Costs and Challenges of CCS

 

CCS costs, like other climate technologies, must be lowered. The figure below summarizes electricity production costs for different technologies. The left hand portion of the figure shows current technology for both high and zero carbon options. The middle section shows emerging technologies, and the far right section shows costs after multiple plants have been built and innovation has lowered costs. The dotted line shows near term electricity production prices. As the figure shows, the costs of all near-zero carbon technologies are more expensive then today's electricity prices. 

Electricity costs of current and emerging technologies

 

Enlarged PDF

Notes:

1.These are US costs. Absolute costs will be much lower in China, as will be the “spread” among the different technologies.

2.For intermittent technologies such as wind, no penalty is added for lower value of non-dispatchable power, or additional capacity that needs to be built to provide back up power to offset unit intermittency. 

 

Three points help place the costs and challenges of carbon capture and storage (CCS) in context:

  1. CCS lowers the total societal cost of addressing climate change by approximately 30%.[1]This does not mean that CCS lowers electricity prices.  It means without CCS, more costly methods are needed to meet carbon dioxide reduction targets, which could add trillions of dollars[2]

    2.  

  2. CCS will not be widely used until carbon dioxide is regulated.  That’s because CCS has only one purpose—compliance with environmental standards.

    3.  

  3. Implementing CCS means a new industry must emerge on a large scale to capture, store and inject carbon dioxide deep underground. It’s not as simple as adding a device to a plant.

    4.  

 

While the actual cost of CCS vary, as a general guide:

 

  • Capture is more expensive than sequestration. Capture accounts for about 3/4 of the total CCS costs.

 

  • CCS raises the costs of electricity (compared to an uncontrolled plant) by between 30 and 80%.[3]  A key factor that drives this increase is the energy penalty associated with capture and compression of CO2 to make it ready for transport and injection.

 

  • Projected electricity prices from an old plant retrofitted with CCS are often lower than the projected prices from a proposed new plant with CCS.  The reason is that the older plant is often fully depreciated and paid off.

 

  • Technology is not static.  Historically, the cost of pollution controls has been far less than originally projected as technology is deployed and improved.

 

Gasification Challenges

With today’s technologies, capturing carbon dioxide from a new gasification plant is normally less expensive than building a new conventional coal plant with post-combustion capture.[4],[5] Gasification challenges include:

 

  • IGCC plants require the gasifier and power production facilities to work together at the same time.  While both gasification and power production are mature technologies, integrating them has been a concern for utilities.

 

  • Construction costs have also been an issue.  IGCC without carbon capture is generally considered to be more expensive to build than pulverized coal without CCS. [6]  Because of the lack of a mandate, carbon market price or regulatory framework, most recent plants have been proposed without CCS, though that is beginning to change.

 

  • Both altitude and coal type can have an effect on IGCC plant costs. Higher altitudes make IGCC plants more expensive to operate, and the higher ash and moisture content of some lower-rank coals can signifcantly reduce the efficiency of some gasification systems.

 

 

Post-Combustion Capture Challenges

Moving to commercial scale, reducing costs, and lowering energy penalties are the key challenges facing post-combustion capture. 

 

  • PCC will significantly increase electricity generation costs from traditional coal power plants.  For new plants, PCC with current technology might increase the levelized cost of electricity by more than 80 percent.[7] Retrofit costs for existing plants will be site-specific but could approach one half the cost of building a new coal power plant (without PCC).[8]

 

  • PCC also imposes a significant “efficiency penalty” on coal power plants.  The energy required to heat today’s PCC solvents and then compress CO2 from exhaust stack to pipeline pressure can reduce the output of an existing plant by 30 percent.  (For a new IGCC plant, the relative decrease is output is about half this much.). This inefficiency results in increased coal use for an equivalent amount of electricity sold, and results in increased plant cooling requirements (with significant implications for plant water use).

 

  • Incremental improvements in the efficiency and costs of PCC processes are likely following initial commercial-scale demonstrations.  Technology developers to date have had little incentive to optimize solvents and process configurations for the power industry.

 

Geologic Storage Challenges

The single largest challenge facing sequestration is scaling up the technology to a level large enough to address climate challenges.  While enhanced oil recovery (EOR) has been used at large scale for decades, there have been relatively few sites where large amounts of CO2 have been injected into geologic brine formations. 

 

More large field demonstration projects are needed worldwide. Science and industry experience strongly indicate that sequestration is safe when practiced in an appropriate site. However, managing hundreds of sources injecting into a single sedimentary basin requires a high level of knowledge sharing and project coordination, as well as research and development support.

 

Monitoring, permitting and long-term care programs must also be developed so that commercial and public sequestration sites can be developed and environmental protection assured.

 

Enabling institutions are important to sequestration.  How will an industry for sequestration emerge from test sites?  In the United States, public utilities that focus solely on sequestration will need to evolve.  A robust public policy framework must support the development of these institutions.

 


[1] Intergovernmental Panel on Climate Change. 2005. IPCC Special Report on Carbon Dioxide Capture and Storage: Summary for Policymakers. http://www.ipcc.ch/pdf/special-reports/srccs/srccs_summaryforpolicymakers.pdf

[2] Dooley, James. 2006. “Macro and Micro: The Role for Carbon Dioxide Capture and Geologic Storage in Addressing Climate Change”. Presentation for the Joint Global Change Research Institute. http://powerpoints.wri.org/ccs_dooley.pdf

[3] Generation “with capture” estimates from MIT’s The Future of Coal report, 2007. 30% estimate is based on an IGCC plant, from a Rubin 2006 study. 80% is based on an 81.6% increase from a subcritical PC plant from a 2002 NETL study using MEA. See tables A-3.C.3 and A-3.C.4. The full report can be found here:  http://web.mit.edu/coal/

[4] US DOE/NETL. 2007. Cost and Performance Baseline for Fossil Energy Plants, August 1, 2007 revision of May 2007 Report, Volume 1. http://www.netl.doe.gov/energy-analyses/pubs/Bituminous%20Baseline_Final%20Report.pdf

[5] MIT. 2007. “The Future of Coal: an Interdisciplinary MIT Study.”Cambridge, MA: Massachusetts Institute of Technology. http://web.mit.edu/coal/

[6] A 2004 EPRI study compared IGCC with PC and NGCC and again exhibited the higher capital costs for IGCC as compared with other power plant types. (see study here).

[7] US DOE/NETL. 2007. Cost and Performance Baseline for Fossil Energy Plants, August 1, 2007 revision of May 2007 Report, Volume 1. http://www.netl.doe.gov/energy-analyses/pubs/Bituminous%20Baseline_Final%20Report.pdf

[8] US DOE/NETL. 2007. Carbon Dioxide Capture from Existing Coal-Fired Power Plants, November, 2007 revision of December 2006 Report. http://www.netl.doe.gov/energy-analyses/pubs/CO2%20Retrofit%20From%20Existing%20Plants%20Revised%20November%202007.pdf

 

CATF is working to

  • Establish carbon capture and storage as a major global industry.
  • Create a new generation of technologies and institutions capable of removing carbon dioxide that has already been released to the atmosphere.
  • Work directly with industry on getting more federal and state money to support these projects. 
  • Communicate with national and international news outlets, seeking to be seen as an honest arbitrator in coal and climate factual disagreements