Tesla Powerwall sales kick off in Australia as local installers named

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One Step Off The Grid

Sales of one of the world’s most talked about energy storage technologies, the Tesla Powerwall residential battery unit, have officially kicked off in Australia, as the first three local installers were unveiled on Thursday.

Electricity retailers Origin Energy and Simply Energy, and Sydney-based solar installer Natural Solar are among the first to be named in what will be a growing list of “authorised resellers” of the sleek-looking 7kWh Powerwall, with Origin saying it would begin sales of the battery unit immediately, with installations expected to begin in February 2016.


Natural Solar, meanwhile, says it plans to begin installing the Tesla batteries across four states and in the ACT in January, as part of its latest 4- and 5kW rooftop solar offerings.

Natural Solar managing director Chris Williams told OneStepOffTheGrid on Thursday that he expected to be able to offer his customers a 4kW solar system with the 7kWh Powerwall integrated using a Fronius hybrid inverter for around $13,990 (GST inclusive and fully installed), with added meter costs. $14,990 for a 5kW solar system.

Coupling the Powerwall with a 4kW SolarEdge system would cost slightly more, at $15,390, Williams said.

Williams also told OneStep that he believed that both the market and the technology were at the crucial point where customers could potentially be offered a zero deal offer on a solar plus storage system using the Tesla Powerwall.

“With the right set up, (such a deal could) see the customer be cash-flow positive immediately and own the system outright within seven years,” Williams said.

Origin, meanwhile, is bundling the Tesla Powerwall with Trina solar panels and the Solar Edge inverter as part of a home energy solution it will offer its customers – including the more than 400,000 with rooftop solar – the retailer said in a release. No price was mentioned.

The announcement of the Australian Powerwall resellers was foreshadowed by Tesla on Wednedsay, with a statement confirming that Australians would be able to “put their money down” for the batteries before Christmas, with delivery expected in early 2016.

The Powerwall – which was originally designed purely for the residential energy storage stprage market, to be coupled with solar – will mostly be offered in Australia as a 7 kWh unit, although Tesla has said it will also offer a 10kWh unit that can store power for a week, for backup use.

As we have noted, it is by no means the only battery storage offering – or potentially even the cheapest – on the Australian market, with a large and growing number of different-sized battery storage systems now being offered, as well as a variety of different chemistries.

LW3A1513-copy-582x776But the Powerwall has been one of the most talked about technologies in the energy storage space, its arrival on the scene often credited with putting a rocket under the sector. Certainly, demand for the Powerwall – and other battery systems – in Australia is expected to be considerable.

According to Williams, the number of inquiries his company has fielded about the Powerwall, specifically, have been “staggering”.

“I have never experienced customers who have no experience quoting on solar or energy storage systems ringing up who just say ‘I want a Tesla’,” he told OneStep.

This brand of customer, coupled with those Williams estimates make up the around 50 per cent of new rooftop solar owners with hybrid system inverters already installed – in the anticipation of adding storage – should see sales set off at quite a clip.

“We see the demand is going to be great,” Williams said. “It’s really a case of rolling it out correctly initially, and then ramping it up in Q2.”

With its head office in Sydney, Natural Solar has installers four capital cities – Melbourne, Brisbane and Adelaide – plus Canberra, and says it is confident that the quantity of units it will get from Tesla will meet customer demand.

Williams says all of his installers have had individual training with Tesla, as well as broader training on energy storage installation, to facilitate a smooth process.

“The standards expected of us being an authorised Tesla reseller are incredibly high,” he told OneStep. “We have been speaking with Tesla for a long time and actively pursuing them.

tesla musk“I think one of the things that attracted us was that they are such a large company and offer a very sound warranty.”

Williams says his company was also attracted to the fact that the Tesla battery was that it was “very clearly” designed for households with solar – his bread and butter.

“The Powerwall very clearly not designed as an off-grid solution,” Williams said.

Likewise, he added, “we’re not trying to get rid of grid 100 per cent. I think it’s still highly beneficial. We’re just trying to work to a standard bell curve and cut out 60-80 per cent of our customers’ bill.”

Other advantages of the Powerwall, he says, are that its lithium-ion chemistry means it can be installed indoors or out, and is functional for both single and three phase households (the latter requiring multiple units). It can also be islanded from the grid in the event of a blackout, Williams adds.

“The world has been waiting for a product just like this unit and we are proud to be at the forefront of its installation throughout the country,” he said.

“We see this opportunity as, a chance to educate the public on this ground-breaking technology and more. Australians are among the world’s early adopters of renewable energy technology.”

This article was originally published on RenewEconomy sister site, One Step Off The Grid. To subscribe to the weekly newsletter, click here.  

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  • Robert Comerford

    It can only store power for a week and it is Lithium ???

    • Craig Memery

      Yeah a slight misinterpretation there in the article – the rated capacity is based on full ‘weekly’ cycling (50 cycles per year, 500 cycles over 10 years). I’ve been assuming that the 10kWh limit is affectively a limit to the depth of discharge, rather than an absolute maximum of energy discharged each week/cycle

      • Jacob

        Your statement does not make sense.

        Perhaps the 10kWh version is 13kWh and allows you to extract up to 10kWh of electrons from it and then it says “that is enough Craig! Recharge me”

        • Craig Memery

          Thanks Jacob, maybe let me know which bit doesn’t make sense for you and we’ll have a go at explaining 🙂
          Agreed on the discharge limit as you describe. The question is one of what you can do with the batt before reaching the 10kWh, in the context of Teslas ‘weekly’ 10kWh limit. Eg could you go from 0 to 9 kWh each each day (cycling 63kWh over a week) without reaching the 10kWh limit? If not, why not? If so, why would one choose the 10kWh weekly battery of the 7kWh daily?

          • Jacob

            Look up the Wikipedia page for it.

            The 7kWh uses a different chemistry and thus can be cycled 5000x.

          • Craig Memery

            Thanks Jacob, but my questions aren’t about chemistry or the 7kWh battery, they are about the utilisation and cycling of the 10kWh battery before it reaches the ‘weekly’ rated maximum depth of discharge. The Wikipedia page doesn’t have that info (and I don’t think any of a other literature that’s crossed our path at ATA has it either)

          • Nev

            My understanding is that the 7kw is designed to be used with PV or other power generation on your premises to store the charge until you want to use it (store power during the day and release it at night when you need it), thus reducing the amount of power you’re buying from the utility company, whereas the 10kw system is designed to be just connected up to your normal mains electricity to maintain a 10Kw charge which will be available when the mains electricity is overloaded or some other kind of outage is causing black or brownouts. This is probably not as necessary in Australia where most people have access to very reliable electricity networks but would be of most benefit if you were somewhere with an unreliable supply, or a very hot climate where everyone turning on their AC at once will cause network outages.

          • Craig Memery

            Hey thanks Nev, that’s really helpful, and makes good sense.
            So I wonder how the 10kWh batt copes with partial discharge and recharge, eg just a few kWh each day with some recharge, and only reaching the 10 kWh max a few times a year? If it can cope and still last 10years, it could be better suited to offgrid domestic applications than the 7kWh batt. Might also work for a few kWh of peak supply on weekday evenings while keeping done in reserve for backup

          • Jacob

            “could you go from 0 to 9 kWh each each day”

            No. Because that would be daily cycling not weekly.

            Having 2 models of the batteries is apparently too much for the main stream media to understand and perhaps they should have only made 1 version of the Powerwall.

          • Craig Memery

            Thanks Jacob. It’s not really a question of what mainstream media understands. It’s more about the lack of detail provided by Tesla with respect to the operational limits of the batteries, and the degree speculation required to fill those gaps. Most battery technologies have info that allows an understanding of the relationship between rated capacity, available capacity, DoD, number of cycles and asset life etc. Tesla has not provided this. If the 10kWh could not be shallowly discharged more frequently without major detriment it would be unlike any other battery. Hence the questions.

          • Jacob

            Put it this way.

            10kWh x 52 weeks = 520kWh/year.

            If you extract 9kWh per day, that is 3285kWh/year.

            Clearly you would be using it way more than it was designed for.

            Tesla has dumbed down the info regarding batteries. Instead of saying “this can be cycled 500 times” they said “this can be cycled once per week for 10 years”.

            Perhaps Tesla should have only made the 7kWh version.

          • Craig Memery

            Thanks Jacob, the 9kW question, that was an illustrative example that you’ve taken out of context. And batteries arent rated in kWh/year (or across their life) as you probably know. Yep, Tesla have simplified the message, as they need to for the mass market, as would be expected. I’m interested in understanding beyond that, because regardless how it’s marketed, with different charge or discharge characteristics they will provide more or less energy over the course of their life. This will be a relevant question for people who are looking for some combination of daily cycling and back up power, or balancing output that varies seasonally, especially if they require multiple batteries (eg 3x7kWh v 2x10kWh).

          • Jacob

            Interestingly the Origin Energy website says the 7kWh Powerwall can only provide 6.4kWh.

          • Robert Haylar

            Latest specifications, and some warranty information;
            Capacity of ‘7kWh’ is 6.4kWh.
            Power output is 3.3kW continuous.
            Round-trip efficiency is 92.5%
            Capacity ‘retention’ is 60% at 10 years (end of warranty)

            The cells will be NMC for the daily version. It is likely that the ’10kW’ unit is NCA. Cycle life is much lower for NCA, epecially for small format consumer-grade cells. Larger cylinders, such as those produced by SAFT (yes, expensive) are good for 10,000 cycles.

            Cell ‘chemistry’ is more than just the electrode materials, but also includes the electrolyte and additives.

            The processes used to produce the electrodes, also influence cycle life. In some cells, anode processing can produce some unexpected results, where cycle life at +/-10% DoD, is less that it is at +/-80%. Without full cycle testing, there is no means of accurately prediciting cycle life, nor the influence of DoD.

            It would be safer to stick with Telsa’s once a day/week claim, than to risk it.

        • Mike Shurtleff

          Idiot proof. This is becoming more common now, especially with lithium batteries. Built Battery Management System (electronic charge/discharge controls) prevents abuse of battery, protects from customer mistakes.

      • Mike Shurtleff

        No, you are wrong. Look it up.

        “Powerwall” is rated for daily full depth cycling, with warranty for 10 years use, i.e. 3,650 cycles over 10 years.
        US$3,000 for 7kWh from Tesla works out to $428/kWh. (Transport to Australia, exchange rate, turn-around efficiency, mark up, and installation will all add to this price.)

        Tesla also has a different battery product, with a different chemistry designed for weekly cycling. …more of a backup battery, not for daily solar PV storage use. I thing this one is lower cost per kWh and warrantied for 10 years use. Mentioned here in article:
        “although Tesla has said it will also offer a 10kWh unit that can store power for a week, for backup use”

        • Mike Shurtleff

          My apologies. I see you are in fact asking about the 10kWh weekly discharge battery from Tesla.

  • juxx0r

    Only $9000, or 44c/kWh. So it will pay itself off when Australia learns how to use an exchange rate calculator, ie. never.

    • Jacob

      There is nothing in the article about $9000

      • juxx0r

        It must be free then, in which case, nevermind.

        • A Wall

          I’m not sure how you get that price (44c/kWh). I calculate $9000 / (7 kWh* 365 days/yr *10 yr) = 35c/kWh (ie. it’s at grid parity in SA). However, if I get one, I can also forgo my grid connection (if I buy a few more PV panels to boost winter production) which probably makes it economic for me at current prices.

          • juxx0r

            I included linear degradation, the impossibility of using a full cycle each day and half the 8% efficiency loss from round trip DC/DC.

          • A Wall

            Fair enough, but surely then you should also consider likely changes in electricity pricing in the next 10 years?

          • juxx0r

            You’re not wrong. But if the powerwall is 44 cents plus the solar to feed it at 10c then we’re talking 54 cents and we could run a genset for half the price, and a fifth the capex.

          • mi

            hey guy, its not just about the bottom dollar, how about, you know like, saving the environment or whatever..

          • Mike Shurtleff

            No, your 44c/kWh is not correct to begin with. 😛

          • Jacob

            As if houses can get electricity from diesel/LNG generators for 30c/kWh.

          • Nick Thiwerspoon

            Isn’t it true that the Powerwall is actually a much bigger battery but that to slow the degradation, Tesla sells it as a 7 kWh battery with software to stop you discharging it completely? And it’s guaranteed by Telsa for 10 years.

          • Jacob

            Where did you get the $9000 price tag from.

          • Mike Shurtleff

            He’s trolling

          • A Wall

            You’ve bandied around accusations of trolling several times in this thread, Mike. I suggest you be more restrained in future.

          • Mike Shurtleff

            Agree, went off here and was wrong. Sorry.
            Don’t, usually more careful of gender references.
            $9,000 is a huge mark up from cost numbers from Tesla I’ve seen.

          • A Wall

            I was referring only to Juxx0r’s original post and questioning their maths — I wasn’t putting the $9k value there as a definitive price (I remain hopeful it will be less)

          • Mike Shurtleff

            $9000 is bs. See comment above.

            “Price of 7kWh powerwall will be $3,000 US$ from Tesla. Probably some shipping cost and some mark up by installer, also conversion from US$ to AU$. Anyone can do that. You are including GST, installation and inverter to get to AU$5.5-AU$6.0. Up to double the retail cost from Tesla.”

            Craig Memery could be correct about about AU$5.5-AU$6.0, but I’m guessing even this is high margin. That means prices will come down with competition.

            Sounds like you’d be saving money at $6,000 anyway …and gaining security from grid failure …and feeling good about cutting your CO2 output. win, win, and win.

          • juxx0r

            Quote from the article, did you even read it:

            “Fronius hybrid inverter for around $13,990 (GST inclusive and fully installed), with added meter costs. $14,990 for a 5kW solar system.”

            Now i just got quoted 5kW of solar with a Fronius inverter for $6k. If you back that out of the 14,990 above, that gives you $8,990 for the powerwall.

            Now i get that you’d be pretty disappointed that $3k USD turns into $9k AUD, but there you have it, that’s the Australia tax.

          • Mike Shurtleff

            Yes I read it, but admit I did not pick apart Natural Solar cost to try and separate battery cost. I’m already familiar with Tesla battery cost here in US. Also, I missed the part where a 5kWh Solar PV system costs $5,000 installed in Australia …plus the inverter.

            Figure about $1,000 for the inverter. You’re getting a 5kW PV system installed for $1/Watt, wow! I did not think residential Solar PV was quite that low-cost in Oz already.

            Your $6k does not include GST or meter cost.

            Beyond that, I admit you have a point. The point is really that this company is charging too much for the full installation. I would wait till a more reasonable price comes around myself. You don’t know where that high cost is coming from. Maybe they are marking up both the Solar PV and the Battery. They do have the marketing benefit of selling a turnkey solution, with just about zero maintenance.

            Still think you are trolling to put all the $9,000 on the Powerwall …and you’ve only just …finally explained where that $9,000 comes from.

          • juxx0r

            Stop telling me what my written quotes dont include. I can furnish them.

            A $6k installed solar system has about $2k profit built in, the margins stay the same when you use cheaper components.

            Now they expect those margins to continue for what is essentially an appliance.

            Don’t get me wrong, I’m disgusted about the $9k being $9k. I think the above article should call it for what it is, an overpriced toy that will never pay for itself. The dude who came round to quote on my $6k solar said he could do a Tesla powerwall for “about another $8.5k” and he said it would pay for itself in “about ten years”. He needs to put down the crack pipe and pick up a calculator.

          • Mike Shurtleff

            Sorry, that’s an incredibly low cost. It’s hard for me to believe. I am not calling you on it. I don’t live there and don’t have a good reference on Oz prices. ..besides your reference below calls the Powerwall cost from Natural Solar $950 and I’ve admitted defeat. Crack pipe is right. Sorry about that.

          • juxx0r

            No Worries Mike, The 5kWh of Solar currently has about $4k of subsidies within it, So the $6k, is really $10k, but the subsidies take up $4k.

          • Mike Shurtleff

            Ah, thanks.

          • Alastair Leith

            plus soft costs on rooftop PV in USA are still comparatively high to Australia and Germany.

          • Mike Shurtleff

            Tesla is selling the 7kWh Powerwall for US$3,000.

            US$3,000 / 7kWh battery = US$428.57/kWh
            For 92% efficiency: (US$428.57/0.92)/3,650 = US 13c/kWh to store your solar electricity at night.

            If Craig Memery (above) is correct and price will be as high as AU$6,000 for this 7kWh Powerwall battery, then:
            AU $6,000 / 7kWh battery = AU $857.14/kWh
            For 92% efficiency: (US$857.14/0.92)/3,650 = AU 26c/kWh to store your solar electricity at night.

            …and I’m using only 3,650 cycles. Powerwall is probably really good for 5,000 deep cycles …and how many will use full rated capacity each day?

            You can see why demand is already very high.

            …and AU $6,000 for the Powerwall in Australia still seems like a very large markup from US $3,000 to me. May be what the market will bare to begin with. Price will come down.

          • Festar

            I have a 4kw solar system in my roof. I enquirer today for 2 separate quotes to upgrade/add a tesla Powerwall. One was just over$12000 retrofit but recommended totall replace at over $15000 as inverter would not be compatible and other quote was around $15000 retrofit or $19000 total replace. Outrageous me thinks.

        • Mike Shurtleff


          • Craig Memery

            Yes Mike, with a dozen argumentative and misinformed comments in the last hour or so, it sure looks like you are.

          • Mike Shurtleff

            I’ll take that hit. Sorry. Powerwall looks like a bad deal in Oz so far. It’ll change, or another competitor will fill the need at a reasonable price. I’m not misinformed on the cost of lithium batteries …hence my mistake. Wow, what a mark up!

    • Mike Shurtleff

      $9000, you are trolling or your head is on sideways.

      • juxx0r

        “Natural Solar managing director Chris Williams said his company would offer a full solution of 20 x 250 watt solar panels, an inverter and Powerwall installed for about $15,000. Adding a Powerwall to an existing solar installation would cost about $9500. A Powerwall and inverter without installation about $1000 to $1200 less.”

        • Mike Shurtleff

          You win. I lose. I’m sorry about the trolling comments.
          Highway robbery.
          Tesla batteries still don’t cost that much. This is strictly a high price aimed at high demand situation. Buy are they taking it to Australian customers. I hope competition from other vendors will help you out soon.

          • juxx0r

            I hope so too. This was supposed to be the breakthrough pricing we needed, but alas it’s not to be….yet.

    • Mike Shurtleff

      I disagree. Tesla is selling the 7kWh Powerwall for US$3,000. Want to show us how you got the price up to $9000? Wouldn’t it be more honest to state what you think the price might reasonably be in Australia and then work out the price of electricity per kWh, including cycle-life, Depth of Discharge=DoD (if not 100%), and fading over that time? Remember this battery is warrantied for daily cycling for 10 years = 3,650 deep cycles. If that is the warranty, then I’m guessing it is easily good for 4,000 deep cycles. I’ve read the normal number is 5,000 deep cycles.
      US$3,000 / 7kWh battery = US$428.57/kWh
      For 92% efficiency: (US$428.57/0.92)/3,650 = US 13c/kWh to store your solar electricity at night.

      If Craig Memery (above) is correct and price will be as high as AU$6,000 for this 7kWh Powerwall battery, then:
      AU $6,000 / 7kWh battery = AU $857.14/kWh
      For 92% efficiency: (US$857.14/0.92)/3,650 = AU 26c/kWh to store your solar electricity at night.

      …and I’m using only 3,650 cycles. Powerwall is probably really good for 5,000 deep cycles …and how many will use full rated capacity each day?

      …and AU $6,000 for the Powerwall in Australia still seems like a very large markup from US $3,000 to me. May be what the market will bare to begin with. Price will come down.

      • juxx0r

        I didn’t get the price up to $9,000. I got the price down from $15,000 by backing out the solar, then i provided you other quotes from other sources who state the same price i do, and they’re the ones selling it. But you’re all up and down this comments thread with only one factoid claiming everyone else is trolling.

        Try using an LCOE calculator for working out the price of stored power, the results are not as optimistic as you think.

        • Mike Shurtleff

          I’m only claiming you are trolling. Nobody else. …and you only have one quote. You do have a point. Tesla storage is not expensive, Natural Solar’s initial bundled offering is.

          LCOE calc. I’ve done that. No, price is more optimistic than you think. Lithium batteries have been on the market for less than $400/kWh hour for years now. What we’re seeing, and have been, is initial introduction prices of integrated storage turn-key systems. Plug it in, turn it on, and leave it alone. New tech introductions always start high …and initial demand often supports that. (Williams comments support that in Australia.) Computers, cell phones, digital cameras, … it’s always that way. You’re exaggerating the situation, just piss’in all over the potential here. That’s trolling in my book …although you are correct, Natural Solar’s price is high. What the market will bare. It will come down. There is competition.

          I am up and down here more than I meant to be. Sorry about that. I was seeing my comment evaporate when I went away and came back. Still not sure if they’re staying put or not.

          You be a little more fair on cost. I’ll drop the trolling comments.

          • juxx0r

            LCOE as per below figures:

          • Mike Shurtleff

            Found the problem. If I access via Disqus reference my newer comments do not show up.

          • juxx0r

            No worries Mike.

          • Pedro

            $9K for a functioning powerwall seems to cheap to me and I sell in this space. Business and installers need to make a buck and they are not going to install for free considering they are wearing 10 years of potential warranty claims. It is an unproven and untested product surrounded by a pile of Hype. I really hope it works and works really well, but I need proof before I would buy or promote it.

  • Stuart Walsh

    I notice that no article about the Tesla mentions price of unit or installation in after market solar installations. Would have me more interested if I knew the cost of the unit outright.

    • Craig Memery

      I saw one estimate of 9.5k. I’ve tried to deconstruct a few recently published packaged prices and estimates, to estimate the retail cost for just the battery, and it looks like the current offers have the 7kWh one (Inc GST, excluding installation and inverter) at about AU$5.5 – 6k.
      It’s just an estimate though… Happy to share workings and assumptions anyone is interested

      • Stuart Walsh

        Hmm, cheaper for the 15 to 20 old style batteries than this one then. You’d want that battery to come down to half or even third the cost before it’s capable of capturing the market against the others available.

        • Craig Memery

          Don’t forget though that the Tesla includes the smarts for charging, a ten year warranty, is containerised and the 7kWh is the actual capacity (not just ‘full’ discharge). The old style batteries cant compete on that basis.

          • Stuart Walsh

            Still, at the price it is its not for those of us who aren’t cash rich. I don’t want to have to mortgage the home for such an expensive item. I noticed that on an overseas site it was much cheaper than here in Australia, so us poor Aussies are paying over and above what they are “really” worth … again!

          • Mike Shurtleff

            …so wait a while and keep paying the utilities more while you wait. Prices will drop significantly. Maybe fairly soon, maybe not.

            It’s what the market there will bear to start with. Obviously, from William’s quoted comments, there’s already enough demand at those prices already. Lot’s of pent up demand.

            Friend of mine with place in California is going with Aquion instead of Tesla, because he needs to replace his lead-acid batteries now and he can’t wait for a Tesla. He figures he’s just spending too much maintaining his lead-acids in Cal, since we live in Washington state. Long drive every few months. A lot of cash positive solutions for Tesla Powerwall out there, particularly in Australia with your outrageously high electricity prices. Competition will bring the prices down.

          • Mike Shurtleff

            Wait for a while then. Price will come down over time.

          • Alastair Leith

            Once there’s a surplus supply of EV batteries and secondhand EV batteries the prices will continue to fall, there will be options and DIY potential. Check out the performance specs on these batteries and consider how much life for stationary energy they might have after a service life in an EV if not having to do 100% discharge cycles on a daily basis.

          • Gangreen

            Consider that your investment in one of these batteries will pay itself off in utilities savings in 7 years, so even if you have to fork out a bit of cash initially, in the long-run you’re better off!

      • Mike Shurtleff

        Price of 7kWh powerwall will be $3,000 US$ from Tesla. Probably some shipping cost and some mark up by installer, also conversion from US$ to AU$. Anyone can do that. You are including GST, installation and inverter to get to AU$5.5-AU$6.0. Up to double the retail cost from Tesla.

        Two points to remember:
        1. Powerwall is designed to work with a variety of inverters. If you already have an inverter, or if you cost it as part your solar PV installation, then it’s not a battery cost. i.e. Don’t count it twice.
        2. Price will come down with competition, as Ms Vorrath points out. I read Tesla is buying batteries from Panasonic at $180/kWh and build car packs for $265/kWh. They think Giga-factory they’re building will bring cost down to $150/kWh by 2018, $100/kWh by 2022.

        There is competition out there in this area. It’s going to grow fast. Prices are going to drop fast.

        • Craig Memery

          Thanks Mike. No the 5.5-6 does not include the inverter or installation. One Tesla installer has indicated about 9.5k to retrofit, including inverter. And actually only a limited number of existing inverters work with the Tesla so most retrofits will need one.

          • Mike Shurtleff

            Well I could be wrong, but I’ve read the Powerwall was designed specifically to work with a variety of inverters. This unit is well designed to work reliably without much thought, i.e. it protects itself well.

            No way the Powerwall is being sold as a loss leader, even at US $3,000 for a 7 kWh battery, that’s $428/kWh. A friend who works with EVs and EV chargers gave me a cost of $385/kWh for Thundersky lithium batteries some years back. I researched and found that price, less than $400/kWh, was common. That is not the full pack, with Battery Management System (BMS) and other packaging and interconnections …but how much extra can that really be? Certainly not double!

            I’ve argued this before relative to EV battery prices. It is now becoming well known they are lower than the $1,000/kWh that was the claim back then (more than double). I can come on a little strong when I think people are making that mistake. I was wrong on two counts here. Again, I’m sorry about those two mistakes. [I still can’t believe $9,500 for a Powerwall. What an incredible mark up! $3,000 / 7kWh or $428/kWh is high imo.]

            I can provide links on four different companies who plan to reach $100/kWh by 2022 just for lithium, all different approaches to getting the price down. That doesn’t include other chemistries/approaches (eg flow batteries, Ambri LMB, Aquion salt water battery, EOS zinc, etc ). There is certainly competition here.

            I cannot tell you “batteries will get any cheaper in a hurry” because the demand is so high. I can tell you battery prices and storage system prices will drop in price at some point. If you think it’s a technology problem, then you’re wrong. The technology for much lower-cost storage is already here and I’m talking 5c/kWh or less. I’m guessing a storage price drop will be significant by the end of the decade. This is a very large market, a lot of money/profits involved. There is already wide competition. Fights for market share will happen.

      • Mike Shurtleff

        Tesla is selling the 7kWh Powerwall for US$3,000

        AU $6,000 for the Powerwall in Australia still seems like a very large markup from US $3,000 to me. May be what the market will bare to begin with. Price will come down.

        I’ve read Tesla is buying Panasonic batteries for US $180/kWh and producing vehicle power packs for US $265/kWh.
        Straubel and Musk want to get production cost from Giga-factory down to $150/kWh by 2018 and down to $100/kWh by 2022. Batteries or assembled packs, I’m not sure. Does it matter. Price will come down over time …down a lot!

  • Alastair Leith

    So are these to be (metal oxide) lithium ion or lithium iron phosphate batteries?

    LiFePO4 is a technology Musk eschewed when looking for Tesla investors at startup even though he was advised it was a superior tech. I’ve read Tesla now has taxpayer funding to develop lithium iron phosphate type batteries (with it’s partner Panasonic presumably) but can’t find confirmation online(?)

    Kinda ironic given that if Musk had have gone in with A123’s technology developed at MIT and commercialised with a US$249 million grant from the U.S. Department of Energy for building battery two production facilities A123 wouldn’t have gone bankrupt, could have claimed another untapped $120 million grant in 2012 and not ended up as competition bought at bankruptcy auction by Chinese automotive components manufacturer Wanxiang Group.

    • Alastair Leith

      Ok so wikipedia says it’s nickel-manganese-cobalt (for the 7 kWh Powerwall only). Fortunately I donated $3 to the fundraiser last month so I don’t feel to bad.

  • bobg

    It would be really good to see a definitive set of specs on the Powerwall. I have seen articles quoting number of deep discharges defined from 1700 to 5000. Any number below 10 years of discharges will allow replacement costs to overwhelm any savings.

    I have also seen numbers that state the 10kWh unit can support steady state discharge of up to 2 kW. That means if you turn on a heater, AC, or other long term high draw load, you will overload the system. It is not clear what the results of such overloads will do, but overheating of cells seems like a possibility.

  • RnD

    $AUD15,000 fully installed (ouch!) for a 7kwh storage facility and infrastructure.

    Average number of sun or partial sun days Melbourne Australia = 185 days (46 full sun, 139 partial sun)
    Current household average daily usage (5 people) ~ 24kwh (from personal bill)
    Curent average price per kwh at same residence ~ 0.24 cents kwh (from personal bill)
    Assume full daily discharge and assume full charge attained 185 days

    185days x 7kwh x $0.24kwh = $pa saved $311
    assume 365 usage and charge = 365days x 7kwh x $0.24kwh = $pa saved $613

    Using the largest saving the apparent payback is $15,000/613 = 24.46yrs

    Obviously these numbers will change with differential draw down and recharge rates.

    Doesn’t work for me.