Hello,
I have two questions about the residential and commercial/institutional fuel combustion emissions in the 2019 EQUATES platform.
(1) How are residential and commercial/institutional fuel combustion emissions temporally allocated? Is a constant fraction of the annual emissions total allocated to each hour of the year? I have found information about the spatial allocation regarding activity data, census information, etc., but nothing about the temporal allocation. I know that the final nonpt emissions have a representative weekday for each month (plus holidays) and a diurnal cycle, but I would like to know how that traces back to fuel combustion specifically.
(2) This page has a note that “The EQUATES base year emissions are from the 2017 NEI. For each sector in the 2017 NEI one of four approaches was applied to estimate emissions for the entire 2002-2019 time period: (1) Develop new methods for creating consistent emissions for all years (2) Use 2016 or 2017 model platform emissions and create scaling factors based on activity data and/or emission control information (3) Use existing modeling platform data for earlier years (2002-2015) (4) Leave emissions flat at 2017 NEI levels.” Which methods were used for the residential and commercial/institutional fuel consumption emissions in the 2019 platform?
Thank you for your help!
Cara Scalpone
UW-Madison
Thank you for your interest in the EQUATES data. I reached out to one of the emissions experts from the EQUATES team, @james.beidler, who was able to provide this information on the temporal allocation:
The nonpt sector fuel combustion sources are temporally allocated based on the source category code (SCC) using three distinct annual-to-month profiles, two week-to-day, and a single diurnal profile. The same profiles were applied across all fuel types within the general industrial, commercial/institutional, and residential fuel combustion source classifications.
Residential and commercial fuel combustion sources had more emissions allocated to the winter and fall months than the summer. Industrial sources receive a flat monthly allocation.
Commercial and industrial emissions had a greater weekday then weekend allocation. Residential combustion source emissions are allocated evenly to each day of the week.
All fuel combustion sources in the nonpt sector get the same diurnal profile with emissions allocated mostly between 8am and 10pm, peaking around 2pm.
In terms of your second question, EQUATES 2019 residential and commercial/institutional fuel consumption emissions were based on the EPA’s 2019 Emissions Modeling Platform. The 2019 Platform Technical Support Document indicates that “The 2019 platform nonpt sector inventory is mostly unchanged from the January 2021 version of the 2017 NEI.” (Documentation for 2017 NEI.)
Another resource for the emissions processing for the EQUATES project is available in this paper, Foley et al., 2023. The methods are described for 2002-2017 (the original timeseries) but also apply for the 2019 emissions, except for some small differences in methods in a few sectors.
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Thank you for providing this information back in July; it has been very helpful for my work!
One more question about the diurnal temporal profile: Could you point me to any documentation on how the diurnal profile (Diurnal Profile 26) was defined/determined? I’m looking at residential heating emissions for my work, and my intuition would be to expect greater emissions at nighttime when temperatures drop rather than peaking at 2 pm local time. Before I make any changes though, I would like to understand why the EPA uses the Diurnal Profile 26 for this sector.
Thank you again,
Cara
I’m not aware of any specific documentation that explains the determination of the assignment of the diurnal profile for residential heating source categories outside of those used for residential wood combustion. Profile 26 is often used for source categories where source-specific diurnal activity data is either not available or has not been assessed. I agree that the typical residential heating activity pattern is unlikely to peak at 2 PM when the outdoor temperatures are highest and people are more often at work.
Thank you for this explanation; this provides good reason for me to look into alternative approaches for the diurnal allocation!
I do have another temporal allocation question: I noticed that kerosene heaters (scc: 2104011000) use a different monthly temporal allocation than the other residential fuel combustion sources. Kerosene is mapped to the 262 monthly temporal profile, which is flat across the year. Is there a reason that kerosene is treated differently than other heating fuel types?
Thanks again!
Cara
I don’t know of a specific reason why kerosene is treated differently than other heating fuel types for the monthly profile. If you are updating temporal profiles you might consider the approach used in more recent modeling platforms where residential natural gas heating emissions are allocated to months using state-level NG consumption data (ex. EIA data). The same has not been done for kerosene or fuel oils, but I suspect that the patterns are similar given that they both represent heating needs.