Solar AC Unit Experiment advice needed please

[vite]

If I purchase solar kit http://www.pricesmart.com/Local/Shop/Product.aspx?productid=271004836&DepartmentID=&CategoryID=&SubCategoryID=

with this set of batteries http://www.amazon.com/Vmaxtanks-VMAXSLR100-4-Solar-generator-application/dp/B00ACO1OEA/ref=sr_1_4?ie=UTF8&qid=1354746133&sr=8-4&keywords=deep+cycle+battery+100ah

can I run this ac unit http://www.panafoto.com/es/cat/prod_detail/61/1677/libero_inverter.html

off grid about 10 hours a day

[vite]

Getting an error for the first link:

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Watch out for batteries branded "for solar, wind turbines...", it's much the same as CD's branded "extra bass recording quality" at 3 times the price.

So no idea on the output but if your spending that sort of cash you need to at least measure for average sunlight to have an idea what output you can expect.

this is the solar array spec Grape Solar Kit con paneles solares de 300W con controlador de 30A e inversor de 2000W

[Photon939]

I assume you do not have access to grid power?

Completely off-grid systems are very expensive, you will need excessive capacity for strings of cloudy days, rain, etc. Completely draining lead-acid batteries will wear them down quickly.

300W (assuming that is the total panel wattage for the kit you linked to) is very small for a solar installation period. You will only get a few hours of full sun a day (there are maps available with this data)

It will take about ~3 hours of full sun at 300W to run that AC system for 1 hour. (probably less due to charging efficiency and inverter losses)

[Photon939]

I'm not well up on solar or air con but 9000btu adds up to 2.64 kw/h so your 2kw inverter with the solar kit wont be able to run it, check up on that though. You'd need the manufacturers specs for current requirements and maybe do some checking up on start up loads for that type of air con unit if they don't supply that info as it could be double or more the current needed to run it.

9000 BTU/hr is the heat removal capacity of the AC unit, which does equate to ~2.6KW but the compressor will use significantly less than that. My window AC unit for example is 5200 BTU/hr (~1.5KW) but it only consumes 400-500 watts of electrical power.

Single stage vapor compression cooling systems almost always have a coefficient of performance greater than 1 (aka you can move more than 1KW of heat per 1KW of energy consumed by the compressor) This is why it is much more economical to run a heat pump heating system versus plain electric resistance heat.

[vite]

well the kit has a 2000 watt inverter.
produces 75 amp hour for 6 hours a day, and a battery bank of 1600 amp hour
the ac unit uses about 30 amp hour when running.

so during the day assuming it only produces with peak sunlight, it be 450 amp stored.

so I can run the ac for about 12 hours a day of grid.

[Photon939]

well the kit has a 2000 watt inverter.
produces 75 amp hour for 6 hours a day, and a battery bank of 1600 amp hour
the ac unit uses about 30 amp hour when running.

so during the day assuming it only produces with peak sunlight, it be 450 amp stored.

so I can run the ac for about 12 hours a day of grid.

See if you can fix your original link, I'll need more info like what voltages the system is set up for and whatnot. You can't just compare amp-hours from a solar panel to batteries to an aircon unit especially with variances in voltage.

[vite]

Hmm 12 volt solar panel and batteries.
Inversor goes from 12v to 110v @ 60 hz
AC 220v @ 60 hz

Breaker box has a special breaker for the ac

[Photon939]

Do you have a working link to the solar kit?

I think you might be confusing watt hours and amp hours somewhere.

You said the panel is 300 watts - at 12 volts and 6 hours a day of full sun you will net 150 amp hours per day. (1800 watt hours)


The problem is that when you use the inverter to convert the 12vdc to 120vac your amperage is cut by a factor of ten (actually more due to efficiency losses in the inverter)

So if you have 150 amp hours stored in your batteries, it is only 1.5 amp hours at 120vac. It is much easier to think about if you use watt hours.

A 9000 BTU aircon system will consume roughly 700-900 watts of power when running. Your 150 amp hours stored at 12vdc is 1800 watt hours. You would be able to run the aircon for only 2-2.5 hours per day (before any efficiency losses).

[benjamindees]

Listen, here's the way to do this.  First, buy batteries with the lowest-voltage cells you can get.  If you're going to spend $1000 on batteries, get 6-volt golf-cart batteries at least, or perhaps even a battery of 2-volt forklift cells if you can find one cheap.  They will last longer, and losing a single cell won't be as catastrophic.  Secondly, make sure to get a pure sine wave inverter with a surge rating that's appropriate for starting an air conditioner compressor.  It takes a lot of power, but 2000 watts should be plenty as long as the inverter is well-made.  Consider a 24 or 48 volt inverter, depending on your battery bank.  Lastly, you definitely need more than 300 watt solar cells.  Even the smallest air conditioner uses around 600 watts while running.  If you want to run the air conditioner more than 3-4 hours a day, you'll need more solar cells.  And, lastly, yeah use watts and watt-hours because your calculations are all wrong.  Learn to use Google Calc.  A battery bank that's rated 400 Ah at 12 V can store 4800 Wh of energy, and will run an 800 W air conditioner for 6 hours.