So says Sci-Am. The article is high on pic and low on facts. Only a small percentage of the CO2 is captured – 1.5% – but that is OK, it is only a demo plant. The key question, of course, is how much extra coal is burnt to achieve this? This vital fact is not clearly provided. The 1.5% is clear And now roughly 1.5 percent of the CO2 billowing from its stack is being captured… but the other half is vague: But the primary benefits of the chilled-ammonia process for capturing CO2 are lower electricity and steam consumption, compared with other potential technologies for carbon capture, such as using amines, another ammonia compound, which can consume as much as 30 percent of the plant’s power just to run, says Shawn Black, product manager for Alstom. The goal here is to get that number down to under 15 percent. So is that 15% of 1.5%, which seems to good to be true, or 15% of the total, which seems too bad to be true?
Wiki says Capturing and compressing CO2 requires much energy and would increase the fuel needs of a coal-fired plant with CCS by 25%-40%. These and other system costs are estimated to increase the cost of energy from a new power plant with CCS by 21-91%. That is more in line with what I was expecting.  turns out to be a 2005 IPCC report. Their table SPM 3 (yes, its true, I didn’t get very far through) says that coal, sans CCS, is 0.04-0.05 $/kWh, and 0.06-0.10 with CCS and geological storage. The Sci Am article is consistent with that, saying Cleaner coal will be more expensive, too, adding at least 4 cents per kilowatt-hour to the power Mountaineer produces at roughly 5 cents per kWh. So I think they do mean 15% or 1.5%, but are probably being optimistic.
Clearly, until carbon acquires a sensible price (hopefully via a carbon tax) these plants will not be commercially viable.
In other news, Mars looks good.