11kW Solar Power System in Sydney Price and Payback

Thanks to record low prices and generous government incentives, it is now becoming common for a family household to install a 10kW-15kW solar system. Let’s have a look at a few of the key numbers including the price of an 11kW solar power system, and the brands you should be considering for a system of this size.

Price of an 11kW Solar System

The price of a fully installed 11kW solar power system has fallen dramatically in recent years. The wholesale price of photovoltaic panels continues to be driven down by market conditions, in particular, the increase in the scale of production in China.

A good quality 11kW solar power system starts at under $10,000 fully installed, including a European-made inverter such as the SMA TriPower, premium tier-one solar panels such as Trina Half Cell 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 11kW solar system, however, this will typically require buying low to mid-range panels manufactured in China, and often without any after-sales support. For a larger system of this size 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 service full-replacement warranties and include 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, an 11kW system can save you up to a little over $4,000 a year on your power bills. Of course, to save $1,000 on a quarterly bill you are going to need to use a lot of power during the daytime – as much as 65 kWh during the daytime over summer. If you are able to get the most out of your 11kW system, you could spend up to $16,000 and get a top of the range system with a return on your investment in only 4 years!

The output of an 11kW Solar System

According to the Clean Energy Council guidelines, an 11kW solar system in Sydney facing north will produce an average of 44kWh 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 a sunny day in summer, an 11kW system will often give our customers over 60 kWh of power. Because this can be too much power for many households, we often recommend splitting the panel array across two orientations to distribute the output of power across the day, and to consider battery storage so that any excess solar power can then be used during the evening.

11kW Solar System Output

An 11kW Solar System – The Key Numbers

11kW System
Number of Panels 30 x 370W Panels
Output 43 kWh a day average (see below)
Potential Savings $800 – $1100 a bill depending on your cost of power
Average Payback Period 3 to 5 years
Cost From around $12000 to around $16000
Suited to Medium to large homes using on average around 44 kWh a day during the daytime (or over 24 hours with battery storage)

How much will an 11kW solar system save me?

The potential savings from an 11kW 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 5-13 cents a kWh for the power you send back to the grid. An 11kW solar system can save you up to around $800 to $1100 per quarterly bill.

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

Number of solar panels for an 11kW 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 33 x 335W panels instead of the standard 42 x 275W panels.

11kW Micro Inverter System

Solaray 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.


  1. Alex Oesterreicher

    What a shame, I got excited and then noticed you don’t service Central Florida, USA… Your prices are fantastic, I am researching getting an 11kw roof system and the quote I was given last night was terrible in my opinion, $38k. So I decided to do some research online to see what the other entities out there offer. Again, I have to say, your prices seem great and I hope you keep them that way. Would be great if you serviced my area…

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