How Many Solar Panels Do I Need For 1000 kWh Per Month?

1000 kWh per month. That’s an amount of electricity that can cover all the electricity needs of an average house. When switching to solar energy, the key question you need to figure out is this:

How many solar panels do I need for 1000 kWh per month?

If you check the data from the US Energy Information Administration, you can see that an average household in the US spent 893 kWh per month in 2020. Needless to say, setting up a solar system with 1,000 kWh capacity will eliminate your electricity bill (if you use adequate battery-based storage; that’s $131.9/month of electricity savings on average).

Calculating how many solar panels you need for 1,000 kWh per month is a two-step process. Here’s what you have to do:

  1. Determine what size solar system you need to produce 1,000 kWh per month. Such a solar system is measured in kilowatts (kW).
  2. Calculate how many individual solar panels are in a system that gives you 1,000 kWh per month capability.

Here is a standard example for a 1,000 kWh system:

Let’s say you live in an area that receives 5 peak sun hours worth of sunlight per day (annual average). To produce 1,000 kW, you will need a 9kW solar system (8.89 kW, to be exact); further on we show you how you can calculate the size of the system yourself. How many solar panels do you need?

If you use small 100W solar panels, you will need 90 solar panels to produce 1,000 kWh per month. Most homeowners use standard 300W solar panels; you’ll need 30 solar panels. If you construct your solar system with 500W solar panels, you’ll need only 18 such panels to produce 1,000 kWh per month.

Now, not everybody gets 5 peak hours. In New York, you get about 4 peak sun hours and you will need a larger than 9kW solar system and more solar panels. In California, you get about 5.75 peak sun hours and you’ll need a smaller than 9k solar system and fewer solar panels to produce an annual average of 1,000 kWh per month.

To help everybody with the calculation, we’ll show you how to calculate the solar system size for your area (and the corresponding number of peak sun hours). For easier calculation, we have designed a Number Of Solar Panels For 1000 kWh/Month Calculator that dynamically determines how many solar panels you’ll need. Here’s how it looks (you can find it further on):

After that, we will look into how many solar panels you need to construct a 1,000 kWh solar system (based on the calculated solar system size). We’ll use 100W, 200W, 300W, 400W and 500W solar panels to construct such a system; you will find all the solar panel numbers for 5 peak sun hour systems (corresponding to 9.2 kW solar system sizes) in a neat table at the end.

Be assured; all this might sound a bit complex but when you get a grip of it, it’s actually pretty simple. Let’s start with calculating how big a solar system do you need for 1,000 kWh per month before we actually determine the number of solar panels you need in your area to construct such a system:

1000 kWh Per Month Solar System Size

To determine if you need a 7kW, 8kW, 9kW, 10kW, or 11kW system, we will use this equation for 1000 kWh per month solar system size:

Solar System Size = 1,000 kWh / (Peak Solar Hours × 0.75 × 30)

1,000 kWh is the desired monthly electricity output. The 0.75 factor is to account for an average of 25% losses due to inverter loss, AC, DC cable losses, temperature losses, and so on. These losses unfortunately happen in any solar system. The 30 factor is to account for the month (30 days).

The only factor is how much sunlight you get; that is denoted by ‘Peak Solar Hours’.

Very sunny areas like California get up to 6 peak solar hours. Less sunny areas like the UK or New York get about 4 peak solar hours. As you might have realized, the number of solar panels you have to install to generate 1000 kWh per month depends on how sunny area you live in. Global Solar Atlas has a great map where you can determine the peak sun hours per day.

To help you out, we have created a calculator that determines the number of solar panels you need to produce that amount of electricity every month:

Number Of Solar Panels For 1000 kWh/Month Calculator

This calculator determines how big a solar system you need (depending on how sunny area you live in) to produce 1,000 kilowatt-hours per month. We use standard-sized 300W solar panels to create such a solar system. You just input the peak sun hours (average is 5 peak solar panels) for your area and you get how many 300W solar panels you need to produce 1,000 kWh per month:

0.00 Solar Panels

Number Of 300W Solar Panels For 1,000 kWh Per Month

 

Let’s solve two examples to illustrate how this calculator works:

Example 1: High Solar Irradiance Area (California; 6 Peak Sun Hours)

Let’s say we live in sunny South California. An annual average peak sun hours there is almost 6 per day. We can calculate the size of the solar system and the number of 300W solar panels needed to produce 1,000 kWh per month manually and with the help of the calculator.

Here’s how we do it manually using the solar output formula:

Solar System Size = 1,000 kWh / (6h × 0.75 × 30) = 7.41 kW

If we were to construct such a solar system with 300W panels, we would require 25 solar panels. That would be a 7.5 kW system, and would even produce a bit more than 1,000 kWh per month.

Let’s confirm this calculation with the calculator:

number of 300W solar panels need to generate 1000 kwh in a sunny region

As you can see, the calculator also tells us that we need 25 solar panels (300W) to produce 1,000 kWh per month in California (high solar irradiance region).

Example 2: Low Solar Irradiance Area (UK or New York; 4 Peak Sun Hours)

It makes sense that we would require more solar panels for 1,000 kWh per month in New York or the UK than in California, right? That’s because New York, for example, gets only about 4 peak sun hours per day (annual average).

Based on this, we can calculate what size solar system we need to produce 1,000 kWh per month:

Solar System Size = 1,000 kWh / (4h × 0.75 × 30) = 11.11 kW

How many 300W solar panels do we need for that? 37, in fact. Such a solar system will produce 1,000 kWh per month in New York, for example.

Let’s confirm this with the calculator:

number of solar panels needed to produce 1000 kwh in low solar irradiance region

Table With Calculated Number Of Solar Panels (100W, 200W, 300W) For 1,000 kWh A Month

Solar Panel Size (in Watts) No. Of Solar Panels For 1,000 kWh (Cold Climate; 4h) No. Of Solar Panels For 1,000 kWh (Cold Climate; 5h) No. Of Solar Panels For 1,000 kWh (Cold Climate; 6h)
100W Solar Panels 112 89 75
200W Solar Panels 56 45 37
300W Solar Panels 37 30 25
400W Solar Panels 28 23 19
500W Solar Panels 22 18 15

With this table, you can adequately estimate how many panels you’ll need to install if you want to produce 1,000 kWh per month.

If you have any questions or would need some additional calculations, you can pose a question in the comments below and we’ll try to help you out.

3 thoughts on “How Many Solar Panels Do I Need For 1000 kWh Per Month?”

    • Hi Stephen, basically, you are producing 33.3 kWh per day. You have to determine how many days of electricity you want to store. For example, if you want to store electricity for 3 days, you would need batteries that can hold 100 kWh of electricity. That’s quite a lot. For example, Tesla Powerwall hold 13.5 kWh. You would need quite a lot of batteries to hold that much electricity. Hope this helps.

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