How are the CO2 emissions by tech calculated?

[Cermouth]

I find the CO2 emissions by tech are mostly positive in the model results, but I think the bioenergy with carbon capture and storage (BECCS) should have negative emissions, because it contains the net-zero emissions from bioenergy use and negative emissions from CCS. But the emissions of these techs are all positive in the emissions by tech queries. Where are the negative emissions of BECCS? How are the CO2 emissions by tech calculated? Thanks for answering :)

[pkyle]

It sounds like you'll want to use the queries with the string (no bio). This query is reporting the physical quantity of CO2 emissions from each technology, with no regard as to whether the carbon in the CO2 came from bioenergy or fossil. The (no bio) queries trace the negative emissions from bioenergy production (temporary sequestration of CO2; see the emissions from regional biomass in the query you're currently running) through to the end uses, and as such do not include any bio-derived CO2 in the emissions quantities reported. These queries also report the negative CO2 emissions from BECCS technologies.

[Cermouth]

@pkyle Thanks for your reply! I thought of the (no bio) queries, but what is the relation between the no bio emissions and the CO2 sequestration? I think for bioenergy, e.g., -2.05885 MTC for no bio emissions of the elec_biomass(IGCC CCS), but 2.058847 MTC for CO2 sequestration of that sector. How can I get the exact negative emissions of the CCS instead of the BECCS? That is, how much carbon is first stored within and then released from the biomass energy, and how much carbon is captured and stored during the CCS process?

Grateful for your help!

[pkyle]

So for a BECCS technology, the first query you ran, co2 emissions by tech, will report the physical volume of CO2 being emitted to the atmosphere (in Mt C). Even for a BECCS technology the capture-fraction isn't 100%, so there are some positive emissions. Note that the carbon is bio-derived and thus wouldn't normally be reported. The query co2 sequestration by tech will report the Mt C being stored; for any technology whose subsector contains the string biomass, this will all be BECCS. The query doesn't care about the source of the carbon (bio vs fossil). This is just the quantity of CO2 that is being captured and stored in geologic reservoirs. The query co2 emissions by sector (no bio) will report the emissions from a technology as they would be reported by standard emission reporting conventions, wherein bio-derived CO2 emissions are not reported, but CO2 stored by BECCS is reported as a negative number.

[Cermouth]

@pkyle Thank you for your help!