The most widely used system in Australia is 6.6kW, but they are now getting bigger. For example, solar panels typically have 390 to 420 and even up to 450 Watts per panel. So you require between 14 and 16 panels to create a 6.6kW system.
A 6.6kW solar system typically produces 24 kWh of power on average. The inverter for your home is often limited to a 5kW inverter in single-phase dwellings, which is also partially why many homes get a 6.6 kW size solar system. A decent quality 6.6kW solar system might cost between $6,000 and $9,000 after rebate once installed.
If you want more than 6.6kW, your installer, depending on which part of Australia you are in, might be required to talk to your Distributed Network Service Provider to gain permission to install an inverter larger than 5kW.
If you have three-phase power, you could install a bigger solar system or a large home battery system and a sizeable solar system (if you have the roof space) and disconnect from the grid (go off-grid).
I want a 6.6kW solar system; how many panels will I need?
6.6kW solar systems are one of the most popular size systems in Australia. A 6.6kW system is made up of panels of specific wattage. So, for example, when solar panels were 300 Watts around 2017, one would need 22 panels to make up a 6.6 kW system. For reference, 6.6 kW is the same as 6,600 watts. Today solar panels range from 390 – 450 Watts. This means you would need between 14 to 16 solar panels nowadays to get close to a 6.6kW solar system.
How much electricity can a 6.6kW solar system generate?
There is no definitive answer to this question, as several factors can increase and decrease the output of your system. These include the direction the panels face, if there is shade, and where you live. For example, a 6.6 kW system in Brisbane will generate quite a bit more than the same size system in Melbourne because Brisbane gets more sun.
In a general statement, the average electricity output from a 6.6kW solar system is about 24kWh. Our output calculator can give you more precise numbers for your specific postcode.
Another good reason why 6.6 kW systems are popular is that one can use a 5kW single phase inverter, and due to design rules regarding oversizing a system, one can add up to 6.6 kW of panels onto it. Also, in some regions, a 5 kW inverter is the most some energy distributors allow for a single phase nowadays due to grid congestion. Grid congestion means there is more than enough solar exported in the middle of the day for the grid to handle.
How much does a 6.6kW solar system cost?
After installing and applying the rebate, a quality 6.6kW solar system can vary between $6,000 and $9,000.
I want more than 6.6kW; what can I do?
If you want more than 6.6kW solar panels, your installer must talk to your Distributed Network Service Provider and get permission to install an inverter larger than 5kW. If you have three phase, usually large inverter sizes are ok.
Alternatively, you could install a large home battery system and a very large solar system and completely disconnect your home from the grid. This would stop your need to talk with your Distributed Network Service Provider, and electricity bills would be zero for years. Nevertheless, we do not recommend such a drastic step, as such an off-grid solar system would be very costly.
So maybe, if technically feasible, upgrading your home power supply to three phase might be a more realistic option. While this may also sound expensive, in the grand scheme of things, maybe a 6.6kW solar system offers the best-sized solar system in Australia today, especially for a single-phase supply.