The costs of CCS are often divided according to the three main steps of the process:
1. Capture of CO2, including compression for transport.
2. Transportation to an injection sink.
3. Underground geological storage.
The bulk of the costs of CCS projects are associated with CO2 capture. For the most cost effective technologies, total capture costs (capital plus O&M costs) are USD 25 to 50 per tonne of CO2 emissions avoided, with transport and storage about USD 10 per tonne [8]. For typical European offshore settings the transport and storage cost is higher than this, and the variation from project to project is substantial [12].
Carbon capture technologies at the scale needed for power plants have not yet been demonstrated. Hence, most reported cost figures are only estimates, based on scaling up of smaller components used in other industries or on manufacturers’ expert judgement based on experience from other (near-) proven technologies. The accuracy of the resulting estimates usually lies within the range of ±30 % [13].
CO2 capture and compression consumes energy, which may result in additional emissions that must be taken into account when evaluating the impact and the cost-efficiency of CCS. The terms CO2 capture cost and CO2 avoidance cost are used for these two different evaluation methods.
Capture cost: Cost of capturing one tonne of CO2.
Avoidance cost: Cost of reducing the CO2 emission by one tonne, assuming same electricity generation.
For power plants, capture cost can be translated into avoidance cost based on the equation:
𝐶𝐶𝑐𝑐𝑐𝑐𝑆𝑆(𝑎𝑎𝑎𝑎𝑐𝑐𝑎𝑎𝑎𝑎𝑎𝑎𝑎𝑎) = 𝐶𝐶𝑐𝑐𝑐𝑐𝑆𝑆(𝑐𝑐𝑎𝑎𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑎𝑎𝑎𝑎)∙ 𝐶𝐶𝐶𝐶 𝜂𝜂𝑛𝑛𝑛𝑛𝑛𝑛
𝜂𝜂𝑜𝑜𝑜𝑜𝑜𝑜 − 1 +𝐶𝐶𝐶𝐶
Where 𝜂𝜂new and 𝜂𝜂old are the electricity efficiencies of the power plants with and without CO2 capture, and CE is the fraction that is captured. For example, if 𝜂𝜂new and 𝜂𝜂old are 35% and 43% and CE is 0.90, the cost ratio
(avoided/captured) is 1.26.
Expressing CCS costs in terms of the cost per tonne of CO2 avoided allows those costs to be directly compared with other CO2 abatement measures in terms of the cost of the environmental effects that have been achieved.
As most coal-fired power plants have a long lifespan, any rapid expansion of CCS into the power sector would include retrofitting. The costs of retrofitting depend much on local circumstances:
• A case study from Norway has suggested that a retrofit would reduce efficiency by 3.3% more than a new integrated system [8]. The average cost of CO2 avoided for retrofits is about 35 % higher than for new plants.
Several factors significantly affect the economics of retrofits, especially the age, smaller sizes and lower efficiencies typical of existing plants relative to new builds. The energy requirement for CO2 capture also is usually higher because of less efficient heat integration for sorbent regeneration [10].
• A case study from Denmark indicates that retrofitting results in very little additional costs and that the electricity efficiency is only marginally lower compared with new projects [4].
There are two main methods of CO2 transportation [14]:
• Pipeline costs are roughly proportional to distance.
• Shipping costs are fairly stable over distance, but have ‘step-in’ costs, including a stand-alone liquefaction unit potentially remote from the power plant. The cost is less dependent on distance.
For short to medium distances and large volumes, pipelines are therefore by far the most cost-effective solution.
Pipeline costs may increase in congested and heavily populated areas by 50 to 100 % compared to a pipeline in remote areas, or when crossing mountains, natural reserves, rivers, roads, etc.; and offshore pipelines are 40 – 70 % more expensive than similar pipelines built on land [10].
References
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2. CO2 Capture and Storage in Geological Formations, by Jacek Podkanski, IEA 2003
3. CO2 Capture at Power Stations and Other Major Point Sources, Jacek Podkanski, IEA 2003 4. Vattenfall, 2010.
5. Uncertainties in Relation to CO2 Capture and Sequestration. Preliminary Results, Dolf Gielen, IEA/EET Working Paper 2003
6. The Future Role of CO2 - Capture and Storage Results of the IEA-ETP Model, Dolf Gielen, 2003 7. www.ieagreen.org.uk
8. “Energy technology perspectives 2008”, International Energy Agency, 2008.
9. “CO2 Capture and Storage. A key carbon abatement option”, the International Energy Agency, 2008.
10. “Carbon Dioxide Capture and Storage”, International Panel on Climate Change (IPCC), 2005.
11. “Carbon Sequestration Leadership Forum Technology Roadmap” (CSLF; www.cslforum.org), 2009.
12. DONG Energy, 2009.
13. "The Cost of Carbon Capture and Storage Demonstration Projects in Europe", JRC Scientific and Technical Reports, European Commission, 2009.
14. "The Costs of CO2 Capture, Transport and Storage", Zero Emissions Platform (ZEP), July 2011.
Data sheets
JRC [13] made a thorough review and analysis of most recent (in 2009) cost assessments of CCS. As a unique feature, all assumptions are presented in the report. All data on this page are from this report.
The mentioned reference values are calculated by a weighted average of data from 13 reviewed reports, the weighting factors determined by the robustness of the reported figures.
The following capture technologies are included:
IGCC-CCS: Integrated Gacification (of coal) Combined Cycle with pre-combustion capture PF-CCS: Pulverized Fuel (coal) with post-combustion capture
NGCC-CCS: Natural Gas Combined Cycle with post-combustion capture Oxyfuel: Oxyfuel combustion with post-combustion capture
All plants have a net capacity of 400 MW, and all costs are in Euro 2008:
JRC calculated the costs of CCS plants including pipelines and storage compared to reference state-of-the-art conventional plants that use the same fuel and are of the same net electricity output. The average costs per tonne of CO2 avoided for the coal-fired CCS plants and the NGCC-CCS plant were 87 €/t and 118 €/t respectively.
The below table, in the same format as other technologies in this report, has been developed using other sources than the above-referenced JRC-report.
Low €/MW/year 60000 42000 44000 27000
High €/MW/year 86000 80000 104000 56000
Reference cost €/MW/year 75000 65000 90000 38000 Variable O&M cost
Reference cost €/tonnne 20
Carbon capture
CO2 transport and storage 405
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The ZEP report [14] is probably the most complete analysis of CO2 transport costs to date. The report describes three methods of transportation and for each of these present detailed cost elements and key cost drivers. The three methods are:
• Onshore pipeliæne transport
• Offshore pipeline transport
• Ship transport, including utilities.
The following table shows the unit transportation cost (EUR/tonne) for such projects, depending on transport method and distance, and with typical capacities in million tonnes per annum (Mtpa):
Technology
2010 2020 2030 2050 Note Ref
Generating capacity for one unit (MW) 1+2+3+4
Capture efficiency (%) 90 90 90 90 A 1
Generation efficiency decrease (%-points) 8-10% 8-10% 8-10% 8-10% B 1+2+3
Nominal investment (M€/MW) 2.3-4.3 3.07 3.00 2.86 C 1+2+3+4;
D The O&M costs are per net generating capacity and net generation, i.e. after deducting the power consumer for CO2 capture.
The nominal investment is per net generating capacity, i.e. after deducting the power consumed for CO2 capture. If you compare two power plants, with CCS (this element) and without CCS (element 01), and with the same net power generating capacity, the difference in nominal investment (e.g. 3.07-2.03 = 1.04 M€/MW in 2020) is the value of the capture equipment. If CO2 capture is added on to an existing power plant, the loss in generating capacity shall be taken into account.
"The Costs of CO2 Capture, Transport and Storage", Zero Emissions Platform (ZEP), July 2011
"UK Electricity Generation Costs Update", Mott MacDonald, June 2010.
CO2 capture (post-combustion), pulverized coal power plant
The non-captured CO2 is released into the atmosphere.
Some of the electricity consumption may be regained as useful heat. The displayed efficiency decreases do most probably take the usage of heat into account.
"ProjectCosts of generating Electricity", IEA & NEA, 2010 Energy/technical data
Financial data
Capture, post-combustion
500 - 740
The ZEP report [14] also provides an update on storage costs: