October 23, 2023

5kW Solar System in South Australia | The Basics

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Purchasing your first 5kw solar system in South Australia is a big investment. Before you make the purchase, there are important pieces of information you must keep in mind. Otherwise, you could spend more money than necessary or be in a bad position if your solar system fails.

The average cost of a 5kw solar system will be $5,000 to $7,000, and the payback period is typically between 4 to 6 years. This will depend largely on your shading, power consumption and when you use the power generated through the system.

The more you use during the day, the faster you can get your money back.

Although panel selection is important, the more important factor is choosing an inverter that is suited to your needs. 

You’re welcome to read as much as you would like on our blog, but it would be so easier if you could just have a quick 5-minute chat so you can get your questions answered.

Who are the solar panel brands I can trust?

Solar panels are an expensive investment and you want to purchase the best panels that your budget can afford. Three brands you should look out for are Q Cells and JA Solar. Each company has been developing solar panels for a long time, and have won awards for their technology.

Q Cells produce solar panels with an efficiency rating of over 20%, converting more sunlight into energy than other panels. Their monocrystalline solar panels are perfect for residential systems, and they offer a 25-year product and performance warranty. One popular solar panel that is used in residential systems is the Q.MAXX BLK-G4+, which has an efficiency rating of 20.8%.

JA Solar is a global leader in solar panel production, and their panels are cheaper than other brands. Their panels, such as their JAM60S20 365-390 V MR model, have efficiency ratings above 20% with several panels providing enough energy for a 5kW system. These panels come with a 12 year product warranty and a 25 year performance warranty.

Take the time to properly shop around and inspect different brands. Contact the manufacturers and installers if you have questions about their suitability for your property.

How many solar panels do I need to generate 5kW?

Generating 5kW of solar power requires approximately 10-14 panels generating approximately 400W each. The average solar panel size for a residential building is around 1.7m x 1m, though these measurements can vary depending on the provider.

Here’s an example of 25 solar panels with Q Cells’s Q.MAXX BLK-G4+ model that creates a 5kW solar system:

If you don’t have much sunlight hitting your home, you may need larger panels to capture the sunlight. This is also true if your energy consumption is high, as solar panels must capture more sunlight to meet the demand. Any shading on your property will block out some sunlight, forcing your panels to work with less energy.

Check with the manufacturer to see their options, and speak with an installer about the practicalities of installing larger solar panels. Every manufacturer has different sizes of solar panels available to meet a variety of needs. Solar installers will look at your home and discuss the necessary solar panel size with you. Don’t be afraid if it doesn’t meet the average size, as every home is different and your panel size reflects your needs.

What inverters should I get for my solar system?

Solar inverters take the direct current (DC) which is generated when sunlight hits the panel and converts it into alternating current (AC). Alternating current is what your home will use for energy, and the conversion won’t happen without the inverter. You can use a microinverter that is attached to each panel, or a string inverter which is better for most residential houses.

String inverters get their name because several strings of solar panels are connected to one inverter. This allows the inverter to convert the DC from those panels.

The Fronius Primo Gen24 Plus is one example of a 5kW inverter, with extremely good warranty and one that we highly recommend.

How much will this 5kw solar system cost?

Every solar power system will have different requirements and will not have the same costs as another household. Apart from solar panels, you pay for a solar inverter and installation costs which depend on site-specific factors. You may also require a solar battery if you require energy storage or have higher power consumption which raises the cost.

The average cost of a 5kW solar system in South Australia is $5,000 - $7,000. Your solar system can be more expensive depending on your power consumption, but beware of systems under $5,000. The quality of the panels, inverter, and battery might not be of high quality. Installation may also be rushed, leading to future problems that impact the energy you save.

Working with a Clean Energy Council accredited installer allows you to take advantage of rebates that bring down the installation cost. Make sure your quotes reflect the money saved by the rebate to ensure you have the most accurate pricing.

What are the feed-in tariffs for South Australia?

If your solar system generates more energy than you need, it can export some of that energy back to the electricity grid. South Australia has a retailer feed-in tariff which varies based on market competition and the current wholesale price of electricity. Cost is calculated in cents per kilowatt hour (c/kWh) and depends on the provider you are connecting with. 

Feed-in tariffs won’t apply if you are unable to send your excess energy into the grid. Check with solar installers and your local energy provider to learn if the grid can support your 5kW solar system. Your power consumption will also determine whether you have enough power to export to make a feed-in tariff worthwhile. Here are some tariffs offered by energy providers:

Origin Energy12c/kWh
Red Energy3c/kWh
AGL5c/kWh, 12c/kWh if system produces 10kW or less.

Are there any solar rebates I can take advantage of?

South Australia used to have a battery rebate, known as the South Australian Battery Scheme. It offered a rebate when you purchased a solar battery. As of July 2022, the rebate is no longer active.

You can apply for a Small-scale Technology Certificate (STC), which is similar to an environmental credit. Each solar system allows you to create a number of certificates, with one megawatt hour (mWh) of output giving you one certificate.

They are managed by the Clean Energy Regulator and are traded like shares in the stock market. You can sign these STCs over to your solar installer, who will sell them and discount the price off of your installation invoice. You can also manage them yourself, though it is a complex process.

The price of STCs are going down and you won’t get as much money from them as the years go on. But it’s still a way to save money on the initial installation instead of paying the full cost.

For a 5kw solar system in Adelaide, here’s a breakdown of the number of STCs you would generate, and the rebate you would’ve received.

YearQuantity of STCsRebate ($36 / STC)

What are the solar consumer guarantees?

The Australian consumer guarantee applies to all products and services, including solar. The retailer who supplied the solar panels can have their own consumer guarantee along with a product and performance warranty. The typical product and performance warranty for solar panels is 25 years, but you should check on the manufacturer’s website.

You should look for the solar panel product and performance warranty, solar inverter warranty, and a workmanship (installation) warranty. Reputable companies will have this information available for you, letting you know how long a product or installation will be covered. Even if you know the average warranty length, it never hurts to check since they can be different. For example, Q Cells offers a 25 year product and performance warranty, but JA Solar offers a 12 year product warranty and a 25 year performance warranty.

If there is a problem with your solar system, contact your solar retailer and see if they can solve the problem. Contact the Consumer and Business Services office if your solar retailer is unable to provide a solution.

What is the best location to install solar?

Solar panels are usually installed on the rooftops, as those are the locations that catch the most sunlight. Several factors influence solar panel placement, such as the amount of sunlight received and the alignment angle.

The ideal alignment for solar panels is to face true north, since being in the southern hemisphere means the sun comes from the north. Your solar panels should also be properly tilted to catch the most sunlight, which depends on your roof and power consumption.

If power consumption is greater during the winter months, a tilt of latitude + 15o is optimal. Greater consumption in summer requires an optimal tilt of latitude - 10o. This ensures your panels capture the most sunlight based on the seasonal changes, giving you a consistent supply of power in different months.

Without proper tilt and alignment, your solar panels generate significantly less energy even if everything is working properly.

Shading - how it affects location

Shade can also affect the amount of sunlight received, even if your solar panels are properly aligned and tilted. Trimming trees or removing other sources of shade can free up more space for properly aligned panels.

If your rooftop isn’t sufficient, alternative locations like a shed or ground installations can be used to install solar as well. Always get the opinion of a solar installer before you start making changes around your property.

What will the payback period on the 5kW solar system be?

The payback period is the time when the money saved from your electricity bills pays for the cost of the system. Depending on the size and requirements of your 5kW solar system, the payback period can take between five to six years. For a more precise calculation, divide the system’s total cost by the annual electricity savings. Your annual electricity savings are calculated by multiplying the amount of energy generated by your solar system with the cost per kWh. The amount of energy will usually be an estimate based on the size of the system and sunlight received. Your energy bill will tell you the cost per kWh for your residential address.

Can the local electricity network support my solar power system?

If your local electricity network cannot support your solar power system, you won’t be able to send energy back into the grid. This prevents you from applying for feed-in tariffs and shortening your payback period. This doesn’t mean you can’t install solar panels, as your home can be powered independently of the local electricity network.

The National Electricity Rules state that all local providers must be able to support solar, even in South Australia. No matter what solar system you install, you should always be able to apply for feed-in tariffs. However, being able to apply for feed-in tariffs doesn’t mean it’s good even if the network can support your electricity.

How do I know my solar system is generating 5kW?

If your solar system isn’t generating 5kW as stated, you aren’t getting the full benefits of solar energy. There may be a fault in the product or something wasn’t installed properly. While some factors such as weather can affect power generation, you must still meet your energy consumption requirements.

Check your solar inverter display to see how much energy is being generated. While fluctuations are expected, something is wrong if your solar system isn’t generating 5kW consistently.

Tracking the output and having a historical record allows you to pinpoint the dates when problems occurred. This gives you a better idea of seasonal changes, or indications that something is wrong with your system. Contact your solar installer or maintenance provider immediately to check the source of the problem.

Your product and performance warranty should cover any faulty solar panels and replace them for free. Any installation guarantees will also apply if there is a problem with the solar system installation.


A 5kW solar system is a significant investment, and doing your research gives you a better understanding of what you should look for. Always go for Clean Energy Council accredited installers and get several quotes. Look at your average power usage and figure out your peak energy consumption times.

You should always be eligible for the Australian federal solar rebate and feed-in tariffs, which affect your payback period. Ensuring you have guarantees in the event your system isn’t working is vital to avoid additional costs. 

While the true cost of a 5kW solar system in South Australia will depend on several factors, having an estimate always helps. Ask questions when speaking to solar installers and listen to what they say about your rooftop and location. Put this information together as you inspect the quotes and you can choose the right 5kW solar system for you.

If you don’t think you have $5,000 - $7,000k to spend on a 5kW solar system, Go Sunny has the ANYTIME Solar Plan, which is a three step process to get your solar system installed with an upfront cost of $0. This allows you to see the savings from your solar system before you pay off the installments.

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