How Many kWh Does A Solar Panel Produce Per Day?

How Many kWh Does A Solar Panel Produce Per Day?_featured image

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How Much Energy Can A Solar Panel Produce Each Day?

How many kWh can a solar panel generate a day?

As a general rule, with an average irradiance of 4 peak-sun-hours/day, 1 watt of solar panel rated power will produce on average 4 watt-hours (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 kilowatt-hours per square meter per day (kWh/m2/day).

For convenience, it’s also known as the location’s Peak-Sun-Hours 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 peak-sun-hours/day is very different from Indiana with 3/day!

See the table below to see solar panel outputs compared across US states:

TABLE: kWh produced per day by solar panels by US State compared

State

Peak-sun-hours (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

Alabama

4 (US average)

200Wh/day

400Wh/day

800Wh/day

1200Wh/day

Alaska

2.5

124

248

496

744

Arizona

7.5

375

750

1500

2250

Arkansas

3.75

187.5

375

750

1125

6

300

600

1200

1800

5.75

287.5

575

1150

1725

Connecticut

3

150

300

600

900

Delaware

4

200

400

800

1200

4.25

210

420

840

1260

Georgia

4.25

210

420

840

1260

Hawaii

4.5

225

450

900

1350

Idaho

4.5

225

450

900

1350

Illinois

3.5

175

350

700

1050

Indiana

3

150

300

600

900

Iowa

4

200

400

800

1200

Kansas

4.5

225

450

900

1350

Kentucky

3.5

175

350

700

1050

Louisiana

4.25

210

420

840

1260

Maine

3.25

162.5

325

650

975

Maryland

3.5

175

350

700

1050

Massachusetts

3

150

300

600

900

Michigan

3

150

300

600

900

Minnesota

4

200

400

800

1200

Mississippi

4.25

210

420

840

1260

Missouri

4.25

210

420

840

1260

Montana

4.5

225

450

900

1350

Nebraska

4.5

225

450

900

1350

6.5

325

650

1300

1950

New Hampshire

3.25

162.5

325

650

975

New Jersey

3.75

187.7

375

750

1125

New Mexico

6.5

325

650

1300

1950

New York

3.25

162.5

325

650

975

North Carolina

4.25

210

420

840

1260

North Dakota

4.25

210

420

840

1260

Ohio

3

150

300

600

900

Oklahoma

4.74

237

474

948

1422

Oregon

4

200

400

800

1200

Pennsylvania

3

150

300

600

900

Rhode Island

3.5

175

350

700

1050

South Carolina

4.25

210

420

840

1260

South Dakota

4.75

237.5

475

950

1425

Tennessee

4

200

400

800

1200

4.75

237.5

475

950

1425

Utah

6.5

325

650

1300

1950

Vermont

3.75

187.5

375

750

1125

Virginia

3.75

187.5

375

750

1125

Washington

4

200

400

800

1200

West Virginia

3

150

300

600

900

Wisconsin

3.5

175

350

700

1050

Wyoming

5.75

287.5

575

1150

1725

How many solar panels to produce 30 kwh per day?

With an average irradiance of 4 peak-sun-hours 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. 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:

How many solar panels to output 30 kwh per day?

Solar panel sizing – irradiance Atlanta, Georgia

Irradiance at this location is 4.634 peak-sun-hours/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 peak-sun-hours 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.

Home-mounted 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 peak-sun-hours.

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 peak-sun-hours 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 peak-sun-hours in Arizona is 3 times more than in Alaska, so the difference van be very big. For most purposes, and estimate using an average irradiance value of 4 peak-sun-hours gives a good idea of solar output.

(Note: Peak-sun-hours is a convenient way of expressing irradiance, which strictly-speaking, is measured in kWh/m2/day (or year.)

How many solar panels to produce 10 kwh per day?

With a typical irradiance of 4 peak-sun-hours 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 peak-sun-hours.

I already worked out that a 200 watt solar panel can generate:

4 peak-sun-hours 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.


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