How Many kWh Does A Solar Panel Produce Per Day? Calculator + Chart

Solar panels can produce quite a lot of electricity. It’s quite interesting to see exactly how many kWh does a solar panel produce per day. We will do the math, and show you how you can do the math quite easily. Moreover, you can also play around with our Solar Panel Daily kWh Production Calculator as well as check out the Solar Panel kWh Per Day Generation Chart (daily kWh production at 4, 5, and 6 peak sun hours for the smallest 10W solar panel to the big 20 kW solar system).

Now, the amount of electricity in terms of kWh any solar panel will produce depends on only these two factors:

  1. Solar Panel Size (Wattage). Most common solar panel sizes include 100-watt, 300-watt, and 400-watt solar panels, for example. The biggest the rated wattage of a solar panel, the more kWh per day it will produce.
  2. How Much Sun Do You Get (Peak Sun Hours). Obviously, the more sun you get, the more kWh a solar panel will produce per day. We measure the amount of sun (sun irradiance) with peak sun hours per day. In the US, for example, we get, on a 12-month average, anywhere from 3 peak sun hours (think Alaska) to 7 peak sun hours (think Arizona, New Mexico). In California and Texas, where we have the most solar panels installed, we get 5.38 and 4.92 peak sun hours per day, respectively.

Quick outtake from the calculator and chart:

  • For 1 kWh per day, you would need about a 300-watt solar panel.
  • For 10kW per day, you would need about a 3kW solar system.

If we know both the solar panel size and peak sun hours at our location, we can calculate how many kilowatts does a solar panel produce per day using this equation:

Daily kWh Production = Solar Panel Wattage × Peak Sun Hours × 0.75 / 1000

As you can see, the larger the panels and the sunnier the area, the more kWh will a solar panel produce. We also have to multiply this by 0.75 factor to account for 25% losses within the system (DC, AC, inverter, charge controller, battery), and divide by 1000 to get from watt-hours (Wh) to kilowatt-hours (kWh).

Quick Example: Let’s say you want to know how many kWh does a 300-watt solar panel produce per day. You live in Texas, and you can use the average yearly 4.92 peak sun hours per day sun irradiance. Let’s insert these figures in the equation like this:

Daily kWh Production (300W, Texas) = 300W × 4.92h × 0.75 / 1000 = 1.11 kWh/Day

We can see that a 300W solar panel in Texas will produce a little more than 1 kWh every day (1.11 kWh/day, to be exact).

We can calculate the daily kW solar panel generation for any panel at any location using this formula. Probably, the most difficult thing is to figure out how much sun you get at your location (in terms of peak sun hours). You can check these US state-by-state sun irradiance averages, or consult this Global Solar Atlas map to figure out how many sun peak hours you get in your country (here is the screenshot):

determining peak sun hours for estimating solar panel kwh daily production
We can see that the countries near the equator get a lot of sunlight (6+ sun peak hours). Here the daily solar panel kWh output will be much higher than in colder countries like Scandinavian countries.

Now, since this is not exactly the back of the napkin calculation, we have prepared a Solar Panel Daily kWh Production Calculator you can use to calculate the daily kWh output for any solar panel. You just insert solar panel wattage and peak sun hours, and you will get daily kWh production.

Below the calculator, you will also find a big chart. Basically, we have calculated how many kWh do single solar panels (like 100W, 200W, 300W, 400W) and big solar systems (3kW, 5kW, 10kW, 20kW) produce per day at locations with less sun irradiance (4 peak sun hours), average sun irradiance (5 peak sun hours) and at very sunny locations (6 peak sun hours). All the results are gathered in this big all-encompassing chart. Let’s first look at the calculator:

Solar Panel Daily kWh Production Calculator


Alright, let’s say you want to figure out how many kWh does a small 100-watt solar panel produce per day. You live in a sunny location that gets 5.79 peak sun hours per day. The calculator will do the calculation for you; just slide the 1st wattage slider to ‘100’ and the 2nd sun irradiance slider to ‘5.79’, and you get the result:

A 100-watt solar panel installed in a sunny location (5.79 peak sun hours per day) will produce 0.43 kWh per day. That’s not all that much, right? However, if you have a 5kW solar system (comprised of 50 100-watt solar panels), the whole system will produce 21.71 kWh/day at this location. This might be enough to cover 100% of your electricity needs, for example.

To illustrate how many kWh different solar panel sizes produce per day, we have calculated the kWh output for locations that get 4, 5, or 6 peak sun hours. Here are all the results, gathered in a neat chart:

Solar Panel kWh Per Day Generation Chart

Solar Panel Size (Watts) kWh Per Day At 4 Peak Sun Hours: kWh Per Day At 5 Peak Sun Hours: kWh Per Day At 6 Peak Sun Hours:
10 Watts 0.03 kWh/Day 0.04 kWh/Day 0.05 kWh/Day
50 Watts 0.15 kWh/Day 0.19 kWh/Day 0.23 kWh/Day
100 Watts 0.30 kWh/Day 0.38 kWh/Day 0.45 kWh/Day
120 Watts 0.36 kWh/Day 0.46 kWh/Day 0.54 kWh/Day
150 Watts 0.45 kWh/Day 0.57 kWh/Day 0.68 kWh/Day
200 Watts 0.60 kWh/Day 0.75 kWh/Day 0.90 kWh/Day
250 Watts 0.75 kWh/Day 0.94 kWh/Day 1.13 kWh/Day
300 Watts 0.90 kWh/Day 1.13 kWh/Day 1.35 kWh/Day
350 Watts 1.05 kWh/Day 1.31 kWh/Day 1.58 kWh/Day
400 Watts 1.20 kWh/Day 1.50 kWh/Day 1.80 kWh/Day
450 Watts 1.35 kWh/Day 1.69 kWh/Day 2.03 kWh/Day
500 Watts 1.50 kWh/Day 1.88 kWh/Day 2.25 kWh/Day
600 Watts 1.80 kWh/Day 2.25 kWh/Day 2.70 kWh/Day
700 Watts 2.10 kWh/Day 2.63 kWh/Day 3.15 kWh/Day
800 Watts 2.40 kWh/Day 3.00 kWh/Day 3.60 kWh/Day
900 Watts 2.70 kWh/Day 3.38 kWh/Day 4.05 kWh/Day
1,000 Watts 3.00 kWh/Day 3.75 kWh/Day 4.50 kWh/Day
1,500 Watts 4.50 kWh/Day 5.63 kWh/Day 6.75 kWh/Day
2 kW 6.00 kWh/Day 7.50 kWh/Day 9.00 kWh/Day
2.5 kW 7.50 kWh/Day 9.38 kWh/Day 11.25 kWh/Day
3 kW 9.00 kWh/Day 11.25 kWh/Day 13.50 kWh/Day
3.5 kW 10.50 kWh/Day 13.13 kWh/Day 15.75 kWh/Day
4 kW 12.00 kWh/Day 15.00 kWh/Day 18.00 kWh/Day
4.5 kW 13.50 kWh/Day 16.88 kWh/Day 20.25 kWh/Day
5 kW 15.00 kWh/Day 18.75 kWh/Day 22.50 kWh/Day
5.5 kW 16.50 kWh/Day 20.63 kWh/Day 24.75 kWh/Day
6 kW 18.00 kWh/Day 22.50 kWh/Day 27.00 kWh/Day
6.5 kW 19.50 kWh/Day 24.38 kWh/Day 29.25 kWh/Day
7 kW 21.00 kWh/Day 26.25 kWh/Day 31.50 kWh/Day
7.5 kW 22.50 kWh/Day 28.13 kWh/Day 33.75 kWh/Day
8 kW 24.00 kWh/Day 30.00 kWh/Day 36.00 kWh/Day
8.5 kW 25.50 kWh/Day 31.88 kWh/Day 38.25 kWh/Day
9 kW 27.00 kWh/Day 33.75 kWh/Day 40.50 kWh/Day
9.5 kW 28.50 kWh/Day 35.63 kWh/Day 42.75 kWh/Day
10 kW 30.00 kWh/Day 37.50 kWh/Day 45.00 kWh/Day
15 kW 45.00 kWh/Day 56.25 kWh/Day 67.50 kWh/Day
20 kW 60.00 kWh/Day 75.00 kWh/Day 90.00 kWh/Day

Now you can just read the solar panel daily kWh production off this chart.

Here are some examples of individual solar panels:

  • A 300-watt solar panel will produce anywhere from 0.90 to 1.35 kWh per day (at 4-6 peak sun hours locations).
  • A 400-watt solar panel will produce anywhere from 1.20 to 1.80 kWh per day (at 4-6 peak sun hours locations).
  • The biggest 700-watt solar panel will produce anywhere from 2.10 to 3.15 kWh per day (at 4-6 peak sun hours locations).

Let’s have a look at solar systems as well:

  • A 6kW solar system will produce anywhere from 18 to 27 kWh per day (at 4-6 peak sun hours locations).
  • A 8kW solar system will produce anywhere from 24 to 36 kWh per day (at 4-6 peak sun hours locations).
  • A big 20kW solar system will produce anywhere from 60 to 90 kWh per day (at 4-6 peak sun hours locations).

Using this chart and the calculator above, you can pretty much figure out how much kWh does a solar panel or solar system produce per day. If you need any help with the calculations or would like for us to do some math for you, you can use the comment section below, give us some numbers, and we will help you out.

8 thoughts on “How Many kWh Does A Solar Panel Produce Per Day? Calculator + Chart”

  1. Been working on a system where I can get about 7 kwh out of 4 – 100 watt panels per day. doing on small scale now, real close to proof of concept. I need scale it up to find out if if process is stable.

      • yep, I know. I call it tunnel vision. I had it. I know yr shaking yr head and smiling, I did too at first. There is a point of diminishing returns though, there has been a few advancements in one of my other projects that I applied to my solar project. currently waiting on larger panels to arrive. I’ll have numbers on those in a week or so. I’ll post them as I use yr calculator’s a lot. I am pulling close to 1.5 kwh off a old harbor freight 100 watt panel with my application. My design will only work on smaller scale arrays. 4 or 5 panels.

      • well I maxed out my 100 watt harbor freight solar panel, my meter was reading using 140 watts going out and my battery and 20 amp mppt were holding their own at around 11.9 volts. I had 2 box fans running on high speed, a 20 w florescent light and an led light strip running. I don’t have the proper testing equipment to get much closer than that. my new 100 watt panels came today so ill be rebuilding the array tomorrow. any way thanks for listening,

  2. I have an 18kw system in Arizona. For some reason, in April it is already producing 104kwh per day. Looking at the provided chart…how is that even possible?

    • Hi there, that’s quite in line with the expectations. If you check this state-by-state chart, you can see that Arizona gets 6.57 peak sun hours of sun per day (12-month average). The expected average output of the 18kW system in Arizona can be calculated like this:
      Electricity Generation (18kW system in Arizona) = 18kW × 6.57 hours × 0.75 = 88.70 kWh per day.
      Now, 88.70 kWh is less than 104 kWh you are generating now. This is because in summer we get more sun (above 12-month average), and April 2023 is incredibly sunny and hot in Arizona. If you check the summer average peak sun hours (7.42h for Arizona), you should be generating 100.17 kWh per day in the summer (on average). So, the 104 kWh is quite in line with that. Good job on the system, always love when people are positively astonished about how much electricity solar systems can generate in sunny locations.

    • Hi Peter, alright, this is a 24kW system and in Florida you can expect 6.16 peak sun hours per day in summer. If we apply the 25% losses, we can calculate the daily kWh output like this: 24kW × 6.16h × 0.75 = 110.88 kWh per day.

      For per month calculation, we just multiply that by 30 days and get this result: 24kW system in Florida will produce about 3,326 kWh per month. Hope this helps.


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