Request: change EPA CEMS variable descriptions

Below I’ve listed the current variable descriptions for each of the EPA CEMS variables, as well as my proposed change. I think these changes are helpful because they’re sometimes more correct (e.g. plant_id_eia vs facility_id) or are more precise about units.

For some variables, particularly steam_load_1000_lbs, facility_id, and unit_id_epa, I’m a little unsure what to write.

CC: @cmgosnell and @gschivley

• id
  • Current: PUDL-issued surrogate key.
  • Proposed: Unique PUDL-issued plant-unit-hour key (may change between PUDL versions).
• state
  • Current: State the plant is located in.
  • Proposed: no change
• plant_id_eia
  • Current: EIA Plant Identification number. One to five digit numeric.
  • Proposed: The unique six-digit facility identification number, also called an ORISPL, assigned by the Energy Information Administration.
• unitid
  • Current: Facility-specific unit id (e.g. Unit 4)
  • Proposed: no change
• operating_datetime_utc
  • Current: Date and time measurement began.
  • Proposed: Date and time measurement began (UTC).
• operating_time_hours
  • Current: Length of time interval measured.
  • Proposed: no change
• gross_load_mw
  • Current: Power delivered during time interval measured.
  • Proposed: Average power in megawatts delivered during time interval measured.
• steam_load_1000_lbs
  • Current: Total steam pressure produced by a unit or source in any calendar year (or other specified time period) produced by combusting a given heat input of fuel.
  • Proposed: Not sure, but should be specific to the hour, not the year
• so2_mass_lbs
  • Current: Sulfur dioxide emissions in pounds.
  • Proposed: no change
• so2_mass_measurement_code
  • Current: Identifies whether the reported value of emissions was measured, calculated, or measured and substitute.
  • Proposed: no change
• nox_rate_lbs_mmbtu
  • Current: The rate at which NOx in was emitted in pounds per million BTU.
  • Proposed: no change
• nox_rate_measurement_code
  • Current: Identifies whether the reported value of emissions was measured, calculated, or measured and substitute.
  • Proposed: no change
• nox_mass_lbs
  • Current: Nitrogen oxide emissions in pounds.
  • Proposed: NOx emissions in pounds.
• nox_mass_measurement_code
  • Current: Identifies whether the reported value of emissions was measured, calculated, or measured and substitute.
  • Proposed: no change
• co2_mass_tons
  • Current: Carbon dioxide emissions in short tons.
  • Proposed: no change
• co2_mass_measurement_code
  • Current: Identifies whether the reported value of emissions was measured, calculated, or measured and substitute.
  • Proposed: no change
• heat_content_mmbtu
  • Current: The measure of utilization that is calculated by multiplying the quantity of fuel by the fuel’s heat content.
  • Proposed: The energy contained in fuel burned, measured in million BTU.
• facility_id
  • Current: The unique six-digit facility identification number, also called an ORISPL, assigned by the Energy Information Administration.
  • Proposed: New EPA plant ID.
• unit_id_epa
  • Current: Unique EPA identifier for each unit at a facility.
  • Proposed: New EPA unit ID.

[gschivley]

From the plain english guide to Part 75.. F-factors are provided in Appendix F of Part 75.

[cmgosnell]

hey @karldw ! Lots of these changes look great to me. I’m also unsure about those three fields, but for implementation you can to add these directly into the models for now on the master branch. I’m able to regenerate the metadata for the data packaging based on the current state of the database and I’ll probably keep that functionality until the actual switch over date… which is probably still two weeks out. Until then, you can change the comments in models and after that you’ll be able to modify the metadata in pudl/src/pudl/package_data/meta/data_package/datapackge.json.