The July/August 2007 issue of World Watch magazine (produced by the Worldwatch Institute) includes a concise demolition of carbon geosequestration in the form of a letter to the editor by one Luc Gagnon, "a senior advisor on climate change for Hydro-Quebec."
I'd quote the letter but the Worldwatch site doesn't have it online yet. So I went searching for more by Gagnon and found this short, powerful PDF making essentially the same point (in almost the same language). An interesting table indeed, of "energy payback ratio of electricity generation options based on life-cycle assessments":
Short summary: No matter how much they dangle the subsidy-bait of carbon geosequestration back and forth like a gold watch in front of our eyes, trying to hypnotize us into the belief that the chimera called "clean coal" actually exists, there are a few key points to remember:
- coal is the enemy of the human race, and
- coal isn't all that hot as an energy source to start with, once you factor in all the other energy costs.
Even if we were to stipulate that perfect geological storage of CO2 (from a leakage perspective) was attainable, the cost in energy makes it a killer for coal.
And the punch line is quoted below:
The future performance of fossil fuels
Fossil fuels already have low Energy Payback Ratios and these will probably be declining over the next decades. This is due to multiple factors:Why is the Energy Payback Ratio a good environmental indicator?
- As the best oil and gas reserves are depleted, they tend to be replaced by wells that require a higher energy investment, as they are often located in far-away regions or under the sea. One obvious example is oil from tar sands. The process energy, mainly natural gas, required to extract oil from tar sands is five times greater than in the case of conventional oil. As a result, the Energy Payback Ratio of oil from tar sands drops from 2.9 to 0.7 if the oil is used in electricity generation. This means that directly burning the natural gas (used in the process) would generate more electricity. Therefore, the development of tar sands is only justified because oil is well suited as a fuel for the transportation sector.
- Various factors could also reduce the future performance of natural gas-fired generation. Longer delivery distances are probable. Moreover, a higher percentage of gas will be delivered by tanker ship, in the form of liquefied methane (at extremely cold temperatures). This type of delivery requires more energy than pipelines.
- Due to severe air quality problems in many countries, coal-fired plants will need to consume more energy to control emissions. There are two main methods of reducing SO2 emissions: using scrubbers (at the plant) to capture the SO2 or using low-sulfur coal. SO2 scrubbing can reduce the overall efficiency of coal-fired generation by 10 to 15%, and more energy is required to manage the sulfur wastes. In the U.S. in the last 20 years, most utilities decided not to install scrubbers and have achieved SO2 emission reductions by switching to low-sulfur coal from the Western states. Consequently, average transportation distance for coal has increased, with greater energy consumed in delivery. Thus, both approaches to controlling SO2 reduce the energy payback of coal-fired generation.
- If technologies for capturing and sequestering CO2 become commercially available, they will require huge amounts of energy. Capturing CO2 can reduce a plant's efficiency by 25% and much energy will then be required to transport and sequester the waste stream. To appreciate the size of the challenge, it is relevant to compare it with SO2 scrubbing. Coal has a sulfur content of 1 or 2% and a carbon content of 70 to 80%. CO2 capture and sequestration is therefore 50 times more difficult. Since SO2 scrubbing has often been rejected, one may question the feasibility of large-scale CO2 capture ...
When a system has a low Energy Payback Ratio, it means that it consumes large amounts of energy, with associated environmental impacts. For fossil fuels, it means significant impacts related to extraction, processing and transportation of the fuel, and also at the generation site. For renewable energy, environmental impacts can arise from the construction itself.
Ask Umbra on ditching dirty things
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feonixrift Posted 7:33 am
18 Jun 2007
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JMG Posted 7:55 am
18 Jun 2007
My seat-of-the-pants, no calculation SWAG is that solar thermal would be better than wind, not as good as run of the river hydro.
Course, my guess and $3.50 will get you coffee; but hey, if you have better, please provide.
Save the world: Reduce greenhouse gas emissions 5% annually.
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sunflower Posted 8:49 am
18 Jun 2007
The energy invested is for steel, glass, aluminum, and concrete (and lots of copper for flat plate hot water systems). Most of those materials are made with heat. Aluminum foundries require electricity.
Concentrators have the best thermal energy returns, total energy payback in less than one year. I think 6 months is achievable. Lifetimes are 20 to 30 years and many of those decommissioned materials can be recycled into new solar collectors... the future energy values would need to be discounted into net present worth.
The economic metric of concentrators is $100 to $200 per m2 and worth the equivalent of one barrel of oil per year in sunny climates.
High-intensity 40% efficient pv cells at 1000 suns concentration (10 cm2) would add $100 for power conversion (340 Watts at $0.29/Watt for pv cells). Cheap and getting cheaper. Most of the cell cost is for exotic materials rather than for energy.
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DogsCatsAndStrays Posted 11:35 pm
18 Jun 2007
This is an emotional remark that hardly expresses the role coal has played in shaping our lives. No-one in the US is proud of coal use; it seems to underscore our lack of progress that after over a hundred years since the industrial revolution we are still burning the remains of Triassic era. No coal miner would argue that coal is dirty; no boiler operator would say that coal burning is clean; no baghouse operator would say that the combustion exhaust is good for you, but coal is a manageable resource.
Most likely you would not have born without the burning of coal. Coal is what makes steel production viable (you can use wood but it's not easy) and steel is what we use to make cars, plows, buildings and everything else you use in modern times. Coal for better or worse is what God gave us; we have more BTU's in coal than any other source of potential energy. I wish God would have given us hydrogen in the ground, or more natural gas, but he didn't, he gave us coal. We can either use it or not, but coal is not the enemy, it is a gift.
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sunflower Posted 12:16 am
19 Jun 2007
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caniscandida Posted 12:24 am
19 Jun 2007
But I trust JMG, and I believe that very limited and arguably misleading battlecry is true enough, so far as it goes.
As for God: It is false to say that God actually put into our hands resources that would bring about the destruction of this beautiful community of living creatures, once we made use of those dangerous resources. God indeed allows God's intelligent creatures to do all sorts of things with the various resources available to them. But certainly there is no way of knowing if that is God's will, when we use those resources for our own self-serving purposes.
To JMG: Please explain those two technical terms, "hydropower with reservoir," and "run-of-river hydropower." Generally, I have not a clue what the hell you are talking about in this post -- but I trust you, I am sure it means something to somebody. At least I have heard of Quebec.
But I should add, "run-of-river hydropower" sounds ominous.
Chickens are our cousins!
So are other sensitive animals!
Enough is enough!
No more factory farms!
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GRLCowan Posted 2:42 am
19 Jun 2007
It may be true that there are more BTUs in US$3-per-million-BTU coal in American terrain than there are in US$0.60-per-million-BTU uranium, but that's largely a function of uranium prices have been much lower in the recent past, so that exploration languished. It has picked up, with the result that, according to Martin Sevior on The Oil Drum,
As of the beginning of 2003 World Uranium reserves were:
Reasonable Assured Reserves recoverable at less than $US130/kgU (or $US50/lb U3O8) = 3.10 - 3.28 million tonnes.
Additional reserves recoverable at less than $US130/kgU (or $US50/lb U3O8) = 10.690 million tonnes.
As of the beginning of 2005 World Uranium reserves were:
Reasonable Assured Reserves recoverable at less than $US130/kgU (or $US50/lb U3O8) = 4.7 million tonnes.
Additional recoverable Uranium is estimated to be 35 million tonnes
The substantial increase (almost 50%) from 2003 shows the results of the world-wide renewed exploration effort ...
US$130/kg translates to 23 US cents per million BTU, far below the recent price. If the recent price were sustainable, and applied only to Rhode Island uranium, they would summon more BTUs from that rock than all US coal contains.
--- G. R. L. Cowan, former hydrogen-energy fan
How do cars gain nuclear cachet?
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JMG Posted 2:57 am
19 Jun 2007
I trust that the explanation from G.R.L. Cowan, F.H.F. makes sense -- w/ reservoir just means hydro as we typically think of it (w/ a dam used to create a reservoir); run-of-river is taking the smaller amount of power available through unrestricted flow (but with a lot less effect on the river system, and a lot less embedded energy).
Save the world: Reduce greenhouse gas emissions 5% annually.
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DogsCatsAndStrays Posted 4:13 am
19 Jun 2007
The above adds nothing to the debate on whether or not coal should be mined and used for energy, but it's raining and was thinking about the sunshine.
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sjjh Posted 7:45 am
19 Jun 2007
"Coal has a sulfur content of 1 or 2% and a carbon content of 70 to 80%. CO2 capture and sequestration is therefore 50 times more difficult. Since SO2 scrubbing has often been rejected, one may question the feasibility of large-scale CO2 capture ..."
I get it that coal has a carbon content of 70-80% but when CO2 is captured and sequestered, in an imagined CO2 capture and sequestration scheme, it isn't just the carbon that is sequestered, it is also the oxygen that the carbon has bonded with, thus the CO2 - can someone with a stronger understanding of science help me understand what volumes are being talked about for sequestration in relationship to the coal burned? Thank you
sjjh
seattle, wa
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GRLCowan Posted 9:36 am
19 Jun 2007
I get it that coal has a carbon content of 70-80% but when CO2 is captured and sequestered, in an imagined CO2 capture and sequestration scheme, it isn't just the carbon that is sequestered, it is also the oxygen that the carbon has bonded with, thus the CO2 - can someone with a stronger understanding of science help me understand what volumes are being talked about for sequestration in relationship to the coal burned? Thank you
The numbers sound about right. What's different is how the two dioxides behave if they get out into the atmosphere. CO2 stays for centuries or millennia and affects the climate but, at levels below, IIRC, half a percent, 5000 ppm, doesn't bother us air-breathers. The 500 ppm that would severely affect climate would not choke those of us who weren't washed or blown away.
SO2, aka brimstone -- why a gas has a name ending in "stone" I'm not sure -- would definitely bother us. It finds ways of forming sulphate and dropping out of the air quickly; as sulphuric acid, in rain, it is the acid in acid rain.
So the hundreds of billions of tonnes of CO2 we have added to the atmosphere and the hundreds of billions more we will add, because of its persistence, spreads through all the air and covers the whole planet. This means we can, when we get around to it, adjust the concentration back down by extracting CO2 at a single point or a few points. Can't do that with SO2: if let out at many points, it attacks the environment near each point, promptly spending itself in so doing.
--- G. R. L. Cowan, former hydrogen-energy fan
Oxygen expands around boron fire, car goes
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caniscandida Posted 10:02 pm
19 Jun 2007
But "untrammeled" is indeed a very beautiful word.
Those Canadians sure can be prickly sometimes. Nevertheless, the Scotch Bar in the great tower of the Chateau Frontenac, overlooking the Fleuve Saint-Laurent, is one of the happiest spaces in North America.
So anyway, regarding what I had written earlier, I should apparently forget about my suspicions of something "ominous." Of course, needless to say, I was worried about the fish, and other wildlife. Hopefully, "run-of-river hydropower" means zero impact on the river ecosystem, or at worst, minimal impact, from which the community of living creatures can recover.
From an historical perspective, the technology of water-wheels, first introduced to European rivers in the High Middle Ages by Cistercian monastic communities, was in principle the same sort of thing as "run-of-river hydropower." But I suspect it is not impossible that the good monks also built dams and created reservoirs.
Chickens are our cousins!
So are other sensitive animals!
Enough is enough!
No more factory farms!
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JMG Posted 2:10 am
20 Jun 2007
Save the world: Reduce greenhouse gas emissions 5% annually.
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GRLCowan Posted 6:54 am
20 Jun 2007
"Prickly"? I recall 'caniscandida' saying something like, I'm not just sure I can understand this hydrogen-economy stuff, and I said something like, try. I do not see myself as prickly, or anyway, not based on that occasion.
One of the nastiest kinds of net troll is the apparently eager student who responds serially to repeated attempts at exposition with, "Can you dumb it down a little, doc?", until you realize you are being played with. Elsewhere -- not here! -- I've had the suspicion they weren't about to understand for the reason Upton Sinclair mentions. That's why I tried to help Canis call upon the principle that the quickest way to understand something is to try to explain it.
--- G. R. L. Cowan, former hydrogen-energy fan
Oxygen expands around boron fire, car goes
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caniscandida Posted 8:40 am
20 Jun 2007
<<
It may be true that there are more BTUs in US$3-per-million-BTU coal in American terrain than there are in US$0.60-per-million-BTU uranium, but that's largely a function of uranium prices have been much lower in the recent past, so that exploration languished.
>>
This is easy? This is clear, and elementary my dear Watkins, to no one who has never heard of a BTU? Or to someone who thinks that "terrain" refers to the subject of landscape painting? Or to someone who thinks that "exploration languished" means the guys just could not get their act together that year?
Face it, dear GRL. But really, that is OK. You economists and engineers continue talking amongst yourselves, and showing up one another, and that is the way it should be.
And nobody wants you to dumb down nothin'.
Chickens are our cousins!
So are other sensitive animals!
Enough is enough!
No more factory farms!
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GRLCowan Posted 9:15 am
20 Jun 2007
Earlier in this thread 'DogsCatsAndStrays' said, in my opinion incorrectly,"we have more BTU's in coal than any other source of potential energy".
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GRLCowan Posted 9:20 am
20 Jun 2007
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