How much does a 12kw solar system produce?

A 12kW solar system is a relatively large system and would produce a relatively high amount of energy. However, the exact amount of energy that a 12kW solar system produces would depend on the amount of sunlight that it receives.

The amount of sunlight that a solar panel receives is quantifiable and depends on things weather and seasons, but mainly, it depends on your location.

In this article, I will show you how to determine the average amount of energy that a 12 kW system would be able to generate in your location, and I’ll also answer a couple of frequently asked questions.

How much does a 12kw solar system produce?

The amount of energy that a 12kW solar system produces each day (or month) will mainly depend on the following factors:

  • Location.
  • Tilt angle and direction.
  • Weather and season.

However, assuming the 12kW solar system is facing south, a system of this size would – on average – produce between 45 and 65 kWh of energy per day. This amount of energy equates to about 1400-2000 kWh of monthly energy production.

To give you an idea, the following table estimates the average daily and monthly energy production of a 12kW solar system for different states in the U.S.:

State  Est. Energy Production per day (kWh/day) Est. Energy Production per month (kWh/month) 
Alabama 55 kWh/day 1700 kWh/month
Arizona 65 kWh/day 2000 kWh/month
Arkansas 50 kWh/day 1600 kWh/month
California 60 kWh/day 1900 kWh/month
Colorado 60 kWh/day 1900 kWh/month
Connecticut 50 kWh/day 1500 kWh/month
Delaware 50 kWh/day 1600 kWh/month
Florida 60 kWh/day 1900 kWh/month
Georgia 55 kWh/day 1700 kWh/month
Hawaii 50 kWh/day 1600 kWh/month
Idaho 50 kWh/day 1600 kWh/month
Illinois 50 kWh/day 1600 kWh/month
Indiana 50 kWh/day 1500 kWh/month
Iowa 45 kWh/day 1500 kWh/month
Kansas 50 kWh/day 1600 kWh/month
Kentucky 50 kWh/day 1600 kWh/month
Louisiana 55 kWh/day 1700 kWh/month
Maine 45 kWh/day 1400 kWh/month
Maryland 50 kWh/day 1600 kWh/month
Massachusetts 45 kWh/day 1500 kWh/month
Michigan 40 kWh/day 1300 kWh/month
Minnesota 45 kWh/day 1400 kWh/month
Mississippi 55 kWh/day 1700 kWh/month
Missouri 50 kWh/day 1600 kWh/month
Montana 45 kWh/day 1400 kWh/month
Nebraska 55 kWh/day 1700 kWh/month
Nevada 60 kWh/day 1900 kWh/month
New Hampshire 45 kWh/day 1400 kWh/month
New Jersey 50 kWh/ day 1500 kWh/month
New Mexico 70 kWh/day 2100 kWh/month
New York 45 kWh/day 1400 kWh/month
North Carolina 55 kWh/day 1700 kWh/month
North Dakota 45 kWh/day 1400 kWh/month
Ohio 45 kWh/day 1400 kWh/month
Oklahoma 55 kWh/day 1800 kWh/month
Oregon 50 kWh/day 1700 kWh/month
Pennsylvania 45 kWh/day 1400 kWh/month
Rhode Island 50 kWh/day 1500 kWh/month
South Carolina 55 kWh/day 1700 kWh/month
South Dakota 50 kWh/day 1600 kWh/month
Tennessee 50 kWh/day 1500 kWh/month
Texas 60 kWh/day 1900 kWh/month
Utah 55 kWh/day 1800 kWh/month
Vermont 40 kWh/day 1400 kWh/month
Virginia 50 kWh/day 1600 kWh/month
Washington 50 kWh/day 1600 kWh/month
West Virginia 45 kWh/day 1400 kWh/month
Wisconsin 45 kWh/day 1400 kWh/month
Wyoming 55 kWh/day 1800 kWh/month
Estimated daily and monthly energy production of a 12kW solar system for different states. (Source)

Please note that the information provided in the table was estimated using the PVWatts Calculator (provided by NREL). The daily and monthly energy production will generally be higher in the summer and lower in the winter.

Also, the information is based on the assumption that the solar array is facing south (Azimuth = 180 degrees) and is tilted at a 20-degree angle (4-5/12 Roof Pitch), and that the overall system losses add up to 14% (86% system efficiency).

However, the best way to get a personalized and more accurate estimate is to use the PVWatts Calculator yourself:

how much does a 12kw solar system produce

Once you submit your address, the next step would be to change the default settings in the System Info section of the tool:

How much does a 12kw solar system produce

In the System Info section, change the following settings:

DC System Size (kW): 

In this case, the DC (Direct Current) system size is 12 kW (kiloWatts).

Tilt (deg):

This setting represents the tilt angle (roof pitch) of the section(s) of your roof on which you’ll install the solar panels. Make sure it’s an unshaded roof section that’s preferably facing south. If the south-facing section of your roof is shaded or too small, go for the East, South-East, South-West, or West-facing sections.

If you know the roof pitch of the section, you can click the “i” icon to determine its equivalent in degrees. If you don’t know the roof pitch of the section, you can measure the tilt angle using an app such as Measure for iOS or Bubble Level for Android.


Azimuth represents the direction that the roof section faces. For example, the azimuth for a south-facing roof section is 180 degrees, the azimuth for a north-facing section is 0 degrees.

To accurately determine the Azimuth, you can use a compass app such as Commander Compass Go for iOS or Azimuth Compass for Android.

The other settings will slightly impact the results, but not nearly as much as tilt and Azimuth settings.

Let’s use the following settings as an example:

  • Location: For the location, I’ll submit an address in Phoenix, AZ.
  • DC System Size: 12 kW
  • Tilt: For the tilt angle, I will assume that the solar panels are installed on a roof section that has a 7/12 roof pitch, which is equivalent to about 30 degrees.
  • Azimuth: I’ll also assume that the roof section is facing South-East, which equates to 135 degrees.

I’ve submitted these details to the calculator, and in the Results section, the following table was provided:

How much does a 12kw solar system produce

Based on the location, the size of the system (12kW), and our description of the roof, the PVWatts Calculator has estimated the annual energy production to be 19650 kWh/year.

You can also see that the monthly energy production differs from month to month. The PV system will generate less energy in the winter as there will generally be less available sunlight.

Watch the following video for more information about the PVWatts Calculator:

How many solar panels does it take to make 12kW?

Residential solar panels differ in size, efficiency, and therefore, differ in power ratings. This means that the exact number of solar panels that you’ll need to create a 12 kW solar system will depend on which solar panels you’re using.

However, residential solar panels will generally be rated at 300-400 Watts, which means you would need around 30 to 40 residential solar panels to make up a 12 kW solar system.

The following table provides some of the most popular residential solar panels, their power ratings, and how many of them would be needed for a 12 kW system:

Solar Panel Model Rated Power Number of solar panels needed for a 12 kW system
LG NeON® R Series 365 – 380 Watts 32
Canadian Solar SUPERPOWER series 290 – 305 Watts 40
FuturaSun FU-M series 300 – 315 Watts 38
Panasonic EverVolt Series 360 – 370 Watts 34
REC Twin Peak 4 Series 360 – 375 Watts 34
LG NeON® 2 72cell Series 390 Watts 30
Hyundai HiS-RI Solar Panels 330 – 360 Watts 36
Canadian Solar MAXPOWER Series 325 – 340 Watts 36
Canadian Solar KuMax series 380 – 400 Watts 30
JinkoSolar’s JKM390M-72H 390 Watts 30
REC TwinPeak 2S MONO 72 Series 370 – 400 Watts 30
The number of solar panels needed for a 12 kW solar installation.

How much roof space do you need for a 12kW solar system?

On average, a single residential solar panel takes up around 20 ft² (1.72 m²) of space. Assuming the 12 kW solar system consists of 34-36 of these solar panels, such an installation would require around 650-750 ft² (60-70 m²) of roof space.

However, as mentioned above, the number of solar panels that you need for a 12 kW system, and the amount of space that these solar panels would take up, will depend on which solar panels you are using.

The following table provides some of the most popular solar panels, their respective areas, and the amount of space that would be required for a 12 kW system that’s made up of each of these panels:

Solar Panel Model Area Roof space needed for a 12 kW system
LG NeON® R Series 18.6 ft² (1.72 m²) 596 ft² (55.3 m²)
Canadian Solar SUPERPOWER series 17.6 ft² (1.63 m²) 704 ft² (65.4 m²)
FuturaSun FU-M series 17.6 ft² (1.63 m²) 668 ft² (62 m²)
Panasonic EverVolt Series 18.8 ft² (1.74 m²) 640 ft² (59.4 m²)
REC Twin Peak 4 Series 19.7 ft² (1.83 m²) 670 ft² (62.2 m²)
LG NeON® 2 72cell Series 22.3 ft² (2 m²) 670 ft² (62.2 m²)
Hyundai HiS-RI Solar Panels 21.1 ft² (1.96 m²) 760 ft² (70.6 m²)
Canadian Solar MAXPOWER Series 21.4 ft² (1.98 m²) 770 ft² (71.5 m²)
Canadian Solar KuMax series 21.4 ft² (1.98 m²) 642 ft² (59.6 m²)
JinkoSolar’s JKM390M-72H 21.7 ft² (2 m²) 651 ft² (60.5 m²)
REC TwinPeak 2S MONO 72 Series 21.6 ft² (2 m²) 648 ft² (60.2 m²)
Roof space required for a 12 kW solar installation.

To learn more about the different types of residential solar panels and their dimensions, please refer to the following page: How big is a solar panel?

Related: How many solar panels can you fit on your roof?

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Hi! My name is Younes. I'm an electrical engineer and a renewable energy enthusiast. I created with a mission of delivering digestible content and information to the people who seek it.

One comment

  1. This is the best site I have found so far that explains the whole solar concept. We have been off grid since 1984 with a combination of solar panels, inverter and batteries. We need to upgrade our system so we can use mini-splits and maybe a plugin hybrid some day. We want to get off of evaporate coolers in summer and propane in winter. We will stay off grid as we do not want to hookup to Edison. I will keep studying your information which is very helpful in creating a separate new system. Thanks

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