THE VINE JULY 22, 2009
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Speaking of coal, what's the deal with those coal plants of the future that will supposedly capture their carbon and store it deep underground, rather than belching it into the air? And, more importantly, how much is it going to cost? Earlier this month, Harvard's Belfer Center put out a new study on "Realistic Costs of Carbon Capture" to try to answer this question.
The central finding here is that coal capture and storage (CCS) may, someday, offer a cost-effective means of curbing greenhouse-gas emissions—if it proves feasible on a large scale. The coal industry would still be ripping apart Appalachia, but at least it wouldn't be roasting the planet. In the short term, however, demonstrating that CCS can actually work is going to be extremely costly. The initial round of plants will capture carbon for around $100 to $150 per ton, which is about ten times as high as the price of carbon will likely be in the first decade under the House climate bill. (A caveat: That pricetag doesn't factor in potential revenue from pumping the captured carbon into wells to recover oil, which, according to the report, could potentially slash the cost of those initial plants by quite a bit.)
This means that if all Congress does is set up a cap-and-trade program to regulate carbon pollution, utilities won't find it worthwhile to build CCS plants for a long time. They'd look toward other, cheaper ways of reducing emissions. CCS will only become a commercial reality via additional subsidies and government-backed demonstration projects. Right now, only a handful of pilot plants exist around the world. That explains why, in the current congressional debate, coal-state Dems are working overtime to subsidize CCS in the climate bill. Without that assistance, coal's screwed.
The semi-cheery tidings for CCS is that as more and more of these plants get up and running, the technology will improve, economies of scale will kick in, engineers will learn how to tweak the designs, and the costs should, in theory, tumble down to about $25 to $50 per ton—making CCS plants competitive under a cap-and-trade regime. Two points here: First, there need to be a fairly vast number of CCS plants up and running—say, 50 to 100 gigawatts worth—for costs to sink to that level. Second, the "learning rate" for CCS plants is pretty comparable to other clean energy sources, except for solar (where costs seem to tumble even faster as more panels are produced) and nuclear (where costs don't appear to fall very much as you build more plants).
If the coal folks cross their fingers, get their lavish subsidies and demo projects, and everything works as hoped for, then here's how much the Belfer Center projects a bunch of different energy sources could cost in or around 2030:
This chart, note, doesn't factor in the effects of a carbon price—under a cap-and-trade regime, the two fuel sources on the left, coal and natural gas, would be a lot more expensive because they have to pay for the pollution they produce. In this scenario, wind power is the cheapest low-carbon source in 2030, followed by CCS, followed closely by solar thermal, followed by nuclear and solar photovoltaic panels. (Actually, photovoltaics would probably be cheaper than nuclear because they have lower transmission costs.)
So should we believe the "clean coal" hype? It's really mixed. According to this report, it's certainly possible for CCS to reach the stage where it's competitive with other low-carbon sources. But getting there will require truckloads of public support in the next two decades, and those first steps will be very costly. It's certainly one option for clean-energy policy, but whether it's the optimal route is another question entirely.
--Bradford Plumer
9 comments
At ~ $130 per MWHR. the chart seems to confirm that CCS is the cheapest way to achieve carbon neutrality, and it is roughly $50 more expensive per MWHR than status quo. What am I missing?
- r.ennis
July 22, 2009 at 5:28pm
Yeah, that's pretty much what the post says--only caveat is that getting there requires a lot of upfront support, because the early demonstration plants are really expensive (the report explains why their estimates for the costs of early plants are higher than other estimates).
- Brad Plumer
July 22, 2009 at 6:00pm
How does the study address the possibility that CCS might simply not work or at least not work in many of the places where we might like to build clean coal power plants? While nuclear, PV, wind, and solar thermal are costly, they are all proven technologies. Somewhere in the world each one of these technologies (except solar thermal perhaps?) is being used to generate electricity on a commercial scale. The same cannot be said for CCS. It is a decidedly UNproven technology, and unanticipated engineering and scientific challenges may yet block its development. For example, how much do local geological conditions influence the feasibility of CCS? And how are the engineers going to guarantee that sequestered carbon STAYS sequestered and for how long? Will the give a 10,000 year guarantee a la Yucca Moutain?
- aeromonas
July 23, 2009 at 9:48am
Will THEY give a 10,000 year guarantee, of course.
- aeromonas
July 23, 2009 at 9:49am
Why does CO2 have to remanin sequestered for 10,000 years? We are bound to run out of all fossil fuels in maybe 100 years or so. 200 at most.
- r.ennis
July 23, 2009 at 10:37am
For CCS, I imagine a series of CO2 pipelines. The pipeline owner collects a tariff by custody tranfer from utilities who inject CO2 into the line. Pipeline owners then manage the disposition - some to enhanced agriculture, some to tertiary oil recovery, some to mineral production (e.g. CaCO3) , some to underground storage in safe locations. The problem is more one of infrastructure, than technology. CO2 capture using amine solutions is well proven technology.
- r.ennis
July 23, 2009 at 10:44am
aeromonas -- "How does the study address the possibility that CCS might simply not work or at least not work in many of the places where we might like to build clean coal power plants?"
That's a good question. I should've mentioned this in the post, but those costs in the chart *don't* include the cost of transporting carbon, so the pricetag could be higher if you can't sequester carbon nearby.
And yes, there's the possibility that CCS could run into challenges that make it unworkable on a large scale (the basic concept seems to work in oil wells, so it's not outlandish). On the other hand, there is a commercial solar thermal plant in Spain that's already up and running, so I think we can put that in the "proven" category:
news.bbc.co.uk/.../6616651.stm
- Brad Plumer
July 23, 2009 at 10:45am
"Why does CO2 have to remain sequestered for 10,000 years? We are bound to run out of all fossil fuels in maybe 100 years or so. 200 at most."
r.ennis, CO2 is quite stable. Unless you do something to alter it chemically, i.e. make it into something other than CO2 such as calcium carbonate, a process that is unlikely to be a part of CCS since it would use up much of the energy generated by fossil fuel combustion in the first place, CO2 retains all it's greenhouse gaseous properties for eons.
Suppose we elect to keep burning up all remaining coal over the next 2 to 3 centuries and avoid catastrophic warming by pumping the CO2 generated deep into the ground. (This is assuming such a mammoth-scale plan is even feasible, which I suspect it's not.) If after a hundred years significant proportions of that CO2 start leaking out of their underground reservoirs into the atmosphere, then all we've managed to accomplish is delaying catastrophic warming by a century or so. This might be seen as better than nothing, at least it gives us longer to prepare ourselves. But if it means burning through all our coal reserves when instead we might've shifted to an economy based entirely on renewables, it's probably a net minus.
I submit that on a geological timescale, CCS is meaningless. If humans look to CCS for a green light to burn all extractable coal, then the earth will return to the ice-free conditions of the early Eocene. At best CO2 sequestration will delay the shift by a few centuries, after which it will take millions of years for the process to be reversed through weathering. Still such a delay may be highly significant on a human timescale. As a simple matter of biology, humans can do just fine under Eocene-like conditions. The question is whether technological civilization can survive a rapid shift to seas 250 ft higher than they are now and subtropic arid zones significantly wider than they are now. I think it probably can, but it ain't a dead cert.
- aeromonas
July 23, 2009 at 11:43pm
CO2 is far from stable. Did you ever hear of photosynthesis?
- r.ennis
July 24, 2009 at 8:51am