How Many Solar Panels to Run an Air Conditioner

Last Updated: October 9, 2021

Ok, here’s a deal. You have to answer a few questions first, and we will try to answer your question, “How many solar panels to run an air conditioner?” The questions are following;

  • Your location? Where do you live? Weather, temperature, sunlight duration, and its intensity in your region?
  • Your solar system type—on-grid? Self-reliant?
  • Your AC star? Tonnage? Your demand from AC? Your AC power consumption?

Done? You might go like, “Come on, man, I can’t do this right now. How would I answer?” Yes, we know that. The notion behind this deal thing was to tell you that NOBODY can answer this question without knowing these factors, not even experts. But you rummage no more through the internet, we understand your intent behind the question and have assumed everything on my own and have my research done, so you could sit back with a coffee (or whatever you prefer) in hand, scroll and figure out the number of solar panels need to run your AC. In the article, we have listed the estimated number of solar panels for the 1-ton AC and 1.5-ton AC on on-grid and off-grid systems. Plus, a solar-enthusiast friend telling us about his solar-powered AC.

Determining the Number of Solar Panels for 1-Ton and 1.5-Ton AC

There are a few things we want you to be must familiar with, so you could assimilate the substantial part. For better depiction, we have subjected 1-ton AC for our calculations. Those are enumerated below;

  • 1-ton AC consumes between around 1000W and 1333W, depends on which star AC you are using.
  • 6kW system means not it will produce 6000kW yearly. Production varies from region to region predominately due to geography and type of equipment.
  • An impeccably placed 6kW system can produce 7000kW+ or (7000000W) in Massachusetts yearly will produce 9000kW+ (2kW more) in California as it gets more sunshine falling on it.

Now let’s get straight to calculations

The latest ACs come with a nameplate having details mentioned, e.g., power consumption, rating, size, etc. That power consumption thing comes in handy when calculating how much power your AC will use approximately annually or in your desired days. OR If you want to figure out your AC power consumption manually, use a Kill A Wattmeter. You have to plug your AC wire into the meter and connect the meter to a socket. It is recommended to study the readings for at least seven days. To calculate how many watts would be used by your AC in a day, multiply the number of hours you want to use by power consumption.  To calculate the number of watts for a whole year, multiply the result by 365 days, or if you want to run for summer, four months, then multiply it by 120 days. Not to mention, less power AC starts consuming after constantly cooling for two to three hours, so calculations would be rough, not exact. For the sake of calculations, we assume your AC adds 3000kW to your bill annually, your solar panel system would have to be producing equal or more to offset additional load.

Number of Panels

To figure out the number of panels, divide the anticipated annual production by the typical production ratio and then divide the result by the number of watts of a solar panel. It is the typical production ratio that tells how many watts your solar system will produce in a specific region, and if wondering how you can calculate the typical production ratio of your region, here is the formula; => Production ratio = one-year production estimate/system size (Watts) => 1.16 = 7000kW/6000 Here is the list of American states with their typical production ratio mentioned in front of their names;

Typical Production Ratio Range
Chart credit goes to EnergySage.

So considering the chart, in Washington, for generating 3000kWh yearly, you would need a solar system producing over 2727W (3000kW/1.1). And producing the same amount in California, you would need a system producing 1875W (3000kWh/1.6). Here is a simple formula to figure out the number of panels required; => The number of panels = Additional watts required / panel size in watts Now it is your choice from here which watts panels you choose. If you go for 590W panels in Washington, you will need five panels (2727W/590 = 4.6220339 = 5) to produce the power required. If you choose 590W panels in California, you will need four panels (1875W/590 = 3.1779661 = 4) to do so. 250-365W panels tend to be available in markets. The number of watts of panels is inversely proportional to the number of them. The higher the watts of panels, the less of them are required to generate targeted energy.

My Friend’s Solar-Powered 1.5-ton Inverter AC

We have a friend living in Karachi, who has a 1.5-ton 5-star inverter AC running on an on-grid solar panel system. His solar panel system has four solar panels of Monocrystalline 590W Canadian Solar and a Lithium-ion battery. He runs AC during the daytime, during which his solar panels produce at 75% to 80% of their capacity given 35-40 degrees celsius. So if we calculate 590*4, it results in 2360W, and if you take 75% of 2360W, it is 1770W, which is more than enough to run a 1-ton or 1.5-ton 5-star AC smoothly. And during winters, when the system is producing at 65% or less, he connects another Monocrystalline 590W solar panel to cover inefficiencies.

Gist

A solar panel system producing 1.7kW+ is enough to run 1-ton or 1.5-ton 5-star AC, and a system producing 2kW would make the process optimal. “The more panels, the better.” Your solar panel system always has to generate extra power to meet inefficacies due to springing up of anything unexpected, e.g., cloudy weather. And if you want to make the same model fully independent and add battery backup for running at night, here is how you can. The peak power consumption is 1.3 kW of the 1.5-ton 5-star inverter air conditioner. It can be lower than this depending on variants. So considering a 1.5-ton 5-star inverter AC, you would need more panels depending on the hours you want a backup for. Let’s assume you want a backup for the whole night—12 hours. Eight hours is the average solar radiation time in Karachi. So considering 75% average output from a panel, you would need 16 Monocrystalline 590W solar panels of Canadian Solar with four lithium-ion batteries of 48V 100A to cover intermittency. So calculations would go like 12*4.8, it is 57.6kWh.  The same model you can implement by figuring out the typical production ratio in your region.

1-ton 5-Star on Self-reliant Energy System

The calculations for a 1-ton 5-star AC on the self-reliant system are utterly based on presumptions, so let’s start with AC;

  • The cooling capacity of 1-ton AC is 12000 BTU or (3517W)
  • The energy efficiency ratio of 1-ton 5-star AC is 3.1

Considering the values, the power input of 1-ton AC would go like following; 3517W/3.1 = 1134.51613W Let’s assume you run AC for 8 hours a day, so over 9076W (1134.51613W * 8) would be consumed by your AC. It can be lower than that. We mentioned earlier in the article that AC starts consuming less power after constantly cooling for three to four hours. As we are doing all these calculations for a self-reliant energy system, we would need a battery and charge controller. Choosing a 48V Lead Acid battery and charge controller with 90% and 95% efficiency respectively, total electricity production would be over 10600 with Ah required 221.04 Ah (10610/48). If we consider sunshine at least for 4 hours, we would need over 55.26 A (221.04/4) every hour. Solar panels of Isc = 5A and Voc = 24V are connected in parallel series, at least four 590W panels would be required to run the AC. You can go for 250W, 350W, depends on your preferences. If we consider an inverter to convert DC to AC, there would be a bit more power loss. Considering the inverter converting 48VDC to 230VAC, efficiency loss is worth considering, so you can say there would be 5% loss during inverter and 1% ohmic of 10600W, and you would need more panels to cover the loss.

AC on already Existing Solar System

If you already have a solar system installed running your home, you can still run your AC. Even if you are tight with energy usage, you have to ask your solar installer to add additional required panels.

Conclusion

Two things play an indispensable role in the whole process; weather and solar panels. The more sunshine and panels, the better.  There is no denial of the fact that AC repletes our rooms with cool air but depletes our pockets. It is like forgoing your $10 coffee and staying sleepy all day to afford a better house.

Recommendation

We would recommend you go with an on-grid system. This way, you would have to worry about running AC at night. But if you want to go on an off-grid system, try to get as many batteries storing as possible.

10 Comments

Add a Comment

Your email address will not be published.