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Appendix A Coal Transportation Rate Data Base Appendix A presents a detailed description of the Coal Transportation Rate Data Base (CTRDB), including its content and data sources, data reliability, data quality, relationship to other data systems and coverage, and data availability.
The CTRDB is a comprehensive database that contains electric utility coal supply contract data and transportation-related data. The data for this system are originally collected by Federal Energy Regulatory Commission (FERC) on Form 580, "Interrogatory on Fuel and Energy Purchase Practices," to conduct reviews of utility fuel and energy purchase practices as mandated by the Public Utility Regulatory Policies Act of 1978 (Public Law 95-617), which amended Section 205 of the Federal Power Act of 1920. The survey is conducted every 2 years. It requires responses from all jurisdictional utilities that either operate at least one steam-electric generating station with a capacity of 50 megawatts or greater, or have an ownership interest in a jointly-owned steam-electric station with a capacity of 50 megawatts or greater. Jurisdictional utilities are facilities involved in the transmission of electric energy in interstate commerce and the sale of electric power at wholesale in interstate commerce. The CTRDB was originally developed to provide information on coal supply contracts, contract tonnage, contract expiration date, and transportation rate by mode for an Energy Information Administration (EIA) model used to project coal supply and transportation. Starting in 1985, coal contract information for 1983 was obtained from FERC. In 1986, all contract and transportation information was collected from the FERC 580 survey responses for the years 1984 and 1985. In 1987, a need for an historical analysis of transportation rates arose. At that point, FERC provided EIA with historical coal contract information from the FERC Form 580 for the years 1979 through 1982. The CTRDB currently contains data for 1979 through 1997 and is updated as new data are collected in the FERC Form 580 survey. The system contains approximately 925 records for each year for as many as 135 investor-owned utilities. Investor-owned electric utilities may be independently operated or part of a holding company. The utilities are usually operating companies that provide basic services for the generation, transmission, and distribution of electricity. Investor-owned electric utilities currently operate in all States except Nebraska. The FERC is not empowered to collect Form 580 information from non-jurisdictional entities such as Federally owned electric utilities or publicly owned utilities including municipalities and cooperatives that do not engage in interstate transmission or generation of wholesale electric power. The Tennessee Valley Authority (TVA), the largest federally owned power producer, with coal receipts of 32.1 million tons in 1997 and electric utility plants operating in Alabama, Kentucky, and Tennessee, is not required to report on Form 580. Texas Utilities Electric Co., a large nonjurisdictional utility that is not required to report on Form 580, had coal receipts of 33.3 million tons in 1997. Publicly owned utilities not reporting on the FERC 580 are concentrated in Arizona, California, Nebraska, Oregon, and Washington. Utilities that do not use the Fuel Adjustment Clause do not have to report on Form 580. In the late 1990's fewer and fewer utilities were using the fuel adjustment clause and therefore fewer are reporting on Form 580. Because FERC Form 580 and thus the CTRDB excludes a significant portion (57 percent in 1997) of the contract coal consumed at and transported to U.S. electric utilities, an effort was made to improve the coverage of the CTRDB and to provide a more comprehensive view of transportation rates. Supplementary data for the CTRBB came primarily from the Surface Transportation Board "Annual Waybill Sample" and from the FERC "Monthly Report of Cost and Quality of Fuels for Electric Plants," Form 423, for utilities not covered by Form 580. The CTRDB was augmented by the inclusion of confidential data from Form 580 and with derived transportation rates that were computed from known mine price and delivered price data. The records contained within the CTRDB are contract- and route-oriented. For each utility plant receiving coal under a specific contract, the CTRDB provides an origin-to-destination record for every route over which that plant's coal flows. A contract record within the CTRDB can be broken down into four subsets of data fields: contract accounting and specification information, plant information, route information, and transportation mode information. A utility company within the database can have several coal supply contracts; one coal supply contract can serve several plants; an individual plant can receive coal from several mines on the same contract; and an individual plant can be covered by several different contracts. The contract accounting and specification information consists of:
The plant-related data consist of:
Route and transportation mode related data consist of:
Coal prices and transportation rate data may be reported in cents per million Btu, dollars per ton, and dollars per million Btu. Coal shipments and base contracted tons are in short tons. Sulfur and ash contents are in percent by weight. Heat content is reported in Btu per pound.
Since the CTRDB is drawn from the FERC Form 580 system survey, its data consistency and coverage can be described in the context of Form 580 and its relationship to other data systems. The Form 580 survey population is a subpopulation within the survey population for Form 423, "Monthly Report of Cost and Quality of Fuels for Electric Utilities." Form 580 covers jurisdictional public utilities while Form 423 covers all public utilities, i.e., investor-owned utilities, federally owned utilities, municipalities, and cooperatives. The Form 580 survey is conducted every 2 years, while the Form 423 survey is conducted monthly. As of 1993, FERC Form 580 covered an average of 135 utilities and 259 plants per year, while FERC Form 423 covered approximately 235 utilities and 700 power plants. As of 1997, the Form 423 coverage was down to 222 utilities and 656 fossil fuel plants, of which 169 utilities and 403 plants had coal receipts. Further, Form 580 collects data for utility contract purchases only, whereas Form 423 collects data for both utility contract purchases and spot purchases. Spot purchases are purchase orders to obtain coal for a period of less than 1 year. Although both surveys collect data on utility contract purchases of coal, more utilities report contract purchases on Form 423 than on Form 580, and thus, the coverage and the contract tonnage reported is higher than for Form 580. Contract tonnage was chosen as the variable to measure consistency of reporting for the two systems. In order to obtain a more comprehensive record of contract tonnage, the Form 580 contract tonnage was augmented with data derived from the Surface Transportation Board (STB) Carload Waybill Sample. Thus the contract tonnage in the CTRDB is the combination of Form 580 contract tonnage and STB Carload Waybill Sample derived contract tonnage. Table A1 shows the breakdown of Form 423 tonnage into contract and spot totals, CTRDB Coal tonnages by Form 580 and augmented data totals, and the CTRDB tonnage as a percentage of both the FERC 423 total tonnage and the FERC 423 contract tonnage. The total contract coal received at U.S. utilities was 721.5 million tons in 1997 according to Form 423. The 520.1 million tons of contract tonnage recorded by the CTRDB accounted for 72.1 percent of the Form 423 contract coal receipts or tonnage, as opposed to 309.7 million short tons reported by Form 580 alone, which would account for only 42.9 percent of the Form 423 contract tonnage total. Survey population differences contribute to four sources of variations between FERC Form 580 and FERC Form 423 data series: (1) frame differences, (2) different reporting periods, (3) requirements based on electric generating station capacity (steam-electric generating station and peaking units with either 24 megawatts capacity or 50 megawatts capacity could have reported on either survey, depending on the requirements at the time), and (4) data reporting procedures, data recording, and processing procedures for the two systems.
The FERC manages all quality control issues, mandates the type of data collected, and handles nonresponses and respondent contact records for the FERC Form 580. Quality assurance measures in the extraction of data from Form 580 responses are handled by the EIA. An effort is made to rectify coding errors, tabulation errors, keying errors, and problems of data interpretation. However, FERC 580 responses may contain estimates or averages of transportation rates for several shipments under one contract and estimates of volumes and distances of shipments, because the data are not collected primarily for input into the CTRDB. The data are coded onto hard copy coding forms as reported by the respondents. The coded forms are then compared with the original responses to detect and correct transcription errors. Once a computer file has been created, the computer file is compared with the coded forms to detect and correct data entry errors. An error detection and correction program is used to detect and correct errors that escape manual screening. This program consists of a set of ranges and range checks for all quantitative data fields within the database. The range values were established in coordination with FERC personnel. When the database is evaluated using this program, values that fall outside of pre-established ranges are identified for investigation. Internal inconsistencies are corrected using a program that compares values from year to year to detect outliers based on the series of values. This program also resolved problems of record redundancy. Table presentations are also examined for regional and national transportation data consistencies. Data record printouts are reviewed and outliers are eliminated where deemed necessary. For a few specific demand regions, supply regions, and/or transportation modes, time series data vary considerably from one year to the next. In most cases, this appears to be due to the small number of records for which transportation rate data were available for that particular region or transportation mode. In those cases, fluctuations in tonnage or rates for one contract could have a substantial influence on the regional average. This situation occurred most frequently for shipments from the "Other Western Interior" region and for shipments by truck and "other" transportation modes (primarily conveyors). Although the averages based on this "thin" data are included in the tables of this report, they were not used for any of the analyses upon which the report's conclusions are based.
The CTRDB data are based on public use data from the FERC 580 for the years 1979 through 1987 and both public use and confidential data for 1988 through 1997. For the years 1979 through 1987, data that were not available due to confidentiality consisted of coal transportation rate and coal minemouth price. Also, some records did not have complete data. To minimize the influence of missing data on statistical calculations, records with missing data were excluded from certain calculations. Furthermore, an effort was made to increase the availability of data through derivation in two ways: (1) when two of the three cost data elements were available, the third one was derived from the available data; i.e., if minemouth price and delivered price were available, the transportation rate was derived by subtracting the minemouth price from the delivered price; and (2) certain FERC 580 confidential data were made available for the years 1988 through 1997 under an agreement between EIA and the FERC to display the confidential data only in an aggregated form. The availability of data on coal transportation rate per ton, distance, and tonnage is important because these variables are used in the calculation of the average distance shipped, average transportation rate per ton, and average transportation rate per ton-mile. Tables A2, A3, and A4 show the number of records and tonnage contained in the CTRDB, the number of records and tonnage obtained from Form 580, the number of supplementary records and tonnage in addition to Form 580, and the number of records and tonnage for unqualified data. The data for Tables A2, A3, and A4 include all transportation modes, not just rail. The unqualified data for Table A2 are records that do not contain data for the distance shipped. The tonnage for these records are not included in the calculation for average distance. In 1997 there are 92 records that did not contain data for distance, as a result 41.5 million short tons of coal was disqualified from the average distance shipped calculation. The records on the three tables include data for all transportation modes, not just rail. Similarly, the unqualified data for Table A3 are the records that do not contain data for the transportation rate per ton. In 1997 there are 67 records that do not contain transportation rate data and 55 million short tons are disqualified from the calculation of average transportation rate per ton mile. Table A4 shows the data available for the calculation of the average transportation rate per ton-mile. The unqualified data for Table A4 takes into account records that are missing both distance data and transportation rate data. Since this is a combination of data from Table A2 and A3 there are more unqualified records (124) and tonnage (67.7 mst) disqualified for the calculation of the average transportation rate per ton-mile.
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