Climate Change Nuclear Renewables

A necessary interlude

Like most interesting things in life, blogs are dynamic beasts. They are a reflection of the personality of their writer(s), projected into cyberspace. They evolve, as the opinions of their writers are shaped by new or unappreciated knowledge, commentary, feedback, and changing circumstances. My blog, Brave New Climate, is no different. After a little over a year in production (here is the first post), it has been a successful venture, albeit exhausting at times, and often exasperating to boot. Still, I feel it has stayed true to its original intention — to provide a rational, evidence-based communication tool for me to engage the public on climate change, and to never compromise on what I believe to be honest and justifiable (irrespective of whether such conclusions are convenient or not). That’s never going to change.

Yet there is no doubt that BNC has taken some unexpected directions. My past swordplay with the climate change sceptics has served a purpose — but my interest in this endless game has waned, and besides, others continue to do it much better than me. I’ll probably still pitch in occasionally, but it’s too much like bobbing for apples in a communal cesspit to make it a regular activity. My exhortations to my readers to understand the seriousness of the climate and sustainability crises, and to better appreciate the urgent need for action, laid an important foundation for the blog — but ultimately, there is only so many times you can say ‘the world is doomed unless we change our wicked ways’ before it starts to become depressingly banal, and people turn off. I continue to see this blog as playing a useful role in communicating snippets of hot news in climate science (although these days, I mostly do this via Twitter) and in hosting guest posts from well-credentialed and thoughtful people with important things to say about climate science, meteorology, carbon trading, psychology, national policy, and the like. But — and I think you can see where I’m going with this — these tasks no longer represent the primary drive behind BNC. It’s now predominantly — and unashamedly — a blog about realistic solutions.

In comments on a recent thread, reader ‘Matt’ asked the following, quite reasonable question of me (see here, comment #53):

“Thank you for a fascinating and sobering series of articles. You, Peter, and Ted, have persuaded me that renewables can’t supply the current (never mind BAU projected increases in) energy requirements of the developed world on their own without vast and unrealistic expenditure in money, time and effort. The numbers seem pretty clear.

I’m sure that when recognition of the CO2 and energy supply problems reaches a critical mass, and the political will and money starts to flow on the required scale, economic forces will do the rest and the nuclear option will indeed be widely deployed. Our current society functions on the basis of large amounts of instantly available energy, and without a major and disruptive reshaping of the way we live- which, incidentally, is what most greens seem to want, and may go some way to explain their attitude to nuclear power- sources of power with high energy densities are going to be necessary.

But I’m a little uncomfortable with the impression I often get from reading this site- that nuclear power is the only viable FF alternative and that it should be pursued vigorously and as soon as possible, to the exclusion of all other options (and wind/solar in particular). Many articles and discussions seem to circle around this idea. As a layman, it’s difficult to know what to make of it- that viewpoint may well be true, but for me there are too many unknown unknowns. How about a broadening of the discussion to consider other pertinent issues? Otherwise, this blog risks becoming a nuclear advocacy site with an occasional bit of climate science commentary thrown in.

These are the sorts of questions I have in mind (apologies if they’ve been discussed previously on the site, but not much showing up with a basic search) : What about the other potentially non (or low) CO2-emitting high energy density option on the table, with a few hundred years left in it- coal with CCS? What role can gas play in reducing CO2 emissions, at least in the short term while we transition to nukes? What about Ted Trainer’s idea of ‘depowering society’ to the extent that renewables can meet energy demand? (I can see many problems with this, but would love to see a critique on the site. More generally, articles exploring the demand side of the problem seem to be thin on the ground). Accepting that renewables can’t supply the developed world’s energy needs in their entirety, do they have a role at all? (in smaller isolated communities, in the developing world etc) How do smart grids work- how much can be done to with transmission systems/distributed storage/demand management etc to increase the number of viable options on the table?”

Below I reproduce my answer, because in my opinion this gets to the heart of why and how the BNC blog has evolved:

It is my conclusion, from all of this, that nuclear power IS the only viable FF alternative.

I am vitally interested in supporting real solutions that permit a rapid transition away from fossil fuels, especially coal (oil will, at least in part, take care of itself). If the conclusion is that wind/solar cannot meaningfully facilitate this transition, why bother to promote them? Now, I should make one thing quite clear. I am not AGAINST renewable energy. If folks want to build them, go for it! If they can find investors, great! Indeed, I’m no NIMBY, and would be happy to have a conga line of huge turbines gracing the hills behind my home, just as I’d be happy to have a brand spanking new nuclear power station in my suburb. But why should I promote something I have come to consider — on a scientific and economic basis — to be a non-solution to the energy and climate crisis? That doesn’t make sense to me.

To your questions:

1. Coal with CCS — doomed to failure. Why? Because the only thing that is going to be embraced with sufficient vigour, on a global scale, is an energy technology that has the favourable characteristics of coal, but is cheaper than coal. CCS, by virtue of the fact that it is coal + extra costs (capture, compressions, sequestration) axiomatically fails this litmus test. It is therefore of no interest and those who promote it can only do so on the basis of simultaneously promoting such a large carbon price that (a) the developing world is highly unlikely to ever impose it, and (b) if they do, CCS won’t be competitive with nuclear. CCS is a non-solution to the climate and energy crises.

2. Natural gas has no role in baseload generation. It is a high-carbon fossil fuel that releases 500 to 700 kg of CO2 per MWh. If it is used in peaking power only (say at 10% capacity factor), then it is only a tiny piece in the puzzle, because we must displace the coal. It it is used to displace the coal baseload, then it is a counterproductive ’solution’ because it is still high carbon (despite what the Romms of this world will have you believe) and is in shorter supply than coal anyway. Gas is a non-solution to the climate and energy crises.

3. The developing world lives in Trainer’s power-down society already, and they are going to do everything possible to get the hell out of it. The developed world will fight tooth an nail, and will burn the planet to a soot-laden crisp, rather than embrace Trainer’s simpler way. Power down is a non-solution to the climate and energy crises.

4. It is nice to imagine that renewables will have a niche role in the future. But actually, will they? They don’t have any meaningful role now, when pitted in competition with fossil fuels, so why will that be different when pitted fairly against a nuclear-powered world? I don’t know the answer, and I don’t frankly care, because even if renewable energy can manage to maintain various niche energy supply roles in the future, it won’t meet most of the current or future power demand. So niche applications or not, renewables are peripheral to the big picture because they are a non-solution to the climate and energy crises.

5. Smart grids will provide better energy supply and demand management. Fine, great, that will help irrespective of what source the energy comes from (nuclear, gas, coal, renewables, whatever). Smarter grids are inevitable and welcome. But they are not some white knight that will miraculously allow renewable energy to achieve any significant penetration into meeting world energy demand in the future. Smart grids are sensible, but they are not a solution to the climate and energy crises.

To some, the above may sound rather dogmatic. To me, it’s the emergent property of trying my damnedest to be ruthlessly pragmatic about the energy problem. I have no barrow to push, I don’t get anything out of it — other than I want this problem fixed. I don’t earn a red cent if nuclear turns out be the primary solution. I don’t win by renewables failing. The bottom line is this — if this website is looking more and more like a nuclear advocacy site, then you ought to consider why. It might just be because I’ve come to the conclusion that nuclear power is the only realistic solution to this problem, and that’s why I’m ever more stridently advocating it. This is a ‘game’ we cannot afford to lose, and the longer we dither about with ultimately worthless solutions, the closer we come to endgame, with no pawn left to move to the back row and Queen.

So what can you expect from BNC in the future? Much more on nuclear power (both Gen III and Gen IV), obviously, since I now consider this technology to be the core climate change solution — whilst openly acknowledging the yawning gulf between the scientific understanding of nuclear power and the public’s perception. This must change, and I hope, in my modest way, I can be an agent for that attitudinal shift. I also plan to launch an extended series on renewable energy, with an aim to break down the often complex and multifaceted critiques being made, into simpler, single-issue chunks, which can be more readily pinned down and understood. I will also profile some of the less well-developed low-carbon technologies, such as tidal, wave, microalgae, and geothermal, and speculate on their possible future roles. I hope in this way that I’ll be able to reinforce people’s understanding of why I no longer hold renewable energy to be a primary solution — and yet, by the same yardstick of maintaining intellectual honesty, I’ll also try my very best to keep an open mind to unconsidered possibilities and caveats that are raised by commenters (be these against nuclear energy, and/or for renewables). As I said, healthy thought should never cease to evolve.

Naturally, some past avid readers of BNC will find, or have already found, these changes in direction of the blog to be uninteresting or even distasteful. So be it — those people must seek and pursue your own interests and solutions. To the rest, I welcome you as partners in this ongoing journey of discovery, disappointment, optimism, and plenty of hard-nosed critical thinking.

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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.

129 replies on “A necessary interlude”

Benson @ 30: At the soonest there won’t be an IFR for 15 years. Probably more.

You know not whereof you speak. While you may be right, the only reason to wait longer than 4 or 5 years will be political inertia. The US designed, built and launched the nuclear navy in 5 years, having started with nuclear power systems in a far more primitive state of development than the IFR, which was proven with years of successful operation. If we have to wait 15 years for an IFR that will be a travesty of political stupidity.


Benson @ 92: In my proposal, all of the exhaust stream, possibly after condensing out the water, is to be returned to the algae farms to provide the extra CO2 that the algae need.

Algae advocates often propose using the CO2 from coal or gas-fired power plants be channeled to algae, and the algae to then be used to create biofuels. This is NOT carbon-neutral by any stretch of the imagination. You’re still taking fossil fuels and ultimately—albeit one step removed—releasing the CO2 into the atmosphere. It’s high time people stopped pretending that natural gas is anything close to environmentally sound, or that algae can magically make fossil-fuel produced CO2 lose its negatives.


I’m not so sure about that Tom. It very much depends on the extent to which the algae forecloses new harvest of fossil fuel. If it merely adds to the supply and drives down the cost so as to foster extra consumption then maybe the net effect is zero — though of course the fossil CO2 source can claim to have lowered its intensity per unit of energy.

If on the other hand, prices remained stable or increased and algae-based fuels substituted …


I should have added of course Tom, that unless one can show that the rate of yield per mole of CO2 in the kinds of closed photobioreactors we’re talking about is greater than for example that in open raceway ponds, then there’s no particular CO2 sequestration/biofuel advantage in where one grows algae.

The main constraint tends to be access ensuring that as much of the microalgae has access to optimal sunlight rather than CO2. Stoichiometrically, there’s only so much CO2 that a given mass of algae with given energy input can mobilise. Closed photobioreactors allow an operator to select for a given algae strain which may well be chosen to optimise lipids or yields under lthe likely conditions obtaining at the plant, so this might make some sense. In the end though, the real question is how much does it cost to produce a unit of biofuel or to sequester a unit of CO2, and this will be true whatever the cost put on CO2 emissions.

I am in the process of revisiting these questions after a couple of years, but at this early stage I’m a little pessimistic about the potential role of biofuels. The economics seem not to be as flattering as I’d once thought and this probably accounts for the lack of interest even when crude was up around $150 per barrell. It may well be the case that the best role for algae is as a carbon sequestration strategy, since this would forecloze the need to keep out invasive algal species in ponds and remove the costly and difficult problem of drying and extracting the lipids and starches needed for fuels.


Adrian #55, Douglas #83:

I answered in #40 & #48 why I prefer IFR to LFTR. A demo model running for 10 years is not required for NRC certification, but a few cycles of reprocessing via pyro would probably be required for a utility to want to buy an IFR, so that would take a few years. Technically, the reprocessing that is outlawed in the US is Pu separation via PUREX — but I agree there ought to be some legislative reassurances (hey, I’m not a lawyer) to ensure that pyroprocessing is fair game. Or, as seems increasingly likely, an IFR and/or LFTR gets built first outside of the US, such as in Russia, China, India, Korea, or perhaps even France. You’ll definitely see them running in your lifetime, unless you’re intending to cark it before the next decade is out!

Gas-cooled pebble bed reactors (graphite moderated — it is not a fast reactor) are not likely to work out, I suspect. You may as well build a modular fast SFR or epithermal LFTR. The pebbles also present real recycling challenges due to their silicon carbide coating (I guess you’d have to crush it and somehow extract the actinides, perhaps GRLC has a comment on that as I recall he once objected when I said you COULDN’T reprocesses the pebbles).


Barry Re #108.

You may be right about the NRC not requiring a 10 year demo as written law, but according to some folk I’ve talked to, they will resist without that. I hope you’re right, but so far Jerry Pournelle’s “Iron Law of Bureaucracy” has not been falsified. Fear of proliferation led to the shutdown of the Integral Fast Reactor project in 1994

You will have to persuade me that molten sodium has any advantage over thorium fluoride. As an engineer with years in the glass industry, fighting many unintended leaks of molten glass, I really like the idea that any leak can be simply caught in a pan underneath the reactor or equipment. As mentioned before I would like to see smaller units, like the Fuji MSR 100MW reactor, dotted around the country to suit demand. I agree entirely that the first units will be built outside the U.S. I was looking for things that could be built here without further delay.

PBRs like S. Africa’s MPBR running helium turbines will be quite efficient if they work. Of course, some think the higher temperatures required will lead to massive problems. The advantage, for me, is that they are proven technology that could be built immediately and a better stop gap solution than wind/solar. As you know, the Chinese are committed to building some 30 of them and plan on factory production. My earlier comment on that was only half in jest.

We should start building something NOW. Who knows what the future will bring. Maybe the Pollywell, or one of the other half dozen contenders, will work. Maybe EEStor’s ultracapacitor is real and make wind/solar practical. I’m certain the ITER won’t result in economic power generation.


The big problem is that their Brayton cycle turbine presented too many stumbling blocks so they decided, as the Chinese had a few years ago, to abandon the gas powered turbine and stuck with a Rankine steam cycle.

The PBMR’s biggest issue is the lack of serious R&D for large closed-cycle Brayton GTs.


re #110
Thanks for the update David. I knew there were problems with the helium turbines but had not kept up-to-date with their plans.


@ David Walters:

To what degree are the engineering challenges associated with the Brayton cycle engines for PBMR-style reactors related to the choice of helium as the working fluid? Does using nitrogen, as Rod Adams advocates, improve the prospects for such technology?


I don’t think it is, Luke. It’ has to do with the lack of engineering expertise on the *closed* aspect of the Brayton cycle. 99% of all Brayton cycle engines are combustion fossil driven *open* cycled GTs like the ones we have on jet planes. There really is no difference. The compressor section of the GT is designed to compressed O2 dense enough to provide the right mix for *combustion*. The compressor cycle on a closed Brayton GT is completely different and serves a different purpose.

I will be honest…closed cycle Braytons have always bewildered me as to how the energy is transferred to the turbine blades and the exact purpose of the compressor sections. How the compressors don’t eat up all the energy when the helium (or CO2, N2, etc) is compressed and expanded through the blades.

At any rate, no one does these sorts of large closed cycle brayton GTs. Rod Adams did an interview, oh, about 2 years ago, with the Westinghouse PBMR director who worked with the S. Africans. He noted the single biggest expense and stumbling block has been the GT, bar anything else.

As you are aware, this is *critical* for the LFTR as it is based entirely on gas cooling and a GT since so much of the cost savings is in the lighter material for a GT as opposed to the Rankine steam engine. Also the high temp drop needed for the low end of the turbine/condenser section as well reducing water consumption.

The Chinese are running their helium through a heat exchanger to make steam on theirs.



FYI…I’m not a *big* fan of the PBMR. I don’t like solid fueled reactors in general and reprocessing, as G.R.L. Cowan noted, is not that straight forward for the TRISO fueled PBMR. I wait with anticipation on seeing what the Chinese will come up with in this regard. And yes, it’s all about the money since *everything* about the Brayton cycle GT has already been “proofed” in one form or other.


closed cycle Braytons have always bewildered me as to how … the compressors don’t eat up all the energy when the helium (or CO2, N2, etc) is compressed

I think that part’s pretty easy. Compressors compress volume, and power extraction turbines expand volume, and when heat is added in the middle, there is more volume exiting the turbine than is coming in through the compressor. Same as in a once-through compressor-and-turbine such as on an airplane.

— G.R.L. Cowan (‘How fire can be domesticated’)


Tom Blees (104) — I just passed along what three nuclear engineers at INEEL wrote in an article. So I fear that 15 years it is.

Tom Blees (105) — Since the methane is to from anaerobic digestion of the algae, it is closed cycle carbon and so carbon neutral. The CSIRO reprt linked above points out that using fossil fueled power plant exhaust to grow algae then avoids the fossil carbon of the replaced down steam fuel, biodiesel replacing diesel in their study.

Fran Barlow (107) — In sunny locations the limiting factor on algae growth is enough CO2 to cause the algae to divide daily; not enough sunlight is only a problem if you attempt to have too great a density of algae, not a problem for the open racetracks proposed in the CSIRO study.

Adrian Ashfield (109) — I agree that we all did to start now! Try lots of ideas to see, in practice, what works at all and what works best in each locality.


Barry, I’m a little late to this conversation since I’m travelling right now but I just wanted to say that following this blog has been an amazing experience. Its had the narrative force of a Tom Clancy novel with what seems to be such a strong story arc that I’ve often wondered if you had plotted it out in advance.

The position you outlined to Matt above is simply where you get to if you apply radical objectivity and radical pragmatism to our present situation. As they say to pilots, “Trust your instruments”, in this case the climate science. Trust your instruments and do what works. Deal with the data with integrity, even if it leads you to places you don’t want to go (here the denialists fail). Plan the response with integrity (and here the renewable advocates fall short).

In the last year I’ve had to come to grips with climate modelling, ecosystem analysis, nuclear fuel cycles, reactor design, renewable energy technologies, oil and gas and proliferation politics and economics, energy storage technologies, power grid design, power transmission, etc. etc. Its been very challenging, and required a lot of work to keep up. I fear that means difficulties ahead in communicating this material to a wider audience, because it is quite technical and most people will have neither the background nor the time to delve into the arguments and own the conclusions for themselves.

Its been interesting to see how the group of active commenters here has changed and evolved as the subject matter has changed and evolved. For that reason I think the subject matter index and the TCASE series will be very useful and necessary, since the material needs to reach a wider, popular audience, and there’s too much material in the form of comment dialogue for newcomers to easily bring themselves up to speed. Remember, if BNC has been running for about a year, thats one whole year out of a very short time to achieve a solution to the climate problem. We can’t afford to spend a year educating each new visitor. There needs to be some sort of bootstrapping process.

Have you considered writing a book based on the content of BNC, to reach more people with a more condensed exposition?

On content for the blog going forward, amongst everything else I hope to continue to see the climate science represented, both the current state of the climate as measured, and implications for how that resets our trajectory for the future. With the focus on the energy technologies, it may not be obvious to recent readers just how dire this situation is. I listened to your CCQ&A talk a while back, and frankly I don’t know how you managed to stay sane putting talk 4 together. I would also be interested in some further discussion of geoengineering options, since it seems we are well past certain tipping points, and at least one of either carbon draw down or albedo modification or sunshades is, objectively and pragmatically, required. So lets see what cards are on that table.

But, like Deep Throat would have said, “Follow the energy”. You’re doing something important here.


Hi all, esp climatologists,

is the hockey-stick in question after all?

Even if the MWP is true, it doesn’t discount the basic physics of what is happening now with CO2. But it would be interesting to find out what natural forcing took the temperature that high and why it didn’t trigger all the feedbacks we’re worried about today. (Maybe it wasn’t that high for very long?)

Any feedback to these ocean records in the normal climate literature and blogs? I didn’t find any on



Barry #102,
I am happy to see that we agree.
Your wording though makes me fear, you might approach this task so as to best accommodate and showcase the existing posts:
a more functional index of BNC as you suggest… to make the archives more accessible.

I have a different idea. Let the index (or any “structuring” effort) be driven by the problem at hand. The problem naturally decomposes into sub-problems, producing a hierarchical structure.

Something like:
The problem is to compare Australia with nuclear power banned, to the Australia with nuclear power permitted/encouraged.
This problem separates into two sub-problems: (all) costs of the optimal nuclear-included case, versus (all) costs of the optimal nuclear-banned case.
Costs of the optimal with-nuclear case split further into normal costs and external costs. The former are… the latter are… etc.

I’ve claimed in #29 “this is not extra work IF…” Here’s what I meant: You seek (or you should) to make comprehensive assessments. You therefore contemplate, for example, this question: did BNC comprehensively address nuclear externalities? In which posts, if any, were those addressed? – and then, if you merely care to write your answer down, what you get is the “Nuclear externalities” node for your index.


Soft green technologies, like wind and solar, are hard on the land. They cause mankind’s land-footprint to increase dramatically. Man has been saving the wilderness with the hard technologies of oil and coal. For a simple reason: you drill a small hole and extract enormous amounts of energy. This is directly opposed to say a solar farm which requires a large surface area to capture the same amount of energy. Simple reasoning suggests the wilderness is threatened by soft green technologies.

We need to save the environment from the environmentalists:


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