The Price of a 6kW & 6.6kW Solar Power System

Trying to work out how much to pay for a 6kW solar system in 2020 isn’t easy – the solar market is awash with super-cheap 6kW and 6.6kW solar deals at the moment.

Unfortunately, many thousands of Sydney households are now finding themselves in a lot of trouble with these dodgy systems, and we want you to know why before you become the next victim.

Most of the 6kW solar systems you see advertised online are far too cheap – they use no-name panels, and we hear stories every week of people being left high and dry by installers who go belly-up, or simply won’t return phone calls. An incredible 1 in 5 solar systems are defected by the Clean Energy Council.

The first thing most people do when they search for a 6kW solar system is to find out the price for a full installation. Here are some typical ads you will see in your search results:

And what about this one! The bottom of the solar market just keeps getting cheaper:

If you are new to solar power, your very first online search could have you believing a good quality 6kW solar system costs between $2500 and $4000. The ads above use words like ‘premium’ and ‘tier 1’.

It all sounds great… except it’s not. $4000 is far too cheap for a good quality 6kW solar system, and by considering this price range you are descending into the murky waters of the cheap end of the solar market.

What’s So Bad About A Cheap 6kW Solar System?

From faulty components to dodgy installations and non-existent service. There are thousands of horror stories posted online, and we get dozens of calls a week from people trying to get their system back online after people give up on trying to get help from their original installer.

The strange thing is, most people know about the dangers of buying a cheap solar system. The entire industry often gets a bad wrap because of the reliability issues with these systems. They are often featured on shows such as A Current Affair:  How to avoid dodgy solar panel installation…

The largest solar installer in Australia in 2017 was renowned for selling cheap solar systems, and it came as no surprise to us when they recently went into liquidation. They have now joined more than 700 installers who have left the industry, in many cases leaving their customers high and dry.

As industry insiders say, the warranties that come with a cheap system aren’t worth the paper they are written on. If your installer and the manufacturer are no longer in business, you will be joining approximately 1 in 3 solar households now know as solar orphans.

We encourage you to read more about these cheap systems here: A warning about cheap solar systems

Why are there so many 6.6kW solar deals around at the moment?

There are a couple of regulations that have resulted in many solar companies offering a 6.6kW system. Firstly, a home with single phase power is limited to a solar system that is 5kW or less, however, the regulation is actually measured by the inverter’s output, not the panels. That means installers can over-size the panel array in comparison to the inverter. This is something that we do as well, in fact, it is a great way to maximise the output of the system.

The other part of the equation is that the Clean Energy Council has regulated at that an inverter can be over-sized by up to 133%, which means on a 5kW inverter you can have a panel array that is up to… you guessed it… 6.6kW.

Price of a 6kW Solar System

A good quality 6kW solar power system starts at around $5,500 to $6,000 fully installed (finance is also available) including a European Made inverter such as the SMA range, premium solar panels such as Trina Honey 330W modules and a standard installation (ie. no cherry pickers etc.).

It is important to note that with solar panels you generally get what you pay for, and most of our customers choose high-efficiency panels from manufacturers such as LG Solar. It is possible to find a cheaper 6kW solar system for under $5,500, however, this will typically require buying low to mid-range panels manufactured in China, and often without any after-sales support. It is then an entirely different matter to start looking at systems at around the $4000 mark.

For a larger residential system it is important to maximise reliability, output and of course longevity, and so spending a little more upfront can save you a lot of money over the life of the system. Solaray systems include full-service warranties and full technical support. This gives our customers the peace of mind that if something goes wrong you will be looked after.

As a rough guide, a 6kW system can save you up to around $2,500 a year on your power bills. Of course, to save $650 on a quarterly bill you are going to need to use a lot of power during the daytime – as much as 30 kWh during the daytime over summer. If you are able to get the most out of your 6kW system, you could spend up to $10,000, get a top of the range system, and see a return on your investment in only 4 years!

You Have Been Warned – Don’t Buy A Cheap 6kW Solar System

If you were to get 3 quotes for a good quality 6kW solar system from reputable solar installers in Australia, you would find that our prices are all within a few hundred dollars of each other. Yes, there can be slight differences, but for the most part, the quotes will be around the same price.

To put it another way, you won’t find a $7,000 6kW system ‘on sale’ for $4000. Even if you’re happy for the installer to cut a few corners (which you shouldn’t be), you simply can’t get top quality brands for that type of money.

Good quality solar panels have dropped in price to the point that it no longer makes sense to consider the bottom end of the solar market when buying a 6kW solar system. You can have the best solar panels from the world’s leading manufacturers, online monitoring, a professional installation, full technical support, and still get a return on your money in 3-5 years.

Remember, solar power is an investment that should provide clean energy & lower power bills for well over 25 years. You really don’t want issues with the system in the next 3-6 years, as this is just around the time you get your money back.

The output of a 6kW Solar System

According to the Clean Energy Council guidelines, a 6kW solar system in Sydney facing north will produce an average of 24 kWh a day, outputting more power in summer and less in winter. We have found that this guideline is a conservative estimate and that by using the top brands you can get considerably more out of our system, for example, our Enphase systems give our customers on average 110% of expected output. On an average in summer, a 6kW system will give our customers around 30 kWh of power. Because this can be too much power for many households, we often recommend considering battery storage so that any excess solar power can then be used during the evening.6kW Solar System Output

How much will a 6kW solar system save me?

The potential savings of a 6kW solar system depend on how much solar power you are able to use in the home at the time of generation. You will typically save around 22 to 30 cents a kWh (depending on how much you pay for your power), and depending on your retailer, you will be paid around 5-12 cents a kWh for the power you send back to the grid. A 6kW solar system can save you up to around $500 to $650 per quarterly bill.

More information is available here: How Solar Power Reduces Your Power Bill

Number of solar panels for a 6kW System

The larger the system, the more important it is to buy quality panels to ensure you maximise reliability, increased output in all weather conditions and the longevity of the system.

The other consideration is roof space. By installing high-efficiency panels, we can use 20 x 330W panels or 17 x 370W panels (instead of 26 x 250W panels like you see advertised).

6kW Micro Inverter System

Enphase Micro-InvertersSolaray is the largest and most experienced installer of Enphase Micro Inverter systems in NSW, and our system design team are experts at putting together a professional solar array that will maximise solar output in all conditions.

The main benefit of microinverters is that each panel is independent of the others, making it possible to design an array across different orientations and at different angles. A common panel layout is to have some panels facing north, and the others west to spread the output of solar power across the day, making it easier to use more of the solar power as it is generated. Having panels west is also advantageous if you are on time of use billing, where households typically pay around 50c per kWh between 2 pm and 8 pm for power.

On larger residential systems, the panels in the middle of the array can get quite hot during summer as airflow under the panels is less than ideal. When panels get too hot, the output can be significantly reduced. Because of this, we recommend using microinverter technology and in fact, over 80% of our systems now include this technology. Find out all you need to know about Enphase: 10 key benefits of microinverter systems.

6kW Solar System on a House With Single Phase Power

In some circumstances, it is now possible to install a system larger than 5kW on a house with single-phase power in NSW. SolarEdge and Enphase solar systems now allow us to limit the amount of power your system sends to the grid to 5 kW. This means you are no longer limited to a 5kW solar system. Here are a few options that we would be happy to talk to you about in more detail depending on your location and your specific requirements:

1. We can install a single-phase string inverter up to 5kW with a 6kW array of panels. A well-designed solar system can save you thousands of dollars and significantly increase output by oversizing the panel array compared to the inverter. Find out more…

2. If you are interested in Enphase, we can install 20 x iQ7 (5kW) Microinverters, or 17 x iQ7+ (4.93kW) Microinverters to stay under the 5kW limit. By over-sizing the Enphase micro inverters, you can install a significantly larger solar array than 5kW with, for example, 20 x Trina Honey M+ panels for a 6.2kW array, or 17 x LG NeON 2 345W panels, for a 5.86kW system. More information is available here

3. If you are using a lot of power during the daytime, or you are considering a large solar battery such as Tesla Powerwall 2, we can install a 5kW SMA system, and then oversize the inverter with a panel array of up to around 6.5 kW. An oversized panel array is a great way to maximise the benefit of your investment, and typically we can go up to 130% of the inverter’s rating. More information is available here…


  1. Lee

    I just want to know how to convert a 100kw output to kwh.
    My home uses around 1200KWh a month
    What KW would I need to produce to break even?
    Or what KW would I need to over produce?
    Nothing so far on google has hinted in that answer!

    • Solaray

      Hi Lee,
      It depends on where you live. In Sydney, a solar system will output around 4 times its size as a daily average, doing more in summer and less in winter. So if your home uses around 40kWh a day, you first need to get a rough idea of how much power you use (or could use) during the day. A 5kW system, for example, will produce around 20kWh a day as an average but do more than 30kWh a day on sunny days in summer. If you are considering batteries, then a 10kW solar system would roughly be a good fit. Give our team a call on 1300 221 586 and we can go through your options in around 10 mins or so.
      More info is also available here:

  2. Scott

    We use 1300kwh/qtr (about 14kwh/day) on a controlled load electric hot water system. If I get panels can the power be used to top up the hot water during the day, or would I need to move the heater to a normal circuit and risk paying on cloudy days?

    • Solaray

      Hi Scott,
      We generally recommend you leave the hot water on off-peak because the tariff is so much lower. The cost of off-peak electricity is often around the same as what you get paid for the excess solar power you send back to the grid. Feed-in tariffs are currently around 8-16 cents per kWh depending on your retailer and the plan you sign up for, so it can vary from house to house but it normally doesn’t make sense to touch the off-peak hot water.
      If you call the office on 1300 221 586, we’d be happy to talk it through, it would help if you had a power bill on hand so we can work with some real numbers.

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