Adjust CEM hourly emission files


I am developing several emission scenarios for the power sector and need to change the hourly emissions for some EGUs. I am testing if changing the values in the "HOUR_UNIT_YY_MM_DD.txt " files will work now. So I reduced all EGUs’ SO2 and NOx emissions (SO2MASS and NOx) to 1% of the original emissions and kept everything else unchanged (Here are two input files I am using:, Then I compared the output files “inln_mole_ptegu_*.ncf” before and after reducing the emissions and the two figures here show the average SO2 emission rates.

Before reducing emission:

After reducing emissions at the input file:

So reducing the emission rates from the cem input files did lead to a decrease in SO2 emissions from the output files. However, the reduction magnitude is quite different. In the input files, emissions were reduced to 1% but the output emissions are around 10% of the previous output emissions.

Is this a reasonable outcome? If not, are there any other files I need to change (eg. cemsum_2015_3_10_2017_final.txt)?


This issue is solved. When I reduced all cem emissions to zero, there is still some emission from other input files.

Glad to hear that you were able to resolve this issue.