Tesla Powerwall 2

Tesla’s Powerwall 2 in Australia: Advice for shoppers

by Solar Choice Staff on February 7, 2017

in Batteries & Energy Storage

Tesla leapfrogged its competitors last year with the announcement of its new generation of battery storage product: Powerwall 2. Tesla’s Powerwall 2 is a more powerful and sophisticated version of the company’s original Powerwall, which itself set a benchmark in Australia for both battery storage pricing and performance. It’s on sale for roughly the same price as its predecessor.

But like many things in Australia’s nascent battery storage market, it’s easy to get confused about details – despite the fact that a proper grasp of the details is essential for anyone who wants to make the best choice possible. We’ve reached out to Tesla directly to make sure that we have the facts straight – and so do our readers.

Below we’ve summarised all of the key things you need to know about Tesla’s Powerwall 2 before making a decision about whether to buy one.

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Powerwall 2 is one of the ‘best value’ battery products in Australia

Battery storage system prices have been coming down steadily in recent years, and Tesla has been leading the curve on cost reductions. Its original Powerwall – which cost about $11,000 fully installed – quickly became the pricing reference point for battery storage system shoppers and industry players alike after its announcement in 2015.

New products flooded the market thereafter, and just as many of them were beginning to compete with Powerwall on price and value, the other shoe dropped and Tesla introduced Powerwall 2. Tesla themselves estimate that a fully installed Powerwall 2 will come with a price tag roughly equivalent to the original (despite the substantial power-ups mentioned below); currently, the Tesla website estimates that a fully installed unit will cost about $10,500. (Actual installation prices may be a bit higher – especially when ‘add-ons’ like backup functonality are taken into account.)

This works out to roughly $780/kWh of usable storage capacity – the lowest price points for lithium batteries of comparable quality now available in Australia. By our estimates, $750/kWh is the point at which battery storage could begin to make good investment sense, depending on how they are used (although $500/kWh would be much closer). Powerwall 2 is the closest to this mark of any other battery product on the market.


Looking back: Powerwall 1 vs Powerwall 2

   Powerwall 1.0 Powerwall 2.0 
 Energy storage capacity (usable)  6.4kWh 13.2kWh
 Power output (continuous/peak)  3.3kW  5kW/7kW
End of life retained capacity 60% 70%
 Inverter  SolarEdge, Fronius or SMA  Built in
Appearance Tesla Powerwall 2 tesla-powerwall-2
Weight   97kg  125kg
 Dimensions (LxWxD)  1302/862/183mm 1150/755/155mm
Mounting Indoor/Outdoor



Floor or wall

Indicative install price $11,000-$15,000 $10,000-$15,000
Indicative price per kWh of storage capacity $1,500-$2,300 $740-$1,100

10 year warranty with two usage scenarios

Most batteries have warranties that stipulate cycle life or ‘energy throughput’ – technical terms that dictate how many times you can charge/discharge your battery per day or over the battery’s lifetime, and how much of the original capacity you can expect it to retain at the end of its life.

Tesla’s Powerwall 2 stipulates two possible usage scenarios. In both situations, the ‘end of life retained capacity’ (the percentage of the original 13.5kWh that should still be usable at the end of 10 years) is 70%, which works out to 9.45kWh. The 70% retained capacity is an improvement on the original Powerwall’s 60%, and means greater energy throughput over the battery’s life relative to its nominal capacity.

  • Where the battery is used only for ‘solar self-consumption‘ – that is, charged only by the sun – there is no limitation set by Tesla on how much it can be used (although there would be a de facto limit based on the amount of sunshine available throughout the year).
  • Where the battery is used for ‘any other application or combination of applications’, the warrantied energy throughput is capped at 38.7MWh (or 38,700kWh). Other applications presumably refer to things like tariff arbitrage (buy energy from grid when it’s cheap to use later) and export to take advantage of high spot market prices (where such programs are available). That works out to roughly same as what you’d get in a solar only charging scenario like the one described above – so if you’re fully cycling (charging/discharging) your battery more than once a day, you may exceed the terms of your warranty before the 10 years is up – although the battery may very well continue to operate long after that point.

There are two versions of Powerwall 2: AC & DC

Please note, the DC Powerwall 2 has been discontinued before hitting the Australian market.

Powerwall 2 comes in both AC and DC variants. While both versions can be stacked together (up to 9x units), come in the same shell and have the same appearance, there are some key differences between them.

DC Powerwall 2

The DC version has no inbuilt inverter, allowing for more flexibility in system design. The DC Powerwall 2 can be used with a range of third-party inverters. The unit has an energy storage capacity of 13.5 kilowatt-hours (kWh) with a depth of discharge of 100% – meaning that the full 13.5kWh of capacity is usable, and making it one of the larger, non-modular battery units on the market. Up to 9x units can be ‘stacked’ behind a single, third party inverter for a total storage capacity of 121.5kWh.

Powerwall 2 is also one of the most powerful units on the market, providing 5 kilowatts (kW) of continuous power output, and up to 7kW in brief 10-second bursts. For most homes, this means that the battery can ramp up to meet all household energy demand, even if you have multiple devices turned on at once.

AC Powerwall 2

The Powerwall 2 with its own inbuilt inverter, so that it can be directly connected to the AC circuits in your home without the need for any other components in between, making it an ideal solution for retrofitting to a preexisting solar PV system. While separate inverter is still necessary for your solar panels, this means that there is no need to replace the existing solar inverter.

The AC version of the Powerwall 2 has a usable capacity of 13.2kWh – accounting for the efficiency losses attributable to the inverter. With 9x units stacked together, it can provide up to 45kW of output power and 118.8kWh of stored energy.

Tesla also says that the AC variant is the better option for off-grid applications, as the inbuilt Tesla inverter is a grid-forming inverter with basic generator control for an off-grid system (estimated to arrive in the the second half of 2017.)

Inside or outside? Wall-mount or ground-mount? Take your pick

Powerwall 2 can be installed indoors or out, on the ground or on a wall. The new rectangular shape also makes it possible for multiple units to be stacked or installed flush with one another side-by-side.

Know what to expect and what to ask for

There are a few different reasons someone might choose to have a Powerwall 2 installed, but almost all of them involve the storage of home-generated solar energy. Previously, we’ve identified a range of possible goal posts that homes might aim for in installing batteries. Below are some of the most common of these goals:

  • A battery retrofit: You have an existing solar system and want to capture excess solar energy for use when the sun isn’t shining (while remaining connected to the grid);
  • A new, custom-sized solar + storage system: You are in the market for a new solar+storage system and want to be energy self-sufficient on a daily basis (while remaining connected to the grid);
  • A stand-alone power system: You want to be fully energy self-sufficient by going off-grid with solar + battery storage.

If your goals are already crystal clear, then it should be easy to ask installers if and how they can help you meet them. If, on the other hand, you’re not yet sure what you’ll be able to achieve within your available budget, it’s worth discussing your situation with a number of installers to get some professional opinions. Which brings us to our next point…

What about payback periods?

Check out our gallery of infographics showing Tesla Powerwall 2 payback periods for each Australian capital city on both flat rate and time of use electricity tariffs, or read our recent article: ‘Is battery storage worth it in 2017?‘.

See payback periods

Who sells Tesla’s Powerwall 2 in Australia?

A number of companies do (including Tesla directly)

Tesla is selling the Powerwall 2 directly to its customers, but the units will also be available through a number of Certified installers who were chosen based on their histories and experience. Even though Powerwall 2’s specifications and warranty are the same across the board, there are still other factors that vary from installer to installer and system to system.

Factors that vary depending on installer and system:

  • History in the industry and experience: A company’s experience is indicative of its ability to deliver on its promises efficiently and punctually. Google reviews online and do your research on the company’s background. Ask for case studies from their other customers.
  • Other components & features of the system (the ‘balance of system’): If you’re looking at a new solar+storage system that includes a Powerwall, for example, what solar panels are they using? Will the system you’ve selected allow you to run on your solar+storage in the event of a grid failure? What sort of performance monitoring will the system have?
  • Installation price: The price of a Powerwall installation is set by the company that sells the system, so you should see a range once you’ve done some investigating. Sometimes the price of Powerwall will be bundled up in the overall cost of a solar PV system, while in other instances you may see the installation itemised separately – as such, it’s important to understand what’s on offer and find a way to make apples-to-apples comparisons on price and components.

All of this brings home the point that consumers will do themselves a favour by shopping around. Don’t automatically go with the first Tesla Powerwall installer who gives you a quote. As with any major purchase, make sure you’re fully informed before you make a decision.

Solar Choice can help you compare quotes from a range of installers in your area.

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© 2017 Solar Choice Pty Ltd

{ 5 comments… read them below or add one }

John June 21, 2017 at 7:16 pm

For what its worth…An honest consumers perspective.
The Powerwall 2 seems like a good product and based on the technical specs, it seems to have stepped up to be a better and more appropriate product. HOWEVER…..
The product price is the least of your concern…once you are locked in to purchase the item online with a large delay to receive it, there is a $3500 to $4000 to install it. That is OFFENSIVE and to be upfront price gouging Australian consumers. Tesla quote a price range on their web site…NOT one of their installers is even close to this. I have tried to find a realistic priced installer and have tried multiple people. No success!

I would like to put it into perspective. The installers all tell me its very technical and their is significant work to connect to the AC switchboard….In short “rubbish”. Its a length of copper, conduit and and AC circuit breaker. (well under $100 in hardware) Lets round up to $200 to be conservative. I also get installers stating their is significant time to program and set up the software???????? That’s not what Tesla experts tell me, someone that is knowledgeable will find it very logical and straightforward? Lets assume that you have a Muppet solar installer and apply some simple mathematics….. $4000 for an A grade electrician at $100 per hour is 40hours work……When you ask the installers that question the topic gets shifted quickly and you will get an new explanation. The short version is they blame Tesla for lack of technical support and problems to download the software etc etc.

– In reality….. there is under $200 in cabling product.
– Installation of the Powerwall 2 and the 2nd controller device, lets be generous and say 1hr to hang on the wall. another 1 hour to cable into the switchboard; lets even allow 6hours to program the device. For the sake of the story lets assume it takes 8 hours (a day) for an installer to be at your home….SO $4000 / 8 hrs = $500 per hour. Hmmmmm That seems expensive?

– The reality is the average installer will do 2 installs day for a competent installer. SO $4000 / 4 hours = $1000 per hour. And by the way the programmer does not have to be an A grade electrician. In my humble opinion NO tradesman is worth $1000-$500 per hour.

I would encourage you to challenge your installer to justify his installation cost.

I would encourage you to contact Tesla and explain that the install cost is not “value for money’. Polite way of saying being ripped off. Possibly a discussion for the ombudsman?

Tesla (Elon Musk) is trying hard in my opinion break new ground, he is entitled to make a profit for the billions he has invested and I am happy to pay him a profit for his risk and capital investment he has done for us. What I detest is fat, lazy scammer solar installers riding on the coat tails of ground breakers like Musk. I still think the Powerwall 2 is expensive and based on a return on investment, it does not pay for its self. Mass replication, innovation and competition will help reduce prices consumers. But installers are milking consumers and we need to apply pressure on installers and Tesla

In summary:
I can by the Powerwall2 with controller off the Tesla AU website for $8750. The blackout software is now supplied free of charge from Tesla. Installers wont installer a Powerwall 2 for the price Tesla suggests on its website. Allow a couple of hundred for cabling supplies. There are no other costs! Tesla is very transparent on the costs. So when any installer offers you a great deal at $12000 to $13000 approx, ask them how long it will take to install and why their days time is $3000-$4000? Remember a good traddie is worth having, however they are not worth $4000 for half a days work! The solar installer industry is scamming consumers and tarnishing the name of Teslas product. If you do the honest numbers on payback on $8750 over 10 or 20 years it is barely worth it. Pay back on $13000 is a down right rip off!

If the install cost for the electrician was under a $1000 I would probably accept that, but think with competition it will get cheaper.

As a consumer I am doing my bit and writing on forums and shinning the light on the exorbitant install cost when I see an appropriate forum. The solar industry Scammers” are killing the idea of cost effective solar and environmental reduction for the future and reduced load on the Australian electrical grid. Please form your own opinion based on my observations and feel free to tell others and write to Tesla.


david April 22, 2017 at 6:53 am

love it


Pat Comerford February 10, 2017 at 8:03 am

Still no information available regarding whether PW2 will be capable of consumption monitoring and display by an app for example. Also will it have an ability to control any loads. These are issues that will influence by purchasing decision


Solar Choice Staff February 14, 2017 at 10:30 am

Hi Pat.

Response from Tesla as below:

The Tesla app will soon enable customers to monitor and control both their electric vehicle and home energy including Powerwall from their smart device 24/7.


Tim Efthymiou April 28, 2017 at 4:24 am

Hi Pat, I’m an early purchaser of PW1 and have been so happy with it, I have ordered the PW2 as well to compliment my 10.5 k.w. solar system. I have a family of 6 and are very big uses of electricity, therefore we need these systems in place to future proof ourselves to future electricity price rises (again there is talk of 20% increase as of 1st July 2017). My electricity bill has gone from $850 a quarter to about $230. that is just the original 5k.w. system and PW1. Now I have recently added another 5.5k.w. solar system and have on order the PW2 should be arriving in the country in the next few weeks (early May, 2017). If you are a big user of electricity, then by all means I highly recommend the PW2, but you will need at least a 5k.w. solar system to be able to charge up a 14k.w. battery, otherwise you will have a situation that the battery will not be getting fully charged at the end of the day. and by the way, tesla has a blackout feature with the PW2 but you have to pay an extra $800 for this feature and you nominate the circuits you want to continue while there is a blackout, e.g. fridge/freezer, some powerpoints etc. I will not be opting for this feature as we have only had 2 blackout in the last 25 years that I have lived in our property and the blackouts only lasted 1-2 hours max. hope this info helps. Cheers, Tim. p.s. my system so far has cost me about $30,000, I expect my bill with the new pw2 installed to be $0. as my system is so large even the daily service fee should be eliminated due to the excess electricity being sold back. Further more the batteries have a warrantee of 10 years, I’m sure if they need replacing in 10 years time, new batteries then will be down as low as a couple of thousand dollars (if not cheaper due to constant increasing competition), already l.g. is offering some fantastic offers. (that’s another story and i’m sticking with pw2).


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