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The Price of a 4kW Solar System

A 4kW solar system in Sydney is a great sized solar system for a medium-sized home. A 4kW system typically has a 12-14 panel array and can save you up to around $400 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 3 to 5 years using top quality brands. This article will look at the benefits of installing a 4kW 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.
Tom Sedgwick
Updated at
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3 min

4kW Solar System Price

As a price guide, a good quality 4kW solar system in Sydney will cost around $5000 to $6000 fully installed, or around only $105 a month over 5 years. This would be using the best panels from a Chinese brand such as Trina Solar and a top of the range string inverter from Sungrow. Expect to pay up to $1,000 on top of this for the latest solar panel technology that will give you around 350W per panel. These price estimates are after the government rebate of approximately $2500 and are fully installed and grid-connected excluding metering. 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 are now Smart Solar Power Systems using the latest technology from Enphase. Enphase microinverters allow for panel-level output and the best online monitoring platform available for households. More information on smart solar is available here: 10 Key Benefits of Smart Solar Systems

Of course, these price estimates 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.

The government rebate on a 4kW system is currently $2500 based on the STC price of $36. The above prices are after the rebate (the price you pay). The STC price can change overnight so please only take these figures as a guideline. When you place an order we lock in your STC price so if you are worried about the government changing the rebate scheme as a part of the renewable energy target, placing an order will remove this risk.

4kW Solar System Output

According to the Clean Energy Council Guidelines, A 4kW solar system in Sydney will output around 16 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 16 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 $500 to $800 (up to around 30 kWh a day excluding any off-peak hot water) to make good use of a 4kW system:

4kW Solar System Output

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 at around 10 am how shade from clouds immediately results in a drop off of solar power, and that even in autumn the system will continue operating until nearly 7 pm if you have the panels installed to catch the late afternoon sun.

4kW Solar System Output

The most important point to take away from this image is that a 4kW 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 as a split system on a tile roof with a normal pitch of about 20 degrees. There are 6 panels installed west and 10 panels facing north. This helps extend the output into the late afternoon, as seen in the graph above. 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 these panels installed at 20 degrees, the output will be higher than average in spring and autumn and slightly lower than average in summer and winter. The peak output on this system during a sunny March day is only 3.15 kW, however, even in March, this 4kW system will typically produce between 20 to 22 kWh a day, much higher than the Clean Energy Council guideline of 15.6 kWh.

1KOMMA5° is the largest and most experienced installer of Enphase Systems in NSW, and our expertise ensures your system is installed in a manner that optimises output and system performance. The performance of our Enphase portfolio is on average 110% of expected output, including systems that are installed on shaded roofs. This real-world performance is why thousands of households in NSW choose 1KOMMA5° for their solar installation.

4kW Solar System Split Array

Do you want this level of system monitoring? 1KOMMA5° is the number 1 installer of Enphase Micro Inverter Systems, and our systems come with full system monitoring free for the life of your system.

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


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