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Tesla Powerwall Price Has Risen By 36% Since 2017

December 9, 2020

By Paul Homewood



We keep hearing how the price of batteries keeps falling (allowing Gummer to get away with the claim that EVs will soon be as cheap as ICEs). However the reality is the opposite, at least as far as Tesla is concerned.

In June 2017, I ran a post on the economics of Tesla Powerwall batteries for domestic use.

This is the what Tesla’s website showed at the time:



Last year, I thought I would check again:





And now?




So in the space of three years, the price of a Powerwall has risen by 36% . (Each quote, by the way, is based on exactly the same specification, the 14 KWh unit).

  1. John Palmer permalink
    December 9, 2020 10:43 am

    As the man in the musical once said “you’ve gotta pick a pocket or two” to become (apparently) the second richest guy on the planet!

  2. December 9, 2020 10:49 am

    Just wait till Harrabin reads this and puts it as a main item on the BBC website.

  3. December 9, 2020 12:58 pm


    I have also studied this. The cost of grid backup is interesting to do, so the true cost of renewables generating alt the energy without without gas support providing most of the. rated output is exposed.

    Recent utility price in USA came out at £480/KWH (2019)

    When I wrote my paper costing batteries I assumed, from a lot of anecdotal evidence of different specific deals, that Li-Ion was $400/KWh, £310/KWh. At this price it is stlll more than commercial grade (not vehicle starter grade) Lead Acid, assuming a 4 year life.

    £1.2 Trillion every 4 years to deliver 1 week of UK demand, 7TWh or more, in a windless February High. Even at an 8 Year life that is £150Billion pa (£1.2T evry 8 years) added to the cost of an all renewable self supporting (no gas backup) grid, which you can pro rate for any amount of renewables not backed up by gas, It effectively increases their cost by £500/MWh, 50p/KWh.

    Not the £1,000/MWh I first calculated. But pointless and aft either way, Nucear is so much cheaper without the backup batteries, even cheaper by a factor of 4 or so on overnight CAPEX per unit energy produced which involves reducing the plated rating by a factor of 4 for intermittency and life.. Both offshore wind and nuclear are normally at $5B per GWh, per the IEA average, not the AREVA /EDF deal. But offshore winf has the problems of duty cycle and life givig the factor of 4 increase per actual unit energy produced, so $20B/GWh, WITHOUT the cost of the backup batteries or uncosted gas support,

    Your numbers may vary. But not by that much. Still Bonkers. Do the arithematic!

    CEng, CPhys, MBA

    • Dave Ward permalink
      December 9, 2020 4:00 pm

      “Lead Acid, assuming a 4 year life”

      And they have the advantage of being easily recyclable, unlike Li-Ion…

      • December 9, 2020 4:10 pm

        The lead acid battery is so recyclable the battery market is considered a closed cycle. Ai least that’s what it said when I researched my paper. But the real problem is storing chemical energy is still low intensity compared to the primary energy source, so takes masses more resources. Laws of physics. Chemical and gravitational potential energy are thin sources requiring masses of physical resource to store. It was interesting that Dinorwig and batteries had the same CAPEX, but DInorwig has a much longer life, so cheaper LCOE, not that it generates, its just an incremental cost to add to renewables to get their true cost per unKWh, etc. A good way to offset a sudden failure, and to re boot the grid power stations if it all goes tits up.

  4. MrGrimNasty permalink
    December 9, 2020 1:30 pm

    Have there been any subsidies withdrawn that were included originally, might help explain the rise?

    • Joe Public permalink
      December 9, 2020 2:57 pm

      Subsidies don’t apply to manufacturers’ selling prices.

      • MrGrimNasty permalink
        December 9, 2020 3:36 pm

        You often see the price of electric cars quoted on manufacturers websites with the local market subsidy already taken off.

        So the question stands.

    • Joe Public permalink
      December 9, 2020 4:59 pm

      So the prices shown by Paul / Tesla are the net prices to the consumer.

      AFAIK for UK, there has never been a lump-sum discount government incentive for a home power battery. In Scotland, there’s an ‘interest-free’ credit scheme.

    • It doesn't add up... permalink
      December 10, 2020 2:33 am

      I think we are seeing the delayed effect of the 2018 price spike. Musk went around buying up loads of lithium and cobalt as prices went stratospheric. Production of lithium carbonate was 53kt in 2017, and surged to 95kt in 2018, before falling back to 77kt in 2019. Prices have fallen back subsequently. But I bet he has a load of metal he signed up for at the top of the market.

      Look at the ten year history (click on 10Y) here:

      A good explanation of the recent market here:

  5. It doesn't add up... permalink
    December 9, 2020 1:40 pm

    I’m finding it hard to get any real figures for grid batteries. All we seem to get are LCOE figures that actually assume a margin between charging cost and discharge earnings to calculate the price they need to break even. That of ourselves is a whole lot of assumptions.

  6. StephenP permalink
    December 9, 2020 2:54 pm

    A problem with battery power for backup is that, once the power has been used, the battery needs to be recharged. So if we are to become dependent on wind power, apart from the massive cost of batteries, we will need more windmills to recharge the batteries over and above the number needed for normal electricity production.
    Looking at gridwatch over the past 8 days, the electricity produced when the wind did blow would have been all taken up in recharging the batteries.

    • ThinkingScientist permalink
      December 9, 2020 3:23 pm

      Wind is currently doing ok – 8.5% of UK demand
      Fossil fuels are providing 58.9% right now, and that will go up as demand increases towards evening peak.

      So currently just to keep up you would have to expand the Wind Fleet by a factor 7x.
      Assuming £10 billion a year now, annual subsidies would rise in proportion.

      In the last couple of weeks there have been days when the UK Wind Fleet would have to be 70x larger to cover the fossil fuel supply.

      So 10x bigger at least.

      Alternatively, the big battery option:

      I did the calculation based on peak fossil fuel requirement being about 55% of demand and added wind at 15%. So when the wind is not blowing we would need batteries to cover 70% at current demand. The numbers are average – not even peak winter! The South Oz Tesla battery was capable of 129 MWh when installed and cost £50 Million

      UK annual demand is about 323,000 GWh
      So daily average is 323,000/365.25*0.7 = 619 Gwh per day
      1 day in SA Tesla Batteries is 619/0.129 = 4800 Tesla batteries

      So 2 days battery backup would cost 4800x2x£50M = £480 billion
      So 7 days battery backup would cost 4800x7x£50M = £1.7 trillion

      The last number is the size as the entire UK national debt before Covid, or about £60,000 per UK household.

      And remind me – what’s the lifespan of the battery? The maintenance cost?

      • December 9, 2020 3:45 pm

        You can double the Li Ion life and it then matches the cost of lead acid battery solution, at £2.4 Trillion every 8 years. So yeah, what you said.

        Roughly, but very definitely stupid and wholly unnecessary if you do it with nuclear, that is 1/4 the CAPEX cost per MWh enrgy output if duty cycle and lifetime are inclconsidered, notpower rating, e.g. based on how much energy is produced per unit CAPEX.

        $5B/GW rated nuclear versus $20B/GW effective rated for offshore for the same lifetime energy. Mixing unitsI know.

      • ThinkingScientist permalink
        December 9, 2020 4:20 pm

        Its clearly not rocket science to work out the back of the envelope costs.

        Here’s another simple way to compare to the cost of supplying the same energy by gas power.

        The retail cost of domestic gas is 2.6p per KWh (on my last bill)

        So 619 GWh / 1 KWh = 619 x 10^6 x 2.6p/100 = £16M per day in gas

        So the cost of supplying the shortfall for 7 days would be £112M

        So just pay as you go using domestic gas retail prices you could cover a 7 day shortfall every year for 15,000 years for the price of the Tesla battery I quoted.

        In fact, for the price of the 7-day Tesla battery you could buy the gas (at retail/domestic rates) for 90 days a year for 1,180 years.

        Who said Green policies were insane and MPs idiots?

      • December 9, 2020 4:34 pm

        More important is what you usefully do with the money wasted on batteries that expensively help overcome the defiencies of wind power we didn’t need to build, in building the most sustainable, lowest footprint, unsubisdised generation at roughly today’s prices that will last 60 years and operate 24/7. And needs no batteries or CCS.

        Nuclear at the real CAPEX of $5B/GW capacity, LCOE £65/MWh?

      • ThinkingScientist permalink
        December 9, 2020 4:40 pm


        If you believe in climate change, choosing renewables is insane. Only nuclear makes sense.

        If you don’t believe in climate change, burn coal for electricity generation and if you want clean cars in towns, convert the vehicle fleet to gas. Cheap and effective and clean with marginal impact on vehicle cost and possible as a retrograde fit (certainly to petrol engines).

  7. Lorde Late permalink
    December 9, 2020 3:19 pm

    So, just like that company’s cars, another virture signaling trinket for the wealthy to discuss when collecting the kids from (private) school.

  8. Allan Shelton permalink
    December 9, 2020 3:55 pm

    Here is a company that is has a process for making batteries better and cheaper.

    Read their articles on thw ebsite.

    • ThinkingScientist permalink
      December 9, 2020 4:37 pm

      Whatever the price of the battery it doesn’t change the fundamental. A battery doesn’t generate electricity, it only stores it. So even if the cost of Wind/Solar generation fell to the marginal cost of generating electricity supply from fossil fuels, in order to make Wind/Solar (or any other intermittent technology) have the key property of deliverabilityyou still still have to add the cost of battery storage on top.

      And Wind/Solar also still have to have over-specified capacity to stand any chance of meeting even average grid demand.

      • Allan Shelton permalink
        December 9, 2020 8:45 pm

        I totally agree with “green energy”. I am a total anti-AGW person.
        But auto makers are building EVs and NanoOne should cash in on the craze.

  9. Nancy & John Hultquist permalink
    December 9, 2020 5:30 pm

    In the USA, I picked up a copy of Forbes Magazine dated December 2020.
    An article referred to as a “Profile” (p.124 -) is about Michael Polsky, titled Windfall.
    He has made millions via the wind farm (sic) route and plans to make a lot more if “only you would get out of the way” and stop opposing construction thereof.

    A final chart (p. 130) is attributed to Lazard Levelized Cost of Energy Analysis, 2020.
    Says “average unsubsidized cost of newly constructed . . .
    Wind and Solar are way below all others.

    If I were not a regular reader of Paul’s “Not a Lot …” postings, I might think all was great and good about this article.
    However, my reaction is – – “This is nuts!”

    • Mack permalink
      December 9, 2020 9:36 pm

      Indeed, wind ‘factories’ only make commercial sense to investors when subsidised by national governments, with the benefit of priority routes to market and constraint payments, and when they don’t have to pay for the transmission lines that connect them to the grid nor the back up when they don’t perform. Ditto solar. Apart from that, they’re cheap as chips!

  10. yonason permalink
    December 9, 2020 7:40 pm

    From 2017…

    “If we assume an all-in cost of £8000, and a ten year life (which matches the warranty), we get an annual cost of £800.

    Add on interest at 5%, and the cost rises to £1200.

    On top of this, of course, is the cost of solar panels etc, to produce the power in the first place.

    Even then, it is highly doubtful whether the set up could provide anywhere near the amount of power I would need.

    My annual electricity bill comes to to about £700.

    Am I missing something?”

    I can’t imagine that a higher price makes them any more attractive.

    From 2015…
    Not so practical then, either…

    And they have an annoying hum?

  11. Pat Swords permalink
    December 9, 2020 10:43 pm

    Pat Swords, Chemical Engineer, Chartered Environmentalist and regulatory specialist has launched his book ”The Polluter Pays, but to Whom, How Much, and On What Basis – Science or the Cult of Witchcraft?’. A badly needed critical evaluation and judgement of the EU’s Energy Related Green Crusade to Net Zero

    Wind Aware Ireland congratulates Pat on this much needed critique of the EU crusade to reach net zero CO2 emissions by 2050, and for all his work in ensuring EU institutions comply with EU and international law. Pat has given so much of his time and shared his expertise with WAI and its members over many years for which we are extremely grateful.

    The book is available for free to download at the link below and may be used by members and include in various submissions you might like to make, ranging from wind farm projects to plans/programmes. All you have to do is refer to the Sections you may find find applicable, such as for example:

    Sections 4.4 and 10.4 for the major illegalities in the Irish wind energy programme, or for the lack of benefit in the Irish wind energy programme to date, which is based on false claims, Section 4.2, or for illegalities with respect to allocation of State aid, Section 4.3, etc.

    Download the Book: The Polluter Pays, but to Whom, How Much, and On What Basis – Science or the Cult of Witchcraft?’

    Again Pat CONGRATULATIONS on your great accomplishment and thank you for your support over the years to Wind Aware Ireland and its Members.

  12. Paul Weeks permalink
    December 10, 2020 2:37 pm

    To Paul Homewood

    Dear Paul

    I was sent this link for California, its not specific to this post but I have no email for you.

    I thought it was a spoof but I presume its real as its not April the first.

    • Sobaken permalink
      December 10, 2020 5:30 pm

      The Babylon Bee is a literal fake news website, much like The Onion.
      The story is sort of real though, Chinese did achieve first plasma on their HL-2M machine, but that is hardly anything special, just another experimental fusion reactor. Although, if I got it right, they’ve managed to sustain 150 million degree plasma for 10 seconds, beating previous records.

      • December 10, 2020 7:22 pm

        JET achieved the first PLasma in 1983 and fusion on Nov 9th 1991, I recall, at similar temperature of 100 MIllion degrees and lasting up to 20 seconds, so 29 years ago. So what records is this device beating?

      • yonason permalink
        December 10, 2020 9:37 pm

        Yes, the “Babylon Bee” is a satire site, but “Not The Bee” with a bit of snark. They aren’t the same. I’ve seen the same story on another site. I doubt the Chicoms are any closer to contained fusion than anyone else is. …probably using stolen technology, as well.

      • yonason permalink
        December 10, 2020 9:45 pm

        As you write, sort of real…

        My comment on “Not The Bee” may not have been clear. What I meant was they are not “Babylon Bee” but I think published by the same people.

        Since this is China we’re talking about, I wouldn’t but much faith in the quality of their work, or of the truthfulness of their media reporting on it.

      • yonason permalink
        December 10, 2020 9:51 pm

        PPS – If that were Babylon Bee, they’d probably have written about the amazing Chinese “coal powered fusion reactor” or something similar.

  13. Charles Robert Bradshaw permalink
    December 14, 2020 3:45 pm

    Paul, Where are we with aluminium electrode batteries? They appear to be extremely competitive with Tesla Li-ion batteries. Can we believe the hype? Allegations of suppression of info by others offering a different source of power for Electric vehicles abound.

  14. December 15, 2020 7:11 pm

    There is concern about the resources (minerals, metals) needed and where they will be sourced to build one powerwall. What is the quantity of metals and which metals are needed to build them?

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