Thanks to record low solar prices an 8kW solar system is now the average size system we are installing. Let’s have a look at a few of the key numbers including the price of an 8kW solar power system and the brands that should be considered for a system of this size.
Price of an 8kW Solar System In 2021
Despite what you might see advertised, a good quality 8kW solar power system starts at around $7,000-$8,000 fully installed with the potential to save you up to around $3400 a year on your power bills. A system in this price range would include a top-quality European inverter such as the SMA Tri-Power inverter, premium solar panels such as Trina Honey 370W 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 cheaper 8kW solar systems on the market, however, this will typically require buying low or mid-range panels manufactured in China, and often without any after-sales support.
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 has full-service warranties and our systems include full technical support. This gives our customers the peace of mind that if something goes wrong – it will be fixed. Not a single Solaray customer over 10 years has ever had to remove one of our systems because it isn’t working.
As a rough guide, an 8kW system can save you up to around $3,500 a year on your power bills.
Of course, to save $850 on a quarterly bill you are going to need to use a lot of power during the daytime – as much as 40 kWh during the daytime over summer. If you are able to get the most out of your 8kW system, you could spend up to $16,000 and get a top of the range system with a return on your investment in less than 5 years!
The output of an 8kW Solar System
According to the Clean Energy Council guidelines, an 8kW solar system in Sydney facing north will produce an average of 32 kWh a day, outputting more power in summer and less in winter.
Typically the peak output of an 8kW solar system will be around 6-7kWh during the middle of the day, and it will vary depending on the weather. This is a good example of output across the day with a system of this size when there is patchy shade from clouds:
We have found that this guideline of 32kWh from the Clean Energy Council is a conservative estimate and that by using the top brands you can get considerably more out of a system.
For example, our Enphase systems give our customers on average 110% of expected output. On an average day in summer, an 8kW system will often give our customers over 40 kWh of power. If this ends up being too much power for a household, we recommend considering battery storage so that any excess solar power can then be used during the evening.
The Key Numbers
|Number of Panels||22 x 370W Panels|
|Output||32 kWh a day average (see below)|
|Potential Savings||$700 - $850 a bill depending on your cost of power|
|Average Payback Period||3 to 5 years|
|Cost||From around $7500 to around $13000|
|Repayments||From around $200 a month over 5 years*|
|Suited to||Medium to large homes using on average around 32 kWh a day during the daytime (or over 24 hours with battery storage)|
* Repayment numbers can vary depending on a number of factors and are an estimate based on a 5-year term. 3-to-7 year terms are available. More information is available here: Solar & Storage Finance
How much will an 8kW solar system save me?
The potential savings of an 8kW 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 28 cents a kWh + GST (depending on how much you pay for your power) for every kWh of solar power used in the home.
Depending on your retailer, you will be paid a feed-in tariff of around 5-12 cents a kWh for the power you send back to the grid.
Based on this, an 8kW solar system can save you up to around $700 to $850 per quarterly bill.
More information about how solar power can save you money is available here: How Solar Power Reduces Your Power Bill
Number of solar panels for an 8kW 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 22 x 370W panels instead of the standard 300W panels.
8kW 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 micro-inverters 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 customer now decide to install this technology.
Find out all you need to know about Enphase: 10 key benefits of microinverter systems.
8kW 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. Enphase solar systems now allow us to limit the amount of excess solar power your system sends to the grid. This means you are no longer limited to a 5kW solar system. Here are a few options for a home with single-phase power 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 5kW single-phase string inverter with a 6.6kW 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. Revolutionary Enphase technology has completely changed the game for single-phase houses in NSW. Up until recently, we could only install a 5kW system, however thanks to export limitation we are now able to use an Enphase system and limit the amount of excess solar power that is sent out to the grid. This allows us to install up to a 10kW solar array, powered by Enphase.
Request a callback today for more information and personalised pricing: