When Tesla made their little product announcement last week it caught me in a moment of ebb rather than flow. I had just handed over some work, done a presentation, had some important meetings… It was Friday and I had no interest being first out of the blocks with analysis. All I could muster was a bit of crystal-balling Twitter sarcasm:

I promptly received a warning in return:

Then, in a moment of life-imitates-sarcasm, Mark Cojuangco proved that he was the prescient one, not me.

This article contains what will probably stand as the most intellectually feeble, thus outright dangerous, bit of hyperbolic overstatement about climate change solutions I will ever read:

Assuming the Tesla system comes anywhere near meeting its announced specifications, and noting that electric cars are also on the market from Tesla and others, we now have just about everything we need for a technological fix for climate change, based on a combination of renewable energy and energy efficiency, at a cost that’s a small fraction of global income (and hence a small fraction of national income for any country).

John, pardon my language, but you must be fucking joking.

Quiggin delivered on my own intended absurdity: “Down tools folks. Pending a bit of market tweaking, we are now on the downhill run to climate stability and energy prosperity for all. Cancel Paris, Elon Musk announced a battery”.

This is more than irritating, it’s dangerous. It’s repeating the pattern of decades past, that an imminent technology breakthrough will wipe out fossil fuels like sunlight on so many vampires. He didn’t merely underplay but outright avoided any examination of complexity. He didn’t even consider the product itself!

This is not what we need. We need hardworking pragmatists who will do the work in helping global society to understand and benefit from technological innovation, across the board, in order to tackle challenges that are gnarlier than any handful of technological breakthroughs can possibly “solve”.

That’s not how Quiggin saw it.

Happy about Tesla? Unhappy about Tesla? What kind of false dichotomy is that? I was happy when my son took home a ribbon from sports day. I’m not interested in happy-clapping technology announcements. I want to understand how they might all hang together into the biggest, deepest, fastest and most effective response to climate change. That means variously criticising nuclear announcements, criticising solar projects, criticising renewable naysayers, and proposing policies that might lead to effective integration and deployment of all useful energy technologies.

So, what do I think will be the impact of the Tesla product? Let’s look at the product alongside Australian household electricity consumption for a start.

The Australian Bureau of Statistics tells us that in 2012 Australian households were using around 125 kWh per week. The Tesla unit will store up to 10 kWh, or about 60 % of the consumption of one single day of use at the Australian average daily consumption.

It is immediately apparent that this battery-plus-panels offering is not the product that is going to take Australians off-grid in droves.

Consider that a great deal of daily consumption occurs overnight even in the long days of summer, especially the very hot nights where air-conditioning will run overnight. In the shorter days of winter plenty of daily consumption is morning and evening lighting and heating where no production will be occurring from rooftop solar, not to mention possibly some overnight heating. Several consecutive days of low solar insolation are simply a given in winter. So, a typically sized household system would not be able to both meet daytime demand and keep that battery full for dark times in a whole variety of conditions and circumstances.

Consider then that we all want electric vehicles charging from our home. That’s more load. Consider that lots of Australians space-heat with gas and heat water with gas. We want to electrify that with clean sources. That’s more load. Pushing in the other direction is general improvement in efficiency of appliances and lighting and insulation improvements in older houses that put downward pressure on load. But to be frank, if those efficiency improvements help household demand even remain static as we electrify the other services, I would regard that as very impressive. To achieve all of this while going off-grid with combinations of solar and batteries would require over-sizing of systems to levels that are completely unrealistic and unaffordable.

So it’s not a matter of liking or disliking the product. It’s just patently clear that this is not the dawn of the off-grid revolution in Australia. It’s not that product (yet?). So what product is it?

At the end of 2014 I wrote:

(We must) Vary our emphasis on solar PV away from electricity supply and toward network management, especially management of peak demand.  The coming of cost effective home energy storage should be emphatically embraced as a potential network service. Consumers should be encouraged to take up small amounts of storage and remain grid connected into the future. An appropriate financial reward should be provided for residents to use and sell their solar power late in the day in response to peak times rather than as –and-when it is generated. This will hold down network costs for each and every consumer, instead of raising them as solar PV does now. The “death spiral” of retail electricity will be averted.

Depending, critically, on how nimble and intelligent our electricity retailers and distribution operators are in response to this product, I believe it could be the solid beginning of this product: smart solar network management. That would be something I absolutely welcome.

Achieving high penetration of embedded solar PV has real challenges, particularly relating to the potential for local over-voltage events in feeders that were never designed to accommodate them. I’m not inventing a problem here; it’s real, it’s recognised, and a lot of literature is dedicated to how these challenges might be overcome. Here’s a summary of some of my recent draft research:

A 2011 review of solar integration in seven nations representing 70 % of the global market share revealed the extent of the challenges (Braun et al. 2012). In nations with higher penetrations such as Germany, voltage overloading is leading to expensive grid-reinforcement requirements and the implementation of a technical code governing voltage rise criteria, active power control and reactive power control (Braun et al. 2012). Photo-voltaic integration in Germany to 2020 is expected to cost €21-27 billion (E-bridge consulting cited in Braun et al. 2012). These costs might be mitigated in the future by the introduction of inverters with active and reactive power control. However of the > 17 GW of photovoltaics installed, more than 90 % do not have these capabilities (Braun et al. 2012). Such inverters are commonly applied at 30 KW and above, and not in the residential range of 1-5 kW, with no apparent technology trend in that direction.

In Belgium, recent strong photovoltaic growth has meant distributed photovoltaic systems “regularly experience disconnection due to overvoltage…in several cases expensive grid reinforcement is required in order to avoid congestion of cables or transformers” (Braun et al. 2012).

Solutions are needed to reduce the overvoltage and other network challenges caused by embedded photovoltaic systems if increasing penetrations are to be accommodated while stable systems and compliance with regulations is maintained (Alam, Muttaqi & Sutanto 2012; Lewis 2011; Samadi 2014). Suggested remedies include intelligent operation of distributed energy storage (i.e., batteries) (Alam, Muttaqi & Sutanto 2012; Samadi 2014), grid reinforcement (Samadi 2014); active power curtailment (i.e., preventing export from the photovoltaics to the feeder, representing a loss of income to the photovoltaics owner) (Samadi 2014), and active and reactive power control from the photovoltaic unit itself, demanding more advanced inverters (Braun et al. 2012; Condon 2011; Samadi 2014). The potential remedies are summarised by Constantin, Lazar and Kjær (2012):

Overall, it has been found that applying standard voltage control techniques in the LV networks helps to increase the PV penetration by approximately 30% from 1.5 kW to 2.0 kW per residence. For higher PV penetration levels, additional solutions must be applied: more complex voltage control schemes, increased self-consumption, storage solutions or active power curtailment.

So, if things go well, I think in Australia the impact of this product could be a grab-bag of mutually reinforcing trends in consumer behaviour and market regulation:

  • Increasing the number of home solar systems, with consequent falls in greenhouse gas emissions
  • Increasing the average size of home solar systems with consequent falls in greenhouse gas emissions
  • Offering distributors a possible solution to the network challenges of increasing PV penetration
  • Pushing retailers and distributors into more intelligent pricing models for households that reward peak-demand management
  • Downward pressure on peak demand leading to appreciable cost-control in operating the distribution network
  • Potentially weighting water and space-heating decisions back towards electricity and away from gas

But it isn’t the end of baseload or centralised generation into transmission networks. It isn’t, then, the end of coal. Hence, isn’t the end of the need for nuclear and wind (funny, actually, how no one seems to suggest this innovation has negated the role of wind turbines connected to the transmission network).

Let’s be clear-headed about what the real potential of this innovation is so that we can work with the relevant stakeholders to make those benefits materialise as soon as possible. Unthinking hyperbole just serves to muddy the water and leads to false hope, false starts and bad policy development. This is a job for analysts*, not cheerleaders.

Alam, MJE, Muttaqi, KM, Sutanto, D, Elder, L & Baitch, A 2012, Performance Analysis of Distribution Networks under High Penetration of Solar PV, CIGRE (International Council on Large Electric Systems), Paris, France.

Alam, MJE, Muttaqi, KM & Sutanto, D 2012, ‘Distributed energy storage for mitigation of voltage-rise impact caused by rooftop solar PV’, IEEE Power and Energy Society General Meeting, pp. 1-8.

Braun, M, Stetz, T, Bründlinger, R, Mayr, C, Ogimoto, K, Hatta, H, Kobayashi, H, Kroposki, B, Mather, B, Coddington, M, Lynn, K, Graditi, G, Woyte, A & MacGill, I 2012, ‘Is the distribution grid ready to accept large-scale photovoltaic deployment? State of the art, progress, and future prospects’, Progress in Photovoltaics: Research and Applications, vol. 20, no. 6, pp. 681-697.

Condon, D 2011, Grid Connected Solar PV and Reactive Power in a Low Voltage Distribution Network, Ergon Energy, Queensland.

Constantin, A, Lazar, RD & Kjær, DSB Voltage control in low voltage networks by Photovoltaic Inverters: Case-study Bornholm, Danfoss Solar Inverters, Graasten, Denmark.

Samadi, A 2014, ‘Large Scale Solar Power Integration in Distribution Grids: PV Modelling, Voltage Support and Aggregation Studies’, Electrical Engineering, Doctoral thesis, KTH Royal Institute of Technology, Stockholm, Sweden.

*I strongly recommend this piece of analysis of the Tesla product announcement


  1. Maybe I’m just in the wrong headspace today but this reply has left me confused: https://twitter.com/JohnQuiggin/status/595066000476803073?s=09

    None of this hype or analytical reticence has helped address any of the foreseeable limts, vis-à-vis https://www.dropbox.com/s/k6n37xl8rtjvcbd/Metals%20for%20a%20low%20carbon%20society.pdf

    Sweet looking battery. Musk has every right to market it hard. Cheerleaders might want to remember he’s on the record as pro-nuclear too.

    1. Tesla battery as a part of a back-up-back-up for power to Nuclear plant systems? Let’s not stop there. Coupled with Solar PV it can replenish during the day.

  2. I like that final comment. Time for the cheerleaders to sit down and take a break.

    “What do we want? Solar! When do we want it? NOW! How can we achieve it….erm….sometime NOW! GOOOOOOO SOLAR!”

  3. I think there are several solutions to the solar power surge problem. One is to restrict the number of new panels which I think is done in Victor Harbour SA. Another is smart inverters notably done in Hawaii with the products made by Enphase. If I recall they use radio or internet signals to curtail grid export from homes at critical times. Another approach is phase shifting transformers on major power lines. Both Poland and the Czech Republic are said to do this to repel power surges from Germany on sunny days.

    I’m not totally against home batteries but if I were to do it I’d build a dedicated shed to house long-life non-igniting nickel iron batteries but still stay connected to the grid. That’s if all the prices were right. An off-grid ‘survivalist’ near me has a dodgy battery pack and a dodgy diesel generator. He said with no prompting from me ‘I’m getting too old for this sh*t … why can’t we just have cheap nuclear electricity?’.

    1. Inverters can also automatically reduce injection when the frequency starts to increase which is an indication of too much power entering the grid. All system in Germany are required to do that automatically when the frequency gets above 50.2 Hz from the normal 50 Hz. Actually it’s optimized so that they don’t shut down at once as described here : http://www.solar-inverter.com/en-GB/797.htm

      1. An user selected FiT price based system might also work subject to trial. Curtail if the price is under 5c export if over 50c per kwh. A couple of years ago I had a bushfire approaching and the mains power went out. The inverter then shut down then my 400 watt rainwater tank pressure pump and garden hoses were useless. I’d still feel more secure with my petrol pump backup than a Powerwall.

  4. My reply to the euphoria on the Arctic Sea Ice Forum over this announcement.

    Elon Musk must be congratulated on producing such a great battery for a low price and like his car it will have a niche market mainly aimed at rich people.

    His marketing ploy is very astute as he taps into the ethos of the environmental movement and thus will get unbelievable coverage as thousands of unpaid green supporters will advertise this product for him free of charge. I see the video has had a million hits already.

    For me personally this battery is almost useless, as the storage is just one day of my electricity use and will cost about A$5K. I only use A$1Ks worth of electricity a year.

    My solar panels produce all the electricity I use in a year but they generate 70% between October and March and only 30% between April and September, yet my electricity use is fairly constant as I use gas for heating in winter.

    So I am a net exporter to the grid during the summer and a net importer from the grid during winter. Batteries cannot store all the surplus electricity generated in summer for use in winter.

    If you look at Musk’s site he already knows this and is marketing the battery as a way to maintain constant power. A house can run exclusively off the battery providing it is topped up by solar during the summer and by the grid during winter.

    I think this is the main selling point as it provides power security 24/7 which is becoming increasingly more important.

    I should have added that if the grid is powered by coal and not nuclear the GHG emissions are still high.

  5. What is not discussed here is how long do the Musk batteries last? As I understand it, the batteries Musk sells, comprise of literally thousands of 3.6V Li-Ion cells that we might use in our torches or remote controls. At some point, after repeated charging/discharge, some of these cells will fail. Replacing these cells either means buying a new battery pack at $3,500 or returning the battery to the factory for cell replacement. With the Tesla cars, the battery replacement can cost thousands of dollars. No problem for the rich Californians who own Tesla cars but deal breakers for home use. We need to get some real world experience with using these Musk batteries before we rush into selling them to the unwitting public for solar backup.

  6. Beats me how they can offer 10 year guarantees not just on the box but the batteries. An excerpt from the Wiki article on Li-ion batteries says
    On average, lifetimes consist of 1000 cycles,[97] although battery performance is rarely specified for more than 500 cycles. This means that batteries of mobile phones, or other hand-held devices in daily use, are not expected to last longer than three years.
    Rich Californians by all means do the testing for us and report back.

  7. Good article Ben and that analysis you link (with the asterisk at the end) is also worth a read …
    particularly this bit:

    “One thing’s for sure: it’s hard to deliver it by storing enough solar power to keep the home running overnight, or otherwise allowing customers to go completely off-grid. That would require the lithium-ion batteries to cycle far too often and too deeply to maintain their capabilities for long enough to pay off their costs. ”

    Tesla’s batteries aren’t anything spectacular in terms of energy storage or basic physics. They are just cheaper than their competition so Musk will make lots of money. But these batteries are just another example that will sucker people who believe that any technology which can be used to reduce GHGs can get us to where we need to be … (almost) completely decarbonised.

    1. Thanks. I also recommend that second listed paper from Alam et al 2012.They look at using batteries optimally to manage voltage rise, and much his made of the need to keep the deep cycling to a minimum.

  8. Unless the Tesla “GigaFactory” can get these things out the door in phenomenal volume, the margin is too low to keep the wheels turning. Gigafactory may end up just another ‘dream factory’, and it shouldn’t surprise anyone if it does. It’s a big punt, hence the big spin to give it a push.

  9. By some accounts, the margin on these units very low (or even non-existent), and the much vaunted “Giga Factroy” will need to keep these things flooding out the door (as they raise the price?) or it will turn into yet one more “dream factory” gone bad. Big punts need big spin to get the wheels turning, and we’ve sure seen plenty of that!

    1. I have wondered this. Is this battery a “loss leader”?

      I’m in favour of metals mining, myself, as long as it is carried out responsibly. Like the Kanmantoo gold mine that’s almost in my backyard, or the proposed Ardrossan copper project which would use a few hectares of the state’s copious barley production area. But the commentators who pronounce this battery to signal nuclear irrelevance? Do they like mining? What about all their keen followers? What odds that they don’t realise they are de facto in favour of more and more of this?http://blogs.reuters.com/photographers-blog/2013/04/05/the-lithium-triangle/

      They have been repeatedly informed of a form of nuclear which requires no fuel mining and that solves every issue they have with the technology.

  10. How good this development is going to be is critically dependant on the number of discharge cycles these batteries will be capable of. The answer will have a huge bearing on the financial costs and just how environmentally friendly PV with storage actually is based on EROEI. It may be several years before we have a reliable answer. If the batteries last much longer than the eight year warranty (which doesn’t cover normal degradation) then they may substantially increase the percentage of renewable energy that ends up as part of the mix.

    If they do change the economics and allow people to start physically leaving the grid, then the whole pricing structure of retail electricity sales will need to be redesigned. From an environmental POV people physically leaving the grid would be a disaster. Much PV energy generated would be wasted once the batteries are full while at other times, days of poor weather may lead to the use of gensets when instead clean energy could be available from the grid. Being able to share clean electricity is not something that should be lost because the industry pricing structure fails to adapt.

    1. Well said. We need to look for good policy to ensure national net benefit here.

      As per reply to Geoff I recommend the second listed paper from Alam et al 2012 about using batteries to manage voltage rise.

      It’s all about using that technology optimally to enable higher penetrations of PV. Provided that’s not too expensive, I think that would be a very good idea.

  11. Ben I think your conclusion that a not insubstantial uptake of domestic battery capacity would be beneficial to our electricity system is correct, and we both hope it would also enable sustainable drops in emissions. Obviously, beyond a fringe of diehards there’ll be none of this hyped grid exodus. The economics just aren’t in its favour.

    As for grid-scale utilisation, the economics aren’t there either and never will be, and it’s frustrating when the potential is presented by some as if the economics don’t matter. Say we all (along with necessary investors) go in on the land, transmission infrastructure and stacks of large-scale Tesla batteries we’d need to provide the equivalent of 100 MW for 2 days from full charge (keeping in mind the whole point is apparently this stuff can displace nuclear, and so therefore coal/gas, too, so this would be about the dubious bare minimum). This would be many millions. We pay for all this plus ongoing O&M (on a FOAK system) and the only product we are selling is electricity. If we somehow don’t have the sense to sell ONLY at peak demand times, I bet our investors will swiftly step in to make it so. Similarly, our major input is electricity and lunchtime, with the sun out, is almost never the cheap time to grab that.

    At the scale needed to fulfil Gundersen’s fantasy, the demands for ROI dictate somewhat the opposite.

    1. Yes, to the extent that our demand curve remains so incredibly “peaky” there is good, society-wide value to be had in “peak lopping” and solar+storage can potentially do this one house at a time with clean energy. The other great economic thing to do would be to be able to fill the demand valleys by electrifying other services e.g. EVs, hot water, desalination etc. That process scores a win for wind, solar and nuclear and the mix can be determined through clever policy.

      I fail to see the win in moving off-grid “just because” which seems to be the argument. An assumption that “disruptive” is the same as “good”. It’s isn’t. As another commenter remarked if/when one moves off grid they cannot trade their clean energy… how is that good? But then if they want to have all the generating and storage capacity to be off grid but then maintain the connection to trade excess energy or, you know, just in case something in their home system screws up, that connection has to be paid for. How, again, is that good? Loads of material resources in every house, and a grid system that would barely change. What a waste.

      I think now is an important time for people to review their assumptions to be clear about not just what they want but especially why they want it.

      1. It turns in to a struggle against the likes of Naomi Klein, who knows how to really sell the message of divesting from a system built on inflexible, polluting fossil fuels or dangerous nuclear by doing it all at the community level instead. They do this, apparently without actually considering the corporate mass production necessary for supplying the technology they choose to rely on – and certainly with no analytical thought to the inefficiencies and associated climate/sustainability impacts involved.

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