How many solar panels do I need For a 5kw system?

Updated: December 6, 2023

To install a 5kw solar system using the most common 320W solar panel, you will need 16 panels total.

16 panels x 320w = 5120w or 5.1kW.

They measure 170cm x 100cm and when set up together in an array they cover 27m2 of roof space.

16 solar panels needed for a 5kW System

Roof space required = 27m2

If you have limited roof space you can go with a higher quality panel that puts out 370w per hour per panel. In this case, you will only need 14 panels saving you almost 24m2 of roof space.

how many panels needed for a 5kW solar system

How much does a 5kw system cost?

The average price Australia-wide for a 5kW system is $5,655 installed. This price can vary depending on the state you live in as government rebates vary and the quality of the system you have installed.

The real price range is $4,900 – $7,900 across all states. If you are getting quoted a price higher than that I would shop around as there are probably better deals out there.

Please check our 5kW solar system cost guide for more details on prices and options.

This is what it would look like on a roof

5kw solar on roof

How much roof space do they need?

Here you can see that a regular 5kW system with 20 panels takes up 32m2 of roof space. Normally you would run them in two rows 10 panels on top and 10 on the bottom.

You can run them in different configurations and if you have an odd-shaped roof, you might be able to split them up into batches depending on the orientation of the various sections of the roof.

How much power will a 5kw generate per day?

On average the 5kw solar system if installed correctly and facing the right direction it should generate a minimum of 20kw-22Kw per day. But weather conditions can also affect the amount of power generated in a day.

It’s called a 5kW system because that is the maximum amount of power it can produce at its peak per hour. This will only happen for about 1-2 hours of the day when the sun is highest in the sky.

Outside those hours it is still producing power to make up the rest of the 20kW for the day. Owing to the fact that the system will produce 10kW in 2 hours and only 10kW more during the rest of the day when the sun is at the wrong angle, shows you how important the orientation of the panels is.

What direction should they face?

It is advisable that the solar panels should face north all the time. This will ensure you get the maximum amount of sunlight on your panels with the natural swing of the sun through the sky during the day.

If you are unsure if your roof is suitable you can phone and speak to a local solar installer and ask them to check your roof. They will be able to go on google maps and check the orientation online.


Ben McInerney head shotAuthor: Ben McInerney is a renewable energy enthusiast with the goal of helping more Australians understand solar systems to make the best choice before they purchase. Having an accredited solar installer in the family helps give Ben access to the correct information, which allows him to break it down and make it easily understandable to the average homeowner.

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