We need to save the environment from the environmentalists:

http://www.marshall.org/article.php?id=174

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.

is the hockey-stick in question after all?

http://www.nicholas.duke.edu/thegreengrok/hockeystick-revisited

http://www.nature.com/nature/journal/v460/n7259/abs/nature08233.html

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 Realclimate.org.

Regards

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.

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.

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’)
http://www.eagle.ca/~gcowan/

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.

David

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?

My speculation on reprocessing pebbles.

(How fire will be domesticated)

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

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 http://www.pbmr.com/index.asp?Content=182 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.

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).

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.