As is the case with rail transportation, the electric transmission system can be vulnerable to initially localized disruptions that ultimately have severe and widespread impacts. For example, the failure to manage tree growth along transmission rights-of-way was cited as the root cause of an August 2003 blackout that affected Ohio, Michigan, Pennsylvania, New York, Vermont, Massachusetts, Connecticut, and Ontario, with estimated costs ranging from $4 billion to $10 billion in the United States alone (DOE/NRC, 2004).
In the future, transport of a range of coal-derived products also may require attention. For example, liquid fuels and substitute natural gas derived from coal are being assessed with increased interest as a result of recent oil and gas price increases and national security concerns. Some of the coal use scenarios described in Chapter 2 include projections for growth in coal-to-liquids and coal-to-gas plants in the post-2020 period. In general, the transport of energy products from such plants would be similar to the pipeline and other distribution systems currently employed at petroleum refineries or gas processing plants. However, should a significant coal-based synthetic fuels industry begin to materialize in future decades, issues related to the transport of energy products from such facilities may require further research.
If geological sequestration of CO2 is implemented on a large scale as a greenhouse gas mitigation measure in the future, it will be necessary to transport large quantities of CO2 from their sources to geological storage sites. Ideally, CO2 sequestration would take place at sites in close proximity to the sources of CO2, generally coal-based power plants or other large industrial facilities that capture and compress CO2 for transport and storage. However, not all coal plants are located immediately above or adjacent to geologic storage sites. In such cases, transport of the CO2 by pipeline would likely be the most economical and preferred method, although it is also possible to transport CO2 in road tankers, rail tankers, or ships (in cases where the sequestration site is located far offshore) (IPCC, 2005). The proximity of potential sequestration reservoirs will need to be considered, along with many other factors (e.g., proximity to coal fields, transport costs, electricity delivery costs, availability of water), when sites for power plants are evaluated. An extensive description and analysis of CO2 transport is presented by the Intergovernmental Panel on Climate Change (IPCC, 2005), and the following two paragraphs are derived from that report.
Currently, there are more than 2,500 km (~1,500 miles) of long-distance CO2 pipelines operating in the western and southern United States. These pipelines transport more than 40 megatons of CO2 per year,3 primarily from natural CO2