OzEA – The second story

The project continues to hum away in the background, building momentum. For those who don’t recall what OzEA is, read these two posts from earlier in the year on BNC:

OZ-ENERGY-ANALYSIS.ORG – open science for the new millennium

OzEA modelling – large-scale wind power using a bucket storage model and gas backup

After much necessary background work, including data collation, website construction, preliminary wheel kicking and a lot of hard thinking (!), we are moving onto some serious analysis and modelling. But scenarios need storylines to hang off. Our first story was about scoping the problem. The second story — reproduced below — is about understanding. This is an exploration framework rather than a real-world proposal. To me, with an extensive experience in working with biological systems, the evolutionary approach we take here appeals. See what you think.

Francis and I would appreciate your critical feedback, either in the comments below or on the relevant OzEA page. Please consider both sites. And remember, OzEA is an experiment, with the tea room being a portal into developments. We always welcome your feedback, on any aspect of the site and its outputs.


The Second Story – Understanding the Problem


In the beginning was The First Story, followed in recent months by round one development through the menu bar (data, analysis, models…). This story ushers in round two.

To briefly reintroduce OzEA: the big picture is a global need for much increased electricity production as we progress through this century. Much increased fossil fuel use to achieve this is problematic given that current human impact on the carbon cycle is widely believed to be impacting on climate. While nuclear power is an alternative to coal and gas, issues around Nuclear Power, or the science of Climate Change, are not discussed here. OzEA seeks to be a broad church; we put our energies into empirical, high level and open analysis of how a high penetration of renewable electricity might be achieved in the Australian context.

In this Second Story we adopt ‘50% by 2030’ renewable electricity as the basis for ongoing work into 2011. Demand management (smart grids) and system evolution are matters that will be central to the integration of renewables, and these are discussed in what follows. Work through to years end is to model the power output from large-scale scenarios of geographically distributed wind and solar power plants. This will provide a solid base for further rational analysis of renewable variability.

The fifty percent renewables by 2030 approach

Adopting 50% renewable penetration by 2030 as a baseline gives structure and coherence to our work plans. In reality Australia is scheduled to have around 20% renewable electricity in 2020 (predominately from wind), driven by the federal governments LRET scheme. The purpose of a 50% target is to drive analysis and thinking, rather than an engineering proposal.

While wind is currently the most mature and economical of the large scale renewable technologies, its variability will eventually make further deployment self limiting; more wind farms = more electricity when the wind blows => depressed prices in the wholesale market. In turn, electricity from solar power can become a more valuable renewable source. The key focus is thus to examineconfigurations of wind and solar that reduce variability and usefully match with demand. (Note: solar = large-scale concentrated solar thermal (CSP); we hold photovoltaics to the margin for now).

Working at the hour-to-hour level we use historical wind and solar data to model ~10 GW average of electricity supply from these sources. Combined with historical demand data, this allows calculation of a ‘demand remainder’ (demand minus renewable supply). The first, naive, approach is to supply this remainder by conventional generators (with a little support from available pumped storage hydro), and to assume that Smart Grid Demand Management does no more than smooth out sub-hour variability and keep demand peaks from growing above current levels.

The naivety above is to suppose demand data from the past can represent demand in the years to come. While past weather data is a good template for the future, the demand can and will change as the electricity system grows and evolves. Hence, the ‘demand remainder’ that we calculate will require a more thoughtful interpretation than simply power required from fossil fuel generators.

Supply and demand; transmission and distribution

These four components provide a template for understanding our electricity system. The transmission network is the backbone that connects region to region, state to state, connecting the power plants that supply electricity. This electricity is taken at substations and feed, at lower voltages, into distribution networks (the poles and wires on our residential streets). Around 25% of overall Demand is residential, with the commercial and industrial sectors making up the balance.

The market operators ensure that, with very high probability, the system remains in balance from second to second; i.e., that supply meets demand. While electricity can be stored economically in the form of pumped storage hydro, this capacity is limited and mostly demand is meet by ramping supply up and down as needed (see The Electricity System discussion).

Peak loads, especially driven by air-conditioner use, present a particular problem for the electricity system. While residential use is one quarter of demand as a blunt average, it is a much higher portion on hot afternoons. Distribution networks in particular can be pushed to their limits, and system planners are faced with the prospect of costly upgrades to these networks. Peaking loads create a real need for mechanisms that can curtail or shift demand, otherwise expensive upgrades are needed in order to provide a much higher network capacity – to a level that is only needed for a small fraction of the year.

Analysis of large-scale renewable integration is necessarily intertwined with peak demand and network development issues, as these pressures are driving system evolution now. From a renewables perspective, the pressure to manage extremes on the demand side crosses over with managing variation on the supply side. This point bears reading again.

Accounting the variability

Power from wind and solar can be very variable; sometimes these sources produce little if any power at all. This is an enormous impediment to making large investments in these renewable power sources. At the simplest level renewable energy can be accounted as free fuel. That is, the system continues to require the same number of coal and gas power plants as before, to cover the times when the wind isn’t blowing and the sun isn’t shining. The saving is on the fuel (and any associated emissions), however, the cost of the renewable infrastructure is much greater than the fuel saved.

Multiple wind and solar farms at different sites will to some extent smooth out the variability. A more involved reckoning of the supply capacity can be had by engaging in statistical calculations of ‘Capacity Credit’. This can be informative, but is only a rough cut at quantifying what is really of interest.

We explicitly model the electricity supply that given Wind and Solar scenarios would produce. This ‘renewable electricity’ time series can be examined in conjunction with the demand that existed over the same time period, and so give the ‘demand remainder’ on an hour-by-hour basis. Analysis of this demand remainder is superior because it empirically captures relationships between electricity demand and renewable supply (e.g. solar on hot days).

Development of a 50% renewables system can only occur as an evolution, and one that includes the demand patterns. Explicit modelling of renewable supply in the context of today’s demand profile shines light directly on the issues and opportunities that demand side evolution presents.

Smart grids and demand management – a necessary detour

As retail consumers it costs you or me the same to use our air conditioners (or heating) regardless of whether the wholesale price is $10 or $12,500 a MWh. Residential demand is disconnected from the supply market, except as a long-term average. This demand inelasticity is a problem crying out for solutions.

Enter stage left, Smart Grids and Smart Meters.

While these terms encompass various aspects, here we focus briefly on: (i) load control, and (ii) interval meters & Time of Use pricing; see the Demand Management discussion page for more extensive comments.

Through a ‘smart meter’, or perhaps simply via the internet, a control hub in your house can manage some appliances in an intelligent way. A pool pump, for example, would be off when the network was struggling. Water heating is the classic ‘off-peak’ appliance. More complicated, but essential, is a mechanism for the compressors (but not fans) of air-conditioners to be switched out for a few minutes when need be, and for the thermostat to ride modestly and intelligently across demand peaks.

Your motivation for smart operation of such appliances is simple; Time of Use metering. At peak times electricity will be more expensive; on a windy night it will be cheap. So called “Interval Metering” is a foundational functionality for a smart meter. While residential time-of-use pricing requires careful implementation, it should save you money if use at peak times is modest. What might be called the “Eco-Saver” electricity plan will allow you, essentially, to withdraw subsidy from those who are punishing the system at peak times by running four, perhaps inefficient, air conditioners flat out.

Smart grids and metering involve a world of detail at both the technical and policy levels. There is discussion and debate. In Victoria interval meters are being rolled out state-wide right now; in South Australia they are resisted. Digging into these issues became a distraction at OzEA, and for now we pull back to a watching brief. The key point is that development of technologies and interfaces for intelligent load control will lay the very foundations for further levels of demand side elasticity.

Big ideas: the ecology of energy and the variability gambit

Large, complex, efficient, systems are rarely imposed through a straightforward engineering plan, where the steps required are foreseen at the outset. The scale, efficiency and sophistication of our current fossil fuel based electricity system would seem fantastical to those who hauled coal in primitive mining operation at Ipswich or Collie a hundred years ago.

The variability problem can be engineered away with high levels of supply redundancy and proven but expensive or inefficient storage mechanisms. What can be done, and what responsible politicians, policy makers, board rooms and bankers, will do are two entirely different things. So far there is no ‘killer app’ on either the supply side (e.g. proven geothermal), or the demand side (e.g. cheap storage). But ‘killer apps’ can be weeds in an ecological context; evolution is not a one-step process nor is it fixed on only one possible outcome. Rather, many small steps act in concert to alter the very fabric of the system from which the next batch of little steps proceeds.

Starting with the system we have now, we ask: “What will happen as more renewable energy is included into the system?” (i.e. how might the system evolve, and what are the selective pressures that will induce change?)

With supply rendered less controllable by the addition of large-scale renewables, and with demand made more elastic in response to the cost of supply, the electricity market develops new niches for balancing supply and demand. Attention is too often focused on handling the occasional lean times (when the electricity price becomes high and dispatchable backup is required), when the real evolution will occur in the frequent plentiful times that come with large scale renewables; this presents enormous possibilities. With abundant electricity we can potentially displace more expensive transport fuels, and otherwise have wealth-producing industries and jobs spring up in the niches that a suitable energy ‘ecology’ (market) would provide.

Assuming we become a high penetration renewable country, to what extent will we look back in 30 or 50 years and see the value of a flexible and frequently abundant system outweighs the costs of maintaining ‘backup’ to cover the gaps? Thinking about this question requires looking past the next immediate roadblock.

The idea here, what we call the Variability Gambit, is to postulate that in time the variability problem is soluble, especially with a deepening of the electricity market and associated integration with the energy sector more generally.

The monster under the bed – how much will it cost?

At the simplest level (straight cost per MWh of electricity produced) the rule of thumb is wind power at twice the cost of coal power, while CSP is around four times as expensive — some forward estimates are more generous. Wind turbines are a mature technology and so the costs here can only be expected to reduce on a modest schedule (maybe a few percent a year), while the less-refined CSP might yet undergo stronger improvements as increased deployment occurs. A tax on carbon emissions would add to the scales, so roughly and at this basic level, costs are seen to be an uphill journey, but a gradual rather than a hopeless one.

The cost and engineering of large-scale renewable plant must include any associated transmission infrastructure. Further, the variability, and consequent need for storage or backup, introduces additional costs that make the task of an economic reconciliation more difficult again. Today’s renewable technologies, placed within todays systems, are not cost competitive as a fit-for-service means of replacing coal and gas.

Consider, as a thought experiment, imposing large scale renewables on the Australian system NOW, at the same time decommissioning our coal power assets and limiting the use of gas turbines (perhaps through a very high carbon price). Broader economic damage and electoral backlashes aside, lucrative opportunities would arise because of extreme variations in the wholesale electricity price. Storage of electricity using hydrogen or compressed air (as examples) would become profitable. Demand management technologies would develop rapidly. Much innovation would occur. After some decades of expensive electricity the system would again evolve into a form with cheap and plentiful electricity.

The question is, can we achieve much the same ends (more gradually) without draconian impositions and economic carnage? Forging that path is the task at hand, and the supply variation of renewables may itself be our most potent tool.

Open Science and the web-site

Doing Open Science (not just talking about it) is a parallel purpose of the OzEA project. In the beginning we imagined lots of community involvement in doing the Science, and now have more nuanced expectations. Certainly many valuable comments have been made, including a handful of really substantive contributions. We look forward to more of these as we knuckle down into 2011. Yet, this is not a blog, and we do not seek comment for the sake of comment, nor provide an arena for generic argument. Rather, the commenting system is largely a virtual lab-book that is open to all; it is a major part of our record keeping. And of course we continue to welcome critical comment, encouragement, focused questions, and the sharing of knowledge and experience.

Breadth first is the approach to analysis we take here, and so some of our analysis is not as sophisticated or refined as the more specialised work of others. What matters is whether an analysis is sufficient for the purposes it is put to. We welcome comparison and criticism in this regard, and are always grateful for nudges and prods into the issues and complications that careful work needs to take into consideration.

Concluding remarks

To mindfully anticipate the future electricity system is not straightforward. The basic difficulty in looking ahead multiple decades is that while some aspects are reasonably predictable, any number of less likely, and even improbable, technological and sociological developments could have significant impacts – if they come to pass. And some of these unlikely events will occur (play enough hands of poker and you will get a royal flush).

Moving into Round Two of data, analysis and modelling, we focus on the variability of supply that comes with high penetration renewables (wind and solar). While capturing the supply variability is a lot of work, it is also a relatively straightforward number crunching exercise. The real significance will be in the ‘demand remainder’, as so many of us seek to explore the implications, opportunities and consequences of increasing the level of renewable supply into the Australian electricity market.

A derisive term, “The Fake Fire Brigade”, has arisen to describe those seen as too optimistic or woolly in their claims for large-scale renewables. Here at OzEA we take a positivistic view; however, we are nobodies’ fire brigade. The wool-free version is simple enough: into the medium term at least, an Australian electricity system with an increasing penetration of renewables will continue to be underpinned with significant (fossil) fuelled supply, while demand side evolution will provide a more elastic response to supply variability. The rate of renewable rollout will be limited by real world costs, and driven by government support.

The importance of demand management to renewable integration is at once tenuous and profound. At the tenuous end, the ability to make modest adjustments to demand, especially in high load situations, provides some assistance with a generation mix that includes renewables. But it does not provide much help when there is little wind for several days in a system reliant on wind power. At the profound end are the pathways opened up for electricity system evolution in the decades to come as devices, houses, industries, suburbs and states interact dynamically with supply.

Implementation of smart grids must be undertaken with due care and forethought. It is easy to speculate about electric (or plug-in hybrid) cars; it is easy to note the long-term sense in houses being intelligently designed for space heating and cooling. It is not hard to see wind and solar power being integrated into the broader energy sector, perhaps via Hydrogen production. While all these points remain vague or speculative, it is simple deduction that building to high penetrations of wind and solar power will involve these sorts of developments.

The question, in the end, is this: can we intelligently and responsibly nurture the necessary evolution in the way our electricity system works? The next step to coherently addressing this question is a solid quantitative grip on the supply variability. As we work this through, it is our goal and commitment to communicate the analysis and its interpretation in as open and useful a way as we can.

By Barry Brook

Barry Brook is an ARC Laureate Fellow and Chair of Environmental Sustainability at the University of Tasmania. He researches global change, ecology and energy.

43 replies on “OzEA – The second story”

Just a note: I see no mention of an important element in electrical transmission and distribution networks – VAR Compensation.

VAR Compensation is an Ancillary Services for providing fast-acting reactive power on electricity transmission networks. It is very important in markets that have a lot of inductive loads, (like air conditioners) switching in and out .

Essentially a VAR Compensator is an automated impedance matching system designed to bring the system closer to unity power factor. If the power system’s reactive load is capacitive (leading), the it will use reactors (coils) to consume VARs from the system. Under inductive (lagging) conditions, capacitor banks are automatically switched in.

This can also be accomplished by a device called a synchronous compensator which is a specialized synchronous motor whose shaft is not attached to anything, but spins freely. Its purpose is not to produce mechanical power, as other motors do, but to either generate or absorb reactive power as needed to support the grid’s voltage thus dynamically maintaining the grid’s power factor at a specified level.

Most modern VAR compensators are of the former, static type, as very fast silicon controlled rectifiers (SCR) can respond quicker than a rotating mass.


Thought I’d look up LRET since it starts in a fortnight’s time
It’s an absolute target (41,000 Gwh) slightly lower than the previous one. Therefore there is no guarantee it will displace any CO2. A relative target of say 20% of total something (generation, biofuel etc) might have had a better chance of displacing CO2. This will need modelling. As Ross Garnaut says if you have a serious CO2 cap the RE part should fall into place.

But wait, there’s less. The unfathomable solar energy multiplier is back. Somehow air source heat pumps are a form of renewable generation. Funny I thought they were a power user. If the CO2 displacement question doesn’t grab how about this; is there any chance of a 4-fold increase in non-hydro renewables between 1/1/11 and 31/12/20? Seeing as how geothermal isn’t doing so well and large wind farms are losing money despite subsidies.

If governments want to say they are on target to meet the LRET it will take some major fudging. Perhaps gas burning can become honorary renewable like the heat pumps.


A thoughtful and informative analysis.
Interesting that you explicitly rule out discussion of nuclear energy in this context, although, as you have emphasized so eloquently elsewhere, uranium (or perhaps thorium) is the only economically practical substitute for coal as the supplier of baseload electricity.
The growing European disillusionment with extensive wind and solar is perhaps an omen that the future of those sources is quite limited. Because they are hopelessly unreliable for peaking duty (without very costly energy-storage capacity), the more they are deployed, the more stand-by natural-gas capacity there has to be. As you point out, their capital cost far outweighs the fuel savings.
Nuclear reactors can follow the load better than coal plants, and it is very likely that small-reactor designs will be flexible enough for much of the residual peaking duty.
In an economy powered by the atom, the various ideas for intelligent grid management will still be useful — and much easier to implement. I can see why you present as a strictly academic exercise your undertaking “to describe what would be involved in running Australia . . . predominantly on renewables.” I suppose the purpose of your analysis is to show in detail that tailoring supply to demand without reliable baseload would be so challenging and expensive that the need for nuclear to provide the bulk of our energy will become self-evident.
— George


George wrote:

I suppose the purpose of your analysis is to show in detail that tailoring supply to demand without reliable baseload would be so challenging and expensive that the need for nuclear to provide the bulk of our energy will become self-evident.

Whilst that is certainly my suspicion of what the outcome is likely to be, it is not necessarily the opinion of Francis; so as a team, we cover off the alternative hypotheses fairly well. The broader and more fundamental point is that if we do the analysis as realistically and even-handedly as possible, the outcome will be what it will be… Data and logic will rule here, not ideology and speculation — which is good, because the latter is currently rife in this energy policy and planning arena.


George, OzEA is no straw-man project. We bring a positive view. It is easy to talk in generalities, and significantly more effort to work through the numbers, looking in particular at ‘the variability problem’. Let’s not pre-judge where this goes. cheers, Francis


I guess somebody has to do this sort of number crunching in order to convince TPTB that they might have to make a move,hopefully a sensible one.
However,as a practical sort of bod I wonder(quite often) about the overall level of intelligence and hardihood of the Australian Homo Saps.It has been 36 degrees Celcius here today and I have managed to survive,nay,prosper,without a skerrick of airconditioning.In winter,when it gets close to zero I have no heating apart fom my metabolism assisted by appropriate clothing.

This was pretty well near the norm 50 years ago.If this is progress then I reckon we are progressing on the wrong track.

So that’s the demand side taken care of.

As for renewables,I have had a 5.4 kw solar PV system for the past year.It is adequate for my needs but the one striking thing about it is the wild variation in output day to day.And,of course,it goes on strike for about 12 hours/day.I doubt if a wind system could do any better.

So how are you going to shoehorn this sort of technology into providing anywhere near 50% of baseload by x date at any sort of realistic cost.The short answer is you won’t because you can’t.The long answer is that if you try and surely fail you can kiss goodbye to anything resembling a civil society.

If you think that a civil society is a sort of optional accessory to modern lifestyles,like a holiday in Bali or whatever,then maybe you should take a few deep breaths,partake of some “In Vino Veritas” , pause,and consider the likely results of an uncivil society.

My apologies for being flippant.My excuse is that I have partaken of a bit of the vino this PM.It may be the wrong vintage for the veritas bit.


Podargus, while I share your experience of (at times) relying on solar, I’m not so pessimistic. Whether it be renewables, nuclear, coal and gas (we have plenty), or some combination, we (as a society) will work it out. What is needed to help work it out is, in my view, less certainty in overreaching views of all the interacting issues, and more careful work on component aspects. That is why OzEA is restrictive in what we consider. In time we expect to nail down some key points and issues, and thus help the discourse around decision makers more rational that it might otherwise be.

For large scale renewables there is not one set of panels in one place – rather there are multiple technologies in different places. Yes, there is still a variability problem; yes, transmission issues are problematic, etc. One piece at a time please. For now you may find it interesting to consider that, maybe, renewables really can replace traditional “baseload”:


The idea of a power system composed of distributed energy resources, where much smaller amounts of energy are produced by numerous small, modular energy conversion units, like renewables which are then integrated into the grid like an energy internet is not practical. Each node whether a gigawatt natural gas power station or a single solar photovoltaic panel needs to be controlled and the necessary number of combined control tasks multiply as devices multiply. requirement of implementing this technology increases the number of control parameters. Accurate information on the state of the network and coordination between local control centers and the generators is essential. An inherent risk of interconnected networks is a domino effect – that is a system failure in one part of the network can quickly spread. Therefore the active network needs appropriate design standards, fast acting protection mechanisms and also automatic reconfiguration equipment to address potentially higher fault levels. On top of which most of the proposed systems require intelligent loads as well, adding to network complexity and cost; these changes are not cheap or easy.

Thus concluding that renewables can manage base load supplies base on simple statistics comparing generator to load values across a wide area, without considering the other network elements like transmission, is without value.


I see WA Premier Colin Barnett has joined Podargus in renouncing air conditioning
This is far from a minor issue if 36% summer electrical demand growth can be attributed to AC. I guess we won’t see CB wearing a dark suit in the next photo lineup of premiers.

Returning to the thread of demand management I think this will be unavoidable in the fossil fuel based economy. That economy will inevitably be constrained by either CO2 limits or depletion. I suspect we will have daily allowances for thermal comfort, cooking, electronic entertainment (incl. internet use), hot water and so on. This will be monitored via smart meters with a few nasty bill shocks to force people into line. If the thermal comfort allowance is 2.5 kwh per day and you have a 2.5 kw (apparent power) AC then there will be one golden hour a day to use it. Trouble is it is likely to be the same hour as everybody else.


DV82XL says:

“Thus concluding that renewables can manage base load supplies base on simple statistics comparing generator to load values across a wide area, without considering the other network elements like transmission, is without value.”

who concludes this? Where?


Nothing personal, Francis, but just about every one that raises this tiresome idea that base load can be replaced by variable sources of generation. The fact is that some modelers have gotten so fascinated with abstract power transmission networks that they’ve ignored the physics of how these things actually work — like electricity infrastructure and this can lead you grossly astray.


Not taking it personally – just annoyed with the emotiveness. Quit the straw men I say, and play the ball, or watch from the sidelines. Any half intelligent person can tear things down with generalities – that’s easy boring and lame (-:
You say the idea is ‘tiresome’ – is this because no one follows through with coherent analysis, or because the analysis has been done over and over?


The existing electric transmission networks have one very important property that cannot be ignored. They are there. Vast sums of money, time and material have been expended over the better part of the last century building these things and polishing the procedures to make them run. The only way we were able to afford these huge systems in the first place is that they grew slowly and the product that they moved was so inexpensive to produce that the consumer could absorb the cost of construction almost without noticing.

Many of the proposals out there, some which are being seriously considered, involve retasking this system, and this critical issue is breezed over in discussion. This is a mistake. These systems are huge and complex, with a bewildering number of control nodes and operate under protocols that been less designed then they have accumulated. They have not been built for two-way traffic, and even in cases where bi-directional flow is physically possible it is often achieved only by overriding system fail-safes, and potentially compromising product integrity. Refitting to allow for this, while certainly doable from the engineering standpoint, would be horrendously expensive, and in some cases would require that large chunks of the network go offline or isolate for extended periods of time and in most cases this factor alone makes conversion unfeasible.

The second overarching technical concern is reliability. We use energy in such a way that an unreliable source is often worse than no source at all. Many of our day-to-day behaviors are predicated on subliminally knowing that the juice will be right there, right now, when we throw the switch or turn the key. If you’re a backwoods camper, or stay in a country place off the grid, you make adjustments, but we cannot run our civilization not knowing from moment to moment if power will be there. Yes, that’s the case in some third world urban pestholes, but those are not the conditions we are striving for.

The only way to assure reliability is obviously, to have reliable reserves on hand at all times placed on the network where they can do the most good, and that is the type of generation that is required for base load.

I do not care what sort of statistical analysis of intermittent sources can be tabled purporting to show that intermittent generation can assume base load. Unless it can be shown that this can be done end-to-end, taking all the critical factors into consideration, it is drivel.

The onus is on those claiming this can be done to show that they have taken everything into account – it is their assertion. And without the sort of engineering analysis, and financial analysis to show that base load can be assumed by these generators is both technically practical, and cost effective, those claiming that it can be done are being tiresome.

“Well we are just saying it may be possible” goes the refrain. No, the only thing you are showing is that one of many possible restrictions may not be fatal, but that is a long, long way from showing the whole idea is practical.


DV82XL, I must now object, and object strongly, to the continuation of straw men argument; and to words such as “drivel”. Abuse me again in this way and I will retreat from taking you seriously. You seem to be escalating after being called on your initial straw man swipe at OzEA, when perhaps it would make more sense to acknowledge that this was careless, and seek to make your points more gradually and politely. Just sayin.

Have you read and reflected on the post? Since when did OzEA suggest anything other than a reliable system? No sackcloth here. Please note that the whole development of the OzEA project IS about evolutionary change. Please also note that the wholesale price of electricity contributes ~25% to the retail price, and this portion could probably be halved if I had access to time of use pricing. There is still a lot of money being spent on developing the system, and the question is where that money is directed into the future.

It can be really valuable to learn more about the way the system is now, and the design and engineering issues that come up in developing the system further. But it is not helpful when these issues are thrown around as ‘so-theres’, as batons, or when you attempt to impose a big-picture view in a sound bite. I have big-picture views also, but do not expect anyone to understand them, let alone agree or disagree coherently, on the basis of a few blog posts. What we are doing here is building out the renewable case. It’s been slow going, and while the project is now moving from “second gear to third”, the work takes time. There is a good plan developing for how the work proceeds. With polite engagement I will put significant efforts into sharing the forward thinking, and making it it open to your input.

I don’t need more spitball detractors – they are a dime a dozen – what I need is people who will put their preconceptions aside and work through the case, or at least observe quietly until they have a specific useful contribution to make. IF we can build a good case, then we have a rational basis for judging it.


[cross posted at OzEA]

If you look at this comment on the OzEA site, and the figure it contains, (or this one, as above) you see where the classic concept of “base load”, “intermediate load” and “peaking load” comes from. I think these figures (including a similar one in the modelling work from mid year) contains a basic abstraction we can build on.

Disconnect the “names” of the demand profile sections from pre-conceived technologies, and rename them “base supply”, “intermediate supply” and “peaking supply” (essentially we can, loosely, still think of the latter two in terms of CCGT and OCGT, although load shifting and other aspects will come into play). What happens is that Wind and Solar become a part of the “base supply” – they are just there, and they are what they are.

We use the “demand remainder” (demand left after subtraction of base supply) to define the shape of the remainder profile, and then seek to shape this profile as best we can with supply mix, storage dynamics and plausible load shifting. What’s left is the combined “intermediate and peaking supply”, and we will use CCGT and OCGT to get demand met. Eventually, a reasonable model of multi-node Gas Turbine dispatch will allow specification of gas and costs.

First, however, the context needs to be clear.

Consider the evolution / ecology / niche metaphors of the second story. To utilise these ideas quantitatively we might take this remainder profile and evolve it through three or four stages, starting with how things are now, and ending with our best scenario for 50% renewable electricity by 2030 (or 40% in 2040, or whatever). Once the whole model is standing, then it becomes open season to cost and compare with other electricity industry paths that are in the ring, including the transmission and distribution network issues and costs.

What we need now is clarity on what the steps might look like. We are currently sketching a three stage model for: 2011->2016, 2017->2023, and 2024-> 2030, and a modest degree of ‘stretching’ the plausible is ok. If you have significant ideas around this, please introduce them. We have some material developed, but for now interested to leave the slate clean for others.


Francis – The usual I see: “I don’t like your tone”; “I won’t take you seriously”; ” I know how this will work but you wouldn’t understand it”; ” Put aside your preconceived notions” (like those I got from physics, and power engineering?) Oh please.

For the record the comment I made at 12:51 PM . was a criticism of the very poor arguments that have been extended claiming that variable sources can assume base load. It was nether a straw-man or directed at your precious OzEA, or directed at you for that matter. And frankly I do not care what you think of me, or if you take me seriously. I don’t take you seriously at all.

As for “observe quietly” I’ll take that from this blog’s owner for what I write here, not from you. But can assure you I will not post to OzEA again.


Where do the quotes come from?
I hope you are not trying to paraphrase me, because if so you have failed badly.
I retreat. And I hope you cool down and don’t feel obliged to maintain the rage.


Francis You belong to the “anything but nuclear” tribe and as such you are my enemy. Fortunately you cannot argue at all. To call into question my emotional state, to try and distance yourself from your own remarks, and to not address the valid point I have made, indicates to me that you are a lightweight and not worth engaging with. But I will jump all over any stupid remarks you make here whether you like it or not. I trust the others that read these threads to judge my words on their content, and see that you have failed to address them.


@DV8 : The electricity distribution grid in Oz is already creaking at the seams , so to speak. We , the consumers will have to cough up more $$ now, and in the future , just to keep it going ! Add to that a carbon tax and the consumer will start squealing . The politicians have no clue , so we are heading for interesting times .


unclepete – The power transmission network in most countries is overtaxed. Flexible AC Transmission System (FACTS) needs to be implemented, to better use current capacity, and reduce losses. But FACTS is not the answer to all the problems in that sector, new transmission corridors still need to be built, nor is it cheap and it will not be implemented on those circuits that do not need them.

The big problem with FACTS is that the first generation of equipment just will not be able to switch fast enough to do all the things that the variable distributed generation supporters hope it will be able to do, and it will be awhile before it can, if ever.

And in the end the fact remains that reliable, robust, generation, built close to the markets it serves, would be the better solution. All of these Rube Goldberg schemes to implement a distributed power network are simply not needed if a commitment is made to nuclear power.


All of these Rube Goldberg schemes to implement a distributed power network are simply not needed if a commitment is made to nuclear power.

The whole ‘renewables’ delusional thought pattern seems to derive from the denial at some level that there is any such thing as nuclear power. When otherwise apparently well-informed, intelligent and sane people buy into this delusion it will usually be at the behest of some overarching and unspoken interest with a compelling motive to drive such obscuration. The only well resourced group with such a motive are the defenders of fossil fuel interests.


Nice work so far, DV8. I am waiting in vain for an indication of rational analysis from your noisy detractor.

The transmission system is no cheaper and no less demanding than the generation side of Australia’s (and other countries’) power systems. It is reckless in the extreme to argue “one step at a time”, when that step fails to recognise and to address transmission limitations and costs.

In Australia, it is disappointing to note that a large percentage of electrical engineers are not fully trained in power engineering, which many universities no longer offer in depth. Hopefully, this situation will be rectified, but it will take time – at least a decade – to play catch up. Meanwhile, the discussion centres on supply and loses sight of distribution.


John Bennetts – to give you some idea of how difficult it is to modernize the electric power transmission network, Supervisory Control And Data Acquisition signals (SCADA) still use 1200 baud to digitally connect electrical substations in the power grid network.

The reason is the system protocols for SCADA systems – from top to bottom – assume there is a dedicated fixed line, and essentially rely on the attributes (speed, latency, etc.) of that fixed line. If it’s changed, even for a faster link like DSL or such, it may break the operation of the overall system.

FACTS requires that utility networks switch away from these vertically integrated communications systems with their hidden system dependencies, and move toward layered protocol network implementations, where different layers can be switched out without unintentionally disturbing the rest of the system. This flies in the face of the “If it ain’t broke, don’t fix it.” culture that these critical networks work under. These lines are generally very reliable. Many of these lines have been in place (at least from a system design perspective) for over 30 years, and work just fine, so why change them?


It does seem highly academic to pursue a solution that is complex and entails ignoring a solution (nuclear) that is not.

DV82XL – you raise the point that we assume that the juice will be there when we need it. It seems to me that one of the useful aspects of smart metres is that they permit some pricing around that expectation. When load shedding is necessary those that pay a higher price for service access (let’s say hospitals, data centers, traffic light operators and no doubt wealthy folk) might be spared from rolling blackouts whilst those that pay a lower service access fee (say most residential users) might be the first to be switched off. This first class, second class approach to service access seems to me a more likely mode of smart metering demand management than pure energy pricing. Not so nice perhaps for the second class crowd especially given that those voting for the green policies of renewable energy tend to be from the upper income brackets.


Yes, it’s admittedly highly academic at this stage – an abstraction, like just about any model I do. But it will serve multiple purposes in scoping the boundaries of the problem. This is what Francis is trying to say, I think. (Aside: Francis is no more anti-nuclear than I am anti-renewables.)

The details – important as they will be for any real-world context – come after the basic framework is in place. If the framework of the house hasn’t even be built, then there is little point in agonizing about the wiring, plumbing and sewage systems.

And evolution of the system – this is at the forefront of our consideration. If that wasn’t clear from the second story, then that’s a message we need to take on board, to sharpen later iterations.


I don’t know of anybody that is anti-renewables in terms of wanting them prohibited or having them otherwise abolished from the market place. Plenty of us are against explicit subsidies for renewables, and implicit subsidies via MRET style schemes but that is another matter. From your statement Barry we should then assume that Francis is opposed to nuclear power prohibition?

As a thought exercise I can see the merit in omitting obvious solutions. A bit like pondering how we would build cities without concrete. Such thinking might lead to novel insights. However you don’t want to get too carried away with such thought exercises.

We do not live in a centrally planned society (thankfully). The best solution would seem to be to put all options on the table, internalise externalities where practical and viable and not prone to rent seeking behavior, and then let things evolve naturally.


For Germany I tried to answer several of these questions.

I managed to obtain 2006’s sources for hourly demand, wind production onshore, wind offshore and photovoltaics production.

The first question I tried to answer was what the best mix of onshore wind (likely dominant for some time) and PV would be and how that changes with renewable penetration. Of course definition of ‘best mix’ depends.

E.g. I chose standard deviation (SD) of residual load vs. SD of demand among other criteria. Simply speaking a relation of 1:1 (=100%) means that the average residual load variability would equal the usual variability of demand. Since our conventional medium+peak load supply already covers that variability we should’t expect adverse effects if that relation does not exceed 100% considerably.

Other residual load analysis were ramp up/down, spread+ extremes, backup switching cycles a.s.o..

The analysis was done using R project. You will find residual load analysis in Chapter 5 here – sorry, the document is in German and automated translation probably requires some crative imagination:

Previous chapters deal with data acquisition, corrections …

Contact: wflamme (at) web dot de


TerjeP – Smart Metering is a regressive form of rationing, or a form of price-gouging – take your pick – but it is not an element of the Smart Grid (FACTS) Load management can be carried out transparently, by the distribution network, and several of these systems are in place, and have been for years.

Barry Brook – An academic exercise is fine, however the degree of abstraction can be so great as to render it useless. As I wrote up thread some modelers have gotten so fascinated with the abstract that they’ve ignored the physics of how these things actually work this can lead them grossly astray. Frankly I think that point has been passed here with this project.

It has been my observation that a good indicator that is a serious disconnect from reality, is the tabling of calculations that purport to demonstrate that variable sources can assume base load based on simple statistics. A further indication is that this position is defended by attempting to dismiss the critical factors of transmission, (or storage) or brush them under the rug, rather than recognize that they must be part of the calculations from the beginning if there is any value to be had from the process.

This machine, this huge machine, that is the electric power network, is in many ways greater than the sum of its parts. You cannot constrain the rest of the system while wholesale changes are made to one of its components, thus the whole must be considered in any remodeling.


DV8, as a civil engineer, I have limited knowledge of the actual SCADA protocols. My point is that the transmission system includes many technically complex issues. SCADA is one. Protection is another. Operator availability for fault finding and rectification is another – I supervised the installation of a couple of GT’s some years ago which, in their declining years, now require somebody to talk nicely to them occasionally to bring them on line despite having control system upgrades in the meantime.

My experience in large multi-disciplinary projects including either medium to large generating plant (say, above 20MW) and medium to large large loads (say, 10MW at 33kV or above) has been that high quality, practical electrical protection engineers familiar with a wide range of new and older plant can be very difficult to come by. Thankfully, these very busy folk are sometimes happy to work with people that they have known for a couple of decades (eg: me). When these guys retire I have no idea who I will be able to work with when new gear is added to old systems which were designed in the 1960’s. This is a non-trivial problem.

Having said all that, I understand Barry’s desire to sweep aside details as far as possible and to deal with principles. See next contribution.


I’m bemused by the atmospherics here, and perhaps feel like Gregor in The Metamorphosis except I’ve woken to discover I’m an eleven headed monster.

OzEA has had its focus on the variability problem since the start. It now seems that we may be getting to grips with that aspect (and thus closer to moving onto others), which DV8 and others seem to find threatening.

So much misquoting, so many straw men, and all the imputation and assertion – mostly as wrong as it is vitriolic. To my mind this forum is the anthesis of a reasoned or rational discussion – it has become about who the “enemy” is. This sort of ‘logic’ is as old as the hills, and the blogosphere is poisoned with it. People follow their heros and hate their villains, more-or-less regardless of what they actually do or say. This is the reason for the OzEA rules of etiquette (including the prohibition on weaving in the Nuclear and Climate debates).

Unfortunately, what might have developed here into a broad and valuable discussion on some of the issues that OzEA will face in the future has degenerated into… farce. If I could rewind two or three days, I might choose my words differently. But, seeing how things are, I am leaving this forum – and will be very happy to discuss the OzEA project on the OzEA site (here, here etc), according to the etiquette linked above.


Some current policies which were introduced to promote renewables will eventually work against long term adoption of them.

EXAMPLE 1. Multiple REC’s. If one consumer is reimbursed for 3 or more times the number of REC’s that his hot water heater actually earns, then everybody will expect similar treatment for ever. This devalues the REC and increases the drain on the public purse. It is fraudulent to seek or to receive unearned rewards, but that is what is happening. Those who come behind, if unable to negotiate similarly generous deals, will cry foul and the whole charade ends up with a bad name.

EXAMPLE 2: Inflated Feed In Tariffs. If the market price of power is about 5 cents yet the legislated FIT is 66 cents for early adopters, as was the case in NSW until recently, everybody else will cry foul when the FIT drops, as it has, to 22 cents for new starters. Those already on the gravy train are grandfathered for 5 years or more. Again, it is no surprise that a stink has erupted. Suppliers are unable to plan their business, which has fallen through the floor. Citizens seeking to festoon their roofs with PV generation will receive only 20% of the return of their neighbours. Envy and greed are good motivators in the short term but are notoriously poor drivers of long term change, yet these are the two predominant factors emerging in the public arena on this issue. Forget for the time being that renters, those with constrained budgets and flat dwellers never had access to this middle class welfare. I contend that this whole muddle has become a long term dampener, rather than an incentive to adapt to renewables.

There is a parallel between the greed and bribery apsects of the above two examples and the NIMBY phenomenon when it comes to develpoments of any kind, especially developments of electrical power generation plant. Nobody wants to live next door to a wind turbine/ solar PV farm/ nuclear power plant/ etc. Given a simple option, nobody would put his hand up and say “come over here – I’d love to have the new neighbour”. Yet society as a whole demands that these types of issues are resolved.

Every time the NIMBY argument succeeds over rational assessment, the same damage is done as when bribes in the form of excessive FIT’s or multiplied REC’s are offered by governments.

What matters is the common wealth of the society, not the grasp or greed of the individual and of corporate rent-seekers. IMHO, this social issue is bigger and more urgent than the engineering costs and system models, because the consequences include blowing models away and multiplication of costs while also raising expectations of a renewables gravy train.

Somebody wiser than me can tidy up the wording, but I think that reader will see what I am getting at.

Subsidy of renewables, especially at the consumer level, works against long-term, sustained adoption of renewables because it is not about energy, it is about greed.


Francis – I hardly think what I see on OzEA threatening, if anything your reactions to my insistence that transmission issues be considered seems to indicate you are the one that fears the implications of doing so. To claim that this is a straw man demonstrates ether an obstreperous refusal to face reality, or a deep ignorance of the problem. If things have not developed into the type of discussion you wanted, I would look no further than your own reaction to my raising a subject you’d rather not face.

So indeed limit your participation in this topic to a forum where you can set the rules such that uncomfortable matters cannot be brought up. In the end you will have to address these issues or your efforts will fade into well deserved obscurity. Meanwhile until I am censored by our host here, I will continue to call it as I see it.

John Bennetts – The problem of skill replacement as the Boomer generation leaves the workforce is a real problem in the West in any number of technical fields. It is one that is going to need to be addressed at the highest levels, but probably won’t be until it is a full-blown crises.

I agree with your analysis of the distorted economics that has crept into the renewables market. I can draw some hope in seeing that several of these programs are now under review in many places around the world, and we may yet see common sense prevail. Ultimately these attempts to support this sector this way will fail because the numbers just don’t work out over the long haul.

In the end both physics and economics will put an end to this farce, because unlike people they haven’t the capacity to suspend disbelief, or ignore factors they would rather not address. Reality always bats last.



In attacking Francis for his failure so far to address the technical and economic issues surrounding renewable power transmission, do you not consider that you might be being somewhat unfair?

It was my understanding that the purpose of OzEA was to take an open minded look at the prospects of renewables ever being able to provide a sensible and affordable amount of power. In this endeavour, the first steps – and only the first – have been taken. It is my judgement and hope that the issues you raise will be addressed at some later stage.

If you are correct, and I strongly suspect that you are, Francis will eventually arrive at your conclusions, but will have done so – and be seen to have done so – in a non prejudiced and dispassionate manner. You may consider the case against renewables to be self evident and may therefore be impatient when you watch what you deem analogous to the re-invention of the wheel. However, what you must appreciate is that many economists, politicians and even some professional energy analysts are not of your mind.

In attempting to convince them, Francis, should he, in fact, eventually come to share your conclusions will prove much more persuasive than you. If he arrives at another conclusion and you find sound reasons not to concur, then is the time to criticise.

I think it unfortunate that Francis has has become overly hostile and defensive, but he may consider that any lesser reponse would have prejudiced the objectivity of his project. I suspect that, at later stages of his work, you would have had the potential to have made valuable contributions. Now, it might have become too politically damaging for Francis to engage with you.


Douglas Wise – I cannot read this persons mind, I am forced to react to what he has written. I have a thick skin when it comes to this sort of debate, but it does not mean I will ignore attempts to avoid answering legitimate questions I have put forward.

Nor do I see the effort to attempt to analyze an issue by this path valueless on its face, however I do not think that a piecemeal approach, rather than a whole system one in this case is valid, and I do not think that this criticism can be airily dismissed as being a straw man.


I will admit up front that I am quite prejudiced when it comes to electrical power sources that should be added to the grid. The power grid exists to serve customers with the product they both want and need. That product is reliable electricity.

The only reason for having a grid is to make up for the imperfections of power supply machinery and to take advantage of the fact that it is often a bit cheaper and cleaner to move electricity from place to place than to move low density, high waste product generating fuel.

(I have been interested in this topic my whole life – dad was a transmission substation engineer whose primary project for the last couple of decades of his career was building “coal by wire” transmission lines aimed at moving electricity from a place near coal mines to a place that values clean air.)

By my way of judging, a power source that cannot provide a semblance of reliable power does not belong on the grid. As a former operator of a small grid that was not connected to any other grids, I know that a single nuclear generator designed to allow load following can do the job about 90-100% of the time. If you put three or four of those reliable generators together, you do not need transmission lines to supply reliable power to a defined area.

I do not “get” the interest in renewables. What benefit to they bring to the goal of providing reliable, affordable, clean power?

Quite frankly, I suspect that most renewable energy advocates are actually natural gas salesmen at heart.


@Rod Adams: “I do not “get” the interest in renewables. What benefit to they bring to the goal of providing reliable, affordable, clean power? Quite frankly, I suspect that most renewable energy advocates are actually natural gas salesmen at heart.”

And right there, we have the reason why you, and others I see posting here, are going to have a very difficult time persuading renewable advocates that nuclear may be a necessary part of a carbon-free power system.

I would wager that the vast majority of renewable advocates don’t want any form of fossil-fuel generation at all. The reason they are interested in renewables is that they don’t contribute to that little problem we have of excess CO2 in the atmosphere…

The problem is that, not being power systems engineers, they don’t understand the limitations (real or potential) of a renewables-only grid.

Me, I’m a mechanical engineer. I used to think renewables-only was viable, but reading on this site and others like it has convinced me that we should really be looking at nuclear for a significant part (even a majority) of our electricity generation.

I must stress this following point – not because you (or others like you) assert it is so, but because the information provided here by Barry & others, and elsewhere, has improved my understanding of electricity generation to the point where I strongly doubt 100% renewables can meet realistic estimates of demand (at least, in an economically-viable manner!).

You need to stop preaching and start explaining more, methinks. Otherwise, you come across as pro-nuclear, in the same way that a PR flack paid by a reactor supplier would. Sadly, that leads many to dismiss your arguments, regardless of merit.

To dismiss the work of OzEA because they are not currently considering the entire system is, I think, an error of judgement, as Douglas Wise points out.
You cannot understand a system unless you understand how each component of it works. OzEA seem to be only part-way through the process of analysing the components.

In any event, I feel the adversarial tone of some of the comments (on both sides!) detracts significantly from the discussion (and I’ve seen similar when folks here have commented over at Skeptical Science). If someone said the sky is blue because that’s what colour air is, you don’t persuade him otherwise by shouting “You’re wrong!” You persuade by explaining (sometimes *very* patiently) about preferential scattering by water molecules & dust, which handily also explains why on some days and at sunrise/sunset the sky *isn’t* so blue…

So, sorry to waffle on a bit, but I really feel that most of you have some valuable inputs to the discussion. The way you write some of the time, however, inclines me to skip over your posts, and that’s not a good outcome for any of us.


Bern -This argument started when I took exception to this passage in one of Francis’ comments:

For now you may find it interesting to consider that, maybe, renewables really can replace traditional “baseload”:

First that looked to me like very premature conclusion, and second I did not like that the term baseload was put in quotes. This is what I was reacting to.

These ideas are, in fact statements about the whole system, and they are in error because the dynamics of the whole system were not being taken into account.

If indeed OzEA in the process of analyzing the components of the power system, its principals, in my opinion, should not be engaging in making even preliminary assertions of this sort, at this time.


Unfortunately, Bern, while I understand and sympathize with your point of view, going into long explanations has not been a winning strategy to counter the bold assertions of the anti-nuclear faction. They make five derogatory comments about nuclear and half the audience is gone before we’ve patiently explained why the first one is wrong.

I do not see NG supporters in every individual that supports renewables – but I cannot fail to see them in anti-nuclear organizations, since it is often the largest part of their response to the obvious reliability and delivery power of nuclear.


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