How Much Do Solar Batteries Cost In Australia?
Last Updated: 18th Dec 2024 By Finn Peacock, Chartered Electrical Engineer, Fact Checked By Ronald Brakels
What does it cost to add solar batteries to your home? Here’s your go-to guide with up-to-date prices throughout.
Solar Battery Costs: October 2024
Here are typical installed prices for popular solar batteries in Australia:
| Battery System | Capacity | Approx. Installed Cost [October 2024] | Cost per kWh | Warranty |
|---|---|---|---|---|
| BYD* | 13.8 kWh | $12,200 | $880 | 10yrs, 60% |
| Tesla Powerwall 2 | 13.5 kWh | $15,500 | $1,150 | 10yrs, 70% |
| Sungrow* | 12.8 kWh | $11,400 | $890 | 10yrs, 60% |
| SolarEdge* | 10 kWh | $13,400 | $1,340 | 10yrs, 70% |
| Enphase | 5 kWh | $10,300 | $2,060 | 15yrs, 60% |
| Jinko* | 6.9 kWh | $9,800 | $1,420 | 10yrs, 60% |
These prices are based on a good-quality, straightforward installation:
- the battery is installed next to the switchboard
- no protection bollards required
- only two backup circuits
- no switchboard upgrades
- no fire-resistant backing required.
What Affects The Cost Of A Home Battery System?
What you pay for a home battery system is the sum of the:
- battery price
- battery inverter price (if required)
- installation cost
- finance cost (if applicable)
And if you want to charge the battery from solar – you, of course, need solar panels too.
Pro-Tip: You don’t need to charge your battery from solar panels. You can charge it from off-peak grid electricity instead. Or you can charge it from a mix of solar and grid. This can make sense because you can now get super off-peak tariffs in WA and SA that can be as low as 8c per kWh.
What Affects Battery Cost?
Battery Cost Factor #1 Battery Capacity
The energy storage capacity of a battery is measured in kilowatt-hours (kWhs). The higher the capacity, the more kWhs it stores, and the more the solar battery costs.
But there is an economy of scale – the more kWhs you buy, the cheaper the batteries become per kWh:
| Battery Model | Capacity | Approx Total installed cost. | Price per kWh |
|---|---|---|---|
| Istore* | 5 kWh | $9,800 | $1,960 |
| Istore* | 10 kWh | $14,200 | $1,420 |
| Istore* | 15 kWh | $18,500 | $1,233 |
| Sungrow SBR* | 9.6 kWh | $11,500 | $1,198 |
| Sungrow SBR* | 12.8 kWh | $13,400 | $1,047 |
| Sungrow SBR* | 25.6 kWh | $20,900 | $816 |
| Telsa Powerwall 2 | 13.5 kWh | $15,500 | $1,148 |
| Telsa Powerwall 2 x2 | 27 kWh | $28,000 | $1,037 |
You can see that buying a small 5 kWh battery costs almost $2,000 per kWh. This is because you only have 5 kWh to share the entire:
- Battery controller cost
- Battery Inverter cost
- Installation cost
Whereas if you buy a 25.6 kWh Sungrow battery, it only costs $816 per kWh. That’s because you only have one battery controller, battery inverter and installation shared amongst all those kWhs. In the case of the Sungrow, this is eight separate 3.2 kWh modules that stack on top of each other. So, the installation of additional modules is very fast.
Pro-Tip: Be careful you are quoted usable capacity, not nominal capacity. Almost all lithium batteries are quoted in usable capacity, but older-style lead-acid batteries are quoted in nominal capacity, which is more than double what you can actually use.
Battery Cost Factor #2 Chemistry
The chemistry of the home battery affects the cost, which will generally use one of two lithium-ion chemistries:
- NMC – Lithium Nickel Manganese Oxide: e.g. Tesla Powerwall 2, LG Chem Resu
- LFP – Lithium Iron Phosphate: e.g. Sungrow, Goodwe, Huawei, AlphaESS
LFP was about 32% cheaper than NMC in 2023.
Nerd Fact: The third generation of Tesla’s Powerwall was rumoured to be LFP to reduce costs, but as more details emerge is seems they’ve stuck with NMC battery cells for the Powerwall 3
Battery Cost Factor #3 Warranty
Cheaper batteries generally have shorter warranties. Don’t be fooled – the marketing may claim ‘10 years’ but look deeper, and they can be as short as 13 months if you discharge them ‘too much’.
A good, reasonably-priced battery will generally have a 10-year warranty that allows you to cycle it once per day, or close to it, for ten years with a guarantee of 70% capacity after ten years.
If you’re in an area with both a morning and an evening peak rate, I recommend looking for warranties that allow over 1 cycle per day for the warranty period so you can charge from solar panels during the day, discharge in the evening peak, and charge from overnight off-peak and discharge in the early morning peak.
What Affects Battery Inverter Cost?
All home batteries need a compatible inverter to charge, discharge, and play nice with the grid. The inverter can be built into the battery appliance (e.g. Powerwall, sonnen) or separate from it (e.g. BYD, Sungrow, Goodwe, iStore).
The inverter’s capabilities directly affect the price of the battery system in 3 ways:
#1 Single or Three Phase?
If you want an energy storage solution that can charge and discharge across all the phases of a three-phase supply – then your battery inverter needs to be a 3-phase inverter. These cost more than single-phase,
Examples:
- Sungrow 10 kW single-phase hybrid inverter: $3,600
- Sungrow 10 kW three-phase hybrid inverter: $4,500
In a Sungrow system with 10kW of power, you’ll pay $900 more for the inverter if you want 3-phase, and – because it’s more complex and more work is involved – at least $500 more for the installation.
Pro-Tip: Save on the cost: If you have a 3-phase home, you don’t need a 3-phase battery system. Single phase works fine for most people.
#2 Inverter Power
When pricing a battery, the main factor is its capacity – how much electricity it can store in kilowatt-hours (kWh).
But another specification that affects price is the battery inverter’s power. The input power limits how fast the battery can charge. The output power limits how quickly it can discharge and how much they can back up.
Examples:
- Sungrow 5 kW hybrid inverter: $2,300
- Sungrow 10 kW hybrid inverter: $3,600
The 10 kW inverter can charge and discharge a compatible battery twice as fast, for an extra $1,300 and also supports a larger solar system.
Nerd Fact: The difference between energy and power – as it relates to solar batteries: Energy (kWh) is how much electricity is stored for later use. The battery’s power (kW) is how quickly it can charge or discharge that energy. Think of energy as ‘amount of electricity’ and power as ‘speed of electricity’.
#3 Buying solar + batteries + hybrid inverter together
If you are buying solar and batteries at the same time – using a hybrid inverter can reduce your total cost because your solar and battery share one inverter. The savings can be around $2,000 compared to retrofitting energy storage to existing solar.
What Affects Battery Installation Cost?
Installation Cost Factor #1: Backup
Most Australians expect backup with their solar battery system. Backup adds to the hardware and installation cost. The backup function is either built into the battery inverter or a separate ‘backup box’.
Some general rules around the price of solar battery backup.
- The more you want to backup, the more it will cost. Backing up lights, refrigeration and a handful of power points requires a smaller battery than one that can back up a whole house.
- If you have loads with high startup currents on your backup circuits – which can be anything with an electric motor in it such as a refrigerator or air conditioner – it can require expensive high-powered battery inverters such as Selectronic or the one built into a Powerwall 3.
- Backup that can use the solar panels during a blackout to top up your batteries usually costs more than backup that disables your solar power system during a blackout.
- Adding an ‘override’ switch will add about $200 to the price but is worth it if it allows you to still power your house in case of a battery system failure. Ask your installer if this is required for their proposed system – as many installers forget to include one.
Installation Cost Factor #2: Battery Location
Distance from switchboard
Australian Standard 5039 mandates where your battery can be located. It is stringent, so you may not have many options. If you can’t or don’t want to install it and associated electronics next to your switchboard, your installers will need to run many metres of cables. This can add $1,000 or more to the installation as it can take at least two people and many hours to get a cable across your house.
Bollards
If your battery is to go into your garage, it will likely need at least one bollard to protect it from errant drivers – like your husband 🤣.
Pro-tip: If the Tesla Powerwall 3’s expansion pack gets ground-mounted in a stacked configuration behind the Powerwall 3, it will stick out further from the wall. Make sure to leave space between battery and bollards if you plan to expand this way. If not, you can always wall-mount the expansion pack 1 metre to the side.
Weather protection
If your battery is installed outside, it should be protected from direct sunlight.
Fire-rated backing
If your battery will be mounted on a wall with a habitable room behind, it must have a fire-rated back sheet behind it, adding to the price.
Cost Of Different Types Of Battery Finance
Cash
Using cash in the bank to buy your battery is not cost-free. You pay an opportunity cost on the missed investment earnings, whether that’s interest or other investment income.
Battery Loans
If you get a regular loan for your battery, your loan provider must itemise the cost of that loan to you. You will pay interest, account-keeping fees and set-up fees.
0% Finance
Be careful of 0% finance. The name implies that it is a cheap or even no-cost loan. That is mostly not true. In my opinion, most 0% finance mobs are full of crap because that ‘0% loan’ is only possible by charging the solar retailer a huge premium – typically 25%. That means a $10,000 battery could have $2,500 of ‘merchant fees’ on top. The finance vendors claim they don’t add to your price, but I hope you can see that for what it is.
Having said that – I know of one 0% finance offer that appears genuine:
Government 0% Battery Loans
Governments sometimes support the purchase of solar batteries by subsidising the cost of financing them. This means you can apply for genuine 0% interest loans to pay for some or all of your system.
ACT and Victoria currently offer limited zero-percent loans.
Battery Rebates?
There is no federal rebate to reduce the cost of solar batteries. However, there is a local rebate in the NT of up to $5,000, and a NSW Battery Rebate starts on November 1st, 2024.
Powerwall Pricing
Powerwall 2 Cost
The Tesla Powerwall 2 is the most popular home battery in Australia. At the time of writing, a Powerwall is about $15,500 with a simple installation included. If you want to add a second Powerwall 2, expect to pay about $13,000 due to the simpler installation and shared ‘gateway’. Tesla publishes a hardware-only price on their Australian website, which varies frequently.
Powerwall 3 Cost
Tesla has just launched the Powerwall 3 in Australia. It has the same energy storage capacity as the Powerwall 2 (13.5 kWh) but costs $1,500 more before installation. The standout feature is its inclusion of a 10 kW solar inverter. This means if you’re investing in both the Powerwall 3 and solar panels simultaneously, you could see savings around $2,000 compared to using a Powerwall 2, as it eliminates the need for a separate hybrid solar inverter.
Wrapping Up: Solar Battery Costs in Australia
- Price Range: Popular solar batteries have an installed cost between $9,000 and $17,000 as of October 2024.
- Economy of Scale: Bigger batteries offer lower cost per kWh.
- Total Costs: The price tag includes battery, inverter, and installation costs. Finance options can add more.
- Battery Chemistry: LFP is cheaper than NMC.
- Warranty: Really cheap batteries often have awful warranties. Look for a 10-year warranty that will actually last 10 years in use or close to it – small print matters.
- Installation: Distance from the switchboard, 3-phase and backup capabilities can add to the cost.
- Financing: Be wary of hidden costs in 0% finance offers. Government loans offer genuine 0% interest.
Ready to install a solar battery? We can help by connecting you to thoroughly pre-vetted, trustworthy installers who focus on quality: