Tesla’s Powerwall solar battery: Revolutionary? A damp squib? Or somewhere in between?

Will the Powerwall change everything?

Will the Powerwall change everything?

Well the release of Tesla’s Powerwall solar battery this week really made waves didn’t it? At a glittering announcement, the company launched the much-lauded new generation in clean energy storage with the type of glitz and glamour unseen since Barack and Michelle first pulled on a boot.

The battery, which as its name suggests may be installed on the wall of a house, is available in either a ten or seven kilowatt hour capacity at a cost of either $US3500 or $US3000. The Powerwall will be available in the northern hemisphere summer and pre orders are now being taken according to the company.

Last week we previewed what the announcement of the new battery would mean for renewable energy and those looking at the Powerwall to deliver household energy independence. We also speculated on what could be a new energy storage revolution and the Tesla rhetoric didn’t disappoint on this score.

Tesla’s Elon Musk came charging out of the selling sheds with a statement saying the revolutionary new wall-mounted battery would change the “entire energy infrastructure of the world”, adding that the Powerwall was the “solution” and the missing energy link in clean energy storage. Etc…etc.

Other news reports have backed this seemingly new phase in solar energy storage, with language reflecting the company’s almost Messianic description of their latest product.

So does the Powerwall solar battery link up to the hype?

Some commentators (including our very own Finn Peacock) have suggested that, while the new battery is a great development, complete independence from the grid at an affordable price is still a way off yet. Crunching the numbers from an Australian perspective, Finn suggests that people take a close look at the figures and specifics before they consider buying the Powerwall, including factoring in the purchase of an inverter/charger.

This article from Nature’s Davide Castelvecchi takes a similar line. While agreeing the announcement represents a major leap in storage technology, Castelvecchi also advises caution in describing the Powerwall as a gamechanger for clean energy storage.

So what have we here? How do we sum up one of the biggest renewable energy announcements in recent times? Perhaps if we say that Tesla’s almighty Powerwall solar battery storage system is a major (even gigantic) step in the right direction with the hint of more to come. However as Finn has pointed out, it may not be the Great Leap Forward in household storage seemingly promised by the electric car company.

Tesla’s Powerwall solar battery announcement may have polarised the experts, but we’re interested to hear what you think. Will the Powerwall tempt you to go hybrid or even completely off grid? Do the numbers stack up for you? Or will you adopt a “wait and see” approach before taking the plunge? Most importantly we’d like to hear your thoughts on whether you believe the announcement this week is a revolution in household solar energy storage.


  1. Tarielle says

    The battery storage system would be great in addition to the solar panels. I wonder though how it will be priced for the Australian market. Will we be having to fork out double the US price?

    • Finn Peacock says

      Hi Tarielle,

      Expect the whole system (batteries, controllers, installation) to be available early next year in Aus for around AU$10,000.

      This is the same price as you can buy the whole shebang in the US for right now. You need a lot more than just the batteries for it all to work with your house.

      Hope That Helps,


  2. Matthew Deegan says

    The exciting news about Tesla’s battery storage and various estimates of its capacity and costings simply reminds us all of something very basic – battery storage can be a waste of good money unless you have first class energy efficiency in place first.

  3. Andy Lemann says

    Rich and Finn, your last two articles about the Powerwall have been very thought provoking. It certainly seems like a big step towards that ‘holy grail of renewable energy’… affordable storage. For me, I still don’t think the numbers stack up because I produce a lot more power than I use. Over the last twelve months we have exported three and a half times as much electricity to the grid as we have imported from it with our 3kW system. This means that our bills are extremely low. Our total energy bill for the year was about $250. This makes it pretty hard to justify spending a further $10k for storage (I’m guessing at the installed price of the Powerwall but Solar city is currently offering it installed to US customers for $7100). Especially because we currently have a very stable electricity supply. We haven’t had one blackout in the last year.

    My parents on the other hand have had numerous blackouts and they only live 15km from us. They have a 5kW system but their bills are still higher (in the order of $1000 a year) so for them the Powerwall might be a VERY attractive option as long as it can provide back-up power during a blackout. This is a KEY point that I have not seen mentioned in any discussion of Tesla’s big announcement. Do you know for sure whether the Powerwall will come pre-configured to take you off the grid in the event of a blackout?

    I think there are a lot of people who would be willing to spend that sort of money just for the security of knowing that they can get through a storm or other blackout event with enough power to keep the fridge running plus a few lights and the tellie. It would require that the Powerwall somehow inform the occupants that they are running on battery power alone so that they knew to reduce their energy use to a minimum. Clearly it can’t store or supply enough power for the average home to keep running large loads like air-con or electric cooktops unless they had multiple Powerwall units. But if the Powerwall could tell them that they are off the grid they could adjust their behaviour accordingly to get them through until the power came back on.

    If it can do that I think the appeal will be very widespread. Then there’s the possibilities offered by the Reposit Power software that Finn mentioned in his last article. It seems too early to be able to predict how that might affect the overall financial equation for solar + storage. If it turns out that I could make a decent return on investment by installing a Powerwall with Reposit Software and selling power to the grid at a much better price than my current 8c feed-in-tarriff, I’d make the investment for sure.

    All of which leads me to think that the electricity companies are likely to keep raising their connection fees (or ‘supply charges’ as they euphemistically call them on my bill) so they can continue to make a profit. Hopefully our regulators will step in to prevent us from getting gouged too severely.

    Thanks for your excellent articles. Andy Lemann, greenyflat.com.au

    • Rich Bowden says

      Thanks Andy for your thought provoking comment. Glad you’re enjoying the articles. The points you raise beg the question: is the Powerwall just a precursor to bigger, better Tesla storage? Or is this as good as it gets? Clearly just one Powerwall may not be enough to power a medium size home though may offer some security during blackouts. As Finn has mentioned it’s the hidden costs that are the killer and at the moment it may not be viable in Australia. But how far down the track before this is so? That’s anyone’s guess.

  4. Rich, Finn, Someone explained this to me the other day and i paraphrase: “if you’re connected to the grid your transformer will switch off if the grid goes down ie you can’t use your solar in a blackout. this is a restriction power companies impose as a term of service.” if your ‘battery’ is on the same circuit this means you probably can’t use your battery. is this correct?

    • Finn Peacock says

      Yes that is correct. At the time of writing, a battery based solar system that can run when the grid goes down is going to be thousands of dollars more expensive than a battery based system that will switch off when the grid goes down. This is because you need an expensive box of electrics to run your house safely in ‘stand alone’ or ‘island’ mode. As batteries become more common, these boxes will go from niche items to high-volume items and the price will plummet. But for now they are expensive – e.g. around $4-$5k for an SMA ‘Sunny Island’.

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