The Price of a 4kW Solar System

4kW LG Enphase 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.

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 China such as Trina Honey Plus 310W modules and a top of the range string inverter from SMA. 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:

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.

4kW Solar System Split ArraySolaray 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 Solaray Energy for their solar installation.

Do you want this level of system monitoring? Solaray 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. Find out more – Enphase Micro Inverter Systems

4kW Solar Systems in Sydney

Standard residential solar panels have been improving rapidly. LG is now offering 345W & 370W panels, and as technology improves we are now seeing high-efficiency panels drop in price. The Trina Honey Range now has a 310W panel as standard. This means that for a 4kW Solar Installation in Sydney, Solaray designers would be putting together 11 to 15-panel arrays, either in series with a string inverter or as a 4kW Micro Inverter System powered by Enphase.

4kW Micro Inverter System

Solaray is the number one 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 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.

Enphase Micro Inverter Systems

4kW String Inverter System

If your roof is unobstructed by shade, is orientated north of either east or west and can fit 16 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 4kW system using a string inverter is that typically we need to have a minimum of 7 panels in each string as this creates enough voltage to run the inverter properly. If you are looking to split a 4kW system into two strings, we will need to have a minimum of 7 panels in each string. 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, so that you have a highly efficient system that works well in all light conditions.

With Solarmax recently 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 4kW Inverter is from Fronius. Both of these inverters come with a 5-year warranty as standard, and yes, you can extend it but most of the time we recommend you save your money and stick with the 5-year option due to the bathtub curve.

4kW Solar System Kellyville

The benefit of a 4kW Solar System

A 4kW solar system in Sydney facing north with no shade will output 5694 kWh a year according to the CEC guidelines. That works out to be around 15.6 kW/h a day as an average. This is a guideline published by the Clean Energy Council. Based on our own output figures taken from thousands of systems across Sydney, this figure is considered to be a conservative guideline.

If you are on time of use billing and you pay an average of 30c a kW/h for your power, a 4kW system will save you up to $1,708 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, 26c a kW/h, a 4kW system will save you up to $1,480.

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 5c to 8c a kWh and it will come off your power bill as a credit.

A Bonus Tip

With solar prices so low these days, we find many customers buying 5kW systems or larger even when their quarterly power bills are less than $600 – the average size system we are currently installing is over 5kW. By installing extra capacity and taking advantage of generous government rebates, we see many households increasing their power usage to invest in their lifestyle by running pool pumps, air conditions and even spas from solar power. As solar batteries become more popular, installing a large enough solar array to power your house from solar power 24 hours a day ensures you are 100% ready to invest in batteries when you choose to do so. Please contact us for more information about battery-ready solar systems to discover what your options are, as not all systems are easily expandable.

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4kW Trina Enphase Bondi Beach

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