Tesla’s Powerwall 3 has just launched in Australia and caused quite a stir. But is it the right choice for every Aussie household that wants a home battery?
I’m here to cut through the hype and give you the lowdown on when the Powerwall 3 shines and when you should look elsewhere.
The Powerwall 3’s Star Features
Here’s what makes the Powerwall 3 stand out compared to the Powerwall 2:
- Integrated 10kW solar hybrid inverter1.
- Impressive 11 kW power output from the battery.
- High surge current means it can kick-start the gruntiest of machines when the grid goes down.
- The promise of easy-to-add, good-value energy expansion packs.
- $1,500 more expensive than Powerwall 2 for the same storage (13.5 kWh).
When Powerwall 3 Makes Sense
- Starting from scratch: If your roof is a blank canvas or your existing system is ready for retirement, the Powerwall 3 could be a great choice. It’s designed to handle up to 20kW of solar panels, enough to cover most Aussie roofs. The integrated inverter means a quicker, cleaner installation, plus the powerful output gives you more options for what you choose to back up, and increases earnings if you join a VPP. Adding kWhs in the future should be easy, too.
When Powerwall 3 Might Make Sense
- Upgrading a small solar system: Do you have an existing solar setup with a 5kW or smaller inverter? Tesla Australia promises the Powerwall 3 will play nice with your current solar array by “AC-coupling up to 5kW of solar.” However, a word of caution: this integration is still new territory in Australia, and Tesla’s promises don’t always come true. Sensible homeowners will let someone else be the first to try adding a PW3 to existing small solar. But if you are brave enough to go first, please let me know how you go!
- You already have big solar: If you already have a decent (>6.6kW) solar system, then the Powerwall 3 is not designed to integrate with your solar inverter. It may be possible to disconnect the solar array from your old inverter and reconnect into the PW3, but not without risking regulatory, technical and warranty issues. I’d recommend leaving your solar alone, and retrofitting a battery system designed for AC-coupling.
- Three-Phase Homes: While you can use a Powerwall 3 in a three-phase home, it comes with limitations. You won’t have full three-phase backup capabilities, and your solar won’t work during grid outages if you have a 3-phase solar inverter.
When Powerwall 3 Does Not Make Sense
- Enphase or SolarEdge Fans: If you’re committed to Enphase or SolarEdge systems, especially for complex roofs with more than three orientations, the Powerwall 3 isn’t for you. It’s not designed to interface seamlessly with panel-level optimisation, whether microinverters or SolarEdge.
- Off-Gridders: Do you live off-grid, or are you planning to? The Powerwall 3 isn’t designed or supported for off-grid living. Stick to systems specifically designed for off-grid use, designed by an off-grid expert.
- Expanding a Powerwall 2 System: If you’re already rocking a Powerwall 2, stick with what you know. Adding another Powerwall 2 is a much smoother option than trying to integrate a Powerwall 3. I have a Powerwall 2, and the PW3 launch has prompted me to buy a second while they’re still available.
- You loathe Elon: Let’s face it – an increasing number of Aussies have strong negative feelings about Elon Musk and the company he leads. If that’s you, rest assured there are plenty of excellent alternatives from brands like Sigenergy, Fronius/BYD, and Sungrow.
The Bottom Line
The Powerwall 3 is a brilliantly thought-through piece of tech. It’s hard to beat for new installations or significant upgrades on single-phase homes. However, in some scenarios, other batteries will serve you better.
Remember, the key to a successful solar and battery setup is matching the technology to your home. Don’t get caught up in the hype of having the latest model if it means trying to install a square peg in a round hole.
Footnotes
- except in Western Australia, where it’s limited to 5kW max AC output / 5kW max battery charge/discharge ↩
About Finn Peacock
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Thanks Finn. I’ve thought about a second PW2. In every season except winter there’d be more than ample surplus to store in it (11.78 kW of panels). In winter on most days it’d be a tough slog to fil 2 PW2s, with our amount of sunshine. And storing an extra 13.5 kWh in the warmer months, I’m not sure we’d use that extra energy, except to maybe charge an EV down the track. Outside using the additional battery for a VPP or for wholesale trading (for example through Amber), do you see a rationale for a second battery in that sort of context? Thanks.
Hi Nick Jacob here! (not Finn 🤠)
Here in Western Sydney we got a letter from our wholesale energy provider that between 10 am and 2 p.m power would be free. So it seems to me that if you are with a company like Amber who gives wholesale rates, you could charge your battery during that time for free! (Here in Western Sydney anyway)
Great advice as usual. I live offgrid and have a few years left in my AGM battery.
My plan is to be patient and wait for Powerwall 3 to support off grid and for PowerShare to work with the model Y so I have an integrated Tesla solution with V2L backup.
Do you think it’s realistic that this will happen in the next 1 to 2 years?
Wal,
Reading point 2 under “When Powerwall 3 Does Not Make Sense”, it seems clear that Off-grid is a different adventure. You’ve already done the heavy miles, husbanding a useful life out of a leaden asset, possibly with at least a bit of DIY pioneering at the time.
Timing for a switch to LiFePO₄ is approaching ideal, with prices coming down in recent months, if you go semi-DIY. If your battery charger is tuneable, then it might be able to be set for the new battery chemistry. I charge mine to 55V Absorption, and 54V Float, that’s well within Pb limits. There is neither Bulk nor Equalisation – the BMS in the box performs cell balancing during Absorption. Your battery inverter shouldn’t see any difference.
While I built my battery from individual prismatic cells, it’s now economical to just whack in one or more 16 kWh 48V boxes, needing only two cable connections, and you’re done.
For a new installation, both Selectronic and Victron provide a lot of monitoring, both local and in the cloud. (I used 39.6 kWh yesterday, most going into the EV and HWS.) Given enough PV (27 kW here), keeping an EV topped up is no problem at all, even in winter, if it can be home on occasional sunny days. (I prefer LiFePO₄ in the EV as well, for battery longevity, safety, and SoC insensitivity. A single phase EVSE charges at 7.3 kW max.)
I’d shop around – this isn’t the only offering out there:
https://lifepo4.com.au/shop/victron-2/51-2v-314ah-16kwh-eve-8000-cycles-lifepo4-battery/ (I’ve seen other featured on the “Off-Grid Garage”)
If you already have a battery inverter, so don’y need the one in a Powerwall, then something like that is half the price with 10 yr warranty, even without the prepay discount.
I’m guessing the current battery isn’t wallmounted, but rack-mount LiFePO₄ boxes probably could be.
My older LiFePO₄ is only rated at 6,000 cycles, but the 46 kWh cycling less than weekly is 120 years, so 20 to 30 years calendar life, I figure.
Wow Erik – appreciate the effort and the detail. I’ll study your response and try and fully understand it.
The reason I asked about off-grid PW 3 was because it was hinted at “as possible in the future” in Finn’s first PW article, and there is some speculation that the Model Y Juniper might support Powershare.
I really want simple off-grid EV charging and V2L backup as required. Your solution may give me that. I’ll study it in detail!
I find buying choices based on “loathe Elon” way beyond bizarre, not to mention stupid. Q. Are people really that dumb? (A. Yes!)
Q. What do these people know about other CEOs? (A: Nothing!)
Tesla is a company built (yes, mostly by Elon) with many thousands of brilliant, dedicated engineers and designers.
The fact that Elon is at the top means very little, whether you like OR loathe him. It’s beyond dumb to let this affect buying decisions.
I know a guy who bought a VW EV in the U.S. “because he didn’t like Elon”. Ignoring the fact that he’s had nothing but trouble with his VW, he’s bought into the company that brought us the lies and corruption of dieselgate.
Now that’s REALLY smart, right?
It’s symptomatic of a mind needing some counselling 😄
Spot on
I’ve got 13.2kW of panels connected to a 10kW 3 phase inverter, so 3.3kW of inverter capacity connected on each phase with a DNSP limit of 10kW/phase.
With PW3 being a single phase device I wonder if I’ll be able to AC couple the existing 3.3kW of inverter capacity on the phase its connected to, then DC couple 6.6kW of additional panels to the PW3 inverter to stay within my 10kW/phase limit.
Another thought – it would be pretty cool if I could charge my Tesla (car) on solar while the existing 10kW inverter and PW3 with its own DC coupled panels co-exist.
I guess we’ll have to wait and see the real world capabilities as they roll out.
If you’ve got a 3-phase solar inverter, the PW3 is not for you. What you’ve described won’t work.
Have a look at Sigenergy. It does everything you want it to – including 3 phase backup and DC EV charging:
https://www.solarquotes.com.au/blog/sigenergy-review-features/
Thanks Finn, appreciate the feedback, I’ll have a look at the Sigenergy.
In WA, Powerwall 3 output is limited to 5kW, meaning WA reduced the integrated inverter capacity to 5kW… Shame
I was just wondering the 11 KW output does it depend on the capacity of the battery or any PW3 can output 11 KW? My BYD can output up to 10 KW but this depends on the size of the battery.
NOOOO – I already have a 10kw inverter Enphase system. I thought this could be added and then I’d use the extra inverter to add a few more panels (so let’s say 28 enphase and 10 on the PW3 inverter) – is this not a thing? Why can’t they play well with each other? Would love some technical expertise commentary please!
Also in that case, am I then just limited to a PW2 (or 2 of them to get the same output)
The Powerwall 3 uses DC coupling. The solar panels DC output goes into the PW3.
Enphase convert the panels to AC at the panel, so there is no DC to plug into the PW3.
Tesla said the PW3 will AC couple 5kW of solar. If that’s correct, it is likely 2 x PW3 will AC couple 10kW of Enphase.
I’m in the same situation, I think. I have 35 panels with approx 10kw from a mix of S370 and IQ7a. I have a PW2 on the Tesla VPP via Energy Locals.
Based on the reported specs of the PW3, I can’t see any path to add additional battery capacity other than another PW2.
I don’t understand why a product as good as the Tesla brand has to cause a meltdown about Elon.
Make it make sense!
Can you put an asterisk in your article about the WA variant being limited to 5kW max AC output / 5kW max battery charge/discharge.
A lot of confused customers thinking they can have 10kW supply to house.
done