200 likes | 464 Views
Form EIA-923 Introduction
E N D
1. Model-Based Sampling Methodology for the New Form EIA-923 ASA-EIA Fall Meeting
October 18, 2007
Joel Douglas
“*This is a working document prepared by the Energy Information Administration (EIA) in order to solicit advice and comment on statistical matters from the American Statistical Association Committee on Energy Statistics. This topic will be discussed at EIA's fall 2007 meeting with the Committee to be held October 18 and 19, 2007.”
2. Form EIA-923 Introduction“Power Plant Operations Report” Merges Data Elements From 5 Current Forms:
EIA-906 “Power Plant Report”
EIA-920 “Combined Heat and Power Plant Report”
EIA-423 “Monthly Cost and Quality of Fuels for Electric Plants Report”
FERC-423 “Monthly Report of Cost and Quality of Fuels for Electric Plants”
EIA-767 “Steam-Electric Plant Operation and Design Report ”
3. Form EIA-923 Data Summary Data of Interest for Monthly Sampling:
EIA-906 - Generation, Consumption, and Stocks
EIA-920 - Generation, Consumption, and Stocks
EIA-423 - Fuel Receipts, Fuel Cost, and Fuel Quality
FERC-423 - Fuel Receipts, Fuel Cost, and Fuel Quality
4. Form EIA-923 Data Summary
5. Sample Selection Goals Sample Size Reduction
Commercial and Industrial Sectors
Smaller facilities
Reduce Both Respondent and EIA Burden
Respondent Burden = Respondent Count
EIA Burden = Facility Count
6. Reasons for Using Model-Based Cutoff Sampling Instead of Design-Based SamplingFor Electric Power Data
Difficulty in collecting smallest respondents require that they be left out of the sample. Smallest respondents tend to have disproportionately large nonsampling error
Due to the highly skewed nature of electric power data, the smallest respondents do not affect aggregated totals very much.
Since very good auxiliary / regressor data are available, regression models are useful (i.e. Low variance and model failure is limited to data that should be modeled anyway)
Better use of resources to raise accuracy and lower respondent and Government burden.
EIA has produced good results for nearly two decades utilizing model based cutoff sampling
7. Sample Selection Outline Sampling groups mirror the generation groups in the Electric Power Monthly publication.
These groups represent the intersection of the following three levels:
Facility Type
Fuel Type
Geographic Region
8. Sample Selection Outline Cont. Facility Types (4)
Regulated (REG)
Independent Power Producers (IPP)
Commercial (COM)
Industrial (IND)
9. Sample Selection Outline Cont. Fuel Types (14)
- Coal
- Geothermal
- Hydroelectric
- Natural Gas
- Nuclear
- Other Gas
- Other Sources
10. Sample Selection Outline Cont. Geographic Regions (10 Modified Census Divisions)
- Middle Atlantic
- South Atlantic
- East Central
- West Central
- East North Central
- New England
- West North Central
- Mountain
- Pacific Contiguous
- Pacific Non-Contiguous
11. Sample Selection Outline Cont.
12. Sampling Methodology Summary Five Steps
Step #1 – Capacity Cutoffs
Step #2 – Reported Value Coverage
Step #3 – Estimation Group Counts
Step #4 – Acceptable RSEs
Step #5 – Additional Facilities
13. Sample Selection Procedure Step #1 Cutoff sampling methodology based on operating nameplate capacity
Ensure adequate capacity coverage by sector, fuel type, and region
Regulated – 70%
Independent Power Producer – 70%
Commercial – 50%
Industrial – 50%
14. Sample Selection Procedure Step #2 Add additional facilities that rank within a preset percentage of actual generation, consumption and stocks and are not included in the capacity cutoff sample.
Regulated – 50%
Independent Power Producer – 50%
Commercial – 25%
Industrial – 25%
15. Sample Selection Procedure Step #3 Ensure adequate estimation group coverage
Estimation groups must have a minimum of 10 monthly observed values
Grouping parameters are similar to the sampling parameters, with a few notable exceptions.
16. Sample Selection Procedure Step #4 Ensure fuel group Relative Standard Errors (RSEs) are within reasonable range at the US regional level.
Regulated – RSE < 5%
Independent Power Producer – RSE < 5%
Commercial – RSE < 10%
Industrial – RSE < 10%
17. Sample Selection Procedure Step #5 Add additional facilities which do not add much to respondent or EIA burden
Mainly large coal and natural gas facilities that are in the current EIA-906 / EIA-920 monthly sample.
Approximately 200 additional respondents added
18. Final Results - Counts
19. Final Results - Percent
20. Final Results – Generation Volume
21. Further Information The sampling methodology is also described in the OMB Federal Register Notice associated with the Electricity 2008 Project.
http://www.eia.doe.gov/cneaf/electricity/page/fednotice/elect_2008.html