Air con Run on solar pannels

[markbrookes]

Hi
Im based in the UK and Im a total beginner to all this. I have a shed with an air conditioner unit and I would like to know what I would need to run this unit 5 hours a day. on solar/Battery The unit is a A Midea AG-09NXD0-and uses approx 1000watts per hour. hope all this makes sence.
thank you
Mark

 

[sunshine_eggo]

You need sufficient solar/battery to provide 6kWh/day.

 

[MichaelK]

I'm assuming that this unit requires standard UK 230V AC at 50Hz? Did I get those specs right? For proper design, you need two numbers, the running wattage, which appears to be ~1000W, and also the starting wattage, called the starting surge, or inrush? That might be in the range of 4X the running wattage. So, first assume you need an inverter that can supply 4000W for at least 1-2 seconds.

A good rule of thumb for power production is to have at least 2X the watts of panels as whatever your biggest single load is. So, for a 1000W air-conditioner, that would be at least 2000W of panels. The good news is that panels are the cheapest component now. Here in California, I can get 2000W for ~ 520$ right now. Look for your local listings on whatever seller's venue you have locally. You'll get the best deals with cash and carry, local pickup. Avoid panel shipments through the mail. That's the single most expensive way to buy panels.

2000W puts you solidly in 24V territory, so shop for a 4000W, 24V sine-wave inverter.

Since this is mostly for daytime use, the battery does not need to be that big. Maybe a golf-cart sized battery in the 250Ah range will work for you. They are typically 6V, so four in series will give you a 24V battery.

So, what you will need....

8 250W grid-tie panels
4 6V golf-cart batteries
1 80A charge controller
1 4000W 24V sine-wave inverter
wires, breakers, Windex, ect...

 

[markbrookes]

Thank you , that’s really helpful.

 

[ianganderton]

Where about are you in the uk?

You need enough solar plus a bit to recharge you battery what ever you use.

Solar production can be calculated using irradiance data. This one is easy to use

Solar Irradiance Calculator

www.solarelectricityhandbook.com

Here is the data for Birmingham. Because your priority is AC I’ve selected the panel angle most suited to summer production



Simply multiply the solar hours by the panel wattage to get the average daily power generation

 

[markbrookes]

Where about are you in the uk?

You need enough solar plus a bit to recharge you battery what ever you use.

Solar production can be calculated using irradiance data. This one is easy to use

Solar Irradiance Calculator

www.solarelectricityhandbook.com

Here is the data for Birmingham. Because your priority is AC I’ve selected the panel angle most suited to summer production

View attachment 111849

Simply multiply the solar hours by the panel wattage to get the average daily power generation

Thank you this is very helpful, and thank you for the time you have taken

 

[markbrookes]

Where about are you in the uk?

You need enough solar plus a bit to recharge you battery what ever you use.

Solar production can be calculated using irradiance data. This one is easy to use

Solar Irradiance Calculator

www.solarelectricityhandbook.com

Here is the data for Birmingham. Because your priority is AC I’ve selected the panel angle most suited to summer production

View attachment 111849

Simply multiply the solar hours by the panel wattage to get the average daily power generation

HI Im in the Birmingham area of the UK,and you are right the standard 230V at 50Hz. Can you get an Inverter that does 12v and 24v ? and could i use standard 12v car batteries ? It looks like it going to be expensive as a one off buy, so if I bought bits and had a play with it and added more Batteries Later. Once again thank you for your help
Thanks Mark

 

[MichaelK]

Can you get an Inverter that does 12v and 24v ? and could i use standard 12v car batteries ? It looks like it going to be expensive as a one off buy, so if I bought bits and had a play with it and added more Batteries Later. Once again thank you for your help
Thanks Mark

No, the inverter MUST be one and only one voltage. The typical choices available today are 12V, 24V, and 48V. The Australians used to implement 36V and even 32V systems, but those have gradually been phased out as obsolete.

Personally, I'd lean towards at 24V. 12V is really only the best choice in mobile applications, so if you system isn't on wheels, it's better to go with either 24V or 48V. You have to remember that watts is the product of V X A, so to get decent wattage you need a LOT of amps with 12V. That means thick (expensive) copper wire.

Car starter batteries are a very poor choice. They are designed to put out a lot of amps in a very short period of time, and then expect to be fully charge back up in an equally short time. They just don't hold up the daily repeated deep drainings, and slow recharges typical of off-grid systems. Off-grid batteries, or "deep cycle" batteries have different internal lead plates that facilitate slow discharging/slow recharging.

You have to understand that solar is NOT cheap. Off-grid solar is simply the very most expensive way to get power. If you are only doing this to save money then you are working on a false premise. Keep in mind that what I outlined above for you is a cheaper, more budget oriented system to begin with. If this appears to be too much for you, cost wise, it might be a good time to completely re-evaluate why you want to do this.