The next generation of Tesla home battery storage, the Powerwall 3, has finally landed in Australia, with an official launch in Sydney on Friday bringing fresh insights on its specs and special talents – and how it differs from the Powerwall 2 – and revealing the local price.
First things first. The 13.5kWh Powerwall 3 goes on sale in Australia for $11,900 for the battery, with its integrated inverter. Added to this price, however, is $1,700 for the Backup Gateway 2 – a compulsory addition the Tesla team describes as “the brains” of the battery, which comes in the form of an extra box.
This takes the total cost of a Powerwall 3 to $13,600, plus the cost of delivery and installation. So, marginally more expensive than the current roughly $12,900 Powerwall 2 but with a bit more bang for buck – in some areas, at least.
So how is Powerwall 3 different from the Powerwall 2?
As One Step Off The Grid reported here, the Powerwall 3 makes its biggest departure from the Powerwall 2 by including a fully integrated solar “string inverter.”
The integrated inverter means that the Powerwall 3 is best suited to customers starting from scratch with a home energy system, but contrary to previous reports, it does not make it incompatible with other inverters.
According to the folk at Tesla, the Powerwall 3 does support AC coupling for those wishing to add a battery to an existing PV system, but it does mean the existing inverter would likely be rendered redundant.
A Powerwall 3 battery cannot, however, be added to existing Powerwall 2 systems, so Powerwall 2 owners wishing to add more storage would add another Powerwall 2.
Once you get past that peculiarity, however, there is a lot to like about the Powerwall 3 and a number of ways it outshines its predecessor.
For a start, the Powerwall 3 uses lithium iron phosphate chemistry – a fact confirmed to One Step Off the Grid, despite this information being conspicuously absent from the list of specs.
This seems an odd omission, considering the pretty well known safety and longevity benefits of LFP compared to Li-ion. But Tesla uses a different chemistries in its EV batteries to its stationary batteries, so has its reasons for not wanting to dwell on the pros and cons of each.
According to the spec sheet, the Powerwall 3 can accommodate up to 20kW of solar (DC), with a maximum continous charge power of 5kW and a nominal output of 5kW.
But the biggest boast of the Powerwall 3 is that it offers more than double the power output of Powerwall 2, with a maximum continuous output of 11.4kW, when needed.
This, along with a maximum load start capability of 185 amps, means it can power most, if not all appliances in an average Australian home through a blackout – and through grid peak power periods, for that matter.
In real terms, Tesla says the inverter can output up to 10kW, “depending on local conditions,” which means a household could continue using its air-con and charging its Model Y through a grid outage – and potentially for hours.
As the Tesla team notes, the qualities of home battery back-up are measured on their mix of power and duration. The Powerwall 3 trumps most other offerings on power, the duration will vary greatly for customers, depending on the loads they’re trying to support.
Which leads into another cool “coming soon” benefit of the Powerwall three. According to the Tesla team, a new product expected to land in 2025 called Power 3 Expansions can essentially add longer backup duration to a Powerwall 3 battery without the need for additional supporting gear or approvals.
“It’s a very easy solution to add energy storage as people go through the electrification journey,” a Tesla spokesperson told One Step Off The Grid.
Tesla says this additional unit would look similar to the Powerwall 3, but slightly slimmer, and could be installed either side by side with the battery or stacked behind it.
As it stands, however, the point is that a Powerwall 3 can power most Australian homes with a single unit, and when it’s not coming to the rescue in an outage, deliver solid energy savings by storing excess rooftop solar for use during peak pricing periods.
According to the literature, Powerwall 3 owners can use the Tesla app to switch their batteries to self-consumption mode, allowing them to reduce their reliance on the grid and power their homes more sustainably.
Further savings can be unlocked through Time-Based Control mode, which allows owners on a Time of Use electricity plan to set their battery to maximise their savings.
And when the Powerwall 3 is connected to a virtual power plant, Tesla says an Australian solar household can save up to 77% a year on their electricity bills.
Another app feature called Storm Watch will automatically charge the Powerwall 3 to its maximum capacity to prepare for an outage.
The final specs worth mentioning are a solar to battery to home/grid efficiency of 89% and a warranty from Tesla of 10 years. The new battery’s dimensions are 1105 x 609 x 193 mm – and it weighs in at 130kg, with options to mount on the wall or the floor.
Final verdict? Certainly, this battery doesn’t suit the energy needs of everyone. But the Powerwall 3 has some great features – particularly as a building block for solar households starting from scratch on a journey to electrify everything, both under the roof and in the driveway.
Sophie is editor of One Step Off The Grid and deputy editor of its sister site, Renew Economy. Sophie has been writing about clean energy for more than a decade.
