Solaray Energy is now called 1KOMMA5° Sydney and 1KOMMA5° Melbourne
Thanks to record low prices and generous government incentives, it is now becoming common for a family household to install a 10kW solar system for under $9,000.
However, nearly all of our customers choose to buy a system with panel-level optimisation for larger residential systems due to the significant benefits to do with system management, monitoring, performance and longevity.
Let’s have a look at a few of the key numbers including the price of a 10kW solar power system, and the brands you should be considering for a system of this size.
The price of a fully installed 10kW 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 10kW solar power system in Sydney starts at $10,000 fully installed, including a SolarEdge inverter, premium tier-one solar panels such as Trina Vertex 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° Solar. These top-of-the-range systems with Enphase Microinverters are around $13,000.
It is possible to find a cheaper 10kW solar system for under $8,000 or so, however, this will typically require buying cheap panels manufactured in China, and they often come without any after-sales support.
For a larger residential system, it is important to maximise reliability, output, and of course longevity, so spending a little more upfront can save you a lot of money over the life of the system.
1KOMMA5° Sydney and Melbourne's full-replacement warranties 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 10kW system can save you up to around $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 65kWh during the daytime in summer. Because of this, most of our customers are now looking to include battery storage with their solar panels. If you are able to get the most out of your 10kW system, you could spend $14,000 and get a top-of-the-range system with a return on your investment in well under 5 years.
A 10kW solar system with battery storage will often be enough to completely eliminate a household’s power bills.
A 10kW solar system with Tesla Powerwall battery storage starts at $22,500, fully installed. This includes a good quality solar system using Trina Vertex panels and a string inverter. A 10kW Smart Solar System from Enphase with battery storage starts at around $26,000, fully installed.
According to the Clean Energy Council guidelines, a 10kW solar system in Sydney facing north will produce an average of 39 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 a sunny day in summer, a 10kW system will often give our customers between 60 and 70 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.
|10kW Solar System
|The Key Information
|Number of Panels
|24 x 415W panels or 23 x 430W panels
|39kWh a day average (see below)
|$700 to $1000 a quarter, depending on your cost of power
|Average payback period
|3 to 6 years on average
|From around $10,500 for a top quality system with SolarEdge, or from $13000 using Enphase
|Medium to large homes using on average around 40 kWh a day during the daytime (or over 24 hours with battery storage)
The potential savings from a 10kW 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 5-8 cents a kWh for the power you send back to the grid. A 10kW solar system can save you up to around $700 to $1000 per quarterly bill.
More information is available here: How Solar Power Reduces Your Power Bill
The larger the system, the more important it is to buy quality panels to ensure you maximise reliability, increase output in all weather conditions, and ensure the longevity of the system.
The other consideration is roof space. By installing high-efficiency panels, we can use 24 x 415W panels instead of the standard 300W panels.
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 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.
If your roof is unobstructed by shade and can fit 28 to 38 panels across 1 or 2 sections of the roof, a string inverter system may be a suitable option for your home. It is important to make sure the roof is clear of shade as if even just one panel is slightly shaded, the whole string of panels will drop down to the output of the worst performing panel. Typically with a 10kW system, there will be two strings.
With a number of manufacturers recently disappearing, it is critically important that you stick to the main brands when choosing an inverter of this size. This will also ensure adequate support post-sale in the event that you need to make a warranty claim. The main European 10kW inverter is the SMA Tri Power which comes with a 10-year warranty.