Nuclear Open Thread

Open Thread 20

The previous Open Thread has gone past is running of the recent posts lists and getting tough to find, so it’s time for a fresh palette.

The Open Thread is a general discussion forum, where you can talk about whatever you like — there is nothing ‘off topic’ here — within reason. So get up on your soap box! The standard commenting rules of courtesy apply, and at the very least your chat should relate to the general content of this blog.

The sort of things that belong on this thread include general enquiries, soapbox philosophy, meandering trains of argument that move dynamically from one point of contention to another, and so on — as long as the comments adhere to the broad BNC themes of sustainable energy, climate change mitigation and policy, energy security, climate impacts, etc.

You can also find this thread by clicking on the Open Thread category on the cascading menu under the “Home” tab.


A new temperature reconstruction by Foster & Rahmstorf (Env. Res. Lett.), which removes ENSO signals, volcanic eruptions and solar cycles, and standardises the baseline.

I’m currently in Auckland, New Zealand, attending the 25th annual International Congress on Conservation Biology. A 4-day event, it’s a great chance to network and catch up with my colleagues, hear the latest goings on in the field of conservation research, and also give a few presentations (me and my students). I’m talking tomorrow on the impacts of climate change in Oceania — this covers a co-authored paper I have coming out in an upcoming special issue of Pacific Conservation Biology (which was actually the first journal I ever published in, back in 1997), entitled: “Climate change, variability and adaptation options for Australia”.

A conversation starter: George Monbiot has written a superb piece on nuclear power and the integral fast reactor over at The Guardian. It is titled “We need to talk about Sellafield, and a nuclear solution that ticks all our boxes” (subtitle: There are reactors which can convert radioactive waste to energy. Greens should look to science, rather than superstition). My favourite quote:

Anti-nuclear campaigners have generated as much mumbo jumbo as creationists, anti-vaccine scaremongers, homeopaths and climate change deniers. In all cases, the scientific process has been thrown into reverse: people have begun with their conclusions, then frantically sought evidence to support them.

The temptation, when a great mistake has been made, is to seek ever more desperate excuses to sustain the mistake, rather than admit the terrible consequences of what you have done. But now, in the UK at least, we have an opportunity to make amends. Our movement can abandon this drivel with a clear conscience, for the technology I am about to describe ticks all the green boxes: reduce, reuse, recycle.

George’s essay includes details on the integral fast reactor and the S-PRISM modules that GEH hope to build in the UK (to, as a first priority, denature the separated plutonium stocks, and thereafter generate lots of carbon-free electricity). The fully referenced version is here.

Although the comments thread contains the typical lashing of misinformation and vitriol one would expect from such topics in a relatively unmoderated stream, it’s also clear George has created some converts — or at least people who are willing to reassess their preconceptions. Great stuff. Feel free to leave a few comments yourself on that post — Ben Heard has certainly weighed in a few times! This is becoming an inescapable reality for rational Greens now. I really feel some momentum, at last.

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.

436 replies on “Open Thread 20”

This is an interesting read:


Click to access 232_Report_Analysing%20the%20technical%20constraints%20on%20renewable%20generation_v8_0.pdf

Scott – please be aware, before you post next time, that BNC requires you to have read any links and be able to express your opinions on the content. As this is on the more relaxed Open Thread your comment will stand.Future violations of this rule may be deleted.


There’s a new story from an undercover reporter at Fukushima Dai-ichi, touting various shenanagans, most unverifiable. One statement I find odd, though I have no experience in the subject (dosimeters) to judge it firmly. Here it is, and if anyone has any comments on the subject I’d welcome them:

He says plant workers regularly manipulate their radiation readings by reversing their dosimeters or putting them in their socks, giving them an extra 10 to 30 minutes on-site before they reach their daily dosage limit.

The full article can be found at


Eamon, on 10 January 2012 at 1:08 AM said:

He says plant workers regularly manipulate their radiation readings by reversing their dosimeters or putting them in their socks

Alpha particles can’t penetrate the paper safety suits the workers at Fukushima wear. Wearing your radiation badge backwards or in your sock just avoids ‘clocking’ radioactive particles that aren’t going to penetrate the paper suit anyway.

On the other hand, I would be surprised if the gamma radiation readings taken at Fukushima were lower at ankle height rather then chest height. The primary contaminant at Fukushima is cesium which tends to bind to the top couple of inches of soil. In theory measuring at the foot rather then the chest would give a higher reading.


Thought some might be interested … review article of LCOE calculations for solar PV across a broad variety of factors and considerations: with particular attention to system costs, financing, operating lifetime, and loan term. Study claims there is widespread inconsistency across research literature on use of these variable inputs and sensitivity factors leading to considerable variability in results. Authors look to document and characterize this variability, and provide a more useful and consistent assessment of solar PV levelized costs.

They present their results in a case study for Kingston, Ontario. Assumptions are as follows: 0.5% degredation rate/year, 100% debt financing, 1.5% insurance cost, 10 year inverter life (replacement cost 9% of total installed system cost), and solar insolation in Kingston (1270 kWh/kW/year). Their analysis provides a range of results for different discount rates (0%, 4.5%, and 10%), loan lifetime (5 – 40 years), installed system costs ($1 – $7/Wp), and more.

Results: they find solar PV grid parity with Ontario electricity rates (at $0.06 – $0.17/kWh in major cities) under the following conditions: “A 30 year system at an installed cost of $2.25/Wp–$3.25/Wp with a zero interest loan at the other assumptions has an LCOE of $0.10/kWh–$0.15/kWh, which is able to compete with grid prices at $0.080/kWh–$0.11/kWh. Regardless of lifetime, Fig. 3 indicates that installed PV system prices still need to decrease by a factor of two to be economically competitive in the current economic system in Ontario” (p. 4477, emphasis added).


A study claiming wind turbines actually increase grid emissions has been released.
Link to the Guardian article, but there are links to the original report and other contributions.

Pretty obviously a flawed report (compares two hypothetical grids, one only running on CCGT, the other wind/OCGT, only one of those has peaking capability) but interesting nonetheless. If for no other reason than a study in how ‘research’ is being used to further one’s pre-determined ends.


harrywr2, on 10 January 2012 at 3:29 AM said:

Thanks for the info Harry

Alpha particles can’t penetrate the paper safety suits the workers at Fukushima wear. Wearing your radiation badge backwards or in your sock just avoids ‘clocking’ radioactive particles that aren’t going to penetrate the paper suit anyway.

I was wondering about that.

On the other hand, I would be surprised if the gamma radiation readings taken at Fukushima were lower at ankle height rather then chest height. The primary contaminant at Fukushima is cesium which tends to bind to the top couple of inches of soil. In theory measuring at the foot rather then the chest would give a higher reading.

Good point!

Regarding caesium, I would think that the radio-isotopic profile would be different in the plant and its immediate environs – though I am no expert on the matter. We have a lot of caesium scattered across Fukushima, but I’d think there would be also be heavier radioisotopes closer to the plant. That said, they’d be largely alpha-emitters, and so amenable to the dosimetry hi-jinks you mentioned above.


@ evcricket, on 10 January 2012 at 8:51 AM:

What’s flawed about recognising that OCGT can support wind but CCGT cannot, because it isn’t flexible enough?

Don’t think of the study as being flawed. Consider that any high penetration wind in a CCGT-dominated system is fatally flawed.

As someone else said once on this site: “Wind is little more than a trojan horse for gas.”

See, for example, this 18 month old study which is one of a series of four studies which demonstrated pretty credibly that wind power fails to deliver carbon emission reductions in the real world.

See also, the very wide ranging Tcase 12 thread on this site, at It is very accessible reading and can be a real eye opener about some of the many factors which affect CO2 emissions from various technologies, either individually or in a mix.

Or read the critique and comments re the ZCA proposal. Again, on this site:

Again, I have intentionally selected 18 month old publications, in part because I want to demonstrate that it was demonstrated conclusively years ago that (wind + gas) is carbon intensive and, at best, is only a marginal improvement on Old King Coal.

The solution to the climate challenge must be much more radical than at first may appear to be the case.


Roger Clifton, on 10 January 2012 at 2:36 PM said:


Why do you “think there would be also be heavier radioisotopes closer to the plant.” ?

I was thinking plutonium and uranium would be scattered, but being heavier than radioisotopes like caesium they’d travel less and so be concentrated more around the plant and it’s environs. Please feel free to poke holes in this – this is a subject I’m new to (though I have an old Physics degree lying around…somewhere)


John et al: I got the impression from reading the guardian article– describing the study asserting that carbon is not significantly reduced by adding wind, but increases, then challenging that same study–that the mainstream arguments defending wind power as reducing carbon are almost all based on models, not real world studies. Is this in fact true?


John, my point is that the findings are invalid; they did not compare like with like. Without entering into any further discussions of the formats grids will/won’t take, the actual finding of the report is not consistent. One option can change load to meet a change in demand, the other can not. Comparing the carbon intensity of those scenarios is not useful.

All of the studies you have provided are interesting at best; they are not informative in an Australian context, which is all I really care about. We do not, and will never, have a grid that is just wind and gas. If we introduce wind in Australia right now, the power produced displaces coal power. Not gas. And contrary to popular belief coal can actually ramp up and down quite a bit.


Weird weather is a novelty at the moment but one day it’s going to be a cause for concern. Mid January is the height of summer and horticulturists plan for temps more like 40C than the sea level 2C we got hereabouts last night. If we have to grow crops like tomatoes entirely under controlled conditions the price of food will go even higher. Some grain harvests suffered because of the lack of a drying period in the wet summer.

Coal apologists tell us if climate change is real it’s easier to adapt. That’s until we get the really costly weather regimes such as the need to grow summer crops indoors. I wonder if big changes are already underway but we don’t realise it yet.


Hi all,

I’ve been digging around trying to get a bit of info on skill set requirements for a nuclear energy industry in Australia. Forgive me if BNC has already touched on this, but I couldn’t find much.

Has anyone had a good look at the state of nuclear education and research required for an industry in Australia? Presuming the ban is lifted on Gens III+ and IV and we decided to pursue such an industry, how are we positioned to deal with such a task?

Of course there are some undergrad courses with nuclear relevance in such disciplines as medicine and science, though nothing directly pertinent to nuclear energy such as nuclear engineering. Taking a look at relative legislation in the parliamentary library, there doesn’t appear to be any block to it’s teaching. Interesting to note however, if we click ‘Nuclear Energy in General’, two sources are provided; ‘Nuclear power & Australia’ (link doesn’t exist) and ‘Friends of the Earth Melbourne: Anti-Nuclear Campaign’, in the case of the latter, I question if it should really belong on the APH site!.

Research schools/facilities such as Uni of Sydney and ANSTO exist of course, without the nuclear energy generation.

The Australian Nuclear Forum has some useful articles on nuclear education with a policy submission to Government. I particularly admire their advocacy for nuclear science to be taught in high school.

I would imagine if we were to build reactors in the near future, GenIII+ would be a good starting point, with a view to develop such technologies such as the IFR. Some questions based on this scenario:

1. What are the sufficient size and depth of educational/research needed in Australia for having a nuclear energy industry?

2. What will it take to modify existing nuclear science/engineering undergrad courses already offered here?

3. Can existing science and engineering graduates easily supplement their degree with nuclear components, e.g. A mech engineer –> nuclear engineer?

4. Could we attract nuclear energy experts from overseas to ‘kick-start’ industry and research?



PaulQ — For a comparison of sorts, Chile is seriously considering acquiring 3 large NPPs. The Chileans have no prior training in nuclear power generation. Thye are resolving this by sending some engineers in France for training with EDF or Areva, I’m not sure. They are sending some others to the USA for a tour of duty with NRC.

What is required is a good understanding of how the operate an NPP. I woud suppose that starting with mechanical engineering is appropriate, especally if there is a course in the relevant nuclear physics which maybe includes some of the helth physics useul in understanding the safety issues.


@Eamon speculated that fragments of heavy metal would fall sooner, and thus closer to the plant.

As far as I know, the cores did not fragment at all, although two of them did melt. However, as well as dissolving some of the skin on the surface of the cores, the violence of the redhot reaction with steam probably did mobilise tiny flakes that travelled as suspensions in the eventual droplets. These would have been too small to affect the terminal velocity of the droplets. A significant amount of the aerosol would have plated out onto the walls and ceilings of the building panels that were subsequently shattered in the explosions. These fragments, that is, of building materials, can be seen in the video footage falling short as sheets of debris. Almost certainly the decreasing size of the fragments remaining in the air would be distributed in decreasing size with distance downwind.

As Finrod has pointed out, the clumping of the showers of debris would have made them easier to find, scrape up and leave the soil cleaned for business as usual. However where they fell would have been more to do with the nature of the building product than any radioactive passengers.


David B. Benson, thanks for the info on Chile’s pursuits and the type of skills needed for NPP operation. On the u/grad courses, do you think this is an easy transition? Are there any bridging course examples you’re aware of overseas (I can’t find any).

I have a suggestion: start preparing Australia for 21st century energy now.

Nuclear reactors may be banned in Australia, but some of the preceding essentials for establishing nuclear power, are not. By that I mean educating a generation of engineers and scientists.

The Energy Minister, Martin Ferguson reminded Australia in the 2011 Draft Energy White Paper that if by 2020, renewables and carbon capture & storage were not technically and economically feasible, then nuclear should be considered as an option. Why wait to start from scratch in 2020? A skills base can be established now (if my interpretation of the Acts are correct;).

I recently partook in a teaching/research planning session in our faculty where I asked the physicists on their thoughts of starting NP courses- it was a unanimous ‘yes’. If we’re serious about mid-long term energy options, I say we stay ahead of the curve, rather than play catch ups.



It appears that a contraction may be looming for Australia’s aluminium smelting industry which has 6 smelters and consumes 11% of all domestic electricity
They don’t blame the impending carbon tax (from which they get substantial export exemption) but perhaps they see tough times ahead regardless. This could be a good thing globally if the industry recycles more or relocates to hydro based production.

However it is not good if the industry relocates to another country that uses not only Australian alumina (refined bauxite) but Australian coal to help generate the electricity. Overseas steel makers can use both our iron ore and our coking coal, steel producing about 1.7 tCO2 per tonne of steel. A tonne of aluminium needs about 15 Mwhe to smelt. If our local industries disappear it seems crazy that we would have to import product made with our own ingredients.

I think the answer has to be something akin to the EU’s proposed airline carbon tax. Right at the moment the public doesn’t see it. However within the decade it seems likely that one or both of Australia’s primary steel producers will close and perhaps half the aluminium smelters. I’ll repeat my 5c worth when that happens.


@PaulQ The problem I see with training nuclear engineers now is convincing people to get serious qualifications in an industry which doesn’t really exist in Australia…


PaulQ & evcricket — My opinion is that other aspects in the curriculum for mechanical engineers are far more difficult; anybody who does adequately in the (mechanical) dynamics course (and also thermo) will find the nuclear aspects smooth sailing.

There is a world-wide need for qualified nuclear engineers. The Idian government as started a training program for Idia’s needs but finds that the graduates are hired abroad (for considerably higher pay).


David, yeah I was being a touch facetious; I think a whole nuke engineering course would be a tough sell in Australia, but Mech is a pretty good fit.

I am a mech eng and can confirm that thermodynamics is hard. I’d be lying if I said I passed first go.

Agree that many of the skills cross over; a nuke plant is just like any other power system, the heat source is just different. I imagine that 95% of the work would be generic mech eng; keep the pumps running, service the turbine, etc. Just the heat source varies.

Used to work closely with an ex-French nuke engineer, one of the sharpest guys I’ve ever met. Most of his skills were applicable outside his field, but his nuke knowledge was fascinating. But like you said, it’s just learning a bunch of rules and if you can manage thermo and kinematics (which was mind boggling) then you can probably handle nuclear equations.


David B. Benson and evcricket: are either of you familiar with the course structure of mech vs. nuclear engineering? I wonder if it is possible to do a Post/Grad Dip to qualify a mech eng to nuclear engineer?

I assume that would be quicker to organize and cheaper to provide!


I have a MechEng MSc., albeit with an emphasis on management side, and had seriously considered another in nuclear engineering. Sadly, at least in my alma mater (Aalto University in Finland) the prerequisite for a MSc. in nuclear engineering is a decent BSc. in engineering physics. While many MechEng skills are transferable or at least useful – particularly if one specializes in power systems, thermodynamics, or some such similar field – at least here the engineering physics curriculum is considerably more math-heavy and, frankly, very demanding.

While undoubtedly not an insurmountable barrier, the required 3-4 years of very intense mathematics before getting on to the nuclear engineering stuff put an end to my aspirations.

I remember from somewhere that before nuclear engineering was a speciality in our university, the nuclear engineers came nearly exclusively from engineering physics/applied physics graduates. Mechanical engineers were and are definitely employed in the nuclear power program as well, but (I believe) mostly on the non-nuclear side of the business.


@ evcricket, on 11 January 2012 at 6:07 AM, re wind+OCGT Vs CCGT alone:

…[M]y point is that the findings are invalid; they did not compare like with like…One option can change load to meet a change in demand, the other can not. Comparing the carbon intensity of those scenarios is not useful.

Sorry to differ, but straight CCGT probably can do an adequate job at load following. The trick would be to keep the first (GT) stages of at least some of the CCGT plant part-loaded, thus retaining some very quick ramp up capability. Ramping down is a snack for CCGT – just back off the GT stages and re-balance the thermal side of things.

The Guardian’s article was comparing reasonably equivalent hypothetical generating mixes, of the type which a solar-starved Britain may eventually become after the Greens have forced closure of NPP’s and political reaction to climate change has forced closure of coal fired thermal which could be the case if CCS remains only a dream. Thus, in a British context, the Guardintly framed.

However, the new twist is to demand that the context be Australian. I cannot go there and this new requirement is irrelevant – the article is from a British newspaper.

Where I can go, however, is to the recent blackouts in South Australia, which happened on hot days under the influence of a widespread High pressure cell. The wind simply did not blow enough to achieve that which wind spruikers often claim to be a truism – that hot days and high air conditioner loads will be matched by higher generation from wind, if not locally, then from somewhere else.

Well, South Australia could not drag enough power across the interstate connectors to supplement its flat out coal and gas system to keep the state running.

If Australian context is what is required, then that is it.

Let’s get away from the endless search for academic, constraint-bound, artificial analyses of the beauty or otherwise of individual protagonists’ affirmations re competing generation sources.

What will produce results in the longer run will be removal of tricks such as legislated high feed in tariffs and mandated renewables quotas and billions of green energy iniatives from the public purse.

It is up to the renewables/unreliables industry to show how they can provide whatever is needed to complete the generation mix – reliable, cheap (ie competitive in a market), safe and flexible. Renewables compaigners have never been able to do this and they know better than to try, except in abstract terms, because the real world numbers don’t add up.

When the Guardian runs an article which kicks at one flat tyre on the renewables’ chariot, it is not reasonable to then argue that somewhere else, perhaps on another chariot, in a far away land, there may be another flat tyre.

In my opinion, there are plenty of flat tyres.

Renewables – They may look good on the showroom floor, but look out for the flat tyres.

In closing, respond to the affirmation that coal’s ability to ramp up and down is contrary to popular belief. I must enquire just what it is that the public was indeed believing, in a SE Australian grid which historically consists of about 9% hydro with limited water and the rest coal. Of course the public appreciate that coal fired units ramp up and down. It is recent blarney from outside of the industry that has sowed this seed. Why water it?


Okay John, you don’t like renewables.

So, coming back to the analysis, you say this:
“Sorry to differ, but straight CCGT probably can do an adequate job at load following. The trick would be to keep the first (GT) stages of at least some of the CCGT plant part-loaded, thus retaining some very quick ramp up capability. Ramping down is a snack for CCGT – just back off the GT stages and re-balance the thermal side of things”

If CCGT can adequately load follow, why not pair it with wind? So then the study could have considered a grid made of wind and CCGT and a pure wind grid; that would have produced a more widely applicable finding don’t you think?

Thanks for this colourful phrasing too:
“Renewables – They may look good on the showroom floor, but look out for the flat tyres.”

It’s interesting, but I prefer my analysis to be a bit more quantitative. This study could have been just that, but alas….


@evcricket, many of the comments I have read here have been very supportive of renewables, and some of those commenters have put lots of their money where their mouth is. However, they too speak in quantitative terms of the problems for household supply and scaling up for community supply.

One of the problems discussed (you can find it yourself using the sidebars) is the rate of change of supply from renewables, relentlessly changing, faster than demand changes and out of step with them. The analysis more or less concluded that open circuit gas turbines would be the only backup that could balance extensive unreliables. By implication, any legislation requiring wind or solar effectively favours the gas industry.

For small grids on the scale from households to townships, you will also find here extensive analysis of storage. Many commenters hope earnestly for a revolution in storage technology. But the 200-year-old lead acid battery is getting to look very much like the other flat tire on the chariot.


@ JB:

Sorry to differ, but straight CCGT probably can do an adequate job at load following. The trick would be to keep the first (GT) stages of at least some of the CCGT plant part-loaded, thus retaining some very quick ramp up capability. Ramping down is a snack for CCGT – just back off the GT stages and re-balance the thermal side of things.

I’m guessing that the legendary 60% thermodynamic efficiency of the CCGT plant is not easily maintained when you start deviating from the optimal configuration. Is this so, or do they have a bit of leeway before efficiency drops off significantly?


Finrod… it’s a turbine, so it has a best efficiency point (BEP). Any deviation from this is less efficient, and described by the pump curve. Pump curve are broadly a similar shape, so +/-5% is a pretty small efficiency loss, then beyond that it drops off more sharply.

Ramp up and down though is probably achieved by baffling/venting with bleed valves. Straight energy loss.


Finrod and evcricket:

Agreed, totally.

The fact is, that there are no ways to generate electricity reliably without some form of overbuild to cover peaks.

To avoid overbuild is to under-supply most of the time. This is unreliable.

Don’t think of it as inefficiency. Think of it as the real world situation, as against the dreamings and authoritarian nonsense which infects that which comes from some ZCA2020 and other optimists’ thinking.

I want to be able to turn my lights on when I choose, not just during the daily window when the Rationing Central dictates that I may.

I drive my car to suit the prevailing conditions, even though that means idling the engine at a stop light and rarely if ever driving flat out. The same applies to generation and distribution of electricity.


Urgh, WordPress crash lost my comment. Anyway, from the top.

Roger, I have no doubt there are many renewables advocates here, and I probably count myself among them. Note though that no where here have I advocated for renewables; I just want to talk about this study and would love to actually answer the question they sought to address properly.

I’m, pretty interested in your claim that the rate of change (dP/dt) in output from renewables is greater than dP/dt of demand; this is of course an important problem in grid design and one I’ve been looking for some answers to. Do you have a link to a paper on this? I wonder too if this takes into account CSIRO’s Wind Energy Forecasting project?

I know quite a bit about storage and in particular small grid stability. I can assure you that lead-acid is probably not the leader in this area any more, thankfully. For some reason as I am much more bullish about the prospects for storage than many people who haven’t studied it; I wonder if that is because it just seems so improbable?

Surely too the problem of ramp rates exists with nukes? How is this problem usually addresses; by making so much power that the unavoidable efficiency drop doesn’t matter, or by teaming up with some other peaking storage/supply? Interesting problem.


@ evcricket:

Ramp up and down though is probably achieved by baffling/venting with bleed valves. Straight energy loss.

Would this process impact the temperature (and therefore the efficiency) of the steam cycle? I imagine that the steam generators are designed for maximum efficiency at a particular temperature.


Finrod, the boiler/heat recovery section will make steam at the temperature the metallurgy in the heat exchanger is designed to handle. Hotter = better here. This won’t change, but the amount of steam reaching the turbine will be throttled to change load. So the temp doesn’t change, but energy is lost through venting steam or throttling the flow of steam.


Perhaps I need to rephraase my question. It should be something along the lines of “Is there any way to isolate the impact of load-following to just one part of the combined cycle, and if so, is it worth doing?”. But really, what I ultimately want to know is what effect such load following has on fuel consumption and CO2 emissions. Up to now, my conventional wisdom has been that load following for technosolar renewables cannot be efficiently performed by CCGTs without significantly compromising efficiency and thus increasing emissions. If the situation is not that bad, then the details are important.


@ evcricket, on 13 January 2012 at 8:32 AM:

I said: “Sorry to differ, but straight CCGT probably can do an adequate job at load following. The trick would be to keep the first (GT) stages of at least some of the CCGT plant part-loaded, thus retaining some very quick ramp up capability. Ramping down is a snack for CCGT – just back off the GT stages and re-balance the thermal side of things.”

Response: “If CCGT can adequately load follow, why not pair it with wind?”

Speed and amount of response are both relevant. A 100% hypothetical CCGT system has 100% of CCGT plant to ramp up and down. That can be adequate, as I said. About one third of the plant consists of the GT sections, the remainder is the boiler fed generation plant which uses the exhaust gas from the GT’s.

However, in a grid with a large percentage of wind, in order to have sufficiently quick response, the need is for OCGT’s. The smaller percentage of CCGT’s, combined with the off-the-edge-of-a-cliff nature of some wind fades will be too slow, too expensive and, as a sideline, would pay a proportionately higher efficiency penalty, because of the ratchetting up and down of the steam side of things or through excessive gas firing of the boilers to keep them stable.

OCGT’s, on the other hand, are cheap, quick to construct, handle ramps, both up and down extremely flexibly, but throw away a lot of heat in the form of exhaust gases.

There is a significant probability that wind will die off across a wide region and need to be 100% replaced by gas, at short notice. This simply not the business of CCGT’s. If anybody wants to pretend that this is not so, then where is there a grid, anywhere in the world, that works this way? There probably is none. For Wind+OCGT, however, there are plenty of examples, including current proposals in Victoria, where the proposals are not for efficient CCGT, but for quick and dirty Open Cycle GT’s to “balance” wind.

Further: “Okay John, you don’t like renewables.”

No, I have nothing against renewables, per se. I object to renewables which are wrapped in handouts and blatant lies. IF renewables were capable of standing on their own feet and delivering the climate outcomes which we need, this site would be about climate change plus renewables. It has evolved differently, as the material posted here demonstrates, to embrace consideration of nuclear energy not only renewablesbecause hard, well thought through analysis via dozens of leading articles have looked every which way at the emerging climate and energy problems and come to the realisation that, absent unexpected major developments in renewables, storage and more, we simply cannot save our globe’s climate system from collapse.

That is far more important than demands that multitudes of studies be repeated in an Australian context because an individual observer is unwilling to consider overseas experience.

I am sure that your knowledge of improvements in energy storage options would interest us all. How about a post some day?


Ahhh. My understanding is that CCGT operates in a pretty narrow efficiency band. Two big thermal processes on the same shaft will be extremely sensitive to changes in load. But this is first-principles stuff, not based on findings in a study or anything like that.

I too would love to see some hard numbers on it.


John, this is something I’ve heard from a number of people:
“IF renewables were capable of standing on their own feet and delivering the climate outcomes which we need, this site would be about climate change plus renewables.”

This seems like a different requirement than every other generation type we have used. Why the double standard? Details of this are discussed here, but from a US study:

No doubt too you acknowledge that nukes will not get up without government assistance, at least in the form of underwriting their insurance? Or would you rather foresake that assistance as you require of renewables?

And on storage, I keep directing people here: this is a brilliant website.

Overall, much like renewables, I doubt we’ll see a ‘step change’ in storage tech. Also like renewables, costs will come down mostly through increases in production. For this reason, my money (figuratively speaking, being a public servant I can’t actually invest in any of this stuff) is on an improvement in capacity manufacturing technology or one of the modular battery units, particularly Na/S batteries.

Further, I also think that we’ll see more integrated renewable installations in the next few years, something like 200MW wind farms with 20-50MW of on site storage. The market is set up so that there is incentive for investors to design their plant in this way, but until the price of electricity goes up the economics don’t make it.


Another story in the gas-is-our-salvation saga ought to raise some questions. Gas from an offshore field between Australia and Timor will be liquefied onshore then sent to overseas customers, Japan mainly I gather.

I understand Darwin will use some of the gas locally as the Amadeus Basin nearer Alice Springs is fast depleting. Nonetheless that existing pipe could carry gas towards south eastern Australia which also faces a looming gas shortage within a decade. The project will need 3,000 workers. If we import those workers and many stay on we will need to support them. This raises a number of questions.

For starters is it an attempt to pre-empt gas processing in Timor when field outsides the Australian zone are developed? If the main customer is Japan will it increase their emissions? (I estimate additional CO2 could be about 24 Mtpa) Given that SE Australia is facing a gas shortage and Australia as a whole faces an oil shortage should we selling most of this gas overseas? If it leads to increased immigration where does our extra energy come from? The thinking on the highest level seem to be that gas is a low carbon bonanza. I suggest we’re essentially digging ourselves deeper into fossil fuel dependence.


@evcricket : “something like 200MW wind farms with 20-50MW of on site storage”

if you intended to say “20-50 MWh of on-site storage”, I would be very interested to hear of the technology used. Such would indeed be a game changer.


@ evcricket:

Two big thermal processes on the same shaft will be extremely sensitive to changes in load.

On the same shaft, you say. I’m under the impression that the gas and steam turbines are separate, and drive separate generators. Can somebody help me here? I’m not getting a goood mental picture of this.


Roger, these guys have something similar:

The little 660kW wind project at Hampton is an example. I wouldn’t like to call it a game-changer BTW… it will probably trickle out slowly as the vaguaries of economics dictate.

I’m mostly making the point that storage won’t be a grid wide problem in the future, it will be handled on site, and there are benefits there for the smart operator.


Finrod, going from Wikipedia it looks like you’re right; the steam cycle is on a different shaft/generator.

Makes some sense too when I think about it. Gas turbines combust the fuel and make electricity. Maybe multiple gas turbines on a site. Then the waste heat from multiple turbines can be collected to power a steam cycle, with one steam turbine. They suggest something like 4 gas turbines and 1 steam turbine. This suggests that the gas side could be ramped a bit and the steam will potter along using what ever waste heat it can manage.


@ Evcricket:
You now have the picture correct. Almost all CCGT’s, AFAIK, are constructed with separate generation for the gas turbine(s) and the steam side. I’m told that they can be run as OCGT’s – that is the way that they are started up from cold.

So, reserve CCGT’s are essentially high cost OCGT’s for a short time after start-up. I don’t know (no reference and no time) but I expect that at least 30 minutes before any usable energy will come from the boiler side; perhaps a couple of hours, depending on warm-through parameters. The larger, the slower.

CCG’s are again shown to be inappropriate as a backup in generation mix with a high percentage of wind turbines. Let’s move on.

I will not further respond to comments re renewables. These issues have been thrashed out here and elsewhere many times in the past.

Re government providing insurance for nuclear power stations, there are American contributors to this site who have explained that a tiny levy on production has more than amply provided for the government’s share of nuclear power responsibilities re insurance and long term storage of spent fuel, etc. Have you considered that the article which you referenced from Climate Spectator could be peddling old, oft-repeated, untruths? Why trust that rag? They never cite the sources. Besides which, that particular author has moved on.


John, a quick read of the article would show that they have thoroughly cited their source:
“According to the study by Nancy Pfund, a managing director of VC firm DBL Investors, and Ben Healey, a Yale graduate, the amount of government subsidies for renewables in the US pales in comparison to that of its energy rivals in their early years.”

Hyperlink has dropped out, but it is there if you would like to challenge their method or findings.


That report looks to be behind DBL investors membership paywall. From what that article states it is clear there are a few questions that are of a concern that need to be addressed (difficult to do unless a member of DBL).

1) Seeing as we are talking about the end product of electricity production it would be good to see those figures expressed in $/MWh. Because to say that they “pale in comparison” you should be comparing like for like, that $0.4bn for renewables could be representing a fraction of the other generators production. Why didn’t they do this?

2) Looking past that and looking at what info we do have, is that we have a report written by a venture capital company that targets Clean Tech projects (amongst other non energy related areas) and a graduate who has worked in an environmental and natural resources department who worked on a Green Energy Fund. Is there a motive here? Bias? Seeing there is real venture capital at stake?

3) These figures are on a news website dedicated to reporting on topics that involve climate change. So it’s not a good peer reviewed source and context can be lost in word limits/journalistic presentation.

None of this says that those figures are wrong, they may be accurate and my questions will go answered accordingly. But I still have my eyebrow raised at this one until I see the calculations made to get to those subsidy figures. Jury is still out on this one. The Paywall persists.


PaulQ — I would have thought that a good degree in MechEngg would suffice as a starter for some courses in nuclear engineering sufficient for operating an NPP. That probably isn’t enough for design engineering, but nobody is suggesting that. The situation in Finland, as sketched by Janne Korhonen in a prior comment on this thread, suggests otherwise. Or else that is done simply to limit the number of graduates. I’d look at actual requirements in several countries before coming to a definite conclusion; after all, if the Chileans can do it the Aussies certainly can also and more easily.


evcricket & Irregular Commentator — It is certainly the case that the United States government put quite a substantial sum into the advanced development stages of nuclear power plants; it remains unclear how to divvy those sums between civilian & military development.


Yes David, that’s the key to this I suspect; much early ‘nuclear’ funding probably went to military spending. We might have thorium reactors across the country now if they’d spent the money making electricity rather than bombs…

The thing I found interesting about that study was the amount of help coal received in the early days. Just dig it up and burn it; I can hardly imagine a cheaper mine/power supply scenario than say Hazelwood, yet it was still subsidised in the early days.


I’m yet to see any evidence the CCGT being built in my area (Canada) can operate at less that 60% of capacity, while the coal units can operate at 20% capacity.
Wind forecasting being, optimistically, a developing skill, that means there needs to be a lot less coal ‘hot’ than gas, if you are anticipating a change in wind output. Most jurisdictions handle that just by exporting more as wind penetration grows. Australia would likely handle it by backing up 1000MW of wind with 200MW of coal, and not 600MW of CCGT (there’s a couple of stories on grid issues during Germany’s recent record wind month at the German Energy blog – both the Czechs and Austrian grids are cited)
Without actual smokestack emissions, I am extremely skeptical of claims that mixing CCGT with wind is much cleaner than using coal – or even OCGT.
There was an American report recently that summarized what needed to occur for wind penetration to increase to a certain level (20%) - The big 3 were:
1. More accurate forecasting
2. More Flexible conventional supply
3. More Transmission.
If the ‘more flexible conventional supply’ emits more, it really begs the question “what is the point?”
The transmission growth is also a challenging one. One candidate for the Republican nomination opined that a transmission line promised, through the state holding the primary, would be buried.
A strange claim to make most places – particularly strange when made where the state slogan is “the granite state”


Energy Minister Ferguson has expressed the hope that Australia will overtake Qatar as the biggest LNG exporter
It is hoped within a decade that annual LNG exports with increase from 20 to 80 Mt. Elsewhere the hope has been expressed that Australia’s coal exports will increase from ~300 to 450 Mt. The article points out Japan’s new found need for coal and LNG.

Some may recall at the Copenhagen climate conference Obama was to give the closing speech but he handed over to our then PM Rudd who stressed the urgency of global carbon cuts. Ultimately annual CO2 from Australian exported coal and LNG will be well over a gigatonne, noting total 2010 global emissions were around 31 Gt. Think of that coal and gas as carbon that has been safely buried under Australia for a few hundred million years and could happily stay there. Now compare that 1000+ Mt of CO2 from exported fuels with the domestic 160 Mt Australia has to lose by 2020. If we’re not on track apparently we’re obliged to buy foreign carbon credits to make up the shortfall which could cost billions of dollars.

Thus Australia
– earns billions selling carbon fuels overseas
– spends billions buying overseas carbon credits
Somehow this makes sense in political circles.


@ Scott Luft, on 13 January 2012 at 3:57 PM:

I’m yet to see any evidence the CCGT being built in my area (Canada) can operate at less that 60% of capacity, while the coal units can operate at 20% capacity.

CCGT units can operate without the boiler section in service. That is the mode under which they start up. Hence, they can operate in OCGT mode.

Typical CCGT’s consist of 2 to 4 OCGT sections, each of which could be fired independently and run within a range.

Thus, I would expect Scott’s local CCGT to be physically capable of operating between about 10% and maximum, although its owners may not like to do so and may choose to bid other units into the system or call on a replacement power option from another generator in preference to uneconomical operation at very low loads.

Regarding coal fired units, operation at 20% of capacity is, in my experience, quite low for coal – there is a limit below which flame stability becomes an issue due to the small number of burners and burner levels in service. A more typical figure, again in my direct experience – not industry wide – is 25 or 30%.

During startup and at very low loads, to ensure flame stability it is common practice to support the pulverised fuel burners by use of oil torches. This represents an increased operating cost when the lower load limit is approached.

In both coal and GT systems, it is good operating practice to be risk averse. I would expect that owners will always like their units to run at a substantial load, not only to achieve optimal efficiency, but to ensure stability.


Hi all,
this TED talk on nano-solar looks interesting. He’s claiming to have an ‘electron storer’ that they are ‘testing’ that could one day eliminate the grid with on site super-cheap solar being stored by his super-cheap ‘battery’. But once again these promises are ‘in testing’. Whatever else he’s developed with nano-solar, storage seems to remain the fatal flaw.


I’d like a little help here. It’s about nuclear power and global warming. I’m not talking about the mining, transporting, building, maintenance, security, decommissioning part where we know fossil fuel is involved. It’s about the actual production of electrical and thermal waste energy and what contribution it does or doesn’t make to AGW.

By adding new energy to the earth aren’t you heating up the water and the air and in the process causing more water vapor and indirectly helping to release more stored CO2 and methane? I realize npps don’t directly produce ghgs, which mediate the earth’s temperature, but indirectly, simply by heating and producing water vapor they would seem to generate ghg increases before having the nuclear power source energy radiate out into space.

I’d appreciate some analysis of this point.


Further to EN’s link, water vapour is short-lived greenhouse gas, so any equilibrium with power plant thermal emissions has been reached long ago (apart from the small increase due to the growth in thermal plants — but as the link EN included shows, this is negligible). More water vapour does not beget more water vapour, whereas more CO2 most definitely does.


Hi Barry,
I hope my link to the TED talk a few posts back is not interpreted as ‘pushing’ solar. I agree that we can’t postpone real action on climate change in the ‘hope’ that some new super-battery comes out.

But as I posted to some friends recently:

“If the super-battery trial mentioned below ever ACTUALLY became a cheap and viable commercial product, I would immediately change my mind about nuclear power. Anyway, ultimately pro-nuclear activists would be swept aside into irrelevance as the marketplace flooded homes and industry with these cheap nano-solar power windows and batteries. Homes and businesses would go off grid so fast that the question of nuclear power would simply evaporate! (Except maybe for submarines and deep space missions). There’s just one problem. How do we know this guy isn’t just asking for funding the way so many other guys have in the past? Do we give up looking at TODAY’s technology, like the Chinese AP1000, in the ‘hope’ of tomorrow’s technology coming to the rescue? The climate people I read say we don’t have the time to wait.”


EN, not at all. No one would be more pleased than me if there was a real breakthrough in cheap energy storage — that would be a game changer for solar PV. I’m just skeptical, on first principles, but with the wonders of nano-engineering, one can never say never.


RC duly noted. It is still along way to Darwin ~900km if I recall. I guess I was insinuating that Australia was muscling in on Timor’s nearby resources and putting them on pocket money. I won’t mention ‘imperialism’. Recall from the SBS program ‘Coast’ there is a 1200 km undersea gas pipeline (Langeled?) from Norway to England. Not sure in that case how much of the heating value is sapped by pumping. I have heard that 45% of the starting heating value of SIberian gas is consumed by pumping to the UK. This evidently troubles the Brits but not the Germans.

Since there are gas pipes from Darwin to Alice Springs via Mereenie that could be the conduit for gas to south eastern Australia. That would materialise Rex Connor’s vision in the 1970s. Imagine gas from next to Timor ending up in Hobart by pipeline not LNG.

Interestingly some Canadians are now questioning the wisdom of exporting tar sands syncrude when it will one day be much needed at home. Ditto Australian offshore gas.


The original pipeline from Mereenie was 150mm bore, from memory – I managed construction of the tank farm on the receiving end of the line in The Alice.

The pipeline between Mereenie and Darwin will not be big enough to run much of SA off NT gas.



If the super-battery trial mentioned below ever ACTUALLY became a cheap and viable commercial product, I would immediately change my mind about nuclear power. Anyway, ultimately pro-nuclear activists would be swept aside into irrelevance as the marketplace flooded homes and industry with these cheap nano-solar power windows and batteries

In 1902, 28% of the vehicles in the US were powered by batteries. It has been a long 100 years of ‘next year’ we will finally solve the problems related to batteries.

I see a Nissan Leaf on a daily basis now. Someone in my office building bought one. They plug it into a ‘maintenance’ outlet in the parking lot and charge it during the daytime peak so they will have a ‘full tank’ to get home on.


If a battery is sufficiently super, it makes more sense to transport it — because it is superlight and superuntroublesome — to a nuclear power plant for charging, and back to the user when it is full, than to require it to bridge periods of reduced availability of solar PV energy at the user’s site. Recall that one of those periods is known as “winter”, and many users have neither roofs nor backyards. I see boron atoms as batteries of just this type.



A few big if’s:
IF there were enough solar panels to provide provide power to meet daytime peaks, and
IF the Nissan Leaf owner was smart enough to charge his car between morning and afternoon peaks, say 0930 to 1200, and
IF the sun shone every single day of the year, and
IF smart metering systems were able to identify loads of all kinds and switch off the non-priority loads (eg Nissan Leafs – or is that “Nissan Leaves”) to manage demand, and
IF this authoritarian arrangement did not result in civil war, started by those who would like to be consulted before the central electricity rationing authority pulled the plug on their appliances,
THEN the Nissan Leaf and its owner would be making a difference, albeit a very small one, towards recovering the energy that is embodied in the Leaf during its manufacture.

Until then, the Leaf is window dressing.

The ages of my last 3 vehicles, each purchased new or almost so, when I sold them still running and registered were 22 years, 22 years and 13 years. That is my contribution towards reducing the impact of manufacturing on the environment and on the world’s resources. If I scrapped my cars at 6 years, there would have been not 3 but 9.5 of them.

How much energy is embedded in an extra 6 tonnes of steel and plastic?

What’s the bet that the Leaf will not last 22 years?


Civil War John? Central Electricity Rationing Authority? A little Orwellian don’t you think?

With a slightly different tone: A Leaf owner could have a timer set to charge outside peaks, and be ready to drive when the timer goes off. Residents could choose to defer their large loads when offered a price signal by their smart meter, much like is already happening on Magnetic Island.

But I agree on the embodied energy stuff. Old cars are best cars.


The Icthys gas project could bring several issues to the the fore including
– is this a good way for Japan to secure its energy supply?
– should we have different standards on the same carbon?
– are claimed carbon offsets illusory?
Audio segment

Apparently the processing plant in Darwin will create some 7 Mt of CO2 a year for 40 years, largely exempt from Australian carbon tax. Fugitive CH4 we take to be minor. The Japanese partner intends to offset some of this CO2 by ‘fire management’ in the NT. I wonder if this is the scheme advocated by Garnaut whereby savannah is burned frequently and this somehow absorbs extra CO2.

Bring it on so we can highlight the issues. If however it does make sense then we’ll all be wiser.


Roger Clifton, on 11 January 2012 at 8:29 PM said:

@Eamon speculated that fragments of heavy metal would fall sooner, and thus closer to the plant.

I was thinking of radioisotopes in the microscopic, not macroscopic sense, as some low-level Plutonium and Uranium contamination has been detected within 50km for the Fukushima Dai-ichi Plant.


As far as I know, the cores did not fragment at all, although two of them did melt. However, as well as dissolving some of the skin on the surface of the cores, the violence of the redhot reaction with steam probably did mobilise tiny flakes that travelled as suspensions in the eventual droplets. These would have been too small to affect the terminal velocity of the droplets. A significant amount of the aerosol would have plated out onto the walls and ceilings of the building panels that were subsequently shattered in the explosions. These fragments, that is, of building materials, can be seen in the video footage falling short as sheets of debris. Almost certainly the decreasing size of the fragments remaining in the air would be distributed in decreasing size with distance downwind.

Thanks for that. I didn’t know if the radioisotopes were aerosolized initially, or after escaping from the plant. Does anyone know of an accessible source on the transport mechanisms of radioisotopes & fallout – I’d like to learn more (Living in Japan we get so much rubbish in the media these days that it’s hard to sift fact from fiction at times.


Hi Harrywr2,

It has been a long 100 years of ‘next year’ we will finally solve the problems related to batteries. I see a Nissan Leaf on a daily basis now. Someone in my office building bought one. They plug it into a ‘maintenance’ outlet in the parking lot and charge it during the daytime peak so they will have a ‘full tank’ to get home on.

Point taken, but the nano-thing isn’t really a chemical battery at all. It’s an electron trapper. Don’t be too flippant in using the term ‘battery’ as you do, because they did NOT have carbon-nano tubes 100 years ago.


A question: I want to translate natgas trading unit prices into US$/kWh. I find that I don’t quite understand how to do this. Thanks for any hints.


David, I recall this but you need to check it out. An oddity in the English system of units is that $/1000 cu feet gas price is the cents per kWh electric price if the plant heat rate is 10,000 BTU per kWh, which is a common heat rate for a not so efficient power plant, such as a gas turbine. Therefore $4/1000cu ft is 4 c/kWh and is also $40/MWh. Also I recall 1000 cu ft natural gas is one million BTUs of heat. This is the one instance where british units are easy to remember and use. You should be able to use any set of units by converting the energy from one form to another. You just have to assume the conversion efficiency. to make the conversion.


DBB they make it hard by variously quoting gas prices in cubic metres, cubic feet, pounds, tonnes = metric tons, decatherms, million British Thermal Units (mmbtu) and gigajoules. Fortunately
1 mmbtu = 1.055 GJ so they can often be equated
Now 1 kwh = 3.6 MJ. Thus
1 mmbtu = 1,055 MJ = 1055/3.6 kwh = 293 kwh rounded


I think we should measure gas by weight to cover each of ambient conditions (1bar, 30C), liquefied (-173C and up, vapour pressure dependent on container), compressed natural gas CNG 220 bar and absorbed natural gas ANG 15 bar. Pressure and temperature don’t matter if we go by mass though pressure tanks can add a lot of weight.


John and DBB, that is a straight energy conversion…. if you want to convert it to electricity it will be about a third as many kWh. Does that make sense?


I’m not sure what the average thermal to electrical conversion efficiency is for gas fired plant. The couple of combined cycle plants said to approach 60% must be run at ideal capacity with river cooling. Then there’s combined cycle run as single cycle, open cycle and what I’d call closed cycle (steam only) like Adelaide’s Torrens Island station. Some say that ceramic fuel cells (as used in some Google data centres) will be much better still if the exhaust heat is used. If the average efficiency was around 40% then a GJ or mmbtu of gas fuel would produce about 120 kwhe.


John Newlands — Thank you for the clarification! I’m interested in comparing wind turbines + backup to just running CCGTs to match the load and I now think I have data which is ‘good enough’.


@ evcricket, on 17 January 2012 at 5:41 AM:

Orwellian, perhaps, but isn’t that the direction we are heading? When there isn’t enough oil being offered to USA or China to drive their economies, do you really expect them to sit idly by or to happily share with every other country on the planet? Civil war and war between nations are not out of the question.

Without rationing, how will the meagre non-fossil fuels going to be stretched? Meeting the challenges of climate change is going to cause enormous social disruption, as the economy is re-tooled around alternatives.

I am entirely serious about my assessment of military and social disruption ahead. A touch frivolous and melodramatic, perhaps, bur emtirely convinced and Not Happy.

With a slightly different tone: A Leaf owner could have a timer set to charge outside peaks, and be ready to drive when the timer goes off. Residents could choose to defer their large loads when offered a price signal by their smart meter, much like is already happening on Magnetic Island.

1. The point, of course, is that there is no such timer on a Leaf.
2. Many so-called smart meters currently being inmstalled should be called “Purposefully not so smart meters”. It is entirely feasible for market prices to be reflected in retail tariffs, perhaps smoothed to remove some volatility, and displayed via in-home screens backed up by SMS messages when the retail tariff goes out of range, either high or low.
3. Such meters, if truly smart, would easily be set to knock out pre-selected power circuits as selected by the customer (not a retailer of market administrator) in response to these price signals, yet there is no proposal I know to provide this functionality anywhere in Australia. I would be happy to have my aircon knocked off for several hours, then at a higher level have my fridge and freezer knocked out, etc. If the retail cost exceeds a certain level, I would even be happy to sit in the dark and shiver – for a while. I ask for retail customers to be given real choice about what price they are prepared to pay for energy and to be given access to the tools which will assist them to do so.

Instead, and in the absense of customer-adjustable options, a central despatcher or system operator will more frequently rotate suburb-wide and life threatening blackouts, as happened thoughout metro South Australia earlier this month. That is what happens right now. That is not melodramatic.

Regarding old cars being good cars. Caveat: If well maintained.

It is also avoidable, if technological solutions are implemented.

But I agree on the embodied energy stuff. Old cars are best cars.


May I suggest that the voltage drawdown might serve as an analogue signal for the price? When a district is drawing a lot of power from a grid of nominal 230 V, the voltage available to a new user is reduced, say 220 V. Power should then be metered at the highest price. Conversely, a district with oversupply may present a voltage of 250 V, when the power should be attractively cheap. No central signalling should be required to tell household meters the obvious.

A smart meter would only need to taste the voltage to know what the current price is, and advise automatic appliances in the household, so that they can switch on/off according to their own thresholds. On the same basis, any stored energy could be sold back to the grid when the price is right.

The size of such a responsive district could be quite small, such as at the end of a long rural powerline, where the line resistance effectively isolates the most distant users from the buffer offered by the main grid.


Roger allowing voltages to vary as a price signal is an extremely bad idea. The voltage must be regulated to be constant as much as possible to minimize losses and to prevent the burning out of equipment such as motors when voltages drop too low or motors stalling altogether. When voltages sag there is a better chance the whole area will voltage collapse and the lights go out altogether. Also when you start monkeying around with voltages. letting them drift, you run into the possibility of over voltages at light load times which can burn out lightning arrestors, and overload transformers, and cause certain kinds of equipment to fail on overvoltage, such as both LED lights as well as incandescent lights.


@ Roger.
At first I thought that you had lost your marbles, so I re-read. There are so many good reasons NOT to allow voltage sags that this suggestion must be ruled out.

Besides which, the wholesale price of electricity has averaged $5/MWh in the NEM for a couple of years. It ranges from negative to above $10,000. Are you suggesting that voltages also reduce proportionally, down to 1VAC at times of high price and, just as bizarre, that overvoltage be permitted during tim es of negative price? Of course you aren’t, but what exactly do you mean?

As for low voltages – how does Mrs Builder and Mr Househusband know when to turn off her electrical power tools and the air conditioning and refrigerator? Presumably, they would need an almost-smart meter which reads the voltage and then either raises an alarm or takes the action directly.

Why not let retail customers determine their own priorities and the prices at which they will exercise them? This is much simpler than trying to convince people to conserve power all of the time, night and day, relentlessly. Feedback from the market can help customers to conserve when it is economical to do so, to load shift (eg refrigeration and pool pumps) on a regular basis and so forth, at minimal loss of perceived value – they still have all of their toys and only play with them under (cost and price) circumstances which suit their value judgement.

I am entirely in favour of hitting large, peak time users (Volt owners included if they are charging up at the hight of a peak period) in the pocket. I am also in favour of being able to organise my affairs to suit my own priorities and preferences – at full, regulated voltage and frequency, if you don’t mind.


I should add, that the power lines inside a household can serve as signal lines as well. Of course, our incredibly smart meter would handle signal frequency interference from switching spikes, and ensure that chattering inside the household would not leak out to everybody else this side of the transformer. For that matter, the power company may find it profitable to bridge each transformer with its own messages to the smart meters beyond it, such as updates to the lookup table of drawdown versus price.


@JB invites me to clarify. In short, I meant to speak of drawdown/overvoltage as cause and thresholded consumption as effect. With proportional pricing as incentive.

Despite all the stabilising devices of the power company, drawdowns do occur. If the consuming appliances in that same area are programmed to switch off when the voltage drops down, they will reduce the drawdown.

Similarly, if there are renewables in the area feeding in, a patch of sunshine or gust of wind will cause a local overvoltage. Again, if some of the consuming appliances in the area are programmed to switch on when the voltage goes high, they will reduce the overvoltage and help protect their locality from the overvoltage.

Responsiveness may not even need a smart meter, perhaps just a switching plug for each appliance, with a twist dial marked with the voltage threshold. Mr and Ms Householder could thus have control over their devices. That would be a simple solution, but it requires the Householders to have a few smarts themselves.

Since a smart meter can measure the drawdown, it can advise the appliances directly. That does requires signalling, with an investment to install the transducers. However, a smart meter could display the bill as it accumulates, which may be all that the Householders need for monitoring their costs.



the primary power regulation in a grid is via frequency control – an increase in load causes the generators to slow down, and every generator uses ‘droop control’ to increase power and speed things up- and of course vice versa.

Voltage regulation is different and is usually related to the power factor of the loads and varies between phases. This isn’t my area of expertise but I’m not sure whether system operators would want consumers trying to turn loads on and off according to grid voltage – could be a recipe for increasing instability.


@Gene, Graham, John … I am not “allowing voltages to vary” at all, I am suggesting how smartness can reduce the variation.

The “voltage” that I am talking about is at distant households, a long way from the power station and its nominal voltage. Specifically, it is a long way down a resistive powerline, after Ohm’s Law has done its damage to the official voltage. For the simple reason that consumption varies in space and time across a grid, so also the voltage at any household must vary. (Yes, even when it doesn’t vary much at the power station bus.)

Until recently, the variations were downwards, so that voltages at the household were a few volts lower than at the power station. Now, with wind and solar feeding in, the variation can be upwards as well. Ohms law does not allow the power station to fully correct for the variation simply because there is resistance between them. However there is much less resistance between households, factories, and windfarms in the same area. They can compensate for each other before the power station has to be involved.

At the very simplest level, the householder would buy a cheap threshold plug, to go between the appliance plug on the wall socket. When the local voltage reached the threshold s/he had set on its dial, the appliance would be switched off, to avoid buying electricity at the expensive rate. Similarly when the voltage rises above a threshold, another appliance might be switched on take advantage of a cheap rate.

Yes, it does imply that prices are different at different places on the grid, however if the smart meter either records the (local!) voltage at the time of consumption, then there’s no problem making up the bill. If the smart meter were supplied with the voltage-price lookup table, it could display expenditures in real time. And yes of course, a limit on the rise time could be required to ensure stability. I hope my suggestion (and its echoes) make more sense now.


Voltage control is always a local activity at a specific point in the network. A voltage problem at a point in the network must be corrected at that location or very close to that location. Power and frequency is always controlled across the entire network. The steady state frequency across the network must be the same. Rapid changes in power flows across the network can cause temporary frequency differences in different parts of the network, but the electrical response is in seconds, which is far too fast to control using market prices. I am sometimes amused by economists who propose ideas using frequency or voltages as economic signals.

However for system protection, it would be useful to have applicances that dropped off line if the frequency of the network dropped too low. There would be value in this, but the applicance would be purchased with this capability and the network operator would see this device on the network. The customer would only be aware that his appiance was off because of a network problem if a little light came on indicating that was the problem. This is actually a good idea for the smart grid. I suppose you could hard wire in a low voltage switch also, so that if the grid voltage dropped too low the appliance would cut off. That would also have value for the grid. I guess we are talking about smart appliances that would replace the need to have the voltages and frequency centrally controlled. Thats an interesting topic for discussion.


In a hilarious coincidence, Climate Spectator has an article today about community attitudes to renewables. No mention of nukes.

The article [] cites two studies, one by CSIRO and one by Pacific Hydro.

Essentially says community opposition to wind is massively over stated by the media and that survey respondents are overwhelmingly in favour of wind power and overwhelmingly opposed to coal.


@ Roger

Thanks for the clarification. I did understand that your original post referred to ‘local’ voltages. I can see the point that you’re making but as Gene said, its not a good idea. The grid isn’t based around Ohm’s law of resistance because most things plugged into the grid aren’t purely resistive – the role of inductive and capacitive loads and the way in which they shift the phase between voltage and current has a significant influence on the ‘local voltage’, hence the need for power correction within grids. Voltage control is more about management of power factor than resistive loads, but different loads within different parts of the network are also going to affect the local voltage.

Power factor correction is used by commercial/industrial customers to reduce their tariff, but I’m not sure what sort of technology/tariff mix would work at a household level. Interestingly, this summary does suggest that solar inverters can perform some power factor correction (only when the sun is out!) (page 13).

Have a look at this summary from AEMO:

Click to access SMI%20Discussion%20Paper%20-%20Function%2010%20Power%20factor%20measurement%20V1.1.pdf

and Voltage Control Ancillary Service:

Click to access 0168-0031.pdf


Gene Preston — Thank you.

About communicating electricity price information:
Around here the advanced digital meters, so-called smart meter, communicate via wireless to transceivers mounted on poer lines; the signals then procedd to the control centers via fibre optic cables strung on the power poles. These devices are lccally read every 5 minutes and there is no reason that the devies could not also read the current price for retransmission in the household. I’m under the impression that some volunteer households are going to demonstrate this ability.

To maintain grid stabiity requires keeping the voltage regulated within the estab lished limits. This is accomplished via reactive power and must be done irrespective of load or price. Protective relays cut out at over or under voltage conditions so the operator needs to stay well away from those limits.


@ Graham Palmer:
Thanks for providing referenecs to current and relevant information re AEMO’s position regarding smart meters.

I note, in particular, that nothing contained in those links suggests that AEMO considers feeding back to consumers, especially domestic consumers, real time information re power factor or load or markets. I say markets, because there are at least two in place: The NEM, regarding wholesale power, which I stated previously to average 5 cents per kWh for the past 2 years in SE Australia.

The second market, which is much more relevant to retail customers, is the retail market which is set in place by individual retailers, who may notbe, and probably will not be, the same corporate entity as the corporation which owns the wires which bring ower to our doors and thus bears the cost of any reactive power loads which are imposed on their system.

My goal, which is in no way addressed by these papers, is to provide two classes of information to retail customers on a real-time basis.

Class 1: Tariff information. This includes the tariff currently applying to the individual customer, plus ideally an indication of tariffs later in the same day, so that the benefit of load reduction and of load shift ing are immediately accessible and apparent. At present, no retail domestic customer knows how many kW he is running at, either resistive or inductive. He knows nothing about the spend per minute or hour. He thus cannot use this information to guide a decision to reduce load, save money, conserve energy – say it however you like. There could so easily be feewdback, but there is not.

Class 2 is the information I have mentioned several times. It is gathered, or could be gathered, by smart meters at no additional cost (as explained in the first referred article – the meters can do it anyway, so why not?).

The only additional costs which a proactive consumer would be required to meet would be for transmission (wireless modem?) to the domestic PC or a dedicated PC. From that point, and using data from the retailer, eg via Broadband from their web site, re tariffs, the issue becomes simply one of calculation and communication. The simplest option would be via the home’s PC, but I want to go further – why not via a small screen in a promonent location, perhaps the kitchen?

At this rate, it’ll take forever to achieve this, because those who are defining the system, AEMO and the retailers, simply do not have this tool for conserving energy on their radar. In the vernacular, they couldn’t give a toss, apparently because it doesn’t put money into their pockets.


What happens to frequency control when every house in an upmarket suburb in summer is exporting PV electricity via inverters? An analogy could be the guitarists are playing too loud to hear the beat from the drummer.


The system frequency is maintained by the amount of power being fed into the grid compared to the load. Generators do this, not loads. The concept of resistance dropping voltage with increasing load shows a lack of electrical engineering knowledge. When complex impedances are considered the voltage is mostly controlled by reactive elements of inductance and capacitance, not resistance. If resistance is high enough to cause a voltage drop that is significant, then losses may be too high also.


@Graham, thank you for your clear explanation of power factor in an A/C grid: variation at the household meter includes phase as well as power, and the switching of appliances can improve one while worsening the other. Wind power, if not solar power, would appear to destabilise the grid.

My scenario needs to be corrected in (at least) two ways. Firstly, the value to the grid of switching in this or that appliance depends on what it does to the phase, so a proportionate price rate would have to be a two-part (complex) number. Because most appliances are either resistive (e.g. heating) or inductive (e.g. motors), a price opportunity would open up for appliances set to capacitive. In particular, since any renewables feeding in would require synchronisation, it would seem a straightforward extra step for them to supply with the phase shift dictated by the current price signal.

In this way responsive devices can contribute to phase balancing as well as load levelling. However, wouldn’t it still be local, because it could cause all three phases to drift away from the rest of the grid? If so, another correction is needed, for synchrony. However, Gene has just told us of signalling between the power company and the smart meters, which clearly could include time signal for synchronisation.


Roger Clifton — Actually, it was I who mentioned the Itron meters and tansceivers installed in this town; apologies for puttine too much in one comment.

First of all, I seriously doubt that a synchronizing time signal could be sent with sufficient reliability over the utility companies equivalent of the internet. Second, wind turbine inverters have no difficulty maintaining frequency and phase with the rest of the power grid. It is true that these are operated from control centers, but the inverter power electronics has been around for many decades and so is designed to operate on electric grids without such control. The same is certainly possible for solar PV inverters but I don’t know the details of what is currently done in the retail market.

As for stability, wind turbines actually promote stability at around the one second level due to the high controlability. For solar PV again I don’t know, but the Germans seem to be able to integrate quite a bit of solar PV without stability issues.


Thanks to DBB for his crucial info, my apologies for miscrediting. Other info I recommend to non-elec-eng’s (such as me) is Graham Palmer’s link to an explanation of power factor and how phase is balanced.


Here is a paen to time-of-use (TOU) pricing
which as implemented in California doesn’t require sending market rates to customers every 5 minutes.

Upon further reflection, the least expense method of sending those market rates to customers (which might also include the instantaneous feed-in tariff) is via the internet. The utility’s server has the ccalculated rates online and customers inquire of the srver what the rates are for the next 5 minutes (and maybe some projections of what is likely to happen over the next few hours). Customers who so desire then have their computer switch off or on various appliances. Less well-to-do (or lazier) customers need not bother with computer control and will do almost as well by seting timers on the individual appliances; much less expensive as well. Finally, the standard Itron meters can continue to be just meters, nothing more, without upgrades or replacements.


TOU pricing is generally considered something different from RTP (real-time pricing).
TOU pricing is generally not a very bright idea, and refers to pricing by hours of the day. With variable supply that would be nonsensical. The case in that article, on LA, is an understandable exception, where it would be nice to bill extra to encourage consumption on the very hottest/highest demand days. But that is more RTP than TOU. Elsewhere in California, they had the brighter idea of rapidly escalated pricing/kWh as usage groupings escalate – if I recall correctly the highest rates are around 40 cents/kWh. That resulted in rich people in big houses having solar panels (to save money!), but powerful folks would like to change that to a feed-in tariff where all ratepayers subsidize rich people to put solar panels up (as in Ontario where).
Regardless, the computer network tie-in would be appealing if RTP was seen as empowering customers. Thus Google developed Powermeter to track home power use (conceptually real-time with smart meter communication), and Microsoft developed Hohm.
Both folded their projects a couple of months ago.
Natural gas is cheap in the USA now – and if utilities are there to serve customers they’ll deliver power when customers want it.
If not, your bill will go up the more the utility spends (they are guaranteed a rate of return on equity), and their business model will remain to think up ways to justify spending more money – marketing the ideas as empowering customers to save money.


My over-riding suspicion is that we overthink residential supply. Houses don’t use that much electricity, and any corrective action will be broadly distributed and therefore at large cost. I can’t imagine residential powerfactor ever being cost effective, nor all that needed. PF drops due to large inductive loads; copper-wound motors. I reckon they’ve got to be above 50kW for that sort of correction to be worthwhile, and even then it would be marginal. Keep in mind PF makes no difference to the user experience, except in inflated demand charges; so no demand charges, no difference. There might be an argument for network operators to correct PF at substations, with the incentive being for them to offset their network upgrades, but again I think this would be a fringe case.

John, up the page, apparently solar feed-in is problematic, but not quite for the reason you suggest. I don’t fully understand this yet, but reactive power performs a regulatory function within the grid. I *think* it’s something to do with how AC power is consumed. If 100MW is produced and used at the same time, is there any bit left over to provide the wave signal to synchronise with? Since reactive power is imaginary, it can oscillate at the same frequency as the VA component, but never be diminished, so provides a strong signal.

The link with solar panels is that for reasons which are beyond my ken, all domestic inverters are set at unity powerfactor; ie exactly 1, so there are is no reactive power component. I think that powerful conventional generation (anything with spinning turbines) can address this, but I still don’t have my head all the way around the problem.


Evc apparently Germany is looking at solar curtailment on sunny days
A price responsive smart meter could help but that’s more capital cost.

An anomaly with grid connected PV is that the inverter will disconnect the panels if it can’t detect 50 Hz from the grid. Farmhouses usually have 400w water pumps drawing from a rainwater tank. If a fire takes out the 240v line to the house that means the garden hoses won’t work even if the PV could produce enough for the electric pump. I had to buy a small petrol driven water pump to cover that situation, a hassle because the motors develop fuel blockages (snot in the carby) from not being used.


@DBB and Scott Luft.

I agree with Scott’s comment re TOU Vs RTP pricing regimes. In a connected world, the only argument against Real Time Pricing is the potential for transferring risk to unwary customers, who might not be aware that the market price has gone through the roof and thus so has their bill. For this type of customer, TOU makes sense.

That is why I am so fixated on making the tools available for individual customers of all sizes to be able to automatically track their usage and the market rates if/when RTP is introduced. Preferably, this would be fed into an energy management system which will knock out low priority loads when prices climb above a threshold and all non-essential circuits when the price goes through the roof. This progressive load reduction will also assist system stability and thus marginally benefit every other user.

The situation where I live is that the incoming supplies are split to 24/7 supply and a separately metered “off peak” supply which is centrally switchable. At present I only have a water heater running off peak. That will soon be replaced by a solar hot water heater without electrical boost. I’ve lived in the bush for long enough not to be scared of cold showers.

Every kWh I use will then cost me the same, day and night. That is inefficient but at present it is the only option available to me and many others.


Although this is irrelevant to the discussion at hand, it is some rather interesting news on Fukushima.

TEPCO have released footage of the conditions inside Reactor 2 after giving the Primary Containment Vessel an endoscopic exam, inserted horizontally 7m from the bottom of the vessel through a pipe in the side. The poor vision in the camera footage is due to moisture and gamma radiation. Also a thermometer at the end of the probe showed the temperature to be 44.7C in the reactor, but the water level was lower than estimated. As you can see it is very rusty inside as well.

Video Link (click on the last tab in the video player, first video):
Last tab – first video.
Report on footage link:


One problem I imagine with time-of-usage (TOU) rates is that they are likely to be piecewise constant. Consequently, the criterion for appliances all over the grid to switch on or off is only met a few times of day, resulting in sudden changes of load (and, I hasten to add, phase!). That is quite apart from any switching surges. On the other hand, real-time-pricing (RTP) would or could be changed gradually, allowing appliances to have various criteria to switch on or off, that spread over long periods in the day.


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