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