Powerwall 3: When It Makes Sense and When It Doesn’t

is powerwall 3 suitable

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:

  1. Integrated 10kW solar hybrid inverter1.
  2. Impressive 11 kW power output from the battery.
  3. High surge current means it can kick-start the gruntiest of machines when the grid goes down.
  4. The promise of easy-to-add, good-value energy expansion packs.
  5. $1,500 more expensive than Powerwall 2 for the same storage (13.5 kWh).

When Powerwall 3 Makes Sense

  1. 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

  1. 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!
  2. 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.
  3. On One Phase Of  A Three-Phase Home: You can use a Powerwall 3 on one phase of a three-phase home, but it comes with limitations. You can only back up the phase the PW3 is on, and your solar won’t work during grid outages if you have a 3-phase solar inverter.

When Powerwall 3 Does Not Make Sense

  1. On All 3 Phases Of A 3 Phase Home:  Although you can add a Powerwall 3 to each phase of a 3 phase home if you really want to, it’s a very expensive solution that won’t work very well if you have any 3 phase loads or a 3 phase solar inverter. Just get a proper 3 phase battery, like Sigenergy, Sungrow or Fronius/BYD.
  2. 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.
  3. 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.
  4. 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.
  5. 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.
  6. When you want Tigo optimisers: If your roof dictates a complex layout or has significant problems with, say a chimney creating hard line shade, then Powerwall 3 is not compatible MLPE (Module Level Power Electronics)

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.

This post was updated on 29th August to give 2 separate 3-phase scenarios, because there are so many proper 3 phase battery systems available these days and PW3 is not one of them.

Footnotes

  1. except in Western Australia, where it’s limited to 5kW max AC output / 5kW max battery charge/discharge
About Finn Peacock

I'm a Chartered Electrical Engineer, Solar and Energy Efficiency nut, dad, and the founder and CEO of SolarQuotes.com.au. I started SolarQuotes in 2009 and the SolarQuotes blog in 2013 with the belief that it’s more important to be truthful and objective than popular. My last "real job" was working for the CSIRO in their renewable energy division. Since 2009, I’ve helped over 700,000 Aussies get quotes for solar from installers I trust. Read my full bio.

Comments

  1. 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)

      • Thanks Jacob! I’ve thought about that, but my energy is already free (from solar) at that time anyway.

        • Sorry I thought you need an extra top up during winter.
          The other dynamic I think about is that now even if you don’t have solar panels you can still have a battery system and charge it at those times for free, maybe someone who is renting could have this.

          • Sorry, yes I had looked at that, but I’d need to use it for a lot of years to recoup the cost. And the surplus in the other 3 seasons easily (for now) covers any excess winter bills.

      • Do you expect Western Australia’s regulations to limit the input and discharge to 5kW to possibly change in the future? Is this a modified hardware unit or just some software that limits it?

        I want to invest in a Powerwall 3 for the extra discharge and charge rate to run our future homes AC on heat wave days whilst not eating into the grid and also possibly to aid charging an EV in the future, if I’m going to spend close to 20k on a solar battery system I would sure hope I don’t ever really need to dig into the grid. I believe a 5kw discharge system will still leave me drawing from the grid in times of peak power.

    • Glad you mention the growing dislike of Elon Musk. For me this is a main reason I would avoid anything Tesla. We really need to support companies with better social and corporate responsibility.

      • For the uninitiated please describe the corporate and social responsibilities you touch on!

        • Read the news much about his behaviour? Do you really need a list such as his sacking staff and then bragging about it with Trump, inciting riots in the UK online, not taking down violent videos after being requested by our government flagging them as inappropriate, falsely accused one of the Thai soccer team rescuers as paedophile publicly, spread hate on X against trans people, disinformation about covid plus heaps of promises that never happen such as hyperloop in the US and everyone waiting for the bullet proof cyber truck..😂 I can understand alot of installers read these blogs and this is a potentially not a great look for their business to be associated with or to admit being true.

          • Musk went all-in supporting Trump in the final few months of his campaign.

            Thereby alienating slightly less than half of Americans who voted, and the rest of the World who think Trump is a less than ideal human being…lol.

            Tesla EV sales…crash?
            Tesla PW3 battery sales…burn?

            Perhaps his plan is to offload cars and batteries, and run with tasty US Government contracts for space and spy satellites etc?

            Anyway, we shall see how things play out, but along with all the other unhinged Musk commentary, I see a lot of unnecessary risk for people buying Tesla products.
            Too big to fail? No such thing.
            Sack the CEO? Tricky, as he hold 23% of the Tesla stock.

          • Anthony Bennett says

            Hi Drew,

            I imagine Tesla would be protected by tariffs on Chinese EVs in the US, but outside of that, in the rest of the world the much lower percentage of people who support trump/musk aren’t likely EV enthusiasts.

            Foreign EV sales are tanking in China, so the incumbent car industry is looking down the barrel now.

      • Hitler created Volkswagen and tens of millions drive them because they’re often great vehicles. I always remember that over 130,000 people work at Tesla, many of them brilliant. No point punishing them because the CEO behaves badly.

    • christopher says

      I still can’t see how batteries make financial sense yet. The cost need to be going down not up!

      After my solar I’m only buying $30 a month of electricity.

      Let’s say best case the battery could eliminate that completely that’s 32.5 years to break even.

      Let’s say I was buying $100 a month and able to completely eliminate it that’s still 11 years to pay off a 13k power wall before you start seeing a benefit.

      • Mine on current trends will pay for itself inside 10 years, which is well within its warranty period. I also challenge the idea that a battery has to be cost-neutral to be worth having. We all own cars when it’s far cheaper to use public transport or even taxis and rideshare. Sometimes you pay for functionality rather than just to save money. In our case we’ve already in 2 years had multiple power outages in the area that we were insulated from. It’s nice to have that security. With the Powerwall you also get the superb analytics through the software for managing your power usage more generally.

        • christopher says

          Yeah but 10 years just to break even means you have paid more for electricity until that 10 year period. That’s like buying 10 years of fuel at a slightly discounted price. There is better ways to save money.

          The cost benefit in time you save for a car you use multiple times a day isn’t even a comparison.

          13k is alot for 2 power outages. You could have alot of fun for 6k during a power outage.

          You can get great power monitoring for $100 and most solar systems come with it.

          The only really valid reason is for environmental reasons.

          • I don’t pay for any electricity, we run a surplus every year. If it pays for itself in 10 years, that’s 10 years of zero electricity bills for us. So essentially it costs us nothing over that period, and we get the extra functionality for that zero outlay.

          • Chris Waters says

            I don’t know what math you are doing.

            If it pays for itself in 10 years that means it’s takes 10 years to pay off the system. Let’s say that system costs 13k

            You would have to save 1300 a year for 10 years. That’s just to get back to $0

            Because you start at -13,000……

          • Chris Waters says
            September 2, 2024 at 12:31 pm
            I don’t know what math you are doing.

            If it pays for itself in 10 years that means it’s takes 10 years to pay off the system. Let’s say that system costs 13k

            You would have to save 1300 a year for 10 years. That’s just to get back to $0

            Because you start at -13,000……

            If I didn’t buy the Powerwall I’d be paying that much for electricty for 10 years. This way I pay the same amount, but get the added functionality of the battery. And it’ll keep running well after warranty, so even financially I end up way ahead.

          • Chris Waters says

            I can’t tell if you are trolling or not…

            Let’s say you have 13k cash. You can either buy a powerwall for 13k and pay nothing for electricity for 10 years.

            Or B you can use it to buy 1300 a year in electricity.

            The net outcome after 10 years is the same. You have a balance of 0 from your 13k.

            After the 10 years when the Powerwall warranty is over then you start to see a financial benefit.

            Not before. And that’s best case scenario.

          • Anthony Bennett says

            Hi Chris,

            Some people put great store in having an extra layer of reliability when for instance, storms lash the southern states like they have this week. It might be a little harder to justify but replacing a freezer full of food and having to move out of your house for a couple days can be an expensive exercise even before you consider the time and inconvenience.

            There’s a lot of different methods to go beancounting but none of them really warrant getting worked up about. It’s like arguing about the return on investment on your couch, or running a cost benefit analysis on your dog. Worse still are the breathless troglodytes who insist EVs are too expensive, only to exclaim about how fast they depreciate after purchase.

          • Chris Waters says
            September 2, 2024 at 8:54 pm
            I can’t tell if you are trolling or not…

            Let’s say you have 13k cash. You can either buy a powerwall for 13k and pay nothing for electricity for 10 years.

            Or B you can use it to buy 1300 a year in electricity.

            The net outcome after 10 years is the same. You have a balance of 0 from your 13k.

            After the 10 years when the Powerwall warranty is over then you start to see a financial benefit.

            Not before. And that’s best case scenario.

            That’s exactly my point. It’s not costing me more to own the battery than not owning it. And I get its functionality. If I didn’t buy the battery, I’d still be $13K out of pocket, but without the functionality. And I’ll get a financial benefit after 10 years as a bonus.

          • Not really you can’t put a price on a pet.

            Ita pretty easy to put a price on electricity.

            Let’s say you have 2 blackouts a year. That’s 6k per Blackout. You can buy yourself a whole new fridge, stay in a fancy hotel and dine out for afew nights for that costs.

            I think I’ve had 4 blackouts in 20 years and they have lasted a few hours. Not sure where you are living maybe buy a backup generator they are cheap. Or a camping fridge with solar even cheaper.

            I’m a big advocate of EVs. If you are in the market for a nice car around the 50 to 60 k Mark you would be silly not to buy an ev.

            You wouldn’t shop a 60k ev against a 30k Mazda 3. You would never see a 30k saving in fuel over the lifetime of the vehicle.

            It’s the same scenario as the battery.

          • Anthony Bennett says

            Hi Chris,

            I have a camping fridge but it’s stored at my Uncles, that’s a 2 hour round trip and at 35 litres it holds less than a tenth of my freezer.

            I’ve done batteries for customers who have paid them off in four hours… because that’s the duration of an outage that will kill $20,000 of pet fish, not including the hours spent cleaning up afterward. An outlier perhaps but perfectly easy to calculate.

            A generator might be cheap but as an off grid electrician I assure you it’s the genny that makes my phone ring. They’re not as reliable as sunrise, nor are they automated unless you buy something upwards of $5000. Plus they need maintenance, fuel, trickle charger and a cranking battery.

            You might shop a $35k MG with 10 year warranty against a Mazda though, especially if it has a V2L inverter and you can use the battery to run your house. Not only does it save money in fuel, it saves money in electricity, and security.

            https://www.solarquotes.com.au/blog/hoem-review/

            Not everything is about price though. Some people just want Tesla’s shiny white marketing.

          • “Let’s say you have 2 blackouts a year. That’s 6k per Blackout. You can buy yourself a whole new fridge, stay in a fancy hotel and dine out for afew nights for that costs.

            I think I’ve had 4 blackouts in 20 years and they have lasted a few hours. Not sure where you are living maybe buy a backup generator they are cheap. Or a camping fridge with solar even cheaper.

            I’m a big advocate of EVs. If you are in the market for a nice car around the 50 to 60 k Mark you would be silly not to buy an ev.

            You wouldn’t shop a 60k ev against a 30k Mazda 3. You would never see a 30k saving in fuel over the lifetime of the vehicle.

            It’s the same scenario as the battery.”

            I’m not sure the maths is difficult here. I’d have to pay the $13K for electricity without the battery. With the battery I don’t. It’s costing me $13K either way, but with the battery I get the extra functionality, of a battery, for my $13K.

  2. 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?

    • Erik Christiansen says

      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!

        • Erik Christiansen says

          Wal,

          My EV charger is just a Victron unit, on a 32 amp circuit. With 12 kW of PV inverters, and 16 kVA (12 kW) of battery inverters, there’s no sweat pushing 7.3 kW into the EV, 2.5 kW into the HWS, and another 2 kW into the electric kettle. Even after a software update, the “Automatic” mode fails to start EV charging, instead showing “Waiting for sun.” in brilliant sunshine. So I just use “Manual” mode, and drop the charge rate via the phone app if overcast moves in. If it’s just intermittent clouds, then the 46 kWh house battery can maintain EV charging for about as long as you like.There are other EV chargers, but I haven’t tried them.

          My MG4 will only deliver 2.5 kW or so of V2L, but if fed into the house battery early enough, then it can handle power peaks. There’s another SQ blog where one or two MG4 owners use the V2L to charge the battery via a spare inverter/charger. Another poster suggested that the neutral earthing in the main switchboard would trigger the MG4’s earth leakage protection if I tried feeding into the Victron inverter’s generator input. I haven’t tried it, as the house battery usually stays well above 80%, as the 27 kW array supplies low level consumption plus slow battery charging even in medium overcast all day. I figure that’s all too complicated for general use, and an integrated bidirectional solution would be very handy. Only Tesla could develop it quickly, I guess. The rest are still figuring out just half of it.

          • thanks again Erik – my setup is similar to yours with plenty of panels and plenty of sun. You have convinced me that I could install a nicely integrated LiFePO based system with EV charging now and use a BYD or MG EV for backup. I have some thinking to do and some decisions to make!

        • Tesla’s products are just not designed for permanent off-grid use. You will be far better served working with products that are, and there are plenty of them.

      • Hi Eric – what do you use to manage EV and HWS charging – the Victron EV Charge Station?

        • Erik Christiansen says

          Wal,

          As mentioned, I just have the Victron EV charger – the newer oval one without display. There had been some problems with the old square one, which may be fixed now, but the oval one serves as a cable “reel”, taking the one loop of the fat cable very neatly indeed, and there’s an accompanying plastic receptacle to take the plug so it doesn’t just dangle.

          Automatic mode doesn’t work for me, even after a software upgrade, so I don’t leave the car plugged in, relying on an auto-start next sunrise. If it’s sunny, I plug the car in, and let the full 7 kW rip unless it’s overcast. In that case, I typically set 16A instead of 32A, for a 3.5 kW rate. If a bit is then taken from the house battery, then with 46 kWh, it doesn’t matter. Charge rate can be set in the EV or by phone app.

          The advertised automatic “Solar surplus only” EV charging has not eventuated, and the Victron wholesaler has no solution, but I get by with the manual method. I could probably manage something with Home Assistant, if I worked my way into it, but there’s so much else to do first.

          I really need to take another look at a power diverter for the HWS, e.g. Catchpower. It works out of the box if you’re on-grid, as a current transformer simply looks for export as a sign of solar surplus. I’ve forgotten whether any of them frequency detect to do the same, as my off-grid system goes from 50 Hz to 52.6 Hz to throttle the AC coupled Fronius inverters when there’s surplus solar. (I’d completed a design and circuit board layout for such a device, but lost momentum in the winter gloom. I need the check it, send the CAD files to China for a couple of boards to be made, populate them, fix any hardware faults, and write a bit firmware for zero crossing detection and frequency discrimination, plus the triac control. It needs a bit of quiet time – not always in ample supply. And don’t tell anyone, but at 70, there are days when energy flags a bit, at least in winter.)

          • Anthony Bennett says

            Hi Erik,

            I’m sure that the CatchControl will respond to frequency so if you’d like I might be able to put you in touch with them?

            Selectronic have an answer for switching loads that’s detailed here https://selectsupport.helpdocsite.com/tech-notes/tn0075-how-to-create-a-low-cost-indicative-irradiance-sensor-pyranometer-for-24v-48v-sp-pro-s

            I can’t recall if the blue boxes have an analogue input that’s suitable for this but I imagine there’s a workaround for it?

            The only other Victron EV charger I’ve had feedback on had the same issue with automatic mode not working.

          • Erik Christiansen says

            Anthony,

            If you have the time for a short blog on “Power diverters for Off-grid vs On-grid” in the near future, it’d help Wal by the sound of it, put the information out to a wider public, and give me just a little time to have another go at an own design, before taking the easy way out.

            It would be an opportunity to show the utility of delta-f in providing simple cooperative energy management in the domestic environment, across vendors. OK, it can occasionally be necessary to configure the throttling stiffness on a PV inverter to match the slope of the gridforming inverter, but it’s still quite simple. If there really are vacuum cleaners and bargain TVs which go wobbly on 53 Hz, then I have never seen it. (And like Donald Sutherland, I’m not sure that the problem isn’t more Moriarty’s negative waves.)

            The 2% of off-gridders is growing, and an illustrative comparison with the on-grid use of a Catchpower would keep the whole audience interested, I figure.

            A few words on compatibility of Selectronic, Victron, and Fronius with phase-control vs burst mode would be wondrous, as the former generates some electrical noise, including radiative, but the load pulsing of the latter might cause funny acoustic noises from the transformer. (I’m in two minds on evenly spaced cycles at low diversion % vs a bit random to reduce transformer core noise if the laminations are very slightly loose.

            My 2.3 kW HWS is plugged into a GPO, and sits above the woodbox in a brick niche in the lounge room, so I just switch it on in sunny weather, and off at dusk. So I’m hurrying slowly with the diverter. Having moved in only half a year ago, I still have to put doors on the HWS alcove. (There’s a chookhouse rebuild under way at the moment.)

          • Anthony Bennett says

            Hi Erik,

            Thanks for the ideas, I think I’ll need you to write it at this point. We should have a yarn sometime 😉

          • Erik Christiansen says

            Anthony,

            If you point me at a Catchpower technical chap for a few product details, then I could pen an article describing the ease of off-grid delta-f interoperability, using the diverter as an example. Dammit, it’d then be best for me to install one, so I could speak from experience – after all, the difference between theory and practice is much greater in practice than it is in theory.

            I figure there’d be a graphic or two we could draw on to convey the installation detail with a minimum of arm waving.

            After an iteration or two, we should have something worth sharing.

      • Hi Erik!
        Do you do off-grid / hybrid design work?
        Cheers

        • Erik Christiansen says

          John,

          I did design mine, the largest my installer had worked on, and it serves me and the EV very well, being a comforting bit more than is currently needed.
          I pulled him up on inadequate load sharing between the two battery inverters, and he ripped out both the DC and AC wiring to them. The former was unequal length, and the latter was daisy chained. Once that was fixed, he put clamp meters on both, and admitted from up the stepladder “They share now!”

          I advised an acquaintance with navy engineering know-how, relating the effect of solar inverter input limits on array dimensioning, and reviewing his design until it came up to scratch. I also gave him 5 pages of things to consider, beginning with the most basic – if you want to drink the water off the roof, then you might just want lead-free panels, through the seasonal benefit of panel elevation angle, to system redundancy and starting motor loads. He was initially keen on going 3 phase, but settled for a hefty single phase installation as simpler and a bit cheaper.

          But to do formal designs, I’d have to gain CEC accreditation. That involves a course and buying a few thousand dollars worth of related standards. I’m more afraid that I’d be buying into a workload that’d leave too little time for my own retirement projects. However, I’m keen to assist folk become more climate resilient, and energy independent. Understanding the architecture of one’s installation and its general capability is worthwhile for an off-gridder, so maybe you could see how far the notes take you, and I could add a system architecture diagram or two, as examples. My favourite, half AC coupled, half DC, has automatic black start, and can be down-scaled by leaving some bits out. And I can discuss cost saving battery options, from experience.

          I’ve installed a wood heater and in-flue water heater. That dramatically reduces winter power needs, in low sun. There’s much to consider for budget off-grid comfort.

  3. 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

    • Purchase choices are not always rational. Perceptions do matter when it comes to selling a brand and sometimes the reputation of the artist affects one’s view of the art.

      If corporate behaviour standards were a purchasing factor, then use of watchdog/ranking sites might prove more helpful, e.g.:
      https://leadthecharge.org/

    • So true. Glad you pointed this out. I know people that bought non Tesla cars and can’t drive out of the cities for fear of non Tesla chargers being out of action. Check Plug share, try doing a non Tesla drive Sydney to Melbourne easily. The bigger picture is that Tesla shouldn’t be defined by its CEO who owns about 13 percent, that’s honestly ridiculous. Their big batteries are ground breaking and are doing more to destroy gas and coal generators than any other company. Do people really want to destroy an excellent company just because of Elon? Let Tesla keep doing their good work in killing legacy car and power generators.
      Anyway, great article. I’ll be getting a PW3 for my new system later this year. I’ll also stick with Tesla for now for now.

      • Kia EV6 Sydney to Brisbane via coast and inland without problems.

        In fact paying more to use slower Tesla chargers makes no sense to me.

        Now get off the east coast road and try drive a Tesla without using alternative charging networks.

        You know the actual spread out ones like Chargefox and Evie that have massively more locations than Tesla.

        The Tesla cult needs to look around and open their eyes. The rest of us are doing just fine without supporting Elone and his horrific business practices.

        Tesla being the class leader was true a decade ago but they didn’t really change since beyond treating their staff and customers in a more toxic manner while the rest of the industries they partake in moved ahead.

        Now I have a pair of powerwall 2s (because at the time of purchase they were the best bang for my buck) and I did plan to add 2 more in the future.

        But the move to powerwall 3 means I will instead be replacing my powerwall 2s with another battery system without the compatibility issues.

        My plan is to have 40 to 50kWh of storage on my 3 phase system with 15kW of Enphase solar that already exists on my roof.

        I want a compatible system I can upgrade when I find it suits me. I don’t want Elone Musk to dictate what I can do with my system in the future. Walled Gardens are bad. Walled gardens controlled by an unstable CEO are horrific for consumers.

  4. Beau Roberts says

    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.

  5. Arthur Bastoni says

    In WA, Powerwall 3 output is limited to 5kW, meaning WA reduced the integrated inverter capacity to 5kW… Shame

    • In WA it really only pays to stick with DC coupled everything. I’ve gone SolarEdge and plan on putting in a SolarEdge DC Battery, knowing that it will cost more, all because of the WA regulations that make it more difficult. The SolarEdge new DC EV Charger is basically all that I am waiting for now, and of course the SolarEdge guidance on increasing rooftop PV with the DC EV Charger (hoping they allow full 200% oversize).

    • Paul Nankervis says

      I am in WA and am considering PW3 even with the 5Kw export restriction. Howerver I would like to clarify whether this will limit the unit to 5Kw of total throughput, or whether on a sunny day the unit will be able to output 5Kw of AC and simultaneously charge the battery with up to 5Kw – thus making 10Kw of panel useful?
      Also I notice that many states are implementing dynamic export limits (seems like a real step forward) – any thoughts on if/when WA will go down this path and whether PW3 will get this capability?

      • Anthony Bennett says

        Hi Paul,

        That’s a question I’m seeking clarification on. Standby for some details.

        Cheers

        • Peter Davidson says

          I’ve already ordered the Tesla PW3 and 13.2kw of Risen panels. Unfortunately our regulations in WA only allow 15amp into backup and 5kw of export, so I’m also very interested in whatever you can find out for Paul.
          I’m hoping that if the regulations change, that the PW3 inverter can just be tweaked to the full 10kw, or if it’s an actual 5kw version, then it can simply be swapped out, same with the 15amp backup limitation, although I’m not holding my breath for Synergy to change anything soon as they simply don’t have any competition to prompt them to offer anything other than what they want to give.
          The thought of going off grid did cross my mind, but as I’m retired to care for my sick wife, the rebates and energy supplements that we’ll get I think are better value and more likely to get me to a no net cost for energy for the next 20 or so years that either of us could potentially last in this house than spending even more to go fully off grid for the same no net cost.
          As we’ll be back to stony broke after investing what lump sum we have the most important consideration for me was longevity, warranty, and simplicity without having to get a bunch of different bits and pieces to get to cover more than just one circuit during a power outage. I don’t want to chose between running the fridge in the kitchen and a cPAP machine in the bedroom. I want both. I can sacrifice the pool pump and the air-conditioning unit and drying my clothes, but it would be nice if the Powerwall 3 was allowed to do what it can do rather than be hobbled in Western Australia, and if the regulations are ever changed at least my system is potentially ready to do that.

          • Peter Davidson says

            This is an extract from the update that I just received from Empower.

            “We’re reaching out with an important update regarding your Tesla Powerwall 3 installation. Western Power has now approved the Powerwall 3 for use within their network, which is a key step forward. However, please note that we still need to submit an individual application for your specific installation.

            Additionally, Western Power requires a zero export limit with AMI (Advanced Metering Infrastructure) control for Powerwall 3 systems. This means that any excess energy your system generates will be stored in your Powerwall 3 for your own use rather than being exported back to the grid. This change is aimed at supporting grid stability while maximizing your self-consumption”

            Installation in 3 weeks time.

    • Paul Nankervis says

      Just wondering if anyone has thoughts on solar export limiting…

      We are slotted in for an installation of a Powerwall 3 in Perth – and for a single phase Western Power connection that means a hard 5Kw inverter limit.

      Western Power also require emergency management of solar export through either a Cloud API to dial the inverter down further, or metering control to completely shut off solar during a management event.

      I would have preferred the Cloud API but this solution is not yet available for Powerwall 3 on the Western Power network. I gather it is still being worked on and I can’t get a date for when it will be available, but possibly late January?

      If we elect to install with Metering control we can be up and running almost immediately. On the Powerwall 3 this would be set up to put the Powerwall into island mode instead of turning off the inverter. So backed up loads would continue with power from the battery/inverter while non-backed up loads would continue on the grid.

      Of course when we choose a particular method we are not allowed to change later.

      I gather that Cloud API management occurs more frequently than metering control. In fact metering control seems to be rather rare in Perth, so far – I can’t see any recent events listed for here. But when it happens we would be limited to 5Kw from whatever was available in our battery. If the battery was flat or there was some other problem we would be sitting in the dark. If we turned on the toaster, the kettle and a couple of other things we could exceed 5Kw.

      I am tempted to sign up with metering control as it can be installed immediately. But perhaps I should wait. Any thoughts?

      • Anthony Bennett says

        Hi Paul,

        The WA rules certainly aren’t solar friendly but it sounds like you’re across the issues. If you have 20kW of DC coupled solar on a PW3 then I’d be surprised if you were to run out of energy during an outage, as the solar will still work when the PW3 is islanded.

        I take it the metering control system is like the initial round of “smarter homes” in SA where they just used a dumb contactor inside the meter to switch solar off. It’s the emergency backstop or last resort option.

        I’d be interested to know if it’s possible to put the PW3 into zero export without disconnecting from the grid, using the meter control circuit to trigger the PW3 instead of just disconnecting it. Whether the DNSP would find that acceptable would be an other question.

        My personal favourite is still the Selectronic SpPro because it’ll give you bulletproof performance in an outage, you can add batteries incrementally and there’s no limit to the amount of DC coupled solar you can install. Worth asking the question about them.

        • Peter Davidson says

          Latest update from my installer, was because Synergy has restricted all new systems to zero export limitations they have now been allowed to apply for unrestricted use of the built-in inverter to supply 10kw of power to the house. This will mean full back up as well. So when the PW3 is not charging, we’ll have upto 10Kw of usable power to run everything in the house. We’re just not allowed to export anything to the grid.

          • Anthony Bennett says

            Hi Peter,

            That’s very interesting, do you have a link for reference? If PW3 can run as a 10kW machine then they’ll have the market sewn up.

            WA power authorities are still despots though, they’ll reap what they’re sowing as battery prices fall.

          • Hi Peter, I did a Synergy application for a 10kW PW3 on a single phase property, with zero export, an hour ago and it went through fine with them, but when I continued with the application through Western Power it was immediately rejected stating that it exceeded the 5kVa limit. So, not sure where your installer is getting their info from, but atm, it’s still not allowed.

  6. 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.

  7. 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)

    • Finn Peacock says

      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.

    • Nick Chettle says

      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.

  8. I don’t understand why a product as good as the Tesla brand has to cause a meltdown about Elon.

    Make it make sense!

    • George Kaplan says

      Politics I’d say. He’s considered Libertarian, votes moderate, but is registered as Independent. If that’s confusing, US politics can be. The problem is that as the Left has gone more extreme, Musk’s been left (no pun intended) behind so is accused of being ‘Right’ and thus intolerable to some.

      Add that he’s anti-censorship – strongly supporting free speech barring things like ‘from the river to the sea’ and other pro-genocide phrases, or that he’s guilty of saying more than few wacky things, and he’s persona non grata in certain circles.

      In a sense it’s similar to every company that has intentionally or unintentionally gotten involved in the culture wars. It doesn’t matter if the product is great, those offended will look elsewhere for options.

  9. 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.

  10. Hi Finn,
    I have 4Kwh of Solar on Enphase Inverters, so could the PW3 still work for me as it’s under 5Kwh? Also will they keep the PW2 for homes where a pW3 doesn’t work?

    • Anthony Bennett says

      Hi Cam,

      If you have 4kW (peak capacity) of solar inverter(s) and another 5kW of PW3 inverter then 9kW total will normally be alright. DNSPs won’t usually allow more than 10kW.

      PW2 is still available but I’m not sure it’ll be a permanent part of the product offering. Depending on the rules where you live it may be worth getting more enphase and PW2 because a hybrid will eat up your approved connection capacity. (eg in SA you can have 10kW of solar and additional 10kW of battery inverters… but 10kW of hybrid is the limit)

  11. I’m building a new house with 3 phase power and a 3 phase car charger. I’m not that worried about backup power from the battery – some would be fine. Charging the car from the solar is a priority.
    Would PW3 be suitable? – maybe it would be comparable to a 3 phase inverter and a cheaper battery.

  12. Thanks, my scenario not covered above, so keen to get views.

    We are in a new build 3 phase house in SA with 13kw of panels and a 10kw Goodwe non hybrid inverter. Have been looking at battery options and given above setup a PW seems best bet. Current best option/quote is some more panels, a second smaller inverter and a PW2 to maximise solar generation and to give blackstart functionality. Main question is based on what is known, would a PW3 potentially be a better solution given inverter is built in?

    • Anthony Bennett says

      Hi Richard,

      I would look at a GoodWe 3phase hybrid and GoodWe EV charger when you need one.

      PW2 with a 5kW single phase solar inverter will do a fine job of essential loads, but it won’t black start if you run the PW2 flat.

      The PW3 might be a goer if you want to add some more solar to it, but it would have to be the Sandgroper Spec 5Kw model to comply with phase balance rules.

      Which brings me back to a 20kW 3ph GoodWe. It will work with your existing inverter as an AC coupled machine, and you could add a heap more solar, all while keeping everything under the same monitoring and management app.

  13. Hi,

    One thing I’m confused about is the 5kw limit for charging the PW3. I’m planning a 13kw solar system so it seems only 5kw can be used to charge PW3 and the rest will go back to the grid if not being consumed? Would it be more effective to have a smaller solar system, say10kw, and a bigger battery or 2 batteries?

    • Finn Peacock says

      Please don’t get small solar! Remember a 13kWp solar system rarely outputs 13kW. e.g. In Sydney a 13kW will peak – on average at about 8 kW. In July about 5kW. ANd that’s only in the middle of the day.

      You size solar to get plenty of solar all year, all day long and in most weather.

  14. If I’m considering a new and large install in WA, 3 roof orientations (west, east and north), is there still merit in the PW3? What are the rules on putting the PW3 within certain distances of doors / windows?

  15. I’ve got a 13.2kW system and just put in an order for a PW3. But just read that PW3 is not designed to be Ac-coupled to systems as big as mine. Can you elaborate? As it was advertised with ability to be both AC and DC coupled.

    • Anthony Bennett says

      Hi Brian,

      Is your place single phase or 3 phase? how big is your inverter?

      Like any other lightweight AC coupled battery inverter, PW2 & PW3 won’t tolerate a solar generator that’s bigger than the onboard inverter for the battery. When operating during an outage they don’t have the capacity to control a large solar inverter without having the grid for stability.

      With PW2, some inverters like Fronius 8.2 can be dialled down to 5kW during an outage, others like Sungrow cant.

      You may be able to take some DC solar strings from your existing system so it doesn’t have the ability to overrun the PW3 and still use your old inverter?

      • My place is single phase with a Goodwe 10kW inverter. Currently the inverter has two strings one 5.72kW and other 7.48kW.

        Are you suggesting I connect one of the strings to the PW3? Or is there a way the PW3 can be AC-coupled to the 10 kW string inverter that’s got the 13.2 kW solar panels?

      • Tony Milner says

        Hmmm, we’ve just had our solar panels installed last week (11.88 kw) and were recommended to go with enphase micro inverters due to potential shading issues, and wait for the PW3 to be released for the battery to be installed (of which there was only an estimated availability date of late 2024 at the time we ordered)

        Based on this article, that appears to be bad advice, not sure where to go from here for battery options?

        We have single phase power

        • Anthony Bennett says

          Hi Tony,

          The PW3 is a pretty gutsy single phase battery and should accept your Enphase system as an AC coupled generator. Where it might be awkward is if your local DNSP has rules about the total capacity hooked up to their poles & wires. If they accept the PW3 as a 10kW battery inverter then they may allow it as an addition to the 10kW of Enphase inverter you already have.

          SAPN would treat the PW3 as a hybrid and you’d have to remove the Enphase gear… or get PW2 I think.

          However I know some DNSPs only allow 10kW of inverter in total, so 10kW of hybrid is ok, or 5kW of Enphase and 5kW of PW2 is the limit, which is a bit ridiculous.

  16. Hi Finn,

    I have a roughly 10kW system with Enphase microinverters and I am looking to add a battery. I was looking at getting a PW2 but it is limited to 5kW power output whereas the PW3 supports 11.5kW output. The higher output on the PW3 would cover any peak power usage in our house when solar is not running, which have generally been around 7-9kW.

    Does my thinking make sense? If so, it then becomes a question of the increased cost of the PW3 (extra $1,500) and how that compares to what I might save by using less from the grid at peak times. On a pure cost basis it might not stack up but it would ensure maximum use of the battery.

    • Anthony Bennett says

      Hi Jeff,

      If you can use the peak output of the PW3 and it helps you avoid demand charges by smoothing spikes in consumption that could be a good reason to have one.

      At the end of the day efficiency is always king. What’s likely most valuable are a few links here; I hate to recommend the Zuccerburg empire but

      https://www.facebook.com/groups/MyEfficientElectricHome

      My Efficient Electric Home has a great community of 115 000 like minded Australians who are ready and willing to offer ideas and valuable expertise on electrification.

      Getting off gas is also a no brainer. It’s cheaper, easier to clean and better for your health.

      https://www.rewiringaustralia.org/

      https://electrify2515.org/

  17. Hi Finn
    I have 3 x 6.6 kw systems and intend the use the original provider to remove the inverters and to Ac couple them to the tesla 3 battery.
    Could this trigger the compliance regulations, warranty and technical issues you pointed out.

    Couldn’t the same apply when retro-fitting a battery to any system as the inverters have to be changed to hybrid inverters such as the sungrow system you recently installed.

    I was going to instal the same Sungrow system but held off till the Tesla 3 arrived because I need the 11.5 kw output to start and run my air con system and car charging system that will eventually be installed and I like the finished look of the Tesla 3.
    Do you envisage any insurmountable problems within reason?

    • Anthony Bennett says

      Hi Samuel,

      I’m assuming you have 3 single phase 5kW inverters on a 3 phase supply, in which case you may be able to leave them in place, assuming you have a Sandgroper Spec™ 5kW PW3 for phase balance.

      I would ask about a 15kW Sungrow 3ph hybrid system. I’ve not asked if the three individual units would play happily with a 3ph master during an outage but assuming they do it would be a great way to use your existing hardware and add more solar and keep everything under one monitoring app.

      • Well the PW3 has an inbuilt inverter. So yes you’ll be good to go with the PW3 as it is will adjust itself to the local DNSP rules

        • Anthony Bennett says

          Hi Saad,

          The PW3 must be commissioned by the installer to work as either 5kW, 10kW or 11kW as dictated by the DNSP. It may be able to dynamically limit output but the inverter can only operate inside the connection agreement from the network. Peak output is fixed.

  18. Hi, Is Tesla going to be discontinuing the PW2 in Aus?
    Seems like the PW3 is better for whole new solar systems where as PW2 is better as an addon for existing solar.

    • Anthony Bennett says

      Hi Dan,

      Word is that PW2 continues for now but Finn has ordered another one for his own place to make sure he gets one.

      You’re right about the new install vs retrofit advantages

  19. David Issko says

    My Melbourne home’s roof has 25.6kW of fantastic LG solar panels, teamed with 65 Enphase IQ7a micros. 2 orientations, north and west. No shading for most of the day. 3 phase for ducted A/C, but not looking to back up the A/C as I know Tesla (and most other battery manufacturers) do not support 3 phase. No issue.

    So, I want to add a PW3, my first home battery I’m considering. Why can’t I just bypass the inverter and use the battery? Then, in 2025, add at least one, if not 2 x PW3 expansion packs.

    Yes, I know I’m paying for ac component of the PW3 I won’t use, but the benefits of the PW3, especially once bundled with an expansion pack (or 2) should offset the extra cost. At least, that’s my thinking.

    Please let me know if you have some additional thoughts on this matter. Looking to have the first PW3 installed early November.

    • Anthony Bennett says

      Hi David,

      Sounds like you already have 366w x 65 = 23.79kW connected inverter capacity.

      One string of 21 micros for 7.68 & two strings of 22 micros for 8.05kW across phases.

      It really depends on where you are and what your local DNSP will allow you to connect… usually it’s 10kW of inverter per phase but batteries may be allowed as additional or it may be a hard limit.

      PW2 has a 5kW inverter, PW3 has up to 11kW but it can be dialed down to Sungroper Spec™ 5kW.

      You can’t use a battery without an inverter, it’s just how the DNSP views it.

      https://www.solarquotes.com.au/grid-connection/

  20. Our late 2016 installed microinverter equipped panels, one row facing east & two west, total 5.3kW. The Enphase S270 inverters aren’t compatible with the IQ Enphase battery which would require an upgrade to the IQ8 series inverters.
    Any thoughts on adding 5kW of additional panels and a Powerwall 3 while leaving the older system alone? We are on a single phase, have an EV charger & car.

    Motivated by a low feed-in-tariff (FiT), a CT clamp allows surplus solar power to be directed to the car battery (in summer). Although an EV power plan now makes charging in the wee hours attractive.

    What methods are used to coordinate household demand and export with two solar systems?

    Although a battery is expensive, a lower FiT has significantly increased our power bills. Furthermore, becoming the annoying Time-of-Use police hasn’t been very profitable. A battery would also make cooling and heating cheaper. Yes, sounds like subjective justification for a PW3, I know.

    • Anthony Bennett says

      Hi Martin,

      I think you’d be a candidate for the throttled down sandgroper spec™ 5kW PW3. Keep your enphase gear, add a heap more solar to the Tesla battery.

  21. Johannes van Schalkwyk says

    Hi Finn,
    I have installed 18.3kW sunpower panels (44x on 3 strings) with a 15kW Sungrow inverter in June 2024 with no battery as I was waiting for the PW3. I have a 3 phase home in Perth, WA. Is the limitation in WA 5kW AC to the home per phase by Western Power. If yes, then do I need to install three PW3 batteries (one battery per phase). Please advise 3 suppliers in Perth WA that I can contact for quotes to install the PW3. Thank you

    • Finn Admin says

      Although you can add a Powerwall 3 to each phase of a 3 phase home if you really want to, it’s a very expensive solution that won’t work very well if you have any 3 phase loads or a 3 phase solar inverter. Just get a proper 3 phase battery, like Sigenergy, Sungrow or Fronius/BYD, and you’ll have a much better system that can back up your whole home and handle 3 phase loads.

  22. Ranbir Singh says

    Based on the recommendations above it makes sense to put Powerwall 3 when it is a new build and that is true in my case but I have a three phase power supply in my new house
    so what I’m not very clear if I put PW3 on one phase or should I put it on all the three phases?
    I’m not concerned if I don’t have a
    1. blackout support as I hardly had any blackout in last 15years.
    2. Feed in tariff, they keep going down

    but what I’m more concerned of is when do I get full benefit of offsetting the retail cost/tariff ? I.e. When it is on single phase or all three phase. And also which is more stable?

  23. I have 13.2kW of REC panels with SolarEdge DC Optimizers and a 10kW SolarEdge Energy Hub single phase inverter. Considering adding a battery but having a really difficult time figuring out which one is best. Looked into the SolarEdge home battery but I dont like the fact it uses NMC chemistry (preferred install location is a brick wall that backs onto my childs bedroom). Hence, I was going to go for the Powerwall 3 but apparently this isn’t a great option for a system like mine ? I liked the idea of it integrating nicely with a Tesla car down the track too. Could you please shine some light on what batteries would be a good option for me ? Do you know if SolarEdge is planning on releasing an LFP version of the Home battery ? Thanks

    • Anthony Bennett says

      Hi David,

      Any AC coupled battery should do but you may struggle to get network approival for mover inverter capacity, as there’s a solar edge inverter as well as one inside the PW3.

      Really I think you’re best off with Solar Edge battery and then you can get their EV charger & hot water controller too. Having everything under the same app is really a boon compared to some of the incompatibilities and workarounds needed otherwise.

  24. hans prychocki says

    DNSP. Dont you just love abbreviations.NOT. As Pauline Hanson says please explain. Regards Hans

  25. I have a 6.6KW solar system on a new house with a 5.5kw Solax Inverter.

    My power bills are on average about $300$ per month for 9 months and $750 for winter months.Winter spikes a lot due to 3 phase ducted air seems to use a lot more electricity to warm than cool).

    My 6.6 array seems to be exporting electricity at around 10kwhs per day on average but the feed in tariff is only 6.8 cents (and falling) so not a lot of credit.

    Am looking to get a battery. Looking at Powerwall3 at about $14,000 or perhaps
    a Sonen EVO 10kW battery plus 2nd inverter for about $8,800.

    So my logic is that the above figures don’t seem to offer a cost effective saving but rather a hedge against future rate increases at which time it would make more sense.

    What do you think?

    Greg.

  26. hans prychocki says

    Thanks Anthony for the clarification and every thing else on that list. Now off to Office works to get a few Reams of copy paper and cartridges, HAH HAH. Regards Hans

  27. Can you have 10.5kw of panels into a 5kw inverter? I see Powerwall 3 can take 20kw of panels and yet the inverter is only 10kw.

    The inverter and panels KW don’t have to be the same?

    Greg

  28. Alex Bailey says

    “Tesla Australia promises the Powerwall 3 will play nice with your current solar array by “AC-coupling up to 5kW of solar.”

    Does this refer to the Inverter output or is this referring to the 5 KW AC charging capacity of the PW3?

    I have 7.66 KW of North-facing Sunpower P3 panels feeding a 6 kw Fronius Inverter (export limited to 5KW) I have a Fronius Smart meter controlling a smart relay that only allows hot water heating when exporting > 3.6 kw ( with an off-peak top up program that runs at night in winter)

    I would now like to add a Powerwall 3, will it work with my existing set up but be limited to charging at 5 KW (leaving 1kw to export)?

    At the same time I would like to add an additional +/- 3.5 kw of solar to a West facing roof to the PW3 inverter to increase solar production predominantly for battery charging in Winter.

    Will this work?

    • Anthony Bennett says

      Hi Alex,

      It really depends if you have 3 phase and where you live, thus how much inverter capacity your network will allow to be connected. PW3 is not a 3 phase machine.

      PW3 having a nominal 11kw, 10kW or optional 5kW capacity means you’d probably need the smallest unit and an exemption from the usual 10kW/phase limit so you could keep the Fronius system. Or you’ll have to remove the 6kW Fronius & connect that solar to the PW3 (assuming it’s compatible)

      With PW2 you can’t have more than 5kW of AC coupled solar when there’s a grid outage, however Fronius have a setting where they can be throttled for this situation. A straight off the shelf solution for you could be PW2 if you can get approval.

      I would like to say you could get a 10kW Fronius Gen 24 with BYD battery, keep the same monitoring platform & not have to lay waste to your 6kW unit, but that isn’t likely with a single phase connection.

    • I would suggest gen24 plus with byd
      Or alternatively Tesla PW3 in conjunction to your existing setup.

  29. Alex Bailey says

    Thanks Anthony, we are single phase and NSW Essential energy so have a 10 kw inverter limit, The appeal of the PW3 was the ability to add a west facing solar array and leave the existing system intact. Replacing the existing 6 kw inverter with a 8 or 10 kw Gen24 and BYD battery is the better option, unfortunately any additional solar would then be on a south facing roof, fine in summer but we really want the extra solar production in winter and during the evening when the existing panels are shaded. staying within the existing setup for monitoring is a plus, Thanks again.

  30. Hi,

    I have 13KW of solar panels, with 3 strings feeding into a Sungrow single phase SGR10RS.

    I understand the Sungrow inverter feeds to my smart meter, then distributes solar generated power across the 3 phases.

    I am planning to add to Tesla PW3, AC coupled, then connect to Amber VPP.

    My question is – Will the Tesla PW3 supply power to all 3 phases of my house ? If yes, Are there any installation considerations.

    Thanks,
    Steve

    • Anthony Bennett says

      Hi Steve,

      Neither your Sungrow nor Tesla will “distribute” power to three phases.

      You will get net metering to even out your retail bill but I’m surprised you have a 10kW inverter approved on a 3 phase supply, as that’s quite unbalanced.

      Search our FAQs for “three phase” and it’ll better explain what the differences are than I can manage via mobile device on Sunday night 😉

      Cheers

  31. Hi guys,
    Can the PW3 black start on a 3ph connection?

  32. I’m building a house later this year then a shed some time in the future. I have room for on the house for 13200W of solar panels. I can put another 6800W of panels on the shed once it is built.

    Since the Powerwall 3 has 3 MPPTs. Is it possible to split the house PV output over two of the MPPTs and run the Powerwall like this until the shed is built and the extra panels come on line.

    All of the house panels are on the same roof section facing the same way with no shading.

    • Finn Peacock says

      Yes

      • Interesting that many people here don’t take into account buying a battery in 2024 dollars is going to improve the financial viability of batteries significantly.

        I am about to get a pw3 installed. We live in rural Victoria and have significant blackouts about 10 times a year. Some for 36 hours many for a few hours. We already have 13kw of panels and are increasing it to 19.6. PW3 has the capability to connect 3 strings of panels so my current panels will use two of them, and the extra panels will use the 3rd.

        We use heaps of electricity and have a 3 hours for free plan in the day. So on a bad weather day we’ll charge the PW3 for free and use the electricity in the peak period. That alone will save us $1500 a year.

  33. Hi, I currently have an approx 10 year old 13.2kw system with 2 fronius 5kw inverters on single phase. I want to add a battery mainly for blackout protection as being rural we get quite a few each year. Is the powerwall 3 something I should be looking at or would I be better off with a sungrow for example? The inverters are out of their warranty period.

    Thanks

    • Anthony Bennett says

      Hi Chris,

      Depends a bit on what you’re aiming for.

      If you want the most robust solution with widest choice of batteries, that will also work with your Fronius snap inverters then get an SpPro

      https://www.solarquotes.com.au/blog/selectronic-sp-pro/

      Using a PW3 would mean binning the Fronius.

      Sungrow would be cheaper, as would Sigen or GoodWe. Though the latter two have good EV charger options, they’re all a little third rate compared to Selectronic.

      • Thanks Anthony,

        I really just want it to keep my whole house going during a blackout and have the ability to run things like ac for example without spending an absolute fortune. Currently during summer I export more than I consume where as in winter I fall short most days matching my consumption with my current system. The idea would be to put on some more panels and end up with around 25kw of storage. The powerwall option to me seems simple where I could put one on now and get an expansion unit later but I am not really savvy with all this solar technology. The SpPro to me seems complicated and the article gives the impression its significantly more expensive than the powerwall for a similar result? Living on a farm we only have diesel 4×4’s so ev charging is not a concern. But we have higher demand for power than most households with various pumps etc running around the property.

        • Anthony Bennett says

          Hi Chris,

          Selectronic isn’t cheap, but nothing any good ever is. The main advantage is that with an SpPro you can treat the grid with contempt. Surge load to start pumps is no sweat. Running a welder won’t bother it. 48v batteries are easy to stack up as you want them. Solar can be added until the cows come home with no permission needed from the network.

          For a farmer I’d liken it to an Australian made OKA 4WD… you can still buy them, custom built, and they’re just unstoppable.

          Telsa isn’t to be sneezed at either but it’s a lightweight hybrid, not warranted for extended off grid use. Like a Hilux, pretty tough but not everything the dedicated fan base might have you believe. If you have 3 phase pumps then Tesla can’t help you without the grid being available.

          Sungrow and GoodWe are solid but not everyone is ready for an LDV or Tata on the farm.

  34. Peter Davidson says

    Just got the approval from Synergy for the new Powerwall 3.

    What does this bit mean?

    “Please note that due to the increase of your inverter capacity, your system will no longer be eligible for the Renewable Energy Buyback Scheme. Eligible customers will be transitioned to the Distributed Energy Buyback Scheme.”

    Does this mean that I’ll need to join a Virtual Power Plant group to see any money? I’m not keen on these as I believe that Synergy only buys power during peak periods, which usually means drawing it from your battery as the sun has already set. I’m not even sure that the PW3 is set up to be in a virtual power plant out of the box, without forking out for more hardware.

    • Finn Peacock says

      The Distributed Energy Buyback Scheme DEBS lets Perth and surrounds residents with 5kW or smaller inverter get paid 2c/kWh before 4pm and 10c/kWh after 3pm for excess solar exported to the grid (50kWh per day limit).

      The PW3 is compatible out of the box with VPPs, no extra hardware required.

  35. Neil Gascoyne says

    Hi guys
    Located Mid North Coast, Red Energy is our supplier.
    I have 13.2kw of solar on the roof connected to a 10kw Gen24 inverter on single phase, it was only installed 10 weeks ago, timing is everything and I would have waited for the PW3 if I had know it was so close to being released. I want to add a battery to the system and would like to go with the PW3 or go with a PW2, the PW3 specs do look better than the PW2 but my knowledge is pretty basic. If I spent the money, would you remove the Gen24 (not sure if I could sell the Gen24 to someone else to offset some cost) and use the inbuilt inverter or does one inverter become redundant. I like the specs and look of the powerwall unit. Happy to look at other batteries as long as they are wall mounted. Any information or recommendations would be appreciated

    • Anthony Bennett says

      Hi Neil,

      Seeing as you’ve claimed STCs against the serial number of the Gen24, it’s not actually worth a great deal as a secondhand unit. You’d have to find someone who wants it.

      I would get a BYD battery for your Fronius, they come in modular blocks and you can mount them on unistrut style galvanised wall brackets used for air conditioning.

      Add a few extra panels to get to 15kW and enjoy the fact you can get a wattpilot EV charger to go with it.

      If you’re prepared to take a hit on the value of the Gen24, the PW3 is a similarly gutsy unit and will accept more solar.

      https://www.solarquotes.com.au/blog/fronius-gen24-review/

      • Neil Gascoyne says

        Thank you for the reply Anthony, I will take a look at the BYD options on the SQ website and make a decision

        Regards
        Neil

  36. “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”

    Assuming an existing array has nominal voltage and current per MPPT for DC coupling to the PW3, what checks and rectifications must an installer perform to a 2019 compliant installation with rooftop isolators and DC cable run through the roof cavity to avoid running afoul of warranty, technical issues and the latest regulations/standards in NSW (Ausgrid)?

    Are there any installers that would consider this, or are they all going to insist, as they have to date, that my choices are to (a) start over by junking my 5KW array and SG5KD or (b) just AC couple a PW2?

    I don’t like the idea of junking perfectly good cells or AC coupling another 5kW inverter. I really want to add a hybrid inverter and a few parallel BESS that can output continuously at 10kW to cover my peak time loads that do occur when the sun aint shining.

    It seems a PW3 can do this as can a SH10RS and SBH HV LFP which seems to have the added advantage of charging at 50A which opens up a few extra uses cases, e.g. supporting the grid when electricity is free between 11 am and 2pm by storing about 36kWh, which is almost equal to my average daily usage between 2pm and 11am

    • Anthony Bennett says

      Hi Doug,

      I agree you shouldn’t have to junk good functional solar. I’ve spoken to one of Tesla’s senior engineers for PW3 and that have no qualms connecting legacy solar (provided it’s within voltage and current spec of course) and it doesn’t endanger warranty.

      Legacy solar does need to be checked to see the insulation is still good. Your electrician might refer to this as “Megger” testing, where they subject the wiring and panels to double the normal operating voltage to see there’s no leakage to earth.

      (The equipment you use to test insulation used to be made by an english company called Megger)

      The other check I would do is a load test and thermal camera image. It needs to be sunny but your sparky can short circuit the array and then measure the temperature of the wiring and particularly the rooftop isolator. Depending on your budget and appetite for risk, I’d recommend removing the roof top isolators in any case. They’re a fire prone point of failure.

      I think PW3 has a limit of 5kW charging rate so you might find Sungrow is better there.

      It would be worth checking your network connection rules, generally 10kW/phase, but if you can get an exception the existing Sungrow could be AC coupled downstream of a new SH10RS.

      The other thing would be to explore AC coupling of your existing solar, but having the PW3 limited to what I call a sandgroper spec™ 5kW unit. ie 5 + 5 = 10kW total.

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