6kW Solar System With Battery Price

Updated: August 29, 2023

A 6kW solar system with battery backup is a viable option if you are a high-energy user. This system will often be enough to power a 3 to 4-bedroom house and can significantly reduce your monthly or quarterly electric bills.

A 6kW solar system generates 24kWh of energy per day and requires a battery with a capacity of 16.6kWh. Installing a 6kW solar system with a battery storage system will cost $19,935 on the low end and $25,235 on average.

The actual cost will depend on the type and quality of the system. Below is a review of the 6kW solar system with battery price.

The average cost of installing a good-quality 6kW solar system is $6,656. The cost ranges between $5,500 and $7,950 and is inclusive of the Australian government’s solar rebate. The gross price of the system is around $9,342.

The system’s actual cost depends on the STC zone in which you live in Australia. Typically, there are 4 STC zones, categorised according to the amount of sunlight received in each zone. Areas receiving the most solar radiation have a high STC rating, meaning they receive a higher rebate.

Learn more about solar STCs and how they work here.

Here is a table showing how much a 6 kW solar system costs in different STC zones in Australia.

STC zoneCityCost (w/out rebate)Cost (after rebate)
Stuart Park
$9,342 $6,301
2Alice springs
Daly Waters
$9,342 $6,459
$9,342 $6,735
$9,342 $7,130

6kW Solar System price with battery backup

If you are a high-energy consumer, installing a 6 kW solar system with battery backup will help you offset your power bills.

Since a 6 kW solar PV system generates about 24 kWh per day, you can store some of that power in a battery system to use during the night when the solar panels are not working or on overcast days when your PV system generates low energy.

6kW Solar System price with battery backup

What battery size would be ideal for a 6kW solar system?

An average Australian home uses about 30% of the electricity generated by its solar systems during daylight hours. Therefore, you will need a battery to store the remaining 70%.

Since a 6 kW solar system generates 24 kWh of electricity per day, you will require a solar battery with a capacity of 16.6 kWh.

If you are limited on cash, you can choose battery systems with lower capacities, such as 10kWh, 11kWh, 12kWh, 13kWh, 14kWh, and 15kWh.

Depending on your battery type, you may need one or more batteries to reach the required capacity. Lithium-ion batteries are the best choice, as they have a discharge depth of more than 80% and do not require much maintenance.

How much does a 16.6 kWh solar battery cost?

A 16.6 kWh battery storage system costs between $13,200 and $18,500. The actual cost will depend on the battery’s type, quality, and solar battery provider.

Since finding one battery that meets the exact capacity may be hard, you may have to combine several batteries to attain the capacity you need.

Here are examples of two batteries that you can consider for your 6 kW solar system:

This Battery-Box Premium HVM is composed of 6 HVM battery modules connected in series to achieve a capacity of 16.6 kWh. It is a cobalt-free Lithium Ion Phosphate battery that offers maximum safety, power, and life cycle. This battery costs $18,455.

This battery comprises 5 x 3.2 kWh solar battery modules to reach a capacity of 16 kWh. It is also a Lithium Ion Phosphate that offers flexibility, safety, and high efficiency. This battery costs $14,181.5.

So, how much will a 6kW solar system with a battery system cost?

Installing a 6 kW solar system with battery backup will cost approximately $20,800 to $26,000. The actual cost can be lower or higher, depending on the type and quality of your solar system and batteries.

If you install your solar system with the SBR160 or BYD HVM 16.6 solar batteries from the above examples, you will spend about $20,837.5 and $25,111, respectively.

The following table shows the average cost for a 6 kW solar system with battery backup. The cost varies widely depending on the type of battery you choose and its capacity.

Battery typeSize of battery in kWhBattery system cost6 kW solar system cost + battery system
BYD Battery-Box Premium HVM 16.6 kW/hrs with BMU16.6 kWh$18,455 $25,111
Sungrow 16 kWh High Voltage LFP Battery SBR16016.0 kWh$14,181.5 $20,837.5
sonnenBatterie Eco14 kWh $15,175 $21,831
Tesla Powerwall 213.5 kWh $14,000 $20,656
Sunverge SIS11.6 kWh $26,000 $32,656
Redflow Zcell10 kWh $12,600 $19,256

Average solar battery storage price in Australia (fully installed)

Average solar battery storage price in Australia fully installed

The average cost of residential solar batteries ranges between $1,000 and $1500 per kWh. The low-end cost averages $668 per kWh, while the high-end price can go up to $2,240 per kWh. The actual cost of solar batteries varies widely depending on the battery type, quality, capacity, and preferred brand.

Here is a table showing the average battery installation prices in Australia, GST included.

Battery size (kWh)Battery only cost Battery cost + inverter/charger
3kWh $4,260 $4,770
8kWh $10,080 $11,120
13kWh $16,380 $17,680
18kWh $23,940 $25,920


  • These costs include costs for installation, wiring, and any other necessary components.
  • The price does not include any solar battery rebates available in the different states of Australia.

Can I get a rebate for my solar battery system?

The federal government does not offer solar battery rebates. There are, however, a few states that provide rebates, incentives, and interest-free loans to their residents to make solar batteries more affordable. Here are some of the solar battery rebate programmes in Australia:

Click here to check out the government battery rebate schemes and assistance you can get in your local area.

Popular solar battery systems in Australia plus price

If you are looking to buy a battery storage system, here is a list of the most popular systems in Australia, plus their prices.

Battery CapacityAverage cost Cost per kilowattType Warranty
Tesla Powerwall 214 kWh$14,000$1,000Lithium ion10 years
sonnenBatterie Eco14 kWh $15,000 $1,071 Lithium ion10 years
Sungrow-Samsung sbp4k84.8 kWh $4,610 $962 Lithium ion10 years
Sungrow-SBR-HV-Battery16 kWh $14,181.5 $887 Lithium Ion Phosphate10 years
Redflow Zcell10 kWh $12,600 $12,60 Zinc-bromine10 years
Enphase Energy1.2 kWh $2,057.00 $1,714 Lithium ion10 years
ZEN Energy10kWh to 20kWh $10,000 to $15,000 $1,000 Lithium ion10 years
AKASOL’s neeoQube5.5 kWh $12,000 $2,143 Lithium ion10 years
Sunverge SIS11.6kWh $26,000 $2,229 Lithium ion
Alpha Ess11 kWh $7,302 $668 Lithium ion10 years
LG9.8 kWh $8,195 $837 Lithium ion10 years
BYD Battery-Box Premium HVM16.6 kWh $18,455 $1,112 Lithium Ion Phosphate

Can I add a battery system to an existing 6 kW solar system?

add a battery system to an existing 6 kW solar system

Yes, you can retrofit a battery system to your existing 6 kW solar system. Solar PV systems are almost always compatible with battery storage systems. However, if the solar system was not originally designed to support a battery backup system, you may have to replace the existing solar inverter with a new one that supports the new battery backup.

If you do not want to replace your inverter system, you can install AC-coupled batteries, as they are flexible and compatible with most solar energy systems.

How much does it cost to retrofit a battery backup to an existing solar system?

Retrofitting battery storage to an existing solar power system costs between $10,000 and $20,000. This cost can go up if you need more than one battery or if you want to replace your existing solar inverter. Retrofitting a battery backup system with a 10 kWh to 13 kWh capacity costs around $13,000.

Adding solar batteries to existing solar power systems tends to be more expensive than installing the systems concurrently. So, if you are looking to install a solar system, consider installing it simultaneously with a battery system if you need one, as you will get a better deal in terms of costs.

What is the payback period of a 6 kW solar power system with battery backup?

What is the payback period of a 6 kW solar power system with battery backup

The payback period for your 6 kW solar system with battery backup can take about 8 to 10.5 years if you have total savings of about $2,400 annually. The payback period can be longer, depending on the battery capacity and cost.

The payback period for a 6 kW solar system without a battery system is between 4 and 6 years. This is how long it will take you to break even or for the ROI to cover the installation cost.

Solar batteries, on the other hand, have a longer payback period. Most solar batteries have a warranty of 10 years, and it can take 9 to 10 years to break even, about which time their warranty expires.

Is it worth getting battery storage with solar?

Yes. We all know that solar PV systems can only generate energy during daylight hours. Adding a battery backup system allows you to store power to use at night and during overcast days when solar panels do not generate enough energy.

This means you can use your stored power instead of paying peak rates. More so, you will remain powered up during power outages; hence, you will not have to draw electricity from the grid.

How long do solar batteries last?

Solar batteries can last between 5 and 15 years. Factors such as the type of battery and its care and maintenance can affect the lifespan of your solar battery. Well-maintained solar batteries will last longer.

  • Lithium-ion batteries have the longest lifespan of 10 to 15 years.
  • Saltwater batteries come in second, with a lifespan of 8 to 10 years.
  • Lead-acid batteries have the lowest lifespan of 5 to 7 years.

Ben McInerney head shotAuthor: Ben McInerney is a renewable energy enthusiast with the goal of helping more Australians understand solar systems to make the best choice before they purchase. Having an accredited solar installer in the family helps give Ben access to the correct information, which allows him to break it down and make it easily understandable to the average homeowner.