought this would be a good start and project to get started with.

Could you folks provide links the do's and dont's and why it is not feasible in this case.

Thank you.

[Johann]

What about a grid tied solar system, would that be better for this ?

[Sunking]

Could you folks provide links the do's and dont's and why it is not feasible in this case.

Not real hard to figure out. Look at your electric bill and see what you pay for a Kwh. Most likely you pay around 10 to 15-cents per Kwh. Take it off-grid battery and you now will pay $1.60 to $2.00 per Kwh

Which do you want to pay? 10 to 15 cents, or $1.60 to $2.00?

Pretty simple decision huh?

[inetdog]

What about a grid tied solar system, would that be better for this ?

Yes, much better if your panel production would meet part or all of your AC needs, but would not produce more power than you actually consume at any point during the day.
If your utility (POCO) provide net metering or other Feed In Tariffs (FIT) as an incentive for selling power back to POCO, you will may really win by using the utility as a big free battery which you charge up during the day (meter running backwards) and draw from at night (meter running forward.) A big problem with a strictly off-grid system is that once the batteries are charged, the remaining power from the panels is being wasted or used for inefficient purposes like hot water heating.

You will also see that the "battery" that POCO represents will let you deliver a net charge all summer and a net draw all winter when the PV output is lower. Try that with real batteries!

[Johann]

Thank you very much.
I will go and change to the right category for grid tie and I will ask questions there.

[iddbbi]

Hi Johann,

My situation is quite similar to yours, need to use solar panels and batteries to run the a/c compressor. Do you have any ideas how many it will take to run the a/c system?

[Johann]

Hi Johann,

My situation is quite similar to yours, need to use solar panels and batteries to run the a/c compressor. Do you have any ideas how many it will take to run the a/c system?

I am still researching that, I am very new to this also, I do not have any solar panel yet.

A 5,000 BTU window air conditioner uses about 500w per hr. To run it 24 hrs a day you would need to generate 12,000 watts. On average throughout the year I get 6 hrs sunlight a day, so in 6 hrs I would need to generate 12,000 watts (just to keep the calculation simple). 12,000w divided by 6 = 2,000 watts of panels....minimum. In real life it would be more.

As far as it concerns the battery, I did not get on my research far enough to give you an calculation or opinion yet.

[Sunking]

As far as it concerns the battery, I did not get on my research far enough to give you an calculation or opinion yet.

I can answer that real easy. At 12 Kwh/day it would take a 3000 pound, $15,000 battery.

[green]

I can answer that real easy. At 12 Kwh/day it would take a 3000 pound, $15,000 battery.

So... For 2 Air Conditioners would I just double those numbers? I'm just kidding of course.

It's pretty safe to say that air conditioners are the worst possible things to try to take off grid.

[Johann]

I can answer that real easy. At 12 Kwh/day it would take a 3000 pound, $15,000 battery.

How did you come to the conclusion ?

How many A HR battery would you need and how would you calculate that ?

A 3000LB battery, interesting...sounds like a electric forklift battery. I could get a used 36V forklift battery for $200. Actually I thought about buying it for my setup I will get in the near future. I need to check how many amp hrs it has. A new one is about $4000.