How Many kWh Does A Solar Panel Produce Per Day?
As a general rule, with an average irradiance of 4 peaksunhours/day, 1 watt of solar panel rated power will produce on average 4 watthours (Wh) of energy. This amount equates to 0.004kWh, so a 300 watt solar panel will generate 1.22kWh/day. The precise amount depends on the location irradiance.
How much kWh does a solar panel produce?
The amount of energy generated by any solar panel depends heavily on the irradiance for the panel’s location measured in kilowatthours per square meter per day (kWh/m2/day).
For convenience, it’s also known as the location’s PeakSunHours and can be used as a quick estimated of a solar panel arrays output per day or year measured in kWh.
It’s an important number. For example, the energy output for a solar panel in Arizona with of 7.5 peaksunhours/day is very different from Indiana with 3/day!
See the table below to see solar panel outputs compared across US states:
TABLE: Average solar panel output per day (kWh) by US States compared
State 
Peaksunhours (Global Solar Atlas)

Wh/day Produced By 50 Watt Solar Panel 
Wh/day Produced By 100 Watt Solar Panel 
Wh/day Produced By 200 Watt Solar Panel 
Wh/day Produced By 300 Watt Solar Panel 
4 (US average) 
200Wh/day 
400Wh/day 
800Wh/day 
1200Wh/day 

2.5 
124 
248 
496 
744 

7.5 
375 
750 
1500 
2250 

3.75 
187.5 
375 
750 
1125 

6 
300 
600 
1200 
1800 


5.75 
287.5 
575 
1150 
1725 
3 
150 
300 
600 
900 

4 
200 
400 
800 
1200 

4.25 
210 
420 
840 
1260 

4.25 
210 
420 
840 
1260 

4.5 
225 
450 
900 
1350 

4.5 
225 
450 
900 
1350 

3.5 
175 
350 
700 
1050 

3 
150 
300 
600 
900 

4 
200 
400 
800 
1200 

4.5 
225 
450 
900 
1350 

3.5 
175 
350 
700 
1050 

4.25 
210 
420 
840 
1260 

3.25 
162.5 
325 
650 
975 

3.5 
175 
350 
700 
1050 

3 
150 
300 
600 
900 

3 
150 
300 
600 
900 

4 
200 
400 
800 
1200 

4.25 
210 
420 
840 
1260 

4.25 
210 
420 
840 
1260 

4.5 
225 
450 
900 
1350 

4.5 
225 
450 
900 
1350 

6.5 
325 
650 
1300 
1950 

3.25 
162.5 
325 
650 
975 

3.75 
187.7 
375 
750 
1125 

6.5 
325 
650 
1300 
1950 

3.25 
162.5 
325 
650 
975 

4.25 
210 
420 
840 
1260 

4.25 
210 
420 
840 
1260 

3 
150 
300 
600 
900 

4.74 
237 
474 
948 
1422 

4 
200 
400 
800 
1200 

3 
150 
300 
600 
900 

3.5 
175 
350 
700 
1050 

4.25 
210 
420 
840 
1260 

4.75 
237.5 
475 
950 
1425 

4 
200 
400 
800 
1200 

4.75 
237.5 
475 
950 
1425 

6.5 
325 
650 
1300 
1950 

3.75 
187.5 
375 
750 
1125 

3.75 
187.5 
375 
750 
1125 

4 
200 
400 
800 
1200 

3 
150 
300 
600 
900 

3.5 
175 
350 
700 
1050 

5.75 
287.5 
575 
1150 
1725 
How many solar panels to produce 30 kwh per day?
With an average irradiance of 4 peaksunhours 25 solar panels rated at 300 watts each would be needed to produce 30kWh per day. This equates to a 7.5kW solar power installation. The solar output will vary depending on the irradiance at any particular location.
Domestic solar panels can have power ratings anywhere from 200 watts to 350 watts.
Lower rated panels such as the very common 100 watt variety are mainly used for small projects, local battery charging, camping vans/RVs, sheds and pergola roofs.
Let’s say the panels in question are 300 watts (we can use this one for reference). I’ll also choose the location of the panels as Atlanta, Ga. Other factors, such as voltage, doesn’t really matter.
Solar panels irradiance in Atlanta, Ga
Find this value on the site Global Atlas Info – see the image below:
Irradiance at this location is 4.634 peaksunhours/day, so a 300 watt solar panel will generate:
4.634 x 300 = 1.39kWh/day
Now we can divide the 30kWh target by the daily energy production to0 find the number of panels needed:
30kWh/1.39 = 21.6 (22) solar panels @ 300 watts rating each
Total solar installation power required is 6.6kW.
Note: Your professional installer would advise, but it’s normal to more capacity because theoretical estimates don’t take into account the various solar losses.
How many solar panels do I need to produce 50 kwh per day?
With a typical irradiance of 4 peaksunhours 62 solar panels rated at 200 watts each are required to produce 50kWh per day. This is equivalent to a 7.5kW solar power system. Solar output is dependent on the irradiance at any geographic location.
Homemounted solar panels normally have individual power ratings from 175 watts to 400 watts.
Smaller panels below 200 watts tend to be used for smaller projects, such as battery charging, emergency power supplies, RVs, or garden structures like pergola roofs.
For this example I’ll use 200 watt panels with an average irradiance value of 4 peaksunhours.
A 200 watt solar panel will produce:
4 x 200 = 0.8kWh/day
If we divide 50kWh by the daily energy generation we get the number of solar panels required:
50kWh/0.8kWh = 62 solar panels @ 200 watts rating each
Total solar power needed is 12.2kW.
Note: Solar system losses of up to 23% means that extra capacity should be added to ensure the target kWh is comfortably achieved.
How many kwh per day does a 5kw system produce?
A 5kW solar power system with an average irradiance of 4 peaksunhours per day will theoretically generate 20kWh per day. This assumes clear skies with no shading and will vary according to location. In practice, a 5kW system may produce less than this, as solar losses reduce the power output.
5000 watts (5kW) of solar power is just about the average size of a US domestic solar system and represents 17 solar panels @ 300 watts each.
The energy output of any solar power systems depends on the sun’s energy, or irradiance, and this varies from state to state.
For example, the irradiance in peaksunhours in Arizona is 3 times more than in Alaska, so the difference can be very big. For most purposes, and estimate using an average irradiance value of 4 peaksunhours gives a good idea of solar output.
(Note: Peaksunhours is a convenient way of expressing irradiance, which strictlyspeaking, is measured in kWh/m2/day (or year.)
How many solar panels to produce 10 kwh per day?
With a typical irradiance of 4 peaksunhours 13 solar panels rated at 200 watts each are required to produce 10kWh per day. This is a 2.5kW solar power system. Solar output will vary according to the irradiance for any geographic location.
I’ll stick with the 200 watt panels used in the last example and average irradiance of 4 peaksunhours.
I already worked out that a 200 watt solar panel can generate:
4 peaksunhours x 200 watts = 0.8kWh/day
Dividing 10kWh by the 0.8kWh/day we will find the number of solar panels needed:
10kWh/0.8kWh = 12.5 (13) 200 watt solar panels
The total kW needed is 2.5kW.
Note: Remember to increase the overall capacity of the solar array to take into account the 23% solar system losses commonly associated with domestic solar systems.
Resources relating to how many kWh solar your roof can generate:
How Much Solar Power Can My Roof Generate? – Sunrun
How Much Energy Does A Solar Panel Produce?  EnergySage
How much energy do solar panels produce for your home
How Much Power (Watts) does a Solar Panel Produce?