As solar system prices continue to fall, the average system being installed in Australia in 2023 is currently from around 5kW to 10kW. Despite this, a 3kW solar system can be a great system for a small to medium-sized home, either with limited roof space or low day-time energy consumption.
The cost of a 3kW solar system varies a lot depending on the brands, with the price of a good quality solar system starting from around $4,500-$5,500 fully installed. A smart 3kW solar system powered by Enphase is around $300 more expensive, and we also recommend looking at high-efficiency solar panels from LG Solar.
Talk to the Solaray Team today for more information and personalised pricing.
A 3kW system typically has a 10-panel array and can save you up to around $300 a quarterly power bill if all of the solar power is used in the home. As solar prices continue to fall, it is now possible to get a return on your money in 4 to 5 years using top-quality brands!
The Price of a 3kW Solar System
As a price guide, a good quality 3kW solar system in Sydney will cost from around $4,500 for a simple installation, or around $85 a month over 5 years using good quality panels from China such as Trina Honey Modules, and a European-made inverter from SMA.
Expect to pay up to around $5,000 to $7,000 for a ‘smart solar system’ including a top-of-the-range high-efficiency panel such as the REC Alpha Pure module and panel-level output using Enphase MicroInverters.
This is after a government incentive of around $1500, and it is fully installed and connected to the grid. Our price is always a fully inclusive price, subject to confirmation by our system designers who will often need to conduct a site inspection.
Over 80% of our installations now feature panel-level output, powered by Enphase. Of course, these prices will depend on a number of factors, which our solar team can confirm with you either over the phone or during a site inspection when required.
This article will look at the benefits of installing a 3kW system, the main brands you should be looking at and provide detailed information to make sure this size system is the right fit for your household.
Is A 3kW Solar System Enough?
For a few years now, we tend to only install a 3kW solar system if we are limited by roof space. For almost all households, a 3kW solar system will not be large enough to cover your home’s energy usage. The average-sized solar system we are now installing is closer to 8kW, with most households choosing to install at least a 6kW system.
We have had a few people tell us they are worried the solar industry is trying to up-sell them when they first enquire about a 3kW system. A good analogy would be to consider someone walking into a computer shop and asking for a computer that was a great option back in 2015. If the 2015 model was still available, but only a little bit cheaper, it isn’t in the customers’ best interest to buy the older computer.
3kW solar systems were common a few years back when solar was a lot more expensive, and when panels were a lot less efficient. Not only has the price per panel plummeted in recent years, but the efficiency of the panels has also improved significantly. The standard residential panel has increased from 250W to 415W, while the price per panel has fallen.
In fact, the price of solar per kWh generated by a solar system is actually cheaper than the feed-in tariff offered by most energy retailers. This has resulted in a huge shift in the systems people are buying to the point where a lot of our customers are literally filling their roofs with panels.
Other reasons why solar systems are now much larger than 3kW:
- The larger the system, the larger the government rebate. This means that the increase in price for the larger system is partially offset by the government incentive that comes directly off the purchase price
- Many households are planning to buy a plug-in hybrid or electric car within the next 10 years. Having a larger solar system means excess solar power can be used to charge the car during the daytime
- Battery storage is now the norm, and most households will have battery storage as a part of their solar system in the coming years. Ensuring the solar system is sized to your 24-hour usage ensures the system is battery-ready
The Output of a 3kW Solar System
According to the Clean Energy Council Guidelines, A 3kW solar system in Sydney will output around 12 kWh a day (averaged out across the year), outputting more on the long summer days, and less in winter. It is important to understand that this 12 kWh of solar power will be produced during daylight hours, and typically as a bell curve as illustrated below. Depending on how much power you use during the day, typically you would want to have a quarterly power bill of around $400 to $600 (approx. 24 kWh a day excluding any off-peak hot water) to make good use of a 3kW system.
A solar system will peak when the sun is shining directly onto the panels, so for an array facing north, this will be for approximately 4 hours during the middle of the day. You can see in the graph how shade from clouds immediately results in a drop off of solar power, and that in summer the system will continue operating until nearly 8 pm if you have the panels installed to catch the late afternoon sun.
An important point to take away from this image is that a 3kW system will almost never reach its peak output. For that to happen, it has to be the right time of the day and the right time of the year. In this example, the system is installed on a tile roof with a normal pitch of about 20 degrees.
In Sydney during summer, panels that are installed flat will be working at their peak efficiency because the sun is so high in the sky. For this system installed at 20 degrees, the peak output will take place in spring and autumn. So as we can see, the peak output on this system during a sunny December day is only 2.37kWs.
But here is the beauty of buying a quality system that is installed and designed by our experts here at Solaray – total system output for the day was 19.9kWs, well above the average. In fact, over the life of this system, it is outputting around 130% of the expected figures, which is fairly typical for our installations.
Reducing Your Power Bill With A 3kW Solar System
With a good quality solar system, you can expect to significantly reduce your power bill if you are able to use around 70% or more of the solar power as it is generated.
*Savings are based on 70% or 100% of solar power being used in the home as it is generated, an average cost of electricity of $0.28 + GST, and a feed-in tariff of $0.12 per kWh. Prices assume a 3% rate of inflation. The output is based on Clean Energy Council Guidelines for an unshaded north-facing roof. All figures are indicative only and are not specific to your system or household.
The Benefit of a 3kW Solar System
A 3kW solar system in Sydney facing north with no shade will output around 4,271 kWh a year according to the Clean Energy Council Guidelines. That works out to be around 11.7 kWh a day as an average. Based on our own output figures taken from thousands of systems across Sydney, our opinion is that this figure is a conservative guideline.
If you are on time-of-use billing and you pay an average of around 35 cents a kWh for your power, a 3kW system will save you up to $1,281 a year off your power bills. This can be even higher if you have your panels facing west of north.
If you pay a flat rate for your power, for example, 28c a kWh + GST, a 3kW system will save you up to around $37,000 over the life of your system. If you don’t use the solar power as it is generated, the solar power will automatically go out to the grid, and you will often be paid a feed-in tariff for this power by your energy retailer. Typically, this FIT is around 12c a kWh and it will come off your power bill as a credit.
3kW Solar Panels
As technology improves we are now seeing high-efficiency panels drop in price, such as the LG Solar NeON 2 panel, while the Trina Split Cell Range is proving to be the best-value option on the market in Australia. This means that for a 3kW Solar Installation in Sydney, Solaray designers are putting together 9-panel arrays, either in series with a string inverter or as a 3kW Micro Inverter System.
3kW Solar Inverters
3kW Micro Inverter System
Solaray is the largest installer of Enphase Micro Inverter systems in Australia, 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 arrays in different orientations and at different angles. A common panel layout is to have some panels facing north, and the others west – to spread out the output of solar power across the day, making it easier to use most of the solar power as it is generated. Having panels west is also advantageous if you are on time-of-use billing, where you typically pay around 50c per kWh between 2 pm and 8 pm for your power.
More information: Smart Solar powered by Enphase
3kW Standard Solar Inverter
If your roof is unobstructed by shade, is orientated north of either east or west and can fit 12 panels (1.7m by 1m), a string inverter system will be the best value option for your home. It is important to make sure the roof is clear of shade, as even if just one panel is slightly shaded, the whole array will drop down to the output of the worst performing panel.
An important point regarding a 3kW system using a string inverter is that it is not best practice to have split arrays. typically we like to see a minimum of 7 panels in each string as this creates enough voltage to run the inverter properly. If you give our team a call, we can run through the pros and cons of a split system, match you up with a good quality dual input inverter and try to convince you to buy an extra two panels (we will give you a good price, I promise), so that you have a highly efficient system that works really well in all light conditions.
With Solarmax disappearing, along with a long list of smaller manufacturers, it is critically important that you stick to the main brands when choosing an inverter. This will ensure adequate support post-sale in the event that you need to claim on the warranty.
The main European 3kW Inverter is the SMA Sunny Boy 3kW. This inverter comes with a 5-year warranty as standard, and you can extend it to 10 years if you register the inverter online with the manufacturer, which you should definitely do once the system is installed.
3kW SMA Sunny Boy Inverter
The SMA Sunny Boy inverter is considered the best residential string inverter on the Australian market.
More than an inverter — the new Sunny Boy 3kW is the next generation of the globally successful Sunny Boy 3000-5000TL range.
SMA Sunny Boy – Smart Connected Service
The big new feature that is included with all SMA Sunny Boy inverters is the integrated Smart Connected service, offering true ease and comfort for PV system owners. After connecting your new system to the internet, automatic inverter monitoring by SMA analyses inverter operation and immediately informs you of irregularities, ensuring optimum service and maximum system availability.
With the Sunny Boy, you as the system owner and us as the installer are always up-to-date. Additionally, thanks to current communication standards, intelligent energy management and SMA storage solutions can at any time be flexibly added to systems with the Sunny Boy.
Interested in more information: SMA Sunny Boy Inverters
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