Ever wondered how much electricity does one solar panel produce in a day, In this article we will see how much electricity does one solar panels produce and how many solar panels will your house need to completely offset your electricity bill.

On an average during sunny days 1 kilowatt(kW) of solar panels generate 4 KWH (units) of electricity in a day.

1 kW of solar panels is equal to 3 solar panels each of 330 watts.

So we can say one solar panel approximately produces 1.33 units of electricity in a day, 40 units of electricity in a month and 480 units of electricity in a year.

Factors Affecting Solar Panels Generation

Before we dive deep into calculating the power generation of one solar panel there are three major things that we need to understand which affects the power generation of solar panels.

1. Geographical Location – If you live in countries where there are more sunny days than the average electricity generation will be more for you. I live in Mumbai, India here we receive at least 5 sun hours daily for 300 days in a year, hence one solar panel produces more power in Mumbai in comparison to areas which receive 200 days of sunlight.
2. Type Of Solar Panel Used – For residential and commercial purposes there are mainly two types of solar panels that are commonly used, mono crystalline and poly crystalline solar panels. To keep it short mono crystalline have more efficiency than poly crystalline (about 2 -5 % more), which means it convert 2-5% more sunlight into electricity. It also has good low light generation. You can read more on types of solar panel over here – Types of Solar Panels.
3. Installation Parameters: If your solar panels are not properly oriented, not given proper inclination and installation is done in shadow affected area then the overall generation will be hampered big time. Also after installation cleaning plays a major role in maintaining the solar panels generation to expected level.

So now we know the parameters that play vital role in solar panels generation, we can calculate the power generation of one solar panel.

How much electricity does one solar panel produce

Before we start with the calculation lets get used to some basics terminology

• Watt and kilowatt are units of power. It basically shows the rate at which power is consumed by a device. For example a 100 watt TV will consumes power at a rate of 100 watts per hour. 1 kilowatt = 1000 watt.

• Kilowatt hour is the actual energy consumed by the device in an hour. For example a 100 watt TV running for 24 hours consumes 100 watt x 24 hours = 2400 watt hour or 2.4 kilowatt hour of electricity a.k.a 2.4 units of electricity.

For more detailed explanation check this article – What is watt, kilowatt and unit of electricity?

On an average in India we receive 5 sun hours in a day so the total power generated by 1kW of solar is 1 kW x 5 hours = 5 kilowatt hour (KWH).

This is an ideal figure which considers uniform solar irradiance throughout the day, proper installation with best orientation, angle of tilt and no shadow impact on solar panels for 5 hours without any dust accumulation on surface.

If we calculate for ideal condition then average monthly power generation from solar panels will be 5 KWH X 30 Days = 150 KWH of electricity.

But not all days are equal some day we will get sunlight some day we won’t, some days the panel will be clean and some days they won’t be, hence we will assume 20% loss of power which gives us average daily generation for 1 kW solar panels to be 4 KWH of electricity and monthly generation to be 120 KWH of electricity.

As we know 1 kW of solar panel has 3 PV panels each of 330 Wp, hence each solar panel generates 1.33 KWH of electricity in a day and 40 KWH of electricity in a month.

Now we know how much power a single solar panel generates lets find out how many solar panels you will need to power your house.

How many solar panels does a house needs?

To calculate your solar requirement you have to perform the following steps

1. Look into your latest electricity bill and take an average of your last 12 months power consumption. The values should be on the electricity bill. if you can’t find it there open the electricity provider website you will find it there.
2. Once done with finding your average monthly consumption, divide that figure with average monthly generation from 1 kW of solar panels (120 KWH).
3. This will give you the kilowatt of solar panels required for your house. Then divide the KW with wattage of individual solar panel you will find the total number of solar panels needed for your house.

Lets see an example to get the idea crystal clear.

You look into your latest electricity bill and find out monthly consumption for the last 12 months is as follows – 500,120,300,400.600.550,100,800,600,300,450,400.

Lets take an average of these 12 values to get average monthly requirement of power.

Average = Sum of values / No of values.

In our example sum of values = 5,120

No of values = 12

Hence average is 426.66 KWH

So your house needs on an average 427 KWH of electricity every month.

Now we know that average monthly generation of power from 1 kW of solar is 120 KWH (Assuming you live in an area where there are 5 sun hours in a day and 300 such days)

Therefore your solar requirement is 427/120 = 3.55 kW.

If we assume you are planning to use 330 Wp of solar panel then no of solar panels required to power your house with solar will be 3550/330 = 10.75.

We can round it of to 11 solar panels each of 330 watts.

This calculation is for a solar on grid/solar net metering system. The calculation will differ for an off grid solar system.

To calculate your house solar requirement more accurately and select which type of solar system you should opt for read this article – Solar system Sizing For House (Ultimate Guide)

Conclusion

To conclude this we can say that one solar panel off 330 Wp produces 1.33 KWH of electricity in a day, 40 KWH of electricity in a month or 480 KWH of electricity in a year.

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Go Green Go Solar !!