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The Price of a 7kW Solar Power System

As power prices continue to rise, households across NSW are installing larger solar systems to cover as much of their power consumption as possible with solar. Let’s have a look at a few of the key numbers of a 7kW solar power system including the price, to see if a 7kW solar system will be a good fit for your household.
Tom Sedgwick
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3 min

Trying to work out how much to pay for a 7kW solar system in 2019 isn’t easy – the solar market is awash with super-cheap 6.6kW solar deals at the moment. Unfortunately, many thousands of Sydney households are now finding themselves in a lot of trouble with these systems, and we want you to know why before you become the next victim.

Most of the 6kW-7kW 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 7kW solar system is to find out the price for a full installation. Here are some typical ads you will see in your search results:

6.6kW System Google Ads

If you are new to solar power, your very first online search could have you believing a good quality 7kW solar system costs around $3000, maybe even less. The ads above use words like ‘premium’ and ‘tier 1’.

It all sounds great… except it’s not. This is far too cheap for a good quality 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 7kW 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 all 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 (Channel 9):  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 many industry insiders say, the warranties that come with these cheap systems 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.’

DC Isolator Fire

The Price of a Good Quality 7kW Solar System

A good quality 7kW solar power system starts at a bit under $7,000 fully installed, including an inverter from SolarEdge, premium tier one solar panels such as Trina 440W 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 1KOMMA5°. It is possible to find a cheaper 7kW solar system for under $7,000, however, this will typically require buying low to 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. 1KOMMA5° 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, a 7kW system can save you up to around $3,000 a year on your power bills. Of course, to save over $700 on a quarterly electricity bill you are going to need to use a lot of power during the daytime – as much as 35 kWh during the daytime over summer. If you are able to get the most out of your 7kW system, you could spend up to $10,000 and get a top of the range system with a return on your investment in as little as 3-5 years!

Total Savings of a 7kW Solar System

The output of a 7kW Solar System

According to the Clean Energy Council guidelines, a 7kW solar system in Sydney facing north will produce an average of 28 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 day in summer, a 7kW system will give our customers around 35-40 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.

7kW Solar System Output

A 7kW Solar System – The Key Numbers

7kW System
Number of PanelsFrom 16 x 440W Panels to 17 x 425W Panels
Output28 kWh a day average (see below)
Potential Savings$600 – $750 a bill depending on your cost of power
Average Payback Period3 to 5 years
CostFrom around $7,000 to around $10,000 for a good quality system and customer support
RepaymentsFrom around $165 a month over 5 years*
Suited toMedium to large homes using on average around 28 kWh a day during the daytime (or over 24 hours with battery storage)

* Repayment numbers are an estimate based on a 5-year term. 3-7 year terms available.

How much will a 7kW solar system save me?

The potential savings of a 7kW 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 28 to 35 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 7kW solar system can save you up to around $600 to $750 per quarterly bill.

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

Power Bill With a 7kW Solar System

* This example assumes a cost of electricity of 28 cents + GST, an average output in line with the guidelines from the Clean Energy Council, and a feed-in tariff of 12 cents per kWh.

Number of solar panels for a 7kW 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 330W panels instead of the standard 26 x 270W panels.

7kW Micro Inverter System

1KOMMA5° 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 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 weekdays.

Flexible Solar Array

Find out all you need to know about Enphase: 10 key benefits of microinverter systems.

7kW 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 power your system sends to the grid to 5kW. This means you are no longer strictly 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:

  • We can install a single-phase string inverter up to 5kW with a 6.5kW array of panels. A well-designed solar system can save you thousands of dollars and significantly increase output by oversizing the panel array by up to 30% of the inverter’s rating.

  • If you are interested in Enphase, we can install up to a 10kW solar system using Enphase IQ7+ Microinverters, or the new IQ7A Microinverter.

Request for a solar or home battery storage quote today to see how much you can save!


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