Solar Panel Output Calculator

Use this solar panel output calculator to find out the total output, production, or power generation from your solar panels per day, month, or in year.

Also, I'm gonna share some tips to get the maximum power output from your solar panel. And the factors which will affect the output. 

Solar Panel Output Calculator

Total Solar Panel System Size
Peak Sun Hours (Per Day)
Output in (Per Day, Month, Or A Year)

Note: Divide the solar power output value (Wh) by 1000 to convert it into kilo-watt hours (kWh).


  • There will be 20% system losses due to various reasons. Like changes in weather conditions or power loss in the charge controller, wiring, etc.

How to use the Solar panel Output calculator?

  • Total solar panel size: Enter the total size of your solar panel system (eg. 4 200w solar panels 4*200= 800w solar system)
  • Peak Sun Hours: These are not the number of daylight hours, to calculate how many peak solar hours your location receives keep reading…

Watt-hour or Wh is the total energy in a given time period

Peak Sun Hours (PSH)

When the sunlight intensity reaches an average of 1000 watts per meter square (1kw/m2) is called pean sun hour (PSH).

Solar panels are tested and rated their power output under standard test conditions (which I’m gonna discuss in a bit in detail).

These conditions include 1000 watt per meter square of sunlight intensity (1kw/m2)

So we use peak sun hours as a baseline when estimating how much power output we can expect from a solar system in a specific location.

The intensity of the sunlight will be different from location to location and also throughout the day

For Example

  • 1.2 Peak sun hour (Noon) = 1200w/meter2 sun intensity
  • 0.2 Peak sun hour (Morning time) = 200w/metersun intensity

How To Calculate Peak Sun Hours

Don’t worry some geniuses have worked for years to make it easy for us to calculate the peak sun hours according to our geographic location

Use this PV solar calculator to calculate the total sunlight intensity your house receives.

Step 1:

How to calculate peak sun hours

Step 2:

How to calculate peak sun hours

Now you’d be able to see how much total solar radiation your house receives per day (month to month)

How many peak sun hours in florida?

Note: I live in Florida city, On average, we receive about 5.87 hours of peak sun hours (5.8 kW/m2 of sunlight intensity) per day. So, I would have to place my solar panels all day long (under the sun) to get those peak hours.

Average solar panel output per day?

Solar panels are designed to produce their rated power under Standard Test Conditions – STC.

STC includes: 1000 watts per meterof sunlight intensity, no wind, and 25oC temperature.

But in real-world conditions, on average, you'd receive about 80% of its rated power during peak sun hours.

I ran a test and collected the 30 days of output data from my 400W solar panel system (in April). The average output per day i receive was about 2.2kWh with 6.95 peak sun hours per day. Which is about 80% of their rated power number.

20-30% power loss or inefficiency will occur due to various reasons, like…

Example of power losses in the solar system

  • Manufacturer’s output tolerance (+-3%)
  • Dirt and grime on panels (+-5%)
  • DC cable loss (+-3%)
  • Temperature derating (+-10 – 20%)
  • Charge controller efficiency (+-2 – 20%)

DC vs AC Output

Solar panels produce power in DC (Direct Current). But to run most of our household appliances we need AC (Alternating current).

To convert DC into AC we use an inverter. And inverters are mostly 90% efficient. So a 10% power loss will occur when converting solar DC into AC power.

Related: Solar DC Watts To AC Watts Calculator

How Much Power Does a Solar Panel Produce

How Much Power Does a Solar Panel Produce
How Much Power Does a Solar Panel Produce?

How much power or energy does solar panel produce will depend on the number of peak sun hours your location receives, and the size of a solar panel. just to give you an idea, one 250-watt solar panel will produce about 1kWh of energy/electricity in one day with an irradiance of 5 peak sun hours.

Here’s a chart with different sizes of solar panel systems and their output per day and per month with 5 hours of peak sun sunlight

Solar Panel System SizeEstimate Power Output
(Per Day)
Estimate Power Output
(Per Month)
100 watt400 Wh12 kWh
200 watt800 Wh24 kWh
250 watt1 kWh30 kWh
300 watt1.2 kWh36 kWh
370 watt1.4 kWh44 kWh
400 watt1.6 kWh48 kWh
500 watt2 kWh60 kWh
600 watt2.4 kWh72 kWh
700 watt2.8 kWh84 kWh
800 watt3.2 kWh96 kWh
900 watt3.6 kWh108 kWh
1 kW4 kWh120 kWh
1.5 kW6 kWh180 kWh
2 kW8 kWh240 kWh
2.5 kW10 kWh300 kWh
3 kW12 kWh360 kWh
4 kW16 kWh480 kWh
5 kW20 kWh600 kWh
6 kW24 kWh720 kWh
7 kW28 kWh840 kWh
8 kW32 kWh960 kWh
9 kW36 kWh1080 kWh
10 kW40 kWh1200 kWh

table: How Much Power Does a Solar Panel Produce


  • 100-watt solar panel will produce around 400 watt-hours of power per day with 5 hours of peak sunlight
  • 200-watt solar panel will produce around 800 watt-hours of power per day with 5 hours of peak sunlight
  • 400-watt solar panel will produce around 1 kilowatt-hour of power per day with 5 hours of peak sunlight
  • 2kW solar panel will produce around 8 kilowatt-hours of power per day with 5 hours of peak sunlight
  • 5kW solar panel will produce around 20 kilowatt-hours of power per day with 5 hours of peak sunlight
Note! 1kw is equal to 1000 watt

How to get the maximum output from your solar system

These are some tips that you can implement to get the maximum output from your solar panels.

1- Place Your Solar Panels At a Right Tilt Angle

Tilt angle is the placement of your solar panels according to the sunlight direction.

The ideal title angle for solar panels is to add an extra 15 degrees to your latitude in the winter and subtract 15 degrees in the summer.

Need a short and simple solution? use this calculator to find out the best tilt angle for your solar panel according to your location every individual month.

2- Choose a right size charge controller

A charge controller is a device that plays a role of a regulator between the solar panel and the battery bank. it regulates the voltage and current produced by the solar panels to safely charge the battery.

Using an under-capacity and wrong type of charge controller will reduce your power output by a huge margin (up to 30%).

There are two types of charge controllers available in the market right now, MPPT and PWM.

MPPT charge controller will adjust the voltage coming from the solar panels according to the battery volts but also will increase the amps to cover up the power loss (Watts = amps*volts).

but on the other hand, a PWM charge controller will only reduce the voltage output from the solar but will not increase the amps. Which as a result can cause up to 30% of power loss.

When to use a PWM charge controller? if you’re on a budget and your solar array is up to 200W then using a PWM charge controller would be a good option and will not make that much of a difference here.

When to use the MPPT charge controller? if you’re not on a budget and wanna squeeze every single watt of solar power then an MPPT charge controller would be the way to go also if your solar array is above 200 watts then using an MPPT charge controller would be the best option.

and also if the voltage of solar panel and battery is different (e.g 24v battery and 12v solar panel then using a PWM charge controller will be a really bad choice).

What size charge controller should I use? to calculate the size of the charge controller for your solar panels use this formula (Charge controller size = Solar panel capacity (W)/battery volts). But I would advise adding some extra space like about 20% for safety reasons.

Read More: Use this guide to figure out what size charge controller is the best suit for you

This guy has explained MPPT vs PWM charge controller in a very simple way for beginners.

3- Use the right size (Guage) for your solar panel system

Every wire size has a limit of current that it can pass. When you use an under-capacity wire, with your solar array it will cause some power losses between 5-15%.

So to reduce those losses, use this chart to figure out what size wire will be a good suit for you.

wire gauge chart

Wire size between the solar panel and charge controller?
with the help of this formula (Amps = Solar panel watts/solar panel operating voltage) calculate the number of amps output from your solar panel or use my Solar Panel Watts to Amps calculator.

Or simply look under the solar panel specs to figure out the operating current (Imp)

Then with the help of the above charge, you would know the suitable cable size for the solar panel to the charge controller

What size wire from the charge controller to the battery bank?
use this formula (amps = solar panel watts/battery volts) to figure out the max current that a cable would have to handle

Then Look at the max current column in the chart to figure out what size (gauge) cable can handle this amount of current

What size cable for an inverter?

Use this table to select the right size cable for your inverter

What size of cable should I use with my inverter and battery?

4- Clean your solar panels from time to time

Dirt or snow on the solar panels will block the solar cells to absorb the sunlight. Which in a result will decrease the efficiency of your solar panels.

So make sure to clean your solar panel If you see any dirt on them.

Frequently Asked Questions About Solar Panel Output

How much does one solar panel produce

a single solar panel will produce on average 70-80% output of its total capacity per peak sun hour. For Example, one 370-watt solar panel will produce about 260-300 watts of output in one peak sun hours

How much power does a 20kW solar system produce per day?

A 20kW solar system will produce about 80kWh of DC power per day in 5 hours of peak solar sunlight. With an average of 80% output of its total capacity in one peak sun hour

How many kWh does a 7kW solar system produce per day?

A 7kW solar system would produce about 28kWh of DC power per day in 5 hours of peak solar sunlight with an average of 80% output of its total capacity in one peak solar hour

How much power does a 10kW solar system produce per hour?

A 10kW solar system would produce about 40kWh of DC power per day in 5 hours of peak solar sunlight with an average of 80% output of its total capacity in one peak solar hour

How much does a 12kW solar system produce per day?

A 12kW solar system would produce about 48kWh of DC power per day with an average of 80% output of its total capacity in one peak solar hour

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Chris Tsitouris is a renewable energy professional with 10+ years of experience as Director of Engineering at Solar Spectrum, previously working as Project Manager at SunPower and Energy Analyst at the National Renewable Energy Laboratory. As a thought leader, Chris has authored numerous articles and research papers.

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