6.6kW Solar System Cost

Updated: January 25, 2022

6kW solar systems (or 6.6kW to be exact) are by far the most common solar system size. They are great for most Australian homes

A 6.6kw solar system will cost $5,240. Different brands, quality, and installers play a role in solar panel prices so the real range is between $4,210 and $6,600.

The state you live in and the amount of rebate you are eligible for also play a factor.

6kW Solar SystemPrice
National Average$5,240
Low Estimate$4,200
High Estimate$6,600

6kW Average Yearly Savings

6kw Sytem Size Average Yearly Savings700x414

How Many Panels Are Needed?

A typical 6kw solar system will require twenty (20) solar panels, each measuring 1m by 1.6m.

However, panel size and the number of panels may vary from manufacturer to manufacturer. Some manufacturers do manage to make solar panels with higher outputs and therefore needing fewer panels for a given output rating. You will need to check your north-facing roof space to see which option is best for you.

Going by the above estimates, you will need at least 40 meters squared space+/- 5 on your roof to install the solar kit.

How Do I Know If The 6kwh System Is the Right Size for Me?

When selecting a solar panel system it’s all about the average Australian reducing their power bills by 90% or more. Ideally, a standard single-phase 6kw system should cover you if you consume an average of 26kWh of power per day. You will need to check your power consumption over the last 12 months.

Some other factors you should use to know if a 6kw system is right for you might include:

Your Household Energy Consumption

Some people prefer to have as much renewable energy as they can afford to reduce their electrical bills and contribute to the green initiative. If you fall into this category and have low to moderate daily power consumption, then a 6Kw solar system or higher could be the best for you. Keep in mind that the higher you go, the bigger the discount you get courtesy of the Australian STC solar rebate system.

A 6kw system is perfect for you if you use less than 26kWh of power per day. Below is a breakdown of common appliances and other electrical things you could run with a 6kw system. Keep in mind that these are just estimates, and solar output may vary according to weather conditions in your city.

Factors to consider when looking at a 6.6kW system


Can you afford a 6Kw system? If yes, does it make sense to you based on your daily consumption? If you can make sense of the figures without factoring in the feed-in tariffs, then you are good to go. As mentioned earlier, installing a solar system whose output you can use is more attractive in terms of the payback periods.


If you live in territories with lots of year-round sunshine, a higher wattage solar system might make a lot of sense. The favorable weather will not only make the solar system cheaper to install, but you will have better returns with surplus output from your solar system.

As an example, if you live in Brisbane and consume 22kWh of power per day, you would feed about 17Kwh to the grid and benefit from the feed-in tariffs at 8c per Kwh. This is because 70% of household power is consumed at night, but all solar power is produced through the day.

Roof space

This actually needs to be the first thing you check. Having enough North facing roof space is paramount for this all to work. IN some cases you can get away with it facing on slightly different angles, but you will need to consult a professional solar installer first before committing to anything.

How Much Power Will A 6kwh System Produce?

Energy outputs from solar systems tend to vary depending on the location they are installed. On average, a 6kwh solar system should produce at least 25Kwh in favorable weather. However, 6Kwh solar outputs are best estimated by location using climate information for solar energy from the Australian Bureau of Meteorology’s datasheets and solar vendor data as follows:

City/LocationEstimated 6Kw solar daily energy output
Canberra and surrounding areas 25.24Kwh
Adelaide and surrounding areas25.66Kwh
Brisbane and surrounding areas27.36Kwh
Melbourne and surrounding areas 21.95Kwh
Perth and surrounding areas29.1Kwh
Sydney and surrounding areas25.6Kwh
Solar panel orientation and tilt

The reason for the different figures based on location is primarily associated with daily solar radiation levels. However, other factors do affect individual solar outputs, such as:

Panel orientation and tilt – Solar panel orientation and tilt will affect how much power a system can generate. It’s, therefore, important to have enough space on the correct side of your roof for the panels.

Different regions may have varying tilt and orientation requirements for solar panels based on solar radiation data. That said, you don’t have to worry about this particular requirement. The solar company will most likely conduct its assessment and place the solar panels at an optimal position for maximum yield.

Solar system quality – Good quality solar panel systems are not the same in terms of quality and efficiency. For instance, a high-quality smart energy solar kit would have slightly higher yields than a lower quality standard kit. Additionally, most solar power systems usually come with an output tolerance of plus or minus two units of their watt rating.

Inverter setup and efficiency – Sometimes, the inverter might affect how much energy you get from a solar system. Your installer may suggest that you get a lower-wattage inverter to overclock the system and optimize solar performance.

Shading – Trees and large buildings blocking direct sun rays to your residence will affect how much power you can generate with your daily solar output. Talk to the solar installer on ways you can mitigate any shading issues to get the best out of your solar system.

Panel Maintenance – over time, dust, debris, and other foreign objects will accumulate on your solar power system. Proper solar panel maintenance is, therefore, a contributing factor to solar system outputs regardless of the rating or radiation levels.

Note: Too much dirt and debris will reduce the output by a small margin, while physical damage such as cracks will have a significant impact.

Ambient temperature – High temperatures hurt solar power system performance. Depending on installation type and panel temperature coefficients, you may get varying solar outputs when temperatures get to certain levels. It’s therefore important to explore the prevailing temperatures in your location and seek some advice from the installer on the best installation type for optimal performance.

Loss – As with most single-phase electrical connections, there will be a negligible loss in the DC and AC cabling that will affect your terminal solar output. This varies from installation to installation based on cabling length, interference, and quality.

6kWh solar system infographic cost

Will I Need A 6Kwh Or A 6.6kW Solar System?

Many people find it hard to choose between the overly popular 6.6Kwh and a 6kW solar system. Personal preferences aside, the 6.6kW solar systems might be a more sensible option for a number of reasons such as:

There is little price difference in final pricing, including installation for both systems. This is even when the 6.6Kw solar system kit provides an extra 0.600Kwh to the mix.

More STCs – For reasons best known to the regulators, going for the slightly bigger 6.6Kwh system will give you more STCs (quite a margin between them). For instance, a consumer buying a 6.6Kw solar system in Western Shore, Tasmania, will receive 86 STCs. In contrast, the same consumer would receive 78 STCs for a 6Kwh system.

Almost similar panel count – Again, there is not much difference in panel count between a 6.6Kwh solar kit and a 6Kwh Kit. Some vendors will sell both systems with a maximum of 20 solar panels, albeit with different rated outputs.

That said, going for a 6Kwh system may make a lot of sense for many reasons, such as your power consumption and payback period. The 6Kwh solar system has a slightly shorter payback time than its close counterpart. However, it’s also important to note that payback times depend on your energy consumption numbers, such as the ratio between the solar energy consumed vs. that coming from the grid.

Will I Need an Inverter?

An inverter is required for any kind of solar power system to convert DC from the solar panels to usable AC commonly used in electrical equipment. The great news is a 5Kw inverter would suffice for a 6.6kw solar systems. This means the price will be cheaper as you won’t have to pony up for a larger inverter. This is because a 5kw inverter can be “over-clocked” quite safely to handle 6kw solar system power loads.

Why not a 6kW inverter?

Well in short it is cheaper. A 6kw inverter is about 30% more expensive. The 5kW inverter has the capacity to do the job easily, and you save money in the process. It’s cheap, so it’s a win-win.

What Is the STC On A 6 Kwh System?

City/ RegionZoneNumber of STCs for 6Kwh Solar installs (11 years to 2030)
Alice Springs2107
Western Shore- South Tasmania478

What Is the Price with A Battery?

Standard solar kits don’t come with battery storage unless you purchase one with an embedded battery. If you are planning on storing surplus energy instead of feeding it back to your energy supplier, a battery with a nominal capacity ranging between 5kw- 6.5Kw would be the most logical option for a hybrid 6Kwh solar system.

A good quality 6.5 battery goes for about $6,00.00 in Australia. Add this to the solar kit with the STC discount applied, and you are looking at approximately $10,000 at the low end. Of course, there are many solar batteries out there to choose from, so feel free to shop around.

Also, do note that solar batteries aren’t covered under the STC solar rebate scheme unless for embedded ones hence the significantly higher costs. 6Kw solar kits that come with embedded batteries usually cost anything between $7000 to $12,000 depending on battery capacity and type.


Short answer? No. The authorities require that a certified and accredited solar installer does the site survey and installation following the set guidelines. According to the Clean Energy Authority, DIY solar installations are not allowed because of the safety and quality requirements set out. This is especially important in conventional grid-connected solar systems where a faulty installation would affect everyone.

Also, be advised that going the DIY route would potentially void your warranties, rebates, feed-in tariffs, and other permits usually bundled with a solar kit. With this in mind, the safest approach would be to let the solar vendor of your choice do the assessment, installation, and even maintenance.

You can save up to $500 per billing cycle depending on how much solar energy you can utilize; solar yield and feed-in tariffs in case of a surplus. Lifetime savings could go up to $50,000, provided you make use of the solar power system throughout the period. For homeowners looking to cut or eliminate their electricity bill, a 6kw solar system is definitely worth every coin spent, plus it pays for itself in the long run.

Feed-in tariffs are payments advanced to solar owners who feed their surplus energy to the grid. Feed-in tariff rates in Australia range from 8c/Kwh to 9c/Kwh. These tariffs may not be worth much, but they do help reduce your payback periods and system sizing.