GHG quantification

General GHG quantification rules can be found in the Rainbow Standard Rules.

Calculations of GHG emissions for the baseline and project scenarios shall follow a robust, recognized method and good practice guidance. The overall methodological approach is a comparative life cycle assessment (LCA) at the project-scale, based on ISO 14064-2:2019.

This methodology shall be used in conjunction with the Rainbow modules listed below. Modules are like mini-methodologies that only cover a part of the project life-cycle. Combining the relevant modules for a project results in a complete picture of the required data, calculations, monitoring plans, and other information needed for a full GHG quantification.

Processing and energy use

Transportation

Infrastructure and machinery

GHG quantifications shall be completed for each monitoring period.

Functional unit

The functional unit shall be 1 tonne of carbon dioxide stored in a geological reservoir.

Data sources

The required data for GHG removal calculations from projects are presented below.

• Table 1 and 2 list the data required for the calculation of project removals for segregated and non-segregated streams, respectively.

• Table 3 lists the primary data measured on a CO₂ stream required to determine the amount of CO₂ in tonnes. Further details on the measurements are provided in the Sampling and measurements section.

• Table 4-7 list the data required for the calculation of project emissions. Further details are provided in the respective Emission sections in this methodology and the Rainbow Transformation modules.

Note that the table does not include all information needed for project monitoring and verification— only the data inputs for ongoing GHG quantification. The full list of information is provided in the minimum requirements for a Monitoring Plan.

Data sources for project removals

Removals: Segregated CO₂ stream

The following data shall be provided for projects that transport and store CO₂ as a segregated stream. This means that the project's captured CO₂ is at all times separate from other CO₂ streams.

Table 1 for segregated streams: Summary of removal data needed from projects and their source for initial project certification and validation. All data sources listed here are required to be monitored and updated during verification (see Monitoring Plan section).

Parameter	Variable	Unit	Source
Amount of CO2 injected at storage site	$CO_{2 \ injected}$	tonnes	Primary data, collect all data listed in Amount of CO2
Total amount of CO2 captured at capture site	$CO_{2 \ captured, total}$	tonnes	Primary data, collect all data listed in Amount of CO2
Amount of co-captured associated CO2	$CO_{2 \ assoc, co-captured}$	tonnes	Primary data, collect all data listed in Amount of CO2
Amount of associated CO2 captured separately	$CO_{2 \ assoc, source}$	tonnes	Primary data, collect all data listed in Amount of CO2
Biogenic fraction of mixed stream	$F_{B}$	fraction	Primary data, measured at capture site via mass balance approach, or C14 testing

Removals: Non-segregated CO₂ streams

The following data shall be provided for projects in which the Project's captured CO₂ is mixed with other CO₂ streams for any transport or injection step.

Table 2 For non-segregated streams: Summary of removal data needed from projects and their source for initial project certification and validation. All data sources listed here are required to be monitored and updated during verification (see Monitoring Plan section). Note that only one of the approaches marked with an asterisk (*) is required for reporting transport losses data.

Parameter	Variable	Unit	Source
Fraction of captured biogenic CO2 transferred for permanent storage, as opposed to CO2 use (CCU)	$F_{RCC}$	fraction	Choice of Project Developer
Total amount of CO2 captured at capture site	$CO_{2 \ captured, total}$	tonnes	Primary data, collect all data listed in Amount of CO2
Amount of co-captured associated CO2	$CO_{2 \ assoc, co-captured}$	tonnes	Primary data, collect all data listed in Amount of CO2
Amount of associated CO2 captured separately	$CO_{2 \ assoc, source}$	tonnes	Primary data, collect all data listed in Amount of CO2
Biogenic fraction of mixed stream	$F_{B}$	fraction	Primary data, measured at capture site via mass balance approach, or C14 testing
Allocation fraction in transport segment $S$ (ratio project CO2 to total CO2 transported)	$F_{S}$	fraction	Provided by transport operator if independently verified, or calculated according to Calculation: Allocation fraction $F_S$
Mass balance approach: Amount of CO2 entering transport segment $S$*	$CO_{2 \ in, S}$	tonnes	Primary data, collect all data listed in Amount of CO2
Mass balance approach: Amount of CO2 leaving transport segment $S$*	$CO_{2 \ out, S}$	tonnes	Primary data, collect all data listed in Amount of CO2
Individual monitoring approach: average emission factor per component $c$ in transport segment $S$ per time period*	$EF_{c,S}$	tCO2eq per time unit	Technical specifications, documents from transport operator
Individual monitoring approach: number of components $c$ in transport segment $S$, multiplied by number of time periods*	$N_{c,S}$	dimensionless	Technical specifications, documents from transport operator
Total amount of CO2 injected into permanent storage at storage site $K$	$CO_{2\ injected, K}$	tonnes	Primary data, collect all data listed in Amount of CO2
Amount of project CO2 injected at storage site $K$	$CO_{2\ project, injected, K}$	tonnes	Contractual agreements with storage site operator
Total amount of CO2 entering storage site $K$	$CO_{2\ in, K}$	tonnes	Primary data, collect all data listed in Amount of CO2
Sum of fugitive emissions of CO2 at storage site $K$	$CO_{2 \ fugitive,K}$	tonnes	Provided by storage site operator
Sum of vented emissions of CO2 at storage site $K$	$CO_{2 \ vented,K}$	tonnes	Provided by storage site operator

Removals: Amount of CO₂

Depending on the type of stream (segregated vs. non-segregated) and the type of CO₂ captured (biogenic CO₂ vs. ineligible CO₂), Project Developers shall determine the amount of CO₂ at different points during capture, transport and storage of the project's CO₂. To determine the amount of CO₂ in tonnes, the following primary data on the stream shall be provided. See Measurement of injected CO₂ for further details.

Table 3: Summary of primary data measured on a CO₂ stream.

Parameter	Variable	Unit	Source
total mass or volumetric flow of stream	$m_{stream}$ or $V_{stream}$	tonne or m3	primary data measured at storage site
concentration of CO2 in the stream	$F_{mass,\ CO2}$	wt%	primary data measured at storage site
density of stream (for volumetric flow measurements)	$\rho_{stream}$	t/m3	primary data measured at storage site

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🇪🇺 CRCF requirement: Data sources

In addition to the data listed in the table above, Project Developers of CRCF-projects shall additionally monitor and update the fraction of injected CO₂ dedicated for carbon removals under the CRCF, $F_{CRCF}$.

Data sources for project emissions

Emissions: Shared data sources

The following data shall be provided by all projects, regardless of the baseline scenario (i.e. retrofit or greenfield project, CO₂ generation), or energy source (external vs. internal, parasitic load).

Table 4: Summary of emission data needed from all projects and their source for initial project certification and validation. All data sources listed here are required to be monitored and updated during verification (see Monitoring Plan section). Those marked with an asterisk (*) shall be provided once, during validation. Note that only one of the approaches marked with two asterisks (**) is required for reporting mobile transport data.

Life cycle stage	Parameter	Unit	Source
CO2 capture	Type of input used by capture process, e.g. fuel electricity heat chemicals (solvents, sorbents, etc.)	Text description	Internal process documents
CO2 capture	Amount of fuel or energy used by capture process	liter, kWh, MWh, GWh, kJ, MJ	Meter readings, bills, internal tracking documents, invoices
CO2 capture	Amount of energy (heat or electricity) recovered from capture process and exported	kWh, MWh, GWh, kJ, MJ	Meter readings, bills, internal tracking documents, invoices
CO2 capture	Amount of chemicals or other inputs used by capture process	kg, liter	Bills, internal tracking documents, invoices
CO2 capture	Material type*	Selection	Technical specifications, bill of materials, invoices, building design documents
CO2 capture	Material amount*	kg, tonne, m3	same as above
CO2 capture	Item lifetime* (optional)	years	same as above
Transport stage, mobile** distance based approach	Distance traveled per transport segment	km	Operational records, conservative justified estimates
Transport stage, mobile,** distance based approach	Weight of CO2 transported per segment	tCO2	Operational records, conservative justified estimates
Transport stage, mobile,** distance based approach	Vehicle type	Category	Vehicle documents or photos
Transport stage, mobile, ** fuel amount approach	Fuel quantity consumed per transport segment	kg or kWh	Operational records, conservative justified estimates
Transport stage, mobile, ** fuel amount approach	Fuel type and (optional) geography	Category	Operational records, conservative justified estimates
Transport stage, mobile, ** fuel amount approach	Number of trips per transport segment	Unit	Operational records, conservative justified estimates
Transport stage, mobile, ** fuel amount approach	Vehicle type	Category	Vehicle documents or photos
Transport stage, infrastructure	Type of input used by stationary transport process, e.g. fuel electricity	Text description	Internal process documents
Transport stage, infrastructure	Amount of fuel or energy used by stationary transport process	liter, kWh, MWh, GWh	Meter readings, bills, internal tracking documents, invoices
CO2 storage	Type of input used by storage process, e.g. fuel electricity	Text description	Internal process documents
CO2 storage	Amount of energy used by storage process	liter, kWh, MWh, GWh	Bills, internal tracking documents, invoices
CO2 storage	Material type*	Selection	Technical specifications, bill of materials, invoices, building design documents
CO2 storage	Material amount*	kg, tonne, m3	same as above
CO2 storage	Item lifetime* (optional)	years	same as above

Emissions: CO₂ generation

Emissions from CO₂ generation are allocated to the project if

• the project is a greenfield, or

• the project is a retrofit that sources additional biomass above its baseline biomass consumption for purposes other than meeting the parasitic load.

The following data shall be provided.

Table 5: Summary of CO₂ generation emission data needed and their source for initial project certification and validation. All data sources listed here are required to be monitored and updated at least every five years during verification (see Monitoring Plan section). Those marked with an asterisk (*) shall be provided once, during validation. Note that only one of the approaches marked with two asterisks (**) is required for reporting transport data.

Stage	Parameter	Unit	Source
CO2 allocation	Economic allocation fraction for CO2 generation	fraction	Calculated using prevailing market prices
CO2 allocation	Total amount of biomass consumed	tonnes	Operational records, conservative justified estimates
CO2 allocation	Retrofit only: Baseline biomass consumption	tonnes	Operational records or regional market analysis
Biomass production	Amount of biomass produced, per type	kg	Operational records, conservative justified estimates
Direct land-use change	Carbon stock per unit area associated with the reference land use	tCO2eq	Calculated following the guidelines for the calculation of land carbon stocks
Direct land-use change	Carbon stock per unit area associated with the actual land use	tCO2eq	Calculated following the guidelines for the calculation of land carbon stocks
Direct land-use change	Productivity of the biomass crop, per type	MJ / area and year	Operational records, peer-reviewed literature
Direct land-use change	Lower heating value of biomass, per type	MJ / tonne of biomass	Operational records, peer-reviewed literature
Biomass processing	Amount of biomass processed, per type	kg	Operational records, conservative justified estimates
Biomass processing	Amount and type of energy and material used in processing step, if no appropriate emission factor available	kg, liter, kWh, MWh, GWh	Meter readings, bills, internal tracking documents, invoices
Biomass transport, distance based approach**	Biomass transported, per type	kg	Operational records, conservative justified estimates
Biomass transport, distance based approach**	Distance traveled	km	Operational records, conservative justified estimates
Biomass transport, distance based approach**	Vehicle type	Category	Vehicle documents, photos
Biomass transport, fuel amount based approach**	Fuel quantity consumed	kg or kWh	Operational records, conservative justified estimates
Biomass transport, fuel amount based approach**	Fuel type and (optional) geography	Category	Operational records, conservative justified estimates
Biomass transport, fuel amount based approach**	Number of trips	Unit	Operational records, conservative justified estimates
Biomass transport, fuel amount based approach**	Vehicle type	Category	Vehicle documents, photos
Biomass storage	Amount biomass stored, per type	kg	Operational records, conservative justified estimates
Biomass storage	Time biomass is stored, per type	manure, slurry: days other: months (rounded up)	Operational records, conservative justified estimates
Biomass storage	Carbon content of biomass stored (for biomass other than manure or slurry), per type	mass%	Measurements, conservative justified estimates
Biomass conversion	Amount of biomass converted, per type	kg	Operational records
Biomass conversion	Amount of energy used in biomass conversion	kWh, MWh, GWh	Meter readings, bills, internal tracking documents, invoices
Biomass conversion	Amount of material used in biomass conversion	kg, liter	Meter readings, bills, internal tracking documents, invoices
Biomass conversion	Amount of fugitive emissions (e.g. CH4, N2O) from biomass conversion, per type	tCO2eq / t biomass	Flue gas measurements, conservative justified estimates
Biomass conversion, embodied emissions (only for biogas sites, simplified approach)	External volume of site's main digester*	m3	Licensing or official design document containing this parameter
Biomass conversion, embodied emissions	Item type*	Selection	NA
Biomass conversion, embodied emissions	Material type*	Selection	Technical specifications, bill of materials, invoices, building design documents
Biomass conversion, embodied emissions	Material amount*	kg, tonne, m3	same as above
Biomass conversion, embodied emissions	Item lifetime (optional)*	years	same as above
Biomass conversion, embodied emissions	List of items that were excluded*	Selection	Description of the system and transparent justification

Emissions: Parasitic load

In a BioCCS project, the energy consumed by the CO₂ capture process may be sourced internally from the facility's own energy output. Emissions from this so called parasitic load are allocated to the project.

The following data shall be provided.

Table 6: Summary of emission data needed to calculate parasitic load emissions and their source for initial project certification and validation. All data sources listed here are required to be monitored and updated during verification (see Monitoring Plan section). Note that only one of the approaches marked with an asterisk (*) is required for reporting parasitic load emissions.

Parameter	Unit	Source
Electricity consumed by capture unit	kWh, MJ	Meter readings, internal tracking documents
Total electricity produced by facility	kWh, MJ	Operational records
Amount of biomass used to produce electricity	tonnes	Operational records
Heat consumed by capture unit	kWh, MJ	Meter readings, internal tracking documents
Total heat produced by facility	kWh, MJ	Operational records
Average temperature of heat	K	Temperature measurements
Amount of biomass used to produce heat	tonnes	Operational records
Lower heating value of biomass	kJ or MJ or kWh or MWh per kg or tonne	Operational records, peer-reviewed literature
Simplified approach: Verified emission factor for facility electricity production*	kWh/ tCO2eq or MJ/ tCO2eq	Official facility certifications
Simplified approach: Verified emission factor for facility heat production*	kWh/ tCO2eq or MJ/ tCO2eq	Official facility certifications
Full approach: Data inputs listed in Table 5: CO2 generation for stages other than CO2 allocation	/	/

Emissions: Leakage

Leakage emissions shall be quantified where required by the rules in the Leakage section. The following data shall be provided.

Table 7: Summary of emission data needed to calculate leakage emissions and their source for initial project certification and validation. All data sources listed here are required to be monitored and updated at least every five years during verification (see Monitoring Plan section)

Leakage emissions	Parameter	Unit	Source
Counterfactual carbon storage	Carbon content of biomass	tonnes	Laboratory measurements, modeled, or representative secondary data
Counterfactual carbon storage	Estimated fraction of biomass carbon stored at 15 years in the counterfactual	fraction	Peer-reviewed literature, modeled, or representative secondary data, recognized national or regional GHG inventory reports, documented industry data or direct measurements
Counterfactual carbon storage	Estimated fraction of biomass carbon emitted within 15 years in the counterfactual, per type of GHG	fraction	Peer-reviewed literature, modeled, or representative secondary data, recognized national or regional GHG inventory reports, documented industry data or direct measurements
Counterfactual carbon storage	Estimated fraction of biomass carbon stored at 50 years in the counterfactual	fraction	Peer-reviewed literature, modeled, or representative secondary data, recognized national or regional GHG inventory reports, documented industry data or direct measurements
Biomass diversion	Amount of biomass diverted from valuable alternative use, per type	tonnes	Operational records
iLUC	Lower heating value of biomass, per type	MJ/tonne	Laboratory measurements
Bioenergy and biomaterial diversion	Electricity output of facility in the business-as-usual (BAU)	kWh, MJ	Operational records
Bioenergy and biomaterial diversion	Electricity output of facility after retrofit (BAU)	kWh, MJ	Operational records
Bioenergy and biomaterial diversion	Heat output of facility in the business-as-usual (BAU)	kWh, MJ	Operational records
Bioenergy and biomaterial diversion	Heat output of facility after retrofit (BAU)	kWh, MJ	Operational records
Bioenergy and biomaterial diversion	Material output of facility in the business-as-usual (BAU)	appropriate unit	Operational records
Bioenergy and biomaterial diversion	Material output of facility after retrofit (BAU)	appropriate unit	Operational records

The ecoinvent database version 3.12 (hereafter referred to as ecoinvent) shall be the main source of emission factors unless otherwise specified. Ecoinvent is preferred because it is traceable, reliable, and well-recognized. The ecoinvent processes selected are detailed in the Appendix.

Assumptions

• The Baseline scope assumes no carbon capture activity would have occurred under business-as-usual conditions.

• For projects sourcing CO₂ from anaerobic digestion of manure or slurry

  • Emissions of N₂O and methane due to manure and slurry storage before the digestion process are linearly related to the amount of days manure and slurry are stored on site. If Project Developers do not have an estimation of this value, an average of 15 days is assumed. In the baseline scenario, this is assumed to be 180 days.

  • Emissions of N₂O from slurry storage are sufficiently small (0.01-0.05% life cycle GHG emissions) that they can be excluded. This is because N₂O emissions from slurry storage are generally small, plus the shortened storage duration in the project scenario minimizes them further.

  • Manure and slurry from pigs, horses, sheep, and other animals are modeled using the same characteristics as cow manure. Only chicken manure is treated differently, due to its high nitrogen content (Table A1 and A2).

  • Embodied emissions from the underlying biogas production sites are modeled and extrapolated from the main digester exterior volume and buildings and main infrastructure at the underlying biogas site have an assumed lifetime of 20 years.

Baseline scenario

A project's Baseline scope is either a retrofit/addition on top of an existing site, or a greenfield, i.e. the installation of a new site. For both scopes, this methodology has a standardized baseline of 0 tCO₂eq stored from BioCCS. Therefore, there are no GHG quantifications for the baseline scenario.

Note that counterfactual carbon storage from alternate biomass use is treated in this methodology under Leakage.

Project scenario

The project scenario is broken down into four main life cycle stages, detailed in the following sections and shown in the figures below

• CO₂ removal

• Emissions from CO₂ capture

• Emissions from CO₂ transport

• Emissions from CO₂ storage

• Emissions from leakage

Figure 1 shows the system diagram of a greenfield project. Figure 2 shows the system diagram of a retrofit project sourcing no additional biomass above its baseline consumption (see baseline biomass fraction). Figure 3 shows that of a retrofit project sourcing additional biomass only to cover the parasitic load (see additional biomass fraction).

Figure 1: System diagram for a greenfield bioenergy and BioCCS project. Emissions from the generation of CO₂ are allocated to the project based on the economic value of the co-products (i.e. CO₂, bioenergy, other services).

Figure 2: System diagram of a retrofit bioenergy site and BioCCS project sourcing no additional biomass. In this example, the parasitic load energy demand is covered by the baseline energy generation, resulting in a reduced output of that energy compared to the baseline, and corresponding leakage emissions. Emissions associated with the generation of the parasitic load are allocated to the project. See Figure 1 for a detailed list of what's included in the CO₂ generation stages.

Figure 3: System diagram of a retrofit bioenergy site and BioCCS project sourcing biomass additional to its baseline consumption, for example to compensate for the parasitic load energy demand. All emissions associated with the sourcing of the additional biomass and its CO₂ generation are allocated to the project. See Figure 1 for a detailed list of what's included in the CO₂ generation stages.

The total net carbon removal of the BioCCS project is calculated according to Eq. 1.

$\textbf{(Eq.1)}\ Net\ Removal = R_{baseline}-R_{project}-E_{project}$

• $R_{baseline}$ represents any baseline GHG removals, representing permanent storage that would have occurred in the absence of the project, in tonnes of CO₂eq. According to the Baseline scope, no removals are considered in the absence of the project, hence $R_{baseline} = 0$.

• $R_{project}$ represents the project's gross GHG removals, in tonnes of CO₂eq and is calculated according to the rules set out it Project CO₂ removal. Its sign is negative.

• $E_{project}$ represents the project's total induced GHG emissions across the project life cycle including leakage emissions if applicable, in tonnes of CO₂eq. Its sign is positive.

🇪🇺 CRCF requirement: Recognition under different schemes

Project Developers can choose to credit part of net carbon removal under a scheme other than the CRCF. In this case, the fraction credited under the CRCF, $F_{CRCF}$ shall be applied to the net removal calculation in Eq. 1 .

The project's total induced GHG emissions are calculated according to Eq. 2:

$\textbf{(Eq.2)}\ E_{project} = E_{capture}+E_{transport}+E_{storage}+E_{leakage}$

• $E_{capture}$ represents the project's GHG emissions in the capture stage, in tonnes of CO₂eq.

• $E_{transport}$ represents the project's GHG emissions in the transport stage, in tonnes of CO₂eq.

• $E_{storage}$ represents the project's GHG emissions in the storage stage, in tonnes of CO₂eq.

• $E_{leakage}$ represents the project's leakage emissions, in tonnes of CO₂eq.

The project's GHG emissions shall include emissions from all additional sources caused by the project mitigation activity. Any emission sources identified by the Project Developer and not listed in the GHG emission sections below shall be reported to the Rainbow Certification team and accounted for.

According to the methodology Certification requirements, each monitoring period and GHG quantification shall cover a maximum duration of 12-months of CO₂ capture activities. If Project Developers are not able to precisely identify the moment when captured CO₂ enters permanent storage, they may count all associated GHG emissions downstream related to the storage of that CO₂ by applying default emission inventory data from the monitoring period, regardless of whether those downstream emissions occurred in the same 12-month period.

Project CO₂ removal

The project's CO₂ removals shall be calculated differently depending on whether or not the project's captured CO₂ stream is at all times transported and injected separately (i.e. segregated) from other CO₂ streams in the transport and storage facilities.

• For segregated streams, the amount of CO₂ removed is measured directly at injection at the storage site,

• For non-segregated streams, it is calculated using the measured amount of CO₂ captured at the capture site, minus CO₂ losses during transport and at the storage site.

Segregated stream

A segregated CO₂ stream is one where the project's CO₂ injected at the storage site can be directly attributed to the BioCCS project (i.e. the project's captured CO₂ is at all times transported and injected separately from other CO₂ streams). CO₂ removal for segregated streams shall be calculated by multiplying the amount of CO₂ injected by the fraction eligible biogenic CO₂ captured.

Amount of CO₂ injected

To quantify the amount of CO₂ injected at each storage site, $CO_{2 \ injected}$, Project Developers shall measure either the mass flow or volumetric flow and density of the stream, and multiply it with the CO₂ concentration. Details on the measurement method is provided in the Sampling and measurement section.

Eligible biogenic fraction of CO₂

To determine the fraction of $CO_{2 \ injected}$ eligible for RCCs, Project Developers shall determine the eligible biogenic fraction in the total amount of CO₂ captured at the capture site. The calculation approach depends on whether the project captures only eligible biogenic CO₂, or CO₂ from ineligible sources along with it.

• Capture of only biogenic CO₂: All CO₂ captured is eligible biogenic CO₂. The total amount of CO₂ captured $CO_{2\ captured, total}$ is defined as the sum of all CO₂ leaving the capture facility at each exit point. Project Developers shall prove there are no ineligible sources of CO₂ in the captured stream through operational data records.

• Capture of ineligible CO₂ alongside biogenic CO₂: If the project captures CO₂ from ineligible sources alongside eligible biogenic CO₂, Project Developers shall measure the amount of CO₂ from ineligible sources and subtract it from the total amount of CO₂ captured, to obtain the eligible amount.

Calculation: Segregated stream removals

$\textbf{(Eq.3)}\ R_{Project, segregated} = \frac{CO_{2\ captured, biogenic}} {CO_{2\ captured, total}} \ \times\sum_{K}CO_{2 \ injected, \ K}\times-1$

• $R_{Project, segregated}$ represents the total project removals for a segregated stream, in tCO_2. It is used in Eq. 1.

• $CO_{2\ captured, biogenic}$ represents the amount of eligible biogenic CO₂ captured at the capture site, in tCO₂. Calculated according to Eq. 7.

• $CO_{2\ captured, total}$ represents the total amount of CO₂ captured at the capture site, in tCO₂. Calculated according to Eq. 4.

• $CO_{2 \ injected, \ K}$ represents the total amount of CO₂ injected at the storage site $K$, in tCO₂. Calculated according to Eq. 5 (mass flow approach) or 6 (volume flow approach).

• It is multiplied by -1 to obtain a negative sign. Removals are reported as a negative value.

The total amount of CO₂ captured at the capture facility that is transferred for transport and storage is defined as

$\textbf{(Eq.4)}\ CO_{2\ captured,total} = \sum_{i} CO_{2\ OUT,project,i}$

• $CO_{2\ captured,total}$ is defined in Eq. 3.

• $CO_{2\ OUT,project,i}$ represents the amount of captured CO₂ that leaves the capture facility at each exit point $i$, in tCO₂. It shall be directly measured following the same approach for $CO_{2 \ injected}$ outlined below.

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$CO_{2 \ injected}$ is calculated using either the Mass flow measurement approach or Volumetric flow and density measurement approach below.

Mass flow measurement approach:

$\textbf{(Eq.5)}\ CO_{2 \ injected} = \sum_{i\ = 1}^{N}(m_{stream, \ i}\ \times F_{mass,\ CO2,\ i} )$

• $\ CO_{2 \ injected}$ is defined in Eq. 3.

• $N$ is the number of days in the monitoring period.

• $m_{stream, \ i}$ represents the aggregated mass flow of the stream on day $i$ , in tonnes.

• $F_{mass,\ CO2,\ i}$ the weighted average daily concentration of CO₂ in the stream, in wt%, reported as fraction.

Volumetric flow and density measurement approach:

$\textbf{(Eq.6)}\ CO_{2 \ injected} = \sum_{i\ = 1}^{N}(V_{stream, \ i}\times\rho_{stream, \ i} \times F_{mass,\ CO2,\ i})$

• $\ CO_{2 \ injected}$ is defined in Eq. 3.

• $N$ is defined in Eq. 5.

• $V_{stream,\ i}$ represents the aggregated volumetric flow of the stream on day $i$, at standard temperature and pressure, in m³.

• $\rho_{stream, \ i}$ represents the density of the stream at standard temperature and pressure on day $i$, in t/m³.

• $F_{mass,\ CO2,\ i}$ the weighted average daily concentration of CO₂ in the stream, in wt%, reported as fraction.

Calculation: Eligible biogenic fraction of CO₂

The amount of biogenic CO₂ eligible for crediting is defined as

$\textbf{(Eq.7)}\ CO_{2\ captured,biogenic} = CO_{2\ captured, total} - CO_{2\ captured, ineligible}$

• $CO_{2\ captured, biogenic}$ is defined in Eq. 3.

• $CO_{2\ captured,total}$ is defined in Eq. 3.

• $CO_{2\ captured, ineligible}$ represents the total amount CO₂ from ineligible sources that is captured at the capture facility, in tCO₂. It is calculated according to Eq. 8 below.

$\textbf{(Eq.8)}\ CO_{2 \ captured, ineligible} = CO_{2 \ captured,assoc} + CO_{2 \ captured,mixed}$

• $CO_{2\ captured, assoc}$ represents the amount of associated CO₂, in tCO₂. It is calculated according to Eq. 9 below.

• $CO_{2\ captured, mixed}$ represents the amount of ineligible CO₂ captured from a mixed stream, in tCO₂. It is calculated according to Eq. 10 below.

Associated CO₂ can be either captured separately from the biogenic CO₂ or simultaneously (i.e. co-captured) with the capture of the biogenic CO₂, and shall be calculated according to

$\textbf{(Eq.9)}\ CO_{2\ captured,assoc} = CO_{2 \ assoc,co\text{-}captured} + \sum_{sources} CO_{2 \ assoc,source}$

• $CO_{2 \ assoc,co\text{-}captured}$ represents the amount of associated CO₂ that is co-captured with the biogenic CO₂, in tCO₂. It shall not be more than the total amount of fossil CO₂ emissions reported for the capture stage in the calculation of the project's associated GHG emissions. It shall be measured following the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq 5 and 6.

• $CO_{2 \ assoc,source}$ represents the amount of associated CO₂ that is captured separately from the biogenic CO_2, in tCO₂. It shall be measured following the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq 5 and 6.

The amount of CO₂ from a mixed stream, generated and captured together shall be calculated as follows

$\textbf{(Eq.10)}\ CO_{2 \ captured,mixed} = (1 - F_B) \times \left( CO_{2\ captured,total} - CO_{2 \ captured,assoc} \right)$

• $F_B$ is the eligible biogenic fraction of the mixed CO₂ stream, measured according to the Sampling and measurements.

• $CO_{2 \ captured, total }$ is defined in Eq. 3.

• $CO_{2 \ captured, assoc}$ is defined in Eq. 9.

Non-segregated stream

If the CO₂ injected at the storage site cannot be directly linked to the BioCCS project, due to logistical or other operational reasons (i.e. the project's captured CO₂ is mixed with other CO₂ streams for any transport or injection step), project removals are calculated using the amount of biogenic CO₂ captured minus CO₂ losses during transport and storage prior to entering permanent storage.

Calculation of transport losses

Transport losses include eligible biogenic CO₂ lost during transport from the capture to the storage site. Transport losses shall be calculated for each transport segment.

A transport segment is a section of the transportation process involving the movement of CO₂ from point A to point B. Transport segments divide up the transportation process so that losses and emissions can be correctly allocated to each part of it.

• If CO₂ captured by the BioCCS project is the only CO₂ passing through the relevant transport infrastructure, the whole transportation process from capture to storage can be counted as a single transport segment. Otherwise, the transportation process shall be divided into a series of transport segments.

• A new transport segment shall be defined if

  • two or more CO₂ streams from different sources are merged together

  • two or more CO₂ streams from different sources are split up

  • the project's CO₂ stream is split up (e.g. when sent to multiple storage sites)

  • the mode of transport changes

Transport losses shall be calculated using one of the following approaches. Different approaches can be used for different segments.

1. Mass balance approach: Using the overall mass balance of all input and output streams across a segment.

2. Individual monitoring approach: Monitoring fugitive, vented and leaked emissions individually across a segment, using the following sources:

   1. Fugitive emissions: measurements at seals, measurement devices, valves, intermediate compressor stations or intermediate storage sites, and calculated in Eq. 15.

   2. Vented emissions: calculated for each transport segment $S$ based on the expected venting identified for that transport segment by the operator of the transport network. If this is not available, venting emissions shall be allocated by segment on a reasonable basis agreed on by the Project Developer and the Rainbow Certification team in agreement with the VVB.

   3. Transport leakage emissions: calculated for each transport segment $S$ based on the amount identified by the operator of the transport network. If this is not available, transport leakage emissions shall be allocated by segment on a reasonable basis agreed on by the Project Developer and the Rainbow Certification team in agreement with the VVB.

Calculation of storage losses

Storage losses are defined as the amount of eligible biogenic CO₂ lost at the storage site before entering permanent storage. Storage losses shall be calculated for each storage site.

To allocate storage losses between the project CO₂ and CO₂ from other sources injected at the storage site, an allocation fraction is defined.

Calculation: Non-segregated stream removals

$\textbf{(Eq.11)}\ R_{project, \ non-segregated} = (F_{RCC} * CO_{2 \ captured, biogenic} \ - \sum CO_{2 \ transport\ losses } \ - \ CO_{2 \ storage \ losses})*-1$

• $R_{project, non-segregated}$ represents the total project removals for a non-segregated stream, in tCO₂. It is used in Eq. 1.

• $F_ {RCC}$ represents the fraction of the captured biogenic CO₂ transferred for permanent storage and RCC issuance, and not used for other purposes (i.e. utilization).

• $CO_{2\ captured, biogenic}$ represents the amount of eligible biogenic CO₂ captured at the capture site, in tCO₂.

  • For purely purely biogenic CO₂ streams, it is calculated according to Eq. 4.

  • For capture of ineligible CO₂ alongside biogenic CO₂, it is calculated according to Eq. 7-10.

• $CO_{2 \ transport\ losses }$ represents the amount of eligible biogenic CO₂ lost during transport from the capture to the storage site, in tCO₂. It shall be summed for all transport segments, calculated in Eq. 12 and/or 14.

• $CO_{2 \ storage\ losses }$ represents the amount of eligible biogenic CO₂ lost at the storage site prior to entering permanent geological storage, in tCO₂.

• It is multiplied by -1 to obtain a negative sign. Removals are reported as a negative value.

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Transport losses: Mass balance approach

$\textbf{(Eq.12)}\ CO_{2\ transport,losses} = F_{RCC} \times \frac{CO_{2\ captured,biogenic}}{CO_{2\ project}}\times\sum_{S}( F_{S} \times ( CO_{2\ in,S} - CO_{2 \ out,S}))$

• $F_{RCC}$ is defined in Eq. 11.

• $CO_{2\ captured,biogenic}$ is defined in Eq.3.

• $CO_{2\ project}$ represents the CO₂ from the project leaving the capture facility and being transferred for storage, in tCO₂. It is calculated according to Eq. 13 below.

• $F_{S}$ represents the fraction of all CO₂ in a given transport segment $S$ that is from the project. It may be

  • provided by the transport operator, if independently verified, or

  • calculated according to Calculation: Allocation fraction $F_S$

• $CO_{2\ in,S}$ represents the total amount of CO₂ entering the transport segment $S$, in tCO₂. It shall be measured according to the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq. 5 and 6.

• $CO_{2\ out,S}$ represents the total amount of CO₂ leaving the transport segment $S$, in tCO₂.It shall be measured according to the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq. 5 and 6.

The amount of CO₂ counted as transported by the project includes the eligible biogenic CO₂ captured and the associated CO₂ captured. It is calculated as:

$\textbf{(Eq.13)}\ CO_{2,\ project} = F_{RCC} \times ( CO_{2\ captured,biogenic} + CO_{2\ captured,assoc})$

• $F_{RCC}$ is defined in Eq. 11.

• $CO_{2\ captured,biogenic}$ is defined in Eq. 3.

• $CO_{2\ captured,assoc}$ is defined in Eq. 9.

Transport losses: Individual monitoring approach

$\textbf{(Eq.14)}\ CO_{2 \ transport,losses} =F_{RCC} \times \frac{\ CO_{2\ captured,biogenic}}{CO_{2\ project}}\times \sum_{S} \ ( F_{S} \times ( CO_{2 \ fugitive,S} + CO_{2\ vented,S} + CO_{2 \ transport \ leakage,S}))$

• $F_{RCC}$ is defined in Eq. 11.

• $CO_{2\ captured,biogenic}$ is defined in Eq. 3.

• $CO_{2\ project}$ is defined in Eq. 13.

• $F_{S}$ represents the fraction of all CO₂ in a given transport segment $S$ that is from the project. Project Developers can use $F_{S}$ values provided by the transport operator if those values are independently verified, or calculate it according to Eq. 19.

• $CO_{2 \ fugitive,S}$ represents the sum of fugitive emissions from CO₂ transported in transport segment $S$, in tCO₂, at seals, measurement devices, valves, intermediate compressor stations or intermediate storage sites. It shall be calculated using Eq. 15.

• $CO_{2 \ vented,S}$ represents the sum of vented emissions from CO₂ transported in transport segment $S$, in tCO₂.

• $CO_{2 \ transport\ leakage,S}$ represents the sum of CO₂ transported in transport segment $S$, that was emitted as a result of the failure of one or more components of the transportation network, in tCO₂.

$\textbf{(Eq.15)}\ CO_{2 \ fugitive,\ S} = \sum_{c} ( EF_{c,S} * N_{c,S} )$

• $EF_{c,S}$ represents the average emission factor per component $c$ in the transport segment $S$ per time period, in tCO₂ per unit time. The factor shall be reviewed at least every 5 years based on newly available techniques and knowledge.

• $N_{c,S}$ represents the number of components $c$ in the transport segment $S$, multiplied by the number of time periods.

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Storage losses

$\textbf{(Eq.16)}\ CO_{2\ storage,losses} = F_{RCC} * \frac{CO_{2 \ captured,biogenic}}{CO_{2 \ project}} *\sum_{K}( F_{K} *( CO_{2 \ fugitive,K} + CO_{2\ vented,K} ))$

• $F_{RCC}$ is defined in Eq. 11.

• $CO_{2\ captured,biogenic}$ is defined in Eq. 3.

• $CO_{2\ project}$ is defined in Eq. 13.

• $F_{K}$ is the allocation fraction for each storage site $K$ and represents the fraction of CO₂ stored at storage site $K$ that is associated with the project. It is calculated according to Eq. 18.

• $CO_{2 \ fugitive,K}$ represents the sum of fugitive emissions of CO₂ at the storage site $K$, in tCO₂. It is based on data recorded by the storage site operator in accordance with the European Commission Implementing Regulation 2018/2066, Annex IX, Section 23, subsection B.1.

• $CO_{2 \ vented,K}$ represents the sum of vented emissions of CO₂ at the storage site $K$, in tCO₂. It is based on data recorded by the storage site operator in accordance with the European Commission Implementing Regulation 2018/2066, Annex IX, Section 23, subsection B.1.

At each storage site $K$, the sum of fugitive and vented emissions shall be equal to the difference between the measured amount of CO₂ entering the storage site and the measured amount of CO₂ injected at the storage site, according to the following equation.

$\textbf{(Eq.17)}\ CO_{2\ fugitive,K} + CO_{2\ vented,K} = CO_{2\ in,K} - CO_{2 \ injected,K}$

• $CO_{2 \ fugitive,K}$ is defined in Eq. 16.

• $CO_{2 \ vented,K}$ is defined in Eq. 16.

• $CO_{2\ in, K}$ represents the total amount of CO₂ entering the storage site $K$, in tCO₂. It shall be measured according to the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq. 5 and 6.

• $CO_{2\ injected, K}$ represents the total amount of CO₂ from all sources that is stored at site $K$ during the monitoring period, in tCO₂. It shall be measured according to the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq. 5 and 6.

The fraction allocating storage losses between the project CO₂ and CO₂ from other sources injected at the storage site, is defined as

$\textbf{(Eq.18)}\ F_{K} = \frac{CO_{2 \ project,injected, K}}{CO_{2 \ injected,K}}$

• $F_{K}$ is defined in Eq. 16.

• $CO_{2\ project, injected, K}$ represents the amount of CO₂ associated with the project that is stored at the storage site $K$ during the monitoring period, in tCO₂. It is determined applying the mass balance approach in the CO₂ traceability section.

• $CO_{2\ injected, K}$ is defined in Eq. 17

Calculation: Allocation fraction $F_S$

To allocate transport losses between the project CO₂ and other CO₂ transported in a segment, an allocation fraction is defined. If independently verified values provided by the transport operator are not available, $F_{S}$ shall be calculated.

$\textbf{(Eq.19)}\ F_{S} = \frac{CO_{2 \ project,S}}{CO_{2 \ total,S}}$

• $F_{S}$ is defined in Eq. 12.

• $CO_{2\ project, S}$ represents the amount of CO₂ associated with the project, that is passing through the transport segment $S$ during the monitoring period, in tCO₂. It is calculated differently for the first than for the following transport segments, as described below.

• $CO_{2\ total, S}$ represents the total amount of CO₂ from all sources passing through the transport segment $S$ during the monitoring period, in tCO₂. It shall be measured according to the Mass flow measurement approach or Volumetric flow and density measurement approach in Eq. 5 and 6.

Project CO₂ in the first transport segment (S=1)

For the first transport segment $S = 1$, $CO_{2\ project, S}$ is equal to $CO_{2\ project}$, the amount of CO₂ associated with the project, leaving the capture facility and being transferred for storage, and calculated according to Eq. 13.

Project CO₂ in following transport segments (S>1)

For subsequent transport segments $S > 1$, $CO_{2\ project, S}$ is equal to the amount of project CO₂ entering the previous transport segment minus any CO₂ losses in that previous segment.

If the Mass balance approach is chosen for the calculation of the transport losses, then Eq. 20 shall be used.

$\textbf{(Eq.20)}\ CO_{2\ project,S} = CO_{2\ project,S-1} -(F_{S-1}* (CO_{2\ in,S-1} - CO_{2 \ out,S-1}))$

• $CO_{2\ project,S-1}$ represents the amount of CO₂ associated with the project, passing through the previous transport segment, in tCO₂.

• $F_{S-1}$ represents the allocation fraction of the previous transport segment.

• $CO_{2\ in,S-1}$ represents the total amount of CO₂ entering the previous transport segment, in tCO₂.

• $CO_{2\ out,S-1}$ represents the total amount of CO₂ leaving the previous transport segment, in tCO₂.

If the Individual monitoring approach is chosen for the calculation of the transport losses, then Eq. 21 shall be used.

$\textbf{(Eq.21)}\ CO_{2\ project,S} = CO_{2\ project,S-1} -(F_{S-1}* ( CO_{2 \ fugitive,S-1} + CO_{2\ vented,S-1} + CO_{2 \ transport\ leakage,S-1}))$

• $CO_{2\ project,S-1}$ is defined in Eq. 20.

• $F_{S-1}$ is defined in Eq. 19.

• $CO_{2 \ fugitive,S-1}$ represents the sum of fugitive emissions from CO₂ transported in the previous transport segment, in tCO₂.

• $CO_{2 \ vented,S-1}$ represents the sum of vented emissions from CO₂ transported in the previous transport segment, in tCO₂.

• $CO_{2 \ transport\ leakage,S-1}$ represents the sum of CO₂ transported in the previous transport segment, that was emitted as a result of the failure of one or more components of the transportation network, in tCO₂.

Where the CO₂ stream is split at a node and sent to multiple storage sites, the project CO₂ shall be allocated across the number of transport segments leaving that node.

For example, a biomass capture plant captures 1,000 t biogenic CO₂, no associated CO₂, and sends 100% of this CO₂ for permanent storage.

The plant sends its CO₂ into a shared pipeline, carrying 500t CO₂ from an unrelated fossil capture plant. The Project Developers uses the Overall mass balance approach for transport losses.

According to Eq. 12, transport losses for the first segment are: $CO_{2\ transport,losses} = F_{RCC} * \frac{CO_{2,captured,biogenic}}{CO_{2,project}} *( F_{S=1} * ( CO_{2\ in,S=1} - CO_{2 \ out,S=1})$

• $F_{RCC}$ is 1

• $CO_{2,captured,biogenic}$ is 1,000 t CO₂

• $CO_{2,project}$ is 1,000 t, according to Eq. 13.

• $F_{S=1} = \frac{CO_{2 \ project,S=1}}{CO_{2 \ total,S=1}}=\frac{1,000 t\ CO_2}{1,500 t\ CO_2}= 0.67$

• $CO_{2\ in,S=1}$ is measured to be 1,500 t CO₂

• $CO_{2\ out,S=1}$ is measured to be 1,470 t CO₂

By substituting the terms with the corresponding values in Eq. 12, the transport losses in the first segment can be calculated as 20.1 t CO₂

The CO₂ is entering a second segment when being transferred from the to a pipeline operated by a different entity.

The project CO₂ entering this new segment 2 is calculated according to Eq. 20:

$CO_{2,project,S=2} = CO_{2,project,S=1} -(F_{S=1}* (CO_{2\ in,S=1} - CO_{2 \ out,S=1}))=1,000t \ CO_2 \ -\ 0.67*(1,500t\ CO_2- 1,470t\ CO_2)=979.9 \ CO_2$

Capture stage emissions

Capture stage emissions are calculated as the sum of emissions from CO₂ generation and CO₂ capture. If the project captures and stores associated CO₂ alongside the biogenic CO₂, the amount of the stored associated CO₂ is deducted from the capture stage emissions.

Calculation: Capture stage emissions

$\textbf{(Eq.22)}\ E_{capture} = F_{RCC}*(E_{CO2 \ generation}\ +F_{CO2\ capture}*(\ E_{CO2\ capture} -CO_{2, stored, assoc}))$

• $E_{capture}$ is defined in Eq. 2.

• $F_{RCC}$ is defined in Eq. 11.

• $E_{CO2\ generation }$ represents the operational and embodied emissions associated with the generation of CO₂, in tCO₂eq. It includes all processes described in the CO₂ generation and biomass allocation section. It is calculated in Eq. 24.

• $F_{CO2\ capture}$ represents the allocation fraction for the emissions from CO₂ capture, between the eligible project CO₂ and any other CO₂ captured alongside it. It is determined according to the table below.

• $E_{CO2\ capture }$ represents the operational and embodied emissions associated with the capture of CO₂ after its generation, in tCO₂eq. This includes emissions from energy and material use and embodied emissions.

• $CO_{2 stored, assoc}$ represents the amount of associated CO₂ stored, in tCO₂eq. It is calculated according to the Storage of associated CO₂ section.

Type of captured CO2	Emission allocation	Allocation fraction
eligible biogenic CO2	No allocation: all emissions attributed to the BioCCS project.	$F_{CO2\ capture}=1$
eligible biogenic CO2 and associated CO2	No allocation: all emissions attributed to the BioCCS project.	$F_{CO2\ capture}=1$
eligible biogenic CO2 and CO2 from mixed stream	Allocation: emissions associated with the capture of the eligible biogenic CO2 attributed to the BioCCS project.	$F_{CO2\ capture}=F_B$, as defined in Eq. 10
eligible biogenic CO2, associated CO2 and CO2 from mixed stream	Allocation: emissions associated with the capture of the eligible biogenic and the associated CO2 attributed to the BioCCS project.	$F_{CO2\ capture}=F_{B, assoc}$ as defined in Eq. 23, below

The allocation fraction $F_{B, assoc}$ is calculated according to the following equation:

$\textbf{(Eq.23)} \ F_{B,assoc} = (1 - \frac{CO_{2\ captured,mixed}}{CO_{2 \ captured,total}})$

• $F_{B,assoc}$ represents the allocation fraction for emissions from CO₂ capture, when associated CO₂ and CO₂ from a mixed stream are captured alongside eligible biogenic CO₂.

• $CO_{2 \ captured,mixed}$ is defined in Eq. 10.

• $CO_{2 \ captured, total}$ is calculated in Eq. 4.

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$\textbf{(Eq.24)}\ E_{CO2 \ generation} = Q_{biomass\ CO2\ generation} \times EF_{biomass}$

• $Q_{biomass\ CO2\ generation}$ represents the tonnes of biomass used by the underlying site allocated to the project for CO₂ generation, calculated in Eq. 32 for greenfield projects and Eq. 31 for retrofit projects.

• $EF_{biomass}$ represents the emission factor for all processes related to biomass used at the site from biomass production, in tCO₂eq/tonne of biomass.

$\textbf{(Eq.25)}\ EF_{biomass} = (E_{b,\ production}+E_{dLUC}+E_{b,\ processing}+E_{b,\ transport}+E_{b,\ storage}+E_{b,conversion}+E_{b,\ leakage}) \div Q _{biomass,total}$

• $E_{b,\ production}$ represents the emissions from biomass production for all biomass used at the site in the monitoring period, in tCO₂eq. It is calculated in the Processing and energy use module by multiplying one of the eligible emission factors in the Calculation of CO₂ generation / Biomass production section by $Q _{biomass,total}$.

• $E_{dLUC}$ represents the emissions from direct land use change for all biomass used at the site in the monitoring period, in tCO₂eq. It shall be calculated using Eq. 33.

• $E_{b,\ processing}$ represents the emissions from processing biomass used at the site in the monitoring period, in tCO₂eq. It is calculated in the Processing and energy use module by multiplying an emission factor for one of the processes described in the Calculation of CO₂ generation / Biomass processing section by $Q _{biomass,total}$.

• $E_{b,\ transport}$ represents emissions from transport of biomass from the sourcing location to the facility and shall be accounted for in the Transportation module.

• $E_{b,\ storage}$ represents emissions from storage of biomass and shall be calculated using Eq. 35 and 36 for manure and slurry, and Eq. 34 for all other types of biomass.

• $E_{b,\ conversion}$ represent any material, energy, fugitive, or embodied emissions from the biomass conversion process for the entire site (e.g., from anaerobic digestion, municipal incineration, bioenergy combustion...), using the Processing and energy use and Infrastructure and machinery modules.

• $E_{b,\ leakage}$ represents the leakage emissions related to biomass, from the Leakage emission section and calculated in Eq. 26.

• $Q_{biomass, total}$ represents the total amount biomass consumed by the underlying facility during the monitoring period, in tonnes.

$\textbf{(Eq.26)}\ E_{b,\ leakage} = C_{counterfactual }+E_{biomass\ diversion}+E_{iLUC}$

• $C_{counterfactual}$ represents the counterfactual carbon storage, in tCO₂eq. It is described in the Counterfactual carbon storage section and calculated in Eq. 48-49.

• $E_{biomass\ diversion }$ represents the leakage emissions from biomass diversion, in tCO₂eq. It is described in the Biomass diversion section and calculated in Eq. 50.

• $E_{iLUC}$ represents the indirect land use change emissions, in tCO₂eq. It is described in the Indirect land use change emissions section and calculated in Eq. 51.

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$\textbf{(Eq.27)}\ E_{CO2\ capture}= E_{external\ energy}+E_{parasitic\ load}+ E_{capture,\ materials}+E_{embodied}$

• $E_{external\ energy}$ represents emissions from all external energy consumption used to power the carbon capture unit in the monitoring period in tCO₂eq. It is described in the External energy section, and calculated in the Processing and energy use module.

• $E_{parasitic\ load}$ is calculated using either the simplified approach in Eq. 42 or the full approach in Eq. 43.

• $E_{capture,\ materials}$ represents emissions from all materials used the carbon capture unit in the monitoring period in tCO₂eq. It is described in the Material consumption section, and calculated in the Processing and energy use module.

• $E_{embodied}$ represents emissions from all infrastructure and machinery used the carbon capture unit in the monitoring period in tCO₂eq. It is described in the Embodied emissions in capture process section, and calculated in the Infrastrucutre and machinery module.

CO₂ generation and biomass allocation

Depending on the context, CO₂ shall be counted as either

• a waste, and enter the project system boundary burden-free, or

• a co-product of the underlying system, and be allocated a share of emissions from its generation.

Under some circumstances, CO₂ can be considered a co-product and not a waste, and the emissions from the CO₂-generating activity at the underlying facility shall be shared between the CO₂/bioCCS project and the primary product. Emissions from CO₂ generation include all upstream emissions up to the point of physical separation of the co-products, such as biomass supply and conversion steps upstream of CO₂ capture.

CO₂ allocation follows biomass allocation. The share of biomass attributed to the BioCCS project is determined in two steps:

1. identifying the quantity of biomass corresponding to the CO₂ considered to be a co-product rather than a waste,

2. applying economic allocation between the BioCCS project and the underlying facility.

Determine the biomass quantity corresponding to CO₂ generation

The biomass quantity subject to allocation differs by project type.

Retrofit projects: Prior to the retrofit, the CO₂ was generated anyway, not used, and was treated as a waste stream (e.g. vented to atmosphere).

• If the facility increased its biomass consumption after the retrofit by more than what is needed to meet the parasitic load, for eligible reasons outlined in Biomass conversion efficiency, the excess above the parasitic load (referred to as the additional biomass) is the quantity subject to CO₂ generation emissions allocation.

• If the facility did not increase its biomass consumption after the retrofit, or increased its consumption only by the amount needed for the parasitic load, the generation of all CO₂ is considered burden-free. No biomass is subject to CO₂ generation emissions allocation. Note that emissions from the parasitic load energy use are accounted for separately in the Internal energy and parasitic load section. Project Developers shall prove that:

  • The biomass consumption did not increase above the baseline consumption rate, or

  • The amount of additional biomass consumed above the baseline consumption rate corresponds to the parasitic load biomass.

Greenfield projects: If carbon capture and primary production are co-designed, the facility simultaneously produces CO₂ and one or more primary products or services. The total biomass consumed is the quantity subject to CO₂ allocation.

Economic allocation of emissions

The amount of biomass whose supply and conversion emissions are allocated to the BioCCS project is multiplied by the economic allocation factor, representing the economic value of CO₂ and RCC issuance relative to other products and services of the underlying facility. The economic value of the co-products shall be determined at the site level.

• The CO₂ price shall be based on the project's average annual revenue from BioCCS carbon removal credits over the past 3 years. If such data is not available for the first verification, the price shall be based on final financial projections of the expected revenues, as presented to investors.

• The price of the primary product or service shall be based on annual average project-specific data over the past 3 years. If such data is not available the use of secondary market data is allowed for the first verification.

Project Developers shall provide documentation and justification of the calculations, conservativeness of the values and sources used.

The validity of the economic values of the co-products is 5 years. Project Developers may update the values at each monitoring period.

The economically-allocated amount of biomass counted for the project for CO₂ generation is multiplied by the biomass' supply and conversion emission factor, $EF_{biomass}$, calculated in Eq. 25.

Calculation: Economic allocation of biomass for CO₂ generation

Retrofit: Additional biomass

In a retrofit scenario, the amount of biomass consumed above the baseline biomass consumption rate is considered additional biomass and defined as:

$\textbf{(Eq.28)} \ Q_{additional \ biomass } = Q_{biomass, total}-Q_{baseline\ biomass}$

• $Q_{additional \ biomass }$ represents the fraction of biomass consumed above the baseline biomass consumption rate in the monitoring period, in tonnes. This is the additional biomass.

• $Q_{biomass, total}$ represents the total amount biomass consumed during the monitoring period, in tonnes.

• ​$Q_{baseline\ biomass}$ represents the baseline biomass consumption rate scaled to the same period, in tonnes. This is the baseline biomass. It shall be provided from:

  • The average annual biomass consumption of the facility over the three years prior to the start of the project activity, derived from primary operational records; or

  • If site specific data is not available, a regional market analysis shall be used to demonstrate that the feedstock type, quantity, and alternative fate are representative of the local market conditions prior to the retrofit.

If any of the additional biomass consumed is used for purposes other than meeting the parasitic load, emissions from the generation of CO₂ from that biomass shall be economically allocated between the CO₂ and the primary product or service.

The share of additional biomass used for other purposes is calculated as:

$\textbf{(Eq.29)} \ Q_{additional\ biomass, other}=Q_{additional\ biomass} -Q_{parasitic\ load, biomass}$

• $Q_{additional\ biomass, other}$ represents the share of additional biomass that is used for other purposes than meeting the parasitic load, and that is allocated to the project, in tonnes. This value is used in Eq. 24 to calculate $E_{CO2\ generation }$.

• $Q_{additional\ biomass}$ is defined in Eq. 28.

• $Q_{parasitic\ load, biomass}$ represents the amount of biomass needed to meet the parasitic load, in tonnes. Calculated according to the rules set out in Internal energy and parasitic load.

Economic allocation of biomass

$\textbf{(Eq.30)} F_{economic,\ CO2}= \frac{Revenue_{CO2,\ RCC}}{Revenue_{CO2,\ RCC}+Revenue_{primary\ product}}$

• $F_{economic, \ CO2}$ represents the economic allocation fraction for CO₂ generation, determined following the rules set out in Determination of the economic value.

• $Revenue_{CO2,\ RCC}$ represents the annual revenue of the site from carbon finance from the equivalent amount of RCCs issued from CO₂ capture and storage.

• $Revenue_{primary\ product}$ represents the annual revenue of the site from generation and sale of other primary product/s and/or service/s.

For retrofit projects:

$\textbf{(Eq.31)} \ Q_{biomass, \ CO2\ generation } = F_{economic,\ CO2}*Q_{additional\ biomass, other }$

• $Q_{biomass, \ CO2\ generation }$ represents the amount of biomass whose supply and conversion emissions are allocated to the BioCCS project, in tonnes.

• $F_{economic, \ CO2}$ is calculated in Eq. 30.

• $Q_{additional\ biomass, other }$ is calculated in Eq. 29.

For greenfield projects:

$\textbf{(Eq.32)} \ Q_{biomass, \ CO2\ generation } = F_{economic,\ CO2}*Q_{biomass, total}$

• $Q_{biomass, \ CO2\ generation }$ is defined in Eq. 31. This is the biomass fraction allocated to CO₂ generation.

• $F_{economic, \ CO2}$ is calculated in Eq. 30.

• $Q_{biomass, total }$ represents the total amount of biomass consumed in the monitoring period, in tonnes.

Calculation of CO₂ generation emissions

Emissions shall be calculated for each biomass type, and include all sourcing steps upstream of the conversion site, detailed in the following sections.

Biomass production

Waste and residues are considered to have zero biomass production emissions up to the point of collection of those materials.

Production emissions of non-waste biomass (i.e. energy crops) shall cover both cultivation and harvesting. This includes all inputs associated with growing and collecting the biomass, such as fertilizer production and application, fuel and energy use for agricultural machinery, pesticide or herbicide use, any on-site storage or handling operations prior to biomass transport to the BioCCS site.

Project Developers shall determine the emissions from biomass production by multiplying the mass of biomass used with an appropriate emission factor. Emission factors shall be sourced from:

• RED III disaggregated default values for term e_ec, where available in Annex V or Annex VI of the Directive; or

• Default values at regional level (NUTS2), where reported by the relevant countries and recognized by the European Commission (available here); or

• representative emission factors from databases or peer-reviewed literature (e.g. ecoinvent database 3.12).

Where values are expressed per unit of energy output, Project Developers shall convert to emissions per unit of feedstock consumed.

🇪🇺 CRCF requirement: Emission factors biomass production

For CRCF-compliant projects, Project Developers shall follow the hierarchical list below for selecting biomass production emission factors:

1. RED III disaggregated default values for term e_ec,

2. Default values at regional level (NUTS2),

3. Calculate averages based on local farming practices based on e.g. data of a group of farms, as an alternative to using a single actual value

Note that the use of representative emissions factors from other databases or literature is not allowed under the CRCF.

Direct land-use change

Biomass cultivation may cause direct land-use change (e.g. deforestation for farmland), leading to decreasing carbon stocks and causing emissions. The land-use categories are

• forest land

• crop land, where crop land and perennial crop land are regarded as one land use

• grassland

• wetlands

• settlements

• other land

Zero direct land use change emissions shall be counted if the use of the land on which biomass was cultivated has not changed since January 2008 or 20 years before the biomass was cultivated, whichever was the later. This shall be proven using relevant sections of the RED-certification of the biomass; signed declaration from the biomass supplier, supported by farm management records evidencing continuous use; historical satellite or aerial imagery showing continuous land-use since January 2008.

If eligible land-use change happened in January 2008 or after, the annualized emissions from carbon stock changes caused by land-use change shall be calculated by dividing total emissions equally over 20 years.

Calculation: Direct land-use change emissions

$\textbf{(Eq.33)} \ E_{dLUC} = ((CS_{R} - CS_{A}) \times 3{.}664\times \frac{1}{20} \times \frac{1}{P} - e_{B})\times Q_{biomass,total}\times LHV_{biomass}$

• $E_{dLUC}$ represents the annualized emissions from carbon stock change due to land-use change, in tCO₂eq.

• $CS_R$ represents the carbon stock per unit area (including soil and vegetation) associated with the reference land use. The reference land use shall be the land use in January 2008 or 20 years before the biomass was obtained, whichever was the later. Calculated following the guidelines for the calculation of land carbon stocks.

• $CS_A$ represents the carbon stock per unit area (including soil and vegetation) associated with the actual land use. In cases where the carbon stock accumulated over more than one year, the value attributed shall be the estimated stock per unit area after 20 years or when the crop reaches maturity, whichever is earlier. Calculated following the guidelines for the calculation of land carbon stocks.

• $P$ represents the productivity of the biomass crop, in unit biomass energy / unit area and year.

• $e_B$ is a bonus of 29 g CO2 eq / MJ biomass energy, applied for a period of 20 years from the date of conversion of the land, provided biomass is obtained from a restored degraded land under the following conditions:

  • Evidence is provided that the land was not in use for agriculture in January 2008 or any other activity, and

  • is severely degraded land, including land that was formerly in agricultural use.

  • A steady increase in carbon stocks and sizable reduction in erosion phenomena for severely degraded land is ensured

• $Q_{biomass, total}$ is defined in Eq. 25.

• $LHV_{biomass,i}$ represents the lower heating value of the biomass type $i$, in MJ/t.

Biomass processing

Emissions associated with the upstream and on-site processing of biomass prior to its conversion (e.g. drying, mixing or shredding of feedstock) shall be accounted for.

Project Developers shall determine the emissions from biomass processing by multiplying the mass of biomass used with an appropriate emission factor.

Emission factors shall be sourced from

• RED III default values for term e_p from Annex V or Annex VI of the Directive, where available. Where Project Developers used RED III default values for the calculation of biomass production emissions, the corresponding default values for processing emissions shall be used.

Where no default value exists, Project Developers shall choose one of the following options

• demonstrate that the processing emissions (upstream and on-site) are included in the biomass production emission factor

• source an emission factor for upstream and on-site processing from reputable databases or peer-reviewed literature

• Calculate the emissions from upstream and on-site processing using the Processing and energy use module.

Biomass transport

Emissions associated with the transport of biomass from the sourcing location to the facility shall be accounted for in the Transportation module. Municipal solid waste and municipal sludge enter the system boundary when deposited at the BioCCS facility and therefore don't have any associated transport emissions.

Biomass storage

Emissions associated with the storage of biomass feedstock ahead of conversion shall be calculated separately for each feedstock that is harvested or collected at the same time and stored in the same way.

Biomass storage emissions are set to zero for each feedstock that Project Developers demonstrate meets at least one of the following conditions:

• the feedstock is coarse woody material that stays naturally well-aerated throughout storage; or

• feedstock is pelleted for storage; or

• feedstocks that do not naturally remain well-aerated, but are either:

  • processed within four weeks of entering storage; or

  • stored at a moisture content of 30% or below;

• Project Developers demonstrate that biomass is stored in a way that avoids significant CH₄ emissions from anaerobic decomposition given the nature of the feedstock and the local conditions

Where none of the above applies, emissions from storage of biomass shall be quantified.

Calculation: Biomass storage emissions

Biomass other than manure and slurry

$\textbf{(Eq.34)}\ E_{b\ storage}=\sum_{i} ( {C_{to}}CH_4\times 0.0013\times Q_{biomass,total, i}\times C_{biomass, total, i}\times (T_{storage}-1))\times GWP_{100,CH4}$

• $i$ represents the share of the total biomass harvested or collected at the same time and stored in the same way.

• $C_{to}CH_4$ represents the molecular mass ratio of methane to carbon, which is 1.335.

• 0.0013 represents the monthly fractional loss of biomass carbon from storage.

• $Q_{biomass, total,i}$ represents the amount of share $i$ of the total biomass, in tonnes.

• $C_{biomass, total, i}$ represents the carbon content of share $i$ of the total biomass, in mass%.

• $T_{storage}$ represents the rounded-up time for which the biomass share is stored, in months.

• ${GWP}_{100,CH4}$ represents the global warming potential of CH$_4$ over 100 years.

Manure and slurry

Manure and slurry may be stored onsite for several days or weeks if they cannot be utilized immediately upon their delivery to the biomass conversion site. During this storage period, methane and N₂O are emitted linearly over time. When the feedstock is stored for 180 days (a conventional manure/slurry management scenario), 2% of its nitrogen is emitted as N₂O, plus some methane expressed as a fraction of its biomethane potential (BMP). The ratio of average days manure and slurry are stored at the biomass conversion site, to the average storage duration of 180 days, is used to adjust the N₂O and methane emission benchmarks detailed in Table A1 and A2 in the Appendix (see example in the box below).

For example, if manure is stored at a biogas site 18 days on average before being added to the digester, this represents 10% of the average 180 days of conventional manure storage. As shown in Table A1, when manure is stored for 180 days:

• 2% of its nitrogen is emitted as N2O, and

• 1.5% of its BMP is emitted as methane.

When this storage time is shortened to 18 days in the biogas scenario, (10% of the conventional storage duration):

• the nitrogen emission rate is reduced to 0.2% (10% of 2%), and

• the methane emission rate is reduced to 0.15% of BMP (10% of 1.5%).

Eq. 35 shall be used if the project uses manure as a feedstock input, to calculate N₂O emissions from manure storage.

$\begin{aligned}\textbf{(Eq.35)}\ E_{ N2O\ manure\ storage} = \sum_{i} Q_{manure, i}\times \ \% N\times R_{N\ as\ N2O}\\ \times N_{to \ N2O}\times \frac{Days\ stored}{180}\times \ GWP_{N2O}\times 10^{-3}\end{aligned}$

• $E_{ N2O\ manure\ storage}$ represents the sum of GHG emissions from N$_2$O due to the storage of manure type i (chicken or cow) in the project scenario, in tCO$_2$eq.

• $Q_{manure, i}$ represents the mass of manure type i used as feedstock in the project scenario, in kg.

• $\% N$ represents the percent of manure mass as nitrogen, reported as fraction.

  • For chicken manure, this is 1.4% of fresh matter as nitrogen, as shown in Table A1 in the Appendix.

  • For cow and all other manure types, this is 0.65% of fresh matter as nitrogen, as shown in Table A1 in the Appendix (2.7% of dry matter as nitrogen * 24% dry matter)

• $R_{N\ as\ N2O}$ represents the rate of nitrogen emitted as N$_2$O from conventional manure storage of 180 days. According to Table A1, this equals 2%.

• $Days\ stored/180$ represents the number of days manure is kept stored. A default value of 15 days can be assumed if no project data is available. 180 represents the conventional manure storage duration of 180 days.

• $N_{to\ N2O}$ represents the conversion of nitrogen to N$_2$O equivalents by multiplying by the ratio of their molecular mass (1.57).

• $GWP_{N2O}$ represents the global warming potential of N$_2$O over 100 years, which is 273 kgCO₂eq/kg N₂O.

• It is multiplied with $10^{-3}$ to convert from kgCO₂ eq to tCO₂eq.

Eq. 36 shall be used if the project uses manure and/or slurry as a feedstock input, to calculate methane emissions from manure and/or slurry storage.

$\begin{aligned}\textbf{(Eq.36)}\ E_{CH4\ storage} = \sum &Q_{manure,i}\times {BMP}_{i}\times E_{BMP,\ CH4}\times \\ &{\rho CH}_{4}\times {\frac{Days\ stored}{180}\times GWP}_{bio\ CH4}\times 10^{-3}\end{aligned}$

• $E_{\ CH4\ storage}$ represents the emissions of methane from storage of manure and/or slurry, in tCO$_2$eq.

• $Q_{manure, i}$ is explained in Eq. 35.

• $BMP_{i}$ represents the biomethane potential of feedstock type ${i}$, in nm$^3$ of CH$_4$ per tonne of fresh matter, presented in Table A1 and A2 in the Appendix.

• $E_{BMP,\ CH4}$ represents methane emissions during storage as % of BMP, presented in Table A1 and A2 in the Appendix.

• ${\rho CH}_{4}$ represents the methane density, which is 0.75 kg/m³.

• $Days\ stored/180$ was described in Eq. 35.

• ${GWP}_{bio\ CH4}$ represents the global warming potential of biogenic CH$_4$ over 100 years, which is 27 kgCO$_2$eq/kg CH$_4$.

• It is multiplied with $10^{-3}$ to convert from kgCO₂ eq to tCO₂eq.

Biomass conversion: energy and material use

Emissions associated with the energy (e.g. fuel, electricity, heat) and material inputs (e.g. chemicals, water) consumed for the conversion of biomass into co-products and any waste disposal processes shall be accounted for in the Processing and energy use module.

Biomass conversion: fugitive emissions

Fugitive emissions associated with the conversion of biomass, e.g. CH₄ and N₂O shall be accounted for in the Processing and energy use module. Any CO₂ emitted from the conversion of biomass is biogenic and therefore considered to have zero associated emissions.

Biomass conversion: embodied emissions

Embodied emissions from the facility's infrastructure and machinery used for biomass conversion to CO₂ and primary product(s) shall be accounted for in the Infrastructure and machinery module.

For BioCCS projects at anaerobic digestion sites, the following simplification for data collection is applied:

• Buildings and main infrastructure at the biogas site have an assumed lifetime of 20 years. Embodied emissions from infrastructure and machinery are modeled and extrapolated from the main digester exterior volume (m³) to simplify data collection. The ecoinvent process for the anaerobic digestion plant present in the Appendix is used, considering 1 m³ of digester volume annually.

Energy use in capture process

Energy consumption for the CO₂ capture process may be sourced externally, or drawn internally from the facility's own energy output (parasitic load).

External energy

If the energy to power the capture unit is not drawn from the facility's own energy production but sourced externally (e.g. electricity or heat from the grid, on-site diesel generator or solar panels) emissions are calculated by multiplying the amount of energy consumed with the emission factor for the relevant energy source (electricity, heat or fuel combustion). See the Processing and energy use module for details on the calculations.

If the project's CO₂ capture unit recovers and exports heat or electricity, this exported energy shall be deducted from the gross external energy consumed by the project. If more energy is recovered and exported than imported, the net amount of energy consumed is negative and the associated emissions shall be set to zero, provided substantial proof is delivered by the Project Developer. Recover and export of energy does not include:

• Heat or electricity produced and consumed on-site at the capture facility, as it is accounted for elsewhere.

• Heat or electricity produced specifically for export from the facility rather than recovered from a necessary process

Internal energy and parasitic load

If the energy to power the capture unit is drawn from the facility's own energy production, the emissions associated with the production of that energy, also referred to as parasitic load, are attributed to the BioCCS project. The emissions are calculated according to the following steps:

1. Calculate the parasitic load (i.e. the amount of energy in kWh or MJ consumed by the capture unit)

2. Calculate the amount of biomass corresponding to the parasitic load (i.e. the amount of biomass needed to generate the amount of energy in the parasitic load)

3. Calculate the life-cycle emissions from supply and conversion of that biomass, using either

   1. Simplified approach: Facility energy emission factor using a verified emissions factor for the facility's energy production, or

   2. Full approach: Biomass-based calculation calculating the emissions from all biomass supply and conversion emissions, $EF_{biomass}$, calculated in Eq. 25.

If the BioCCS project captures CO₂ from a process that converts biomass feedstock including food and feed crops or food and feed crop-based fuels, energy produced from the conversion of that feedstock shall not be used to operate the capture process, except for the case of recovered heat.

🇪🇺 CRCF requirement: Parasitic load approach

Project Developers seeking certification under the EU CRCF shall only use the full approach (biomass-based calculation) to determine emissions from parasitic load demand.

Calculation: External energy and parasitic load energy demand

The parasitic load is calculated by dividing the energy consumed by the capture unit by the energy efficiency of the entire facility.

For facilities producing only electricity or only heat, the term in the equation that corresponds to the absent energy output (i.e. heat or electricity) is set to zero, and the equation simplifies.

$\textbf{(Eq.37)} \ Q_{Parasitic\ load, energy} = \frac{C_{elec} * Q_{elec, capture, parasitic} + C_{heat} *Q_{heat, capture, parasitic}}{C_{elec}* \eta_{elec} + C_{heat} * \eta_{heat}}$

• $Q_{Parasitic\ load, energy}$ represents the parasitic load, in kWh or MJ.

• $C_{elec}$ represents the exergy fraction of electricity, set to 1.

• $Q_{elec, capture, parasitic}$ represents the electricity consumed by the capture unit as the parasitic load, in kWh or MJ, provided via primary project data.

• $\eta_{elec}$ represents the electrical efficiency of the facility. It is dimensionless.

  • For facilities producing either electricity or heat, it shall be calculated according to Eq. 40.

  • For facilities producing both electricity and heat, it may be calculated according to Eq. 40 or set for the entire certification period based on technical documentation of the facility.

• $C_{heat}$ represents the Carnot efficiency of the heat, defined as $(T_{heat} - T_0) / T_{heat}$, where $T_{heat}$ is the average temperature of the heat in K, and $T_0$ is the ambient temperature, 273.15 K.

• $Q_{heat, capture, parasitic}$ represents the heat consumed by the capture unit as the parasitic load, in kWh or MJ, provided via primary project data.

• $\eta_{heat}$ represents the heat efficiency of the facility. It is dimensionless.

  • For facilities producing either electricity or heat, it shall be calculated according to Eq. 40.

  • For facilities producing both electricity and heat, it may be calculated according to Eq. 40 or set for the entire certification period based on technical documentation of the facility.

$\textbf{(Eq.38)} \ Q_{heat/elec, net,external} = Q_{heat/elec, gross,external} - Q_{heat/elec,capture, recovered}$

• $Q_{heat/elec, net,external}$ represents the net amount of external heat or electricity consumed by the capture process, if it comes from a singular source. If it comes from multiple sources, it shall be calculated using Eq. 39.

• $Q_{heat/elec, gross,external}$ represents the gross amount of heat or electricity imported from outside the facility for direct use by the capture process.

• $Q_{heat/elec,capture, recovered}$ represents the amount of heat or electricity recovered from the capture process and exported. This is zero if the site doesn't recover and export any energy.

If the heat or electricity is imported from more than one source, the net consumption of each source shall be calculated proportionally, based on its share of the gross consumption

$\textbf{(Eq.39)} \ Q_{heat/elec, net,external,i} = Q_{heat/elec, gross,external,i} * \frac{\sum_{i} Q_{heat/elec, net,external,i}}{\sum_{i} Q_{heat/elec, gross,external,i}}$

The electrical or heat efficiency of the facility is calculated by dividing the total energy produced (electricity or heat) by the theoretical energy available in the input biomass feedstock.

$\textbf{(Eq.40)} \ \eta_{elec/heat} = \frac{Q_{elec/heat, total} }{Q_{biomass, total}* LHV_{biomass}}$

• $\eta_{elec/heat}$ represents the electrical or heat efficiency of the facility. It is dimensionless.

• $Q_{elec/heat, total}$ represents the total electricity or heat production of the facility including the parasitic load (i.e. the electricity or heat consumed by the capture unit) during the monitoring period, in kWh or MJ.

• $Q_{biomass, \ total}$ represents the total biomass input of the facility for the production of electricity or heat during a monitoring period, in tonnes.

• $LHV_{biomass}$ represents lower heating value of the biomass input, in an appropriate energy per mass unit (e.g. MJ/t, kWh/t).

Calculation: Parasitic load, corresponding biomass

The amount of biomass corresponding to the parasitic load, the parasitic load biomass, is calculated by dividing the parasitic load by the theoretical energy content of the biomass used as input.

$\textbf{(Eq.41)} \ Q_{Parasitic\ load, biomass} = \frac {Q_{Parasitic\ load, energy}}{LHV_{biomass} }$

• $Q_{Parasitic\ load, biomass}$ represents the amount of biomass corresponding to the parasitic load, in tonnes.

• $Q_{Parasitic\ load, energy}$ is defined in Eq. 37.

• $LHV_{biomass}$ is defined in Eq. 40.

For example, a retrofit BECCS facility produces 10,000 MWh of electricity during the monitoring period, including the electricity used by the capture unit, which amounts to 1,000 MWh. To produce the total electricity, the facility requires 9,000 tonnes of wood pellets with a LHV of 17 MJ/kg.

Step 1: Calculate parasitic load energy demand

Substep 1: Calculate electricity efficiency, Eq. 40

$10,000\ MWh / (9,000 \ t \ * 17 \frac{MJ}{kg} \ * 1,000 \frac{kg}{t} \ * \frac{1 }{3600}\frac{MWh}{ MJ})=0.235 = 23.5\%$

Substep 2: Calculate parasitic load energy demand with electrical efficiency, Eq. 37

$(1*1,000 \ MWh) / (1*0.235)=4,255 \ MWh$

Step 2: Calculate the corresponding amount of biomass, Eq. 41

$4,255\ MWh / (17 \frac{MJ}{kg} \ * 1,000 \frac{kg}{t} \ * \frac{1 }{3600}\frac{MWh}{ MJ})=900 \ t$ The parasitic load emissions shall be calculated for the sourcing, processing and conversion of 900 t wood pellets. For facilities producing only electricity or only heat, the share of energy used by the capture unit to the total energy production (including the internally consumed energy) simply corresponds to the share of biomass needed to provide this energy to the total biomass input.

In this example, the capture unit consumes 10% of the total electricity production, so the amount of biomass required to provide this share corresponds to 10% of the total biomass input.

For facilities producing both electricity and heat, the relation is not as simple, as the heat efficiency is different to the electricity efficiency and the Carnot efficiency of the heat has to be considered.

Calculation: Emissions associated with the parasitic load biomass

Project Developers shall choose one of the following approaches to calculate the emissions associated with the parasitic load biomass.

Simplified approach: Facility energy emission factor

Where a verified emission factor for the energy produced by the facility is available, Project Developers may use this value and multiply with the net energy consumed by the capture unit $Q_{elec, capture, net}$ or $Q_{heat, capture, net}$, to determine parasitic load emissions, provided full justification and underlying calculations are submitted. The emission factor shall be calculated for the total energy produced (including energy consumed internally), not for the total energy exported.

$\textbf{(Eq.42)} E_{Parasitic \ load} =Q_{elec, \ capture, net}*EF_{electricity \ production }+Q_{heat, \ capture, net}*EF_{heat \ production }$

• $E_{Parasitic \ load}$ represents the parasitic load emissions, in tCO₂eq.

• $Q_{elec, \ capture, net}$ is defined in Eq. 38.

• $Q_{heat, \ capture, net}$ is defined in Eq. 38.

• $EF_{electricity \ production }$ represents the verified emission factor of the facility's total electricity production, in tCO₂eq / kWh or MJ.

• $EF_{heat \ production }$ represents the verified emission factor of the facility's total heat production, in tCO₂eq / kWh or MJ.

Full approach: Biomass-based calculation

$\textbf{(Eq.43)} E_{Parasitic \ load} =Q_{Parasitic\ load, biomass}\times EF_{biomass}$

• $E_{Parasitic \ load}$ represents the parasitic load emissions, in tCO₂eq.

• $Q_{Parasitic\ load, biomass}$ represents the amount of biomass corresponding to the parasitic load, in tonnes, calculated in Eq. 41.

• $EF_{biomass}$ represents the emission factor for all processes related to biomass used at the site from biomass production, in tCO₂eq/tonne of biomass, calculated in Eq. 25.

Material consumption in capture process

Emissions associated with material consumed solely by the CO₂ capture process, meaning consumed for capture after the point of CO₂ generation (e.g. solvents, adsorbents, and other process chemicals, material consumed for disposal of chemical waste, water) shall be fully attributed to the project.

See the Processing and energy use module for details on the calculations

Embodied emissions in capture process

Embodied emissions from infrastructure and machinery that are only used for the CO₂ capture process, and are used for capture after the point of CO₂ generation (e.g. liquefaction, compression equipment) shall be fully attributed to the project.

See the Infrastructure and machinery module for details on the calculation.

Storage of associated CO₂

If a BioCCS project captures associated CO₂ alongside eligible biogenic CO₂ and permanently stores it, the amount of associated CO₂ that ends up in permanent storage shall be excluded from the calculation of the capture stage emissions.

The amount of associated CO₂ stored is the amount of associated CO₂ captured minus any losses attributable to the associated CO₂ prior to entering storage.

Calculation: Associated CO₂ stored

$\textbf{(Eq.44)} \ CO_{2\ stored, assoc} =CO_{2\ captured,assoc}- CO_{2\ transport\ losses, assoc }-{CO_{2\ storage\ losses, assoc}}$

• $CO_{2\ stored, assoc}$ is defined in Eq. 22.

• $CO_{2\ captured,assoc}$ is defined in Eq. 9.

• $CO_{2\ transport\ losses, assoc}$ represents the amount of associated CO₂ lost during the transport stage, in tCO₂.

• $CO_{2\ storage\ losses, assoc}$ represents the amount of associated fossil CO₂ lost during the storage stage, in tCO₂.

Transport losses of the associated CO₂ shall be calculated following the rules in the Calculation of transport losses section. In order to calculate the losses attributed to the associated CO₂, in Eq. 12 (Overall mass balance approach) and 14 (Individual monitoring approach), the term $F_ {RCC}* \frac{CO_{2\ captured, biogenic}}{CO_{2\ project}}$ shall be replaced with $\frac{CO_{2\ captured, assoc}}{CO_{2\ project}}$.

Storage losses shall be calculated following the rules in the Calculation of storage losses section, and replacing the term $F_ {RCC}* \frac{CO_{2\ captured, biogenic}}{CO_{2\ project}}$ with $\frac{CO_{2\ captured, assoc}}{CO_{2\ project}}$ in Eq. 16.

Transport stage emissions

Emission sources from the transport stage include all operational and embodied emissions related to the transport of the project CO₂ stream, from leaving the capture site to entering the storage site. Transport may happen via pipeline networks, rail, road, shipping or a combination of those.

Transport emission sources include:

• energy use from any transport via rail, road, maritime vessel, or pipeline

• energy use from any stationary processes (e.g. intermediate storage),

• embodied emissions from infrastructure and machinery used in transportation and stationary processes.

Details on the calculation of emissions from the transport stage can be found in the Rainbow Transportation module.

Emission allocation

Only emissions associated with the transport of project CO₂ shall be attributed to the BioCCS project. For each transport segment $S$, emissions are allocated using the allocation fraction $F_S$, as defined in Calculation: Allocation fraction $F_S$, regardless of whether the project CO₂ stream is at all times segregated from CO₂ stream from sources or not.

Although a segregated stream is never mixed with CO₂ from other sources, the amount of project CO₂ transported does not necessarily correspond to the total amount of CO₂ transported.

For example:

• if the project captures and transports eligible biogenic CO₂ and ineligible CO₂ from a mixed stream, only the emissions associated with the transport of the eligible biogenic fraction are attributed to the project.

• For CRCF-projects only: if the project captures eligible biogenic CO₂, but designates part of the captured CO₂ for storage under an alternative framework other than the CRCF (i.e. $F_{CRCF} < 1$), only emissions associated with the fraction stored under the CRCF are be attributed to the project.

In all other cases, the allocation fraction simplifies to 1.

Storage stage emissions

Emissions sources at the storage stage include all operational and embodied emissions from CO₂ storage, from the project CO₂ entering the storage site to going into permanent geological storage.

Storage emission sources include:

• energy use from injection of CO₂ and any associated processes,

• energy use from any intermediate storage or processing operations,

• energy and material use from any storage site monitoring operations, i.e. all necessary activities to ensure the integrity of the CO₂ storage (e.g. water sampling, soil fluids monitoring, plume modeling), including estimated emissions for post-closure monitoring of the storage site scaled per tonne of CO₂ injected.

• embodied emissions from infrastructure and machinery used at storage site (e.g. injection well, transport infrastructure at storage site, monitoring wells).

Emissions from the storage stage shall be accounted using the

• Processing and energy use module for operational emissions (e.g. electricity and heat consumption, fuel combustion, material consumption)

• Infrastructure and machinery module for embodied emissions

Emission allocation

Only emissions associated with the storage of project CO₂ shall be attributed to the BioCCS project. For each storage site $K$, emissions are allocated using the allocation fraction $F_K$, as defined in Eq. 16, regardless of whether the project CO₂ stream is at all times segregated from CO₂ stream from sources or not

Although a segregated stream is never mixed with CO₂ from other sources, the amount of project CO₂ stored does not necessarily correspond to the total amount of CO₂ stored.

For example:

• if the project captures and stores eligible biogenic CO₂ and ineligible CO₂ from a mixed stream, only the emissions associated with the storage of the eligible biogenic fraction are attributed to the BioCCS project.

• For CRCF-projects only: if the project captures eligible biogenic CO₂, but designates part of the captured CO₂ for storage under an alternative framework other than the CRCF (i.e. $F_{CRCF} < 1$), only emissions associated with the fraction stored under the CRCF are attributed to the project.

In all other cases, the allocation fraction simplifies to 1.

Capture of fossil CO₂ at the storage site

Fossil CO₂ emitted as a result of fuel combustion at the storage site may be captured and permanently stored at the storage site. In this case, the amount of the fossil CO₂ captured minus any losses prior to entering permanent storage shall be deducted from the storage stage emissions.

Leakage emissions

Emissions from leakage include biomass-related leakage and bioenergy/material diversion leakage. All leakage types are described in detail in the Principles & Requirements section, and their quantification approaches are outlined below.

Note that biomass-related leakage emissions (counterfactual carbon storage, diversion of biomass and iLUC) are accounted for in the biomass emission factor in Eq. 25. Biomass-related leakage emissions are considered for the following biomass fractions:

• Greenfield:

  • Biomass fraction allocated to CO₂ generation

  • Parasitic load biomass fraction

• Retrofit:

  • Baseline biomass fraction (if used for parasitic load)

  • Additional biomass fraction

Counterfactual carbon storage

The leakage from counterfactual carbon storage is defined as the fraction of biomass carbon that would have likely have remained stored in the alternative fate scenario, rather than being decaying and being released. This fraction is not eligible for crediting and shall be deducted from the project's removals.

• If all of the carbon stored in the biomass would be released within 15 years, the counterfactual carbon storage is zero, and all biomass carbon is eligible for crediting.

• If the counterfactual emissions of CO₂ and CH₄ within 15 years do not exceed the amount of biomass carbon lost through decay after 50 years, then the leakage from counterfactual carbon storage is calculated as the total biomass carbon minus the counterfactual emissions within 15 years.

• If the counterfactual emissions of CO₂ and CH₄ within 15 years exceed the amount of biomass carbon lost through decay after 50 years, the leakage from counterfactual carbon storage corresponds to the carbon storage in the biomass at 50 years. This increases the eligibility of slow-decaying biomass feedstock with comparably large near-term emissions of methane.

The counterfactual emissions within 15 years are the sum of all GHG emissions from decay of the biomass over that period. For each gas, emissions are calculated as the carbon released within 15 years multiplied by the fraction emitted as that gas (CO₂ and CH₄) and converted to tCO₂eq using the 100-year Global Warming Potential.

If the project uses agro-food waste as feedstock, Project Developers shall include the soil organic carbon (SOC) gains from biomass decay in the counterfactual in the quantification of the counterfactual carbon storage. The assessment shall be based on secondary literature or models.

The assessment of the counterfactual emissions shall be based on peer-reviewed literature, recognized national or regional GHG inventory reports, documented industry data or direct measurements, and shall be representative of the biomass type and the specific alternative fate scenario (e.g. relevant geographic or climatic conditions).

Example 1

A Project Developer of a BioCCS retrofit sources an additional 200t of corn stover to meet the energy demand of the capture unit. The alternative fate of the biomass is demonstrated to be burned on the field. In this case, no counterfactual carbon storage is considered, as 100% the carbon stored in the biomass is proven to be released to the atmosphere in the near term.

Example 2

A Project Developer of a BioCCS retrofit sources an additional 200t of cashew nut shell cake to meet the energy demand of the capture unit. The biomass contains 100t of carbon. The alternative fate of the biomass is to be left in piles to decay. After 15 years, 20% of the carbon remains stored in the biomass, 1% remains after 50 years. 1% of the carbon is released as methane within the first 15 years.

• The counterfactual emissions within 15 years are 290 tCO₂eq for the carbon emitted as CO₂ (99% of the 80% of total biomass carbon emitted) and 29 tCO₂eq for carbon emitted as CH₄ (1% or the 80% of total biomass carbon emitted), which sums up to 319 tCO₂eq.

• The biomass carbon lost in the counterfactual due to decay at 50 years is 363 tCO₂eq (99% of the total biomass carbon).

The counterfactual emissions after 15 years do not exceed the counterfactual carbon loss at 50 years (319 tCO₂eq emissions < 363 tCO₂eq storage). The leakage from counterfactual carbon storage equals to the total biomass carbon minus the counterfactual emissions within 15 years, which is 48 tCO₂eq) (367 tCO₂eq total biomass carbon - 319 tCO₂eq emissions).

Example 3

A Project Developer of a BioCCS retrofit sources an additional 200t of sustainably sourced wood chips to meet the energy demand of the capture unit. The biomass contains 100t of carbon. The alternative fate of the biomass is to be left in piles to decay. After 15 years, 20% of the carbon remains stored in the biomass, and after 50 years 5% remain. 2.5% of the biomass carbon lost due to decay is released as methane within the first 15 years.

• The counterfactual emissions within 15 years are 286 tCO₂eq for the carbon emitted as CO₂ (97.5% of the 80% of total biomass carbon emitted) and 72 tCO₂eq for carbon emitted as CH₄ (2.5% of the 80% of total biomass carbon emitted), which sums up to 358 tCO₂eq.

• The biomass carbon lost in the counterfactual due to decay at 50 years is 348 tCO₂eq (95% of the total biomass carbon).

The counterfactual emissions after 15 years exceed the counterfactual carbon loss at 50 years (358 tCO₂eq emissions > 348 tCO₂eq storage). The leakage from counterfactual carbon storage equals to the biomass carbon still stored at 50 years, which is 18 tCO₂eq (5% of total biomass carbon).

Biomass diversion

Leakage associated with the diversion of the biomass from its alternative use shall be quantified for each biomass type and source. To quantify the leakage emissions, Project Developers shall:

1. Determine the quantity of the biomass type $i$ used by the project, that would have had a valuable alternative use.

2. Follow Alternative fate section guidelines to determine the alternative use scenario of the biomass.

3. Identify the most likely replacement product or process for the diverted biomass.

4. Source an appropriate conversion factor to calculate the quantity needed to replace the original function of the biomass based on the business-as-usual (BAU) function.

5. Source an appropriate emission factor for the production and use of the replacement product.

6. Calculate the associated emissions according to the equation below

7. Repeat for each biomass type $i$ with a valuable alternative use.

Indirect land use change emissions

To quantify iLUC emissions when required according to the Principles & requirements, the Project Developer shall classify each energy crop, or the feedstock from which the forestry or agro-food waste is derived, according to Table 8 below.

For crop types not listed, or for which direct land use change emissions have been calculated, no iLUC emissions are considered.

Table 8: iLUC emission factors for different crop types.

Crop Type	iLUC emission factor (gCO2eq/MJ)
Cereals and other starch-rich crops	12
Sugar crops	13
Oil crops	55

Diversion of bioenergy and biomaterial

For energy leakage calculations, if a retrofit project produces and exports less energy than the BAU, and this reduction is directly related to retrofitting the facility, additional emissions associated with the compensation of the reduced output shall be quantified. This includes but is not limited to electricity, heat, biogas, and biomethane export.

For material leakage calculations, if a retrofit project produces and exports less material than the BAU, and this reduction is directly related to retrofitting the facility, additional emissions associated with the compensation of the reduced output shall be quantified by identifying the quantity of the marginal material and multiplying it with an appropriate emission factor reflecting its production.

Calculation: Leakage

$\textbf{(Eq.45)} \ E_{leakage} = E_{energy/material\ diversion}$

• $E_{leakage}$ represents the leakage emissions term, in tCO₂eq, used in Eq. 2.

• $E_{energy/material \ diversion }$represents the leakage emissions from the diversion of bioenergy and biomaterials, in tCO₂eq.

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Counterfactual carbon storage

Calculation of counterfactual emissions within 15 years:

$\textbf{(Eq.46)} \ E_{counterfactual\ emissions,15}=C_{biomass}\times (1-F_{carbon, stored,15})\times \sum_{i}F_{carbon, emitted,15,i}\times C_{to}i\times GWP_{100,i}$

• $E_{counterfactual\ emissions,15 }$ represents the counterfactual emissions from the biomass within 15 years, in tCO₂eq.

• $C_{biomass}$ represents the total carbon content of the biomass feedstock, in tonnes.

• $F_{carbon, stored, 15}$ represents the estimated fraction of biomass carbon still stored at 15 years. It shall be provided using secondary sources.

• $F_{carbon, emitted,15,i}$ represents the estimated fraction of biomass carbon emitted as greenhouse gas $i$ (CO₂ or CH₄) within 15 years. The fractions across all GHGs $i$ shall sum to 1. It shall be provided using secondary sources.

• $C_{to}i$ represents the conversion of carbon to the greenhouse gas $i$ by multiplying by the ratio of their molecular mass. This is 3.667 for C to CO₂ and 1.333 for C to CH₄.

• $GWP_{100,i}$ represents the 100-year Global Warming Potential of greenhouse gas $i$, in CO₂ eq / $i$. This is 1 for CO₂ and 27 for CH₄.

Calculation of counterfactual carbon loss at 50 years:

$\textbf{(Eq.47)} \ C_{carbon, loss, 50}=(C_{biomass}\times C_{to}CO_2) \times (1-F_{carbon, stored,50})$

• $C_{carbon, loss, 50}$ represents the amount of biomass carbon lost due to biomass decay at 50 years in the counterfactual, in tCO₂eq.

• $C_{biomass}$ is defined in Eq. 46.

• $C_{to}CO_2$ represents the conversion of carbon to CO₂ equivalents by multiplying by the ratio of their molecular mass (3.667).

• $F_{carbon, stored, 50}$ represents the estimated fraction of biomass carbon still stored after 50 years. It shall be provided using secondary sources.

The leakage from counterfactual carbon storage is calculated

• according to Eq. 48 (Option A) for biomass feedstock whose counterfactual emissions within 15 years do not exceed the biomass carbon loss at 50 years as the difference between total biomass carbon and counterfactual emissions within 15 years.

• according to Eq. 49 (Option B) for biomass feedstock whose counterfactual emissions within 15 years do exceed the biomass carbon loss at 50 years as the biomass carbon still stored at 50 years.

Option A

$\textbf{(Eq.48)} \ C_{counterfactual}=(C_{biomass}\times C_{to}CO_2)-E_{counterfactual \ emissions,15}$

• $C_{Counterfactual}$ represents the leakage from counterfactual carbon storage for all biomass used at the site in the monitoring period, in tCO₂eq.

• $C_{biomass}$ is defined in Eq. 46.

• $C_{to}CO_2$ is defined in Eq. 47.

• $E_{counterfactual\ emissions,15 }$ is defined in Eq. 46.

Option B

$\textbf{(Eq.49)} \ C_{counterfactual}=(C_{biomass}\times C_{to}CO_2) \times F_{carbon, stored,50}$

• $C_{Counterfactual}$ is defined in Eq. 48.

• $C_{biomass}$ is defined in Eq. 46.

• $C_{to}CO_2$ is defined in Eq. 47.

• $F_{carbon, stored, 50}$ is defined in Eq. 57

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Biomass diversion

$\textbf{(Eq.50)}\ E_{biomass\ diversion} =\sum_{i} Q_{biomass,total, i}\times F_{conversion, i}\times EF_{alternative \ use, i}$

• $E_{biomass\ diversion }$ represents the leakage emissions from the diversion and replacement of all biomass used at the site in the monitoring period, in tCO₂eq.

• $Q_{biomass, total, i}$ represents the total amount biomass consumed by the underlying facility during the monitoring period, in tonnes.

• $F_{conversion,i}$ represents an appropriate conversion factor for biomass type $i$, in appropriate unit/tonnes.

• $EF_{alternative \ use,i}$ represents the appropriate emission factor for the replacement product of biomass type $i$, in tCO₂eq/appropriate unit.

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Indirect land use change

$\textbf{(Eq.51)}\ E_{iLUC} =\sum_{i} Q_ {biomass, total,i} \times iLUC_ {i}\times LHV_ {i}\times 10^{-6}$

• $E_{iLUC}$ represents the indirect land use change emissions of the project for all biomass used at the site in the monitoring period, in tCO₂eq.

• $Q_{biomass, total,i}$ represents the total amount biomass consumed by the underlying facility during the monitoring period, in tonnes.

• $iLUC_{i}$ represents the iLUC emission factor for biomass type $i$, in gCO₂eq/MJ, taken from Table 8.

• $LHV_{i}$ represents the lower heating value of the biomass type $i$, in MJ/t.

• it is multiplied by $10^{-6}$ to convert from gCO₂eq to tCO₂eq.

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Diversion of bioenergy and biomaterial

For energy leakage:

$\textbf{(Eq.52)}\ E_{energy\ diversion} = \sum_i(Q_{energy,i, baseline}-Q_{energy,i, retrofit})\times EF_{energy,i}$

• $Q_{energy,i, baseline}$ represents the energy of type i delivered to the grid in the baseline (BAU), in kWh or MJ.

• $Q_{energy,i, retrofit}$ represent the energy of type i delivered to the grid by the BioCCS project, in kWh or MJ.

• $EF_{energy,i}$ represents the energy of type i grid emissions factor and shall be taken for the national grid (at the maximum granularity) or bidding zone level, and if possible, regional mixes shall be used.

For material leakage:

$\textbf{(Eq.53)}\ E_{material\ diversion} = (Q_{material, baseline}-Q_{material, retrofit})\times EF_{material}$

• $Q_{material, baseline}$ represents the amount of material exported in the baseline (BAU), in an appropriate unit.

• $Q_{material, retrofit}$ represents the amount of material exported by the BioCCS project, in an appropriate unit.

• $EF_{material}$ represents the material production emission factor.

Uncertainty assessment

An uncertainty assessment is presented below for all aspects of GHG quantification set at the methodology level. The findings from this assessment are then applied at the project level, where project-specific GHG quantification also undergoes an uncertainty assessment.

The overall project GHG quantification uncertainty is determined by qualitatively combining both the methodology-level and project-specific uncertainties for each identified source of uncertainty.

The assumptions made at the methodology level are assessed qualitatively.

• The assumption that no carbon was stored in the absence of the project has low uncertainty. In the absence of the project, feedstock materials would follow their conventional fate and the CO₂ would not have been captured and stored. Any indirect carbon storage is accounted for within the leakage assessment.

• The assumption made for the calculation of embodied emissions of the underlying biogas production site in a retrofit scenario (buildings and main infrastructure have a lifetime of 20 years, and calculation based on the external volume of the main digester) has low uncertainty. It is based on the assessment of numerous certification projects under the Rainbow Biogas from anaerobic digestion methodology, that showed minor impacts from infrastructure (1-2% of project life cycle GHG emissions).

• The assumptions made for the storage emissions from manure and slurry have low uncertainty.

The qualitative uncertainty at methodology level is low, which translates to a discount factor of 3%.

At the project level, Project Developers shall quantify the uncertainty in the GHG quantification, using e.g. statistical analysis of project data, calibration records or manufacturer specifications. Where a direct quantification is not possible, uncertainty estimates from reputable sources (e.g. peer-reviewed literature or local/national regulations) may be used, if justified. Common sources of uncertainty are

• measurement uncertainty (e.g. accuracy of the flow meters used to measure CO₂ flow),

• sampling uncertainty (e.g. statistical distribution in the value for the concentration of CO₂ in the stream),

• models (e.g. equation of state to model the density of the stream),

• estimates or secondary data used (e.g. when project data is not available).

To combine quantitative uncertainties, Project Developers shall follow the principles set out in the IPCC: Good Practice Guidance and Uncertainty Management in National GHG Inventories (Chapter 6, Section 3), using either an error propagation approach or Monte Carlo simulation. Uncertainty shall be assessed based on the 95% confidence interval.

The discount factor corresponds to the higher of the two uncertainty values, methodology- or project-level, and is deducted from the net GHG removals. If the discount factor exceeds 15%, the project is deemed ineligible for crediting.

🇪🇺 CRCF requirement: Discount factor

For CRCF-projects, the discount factor is applied to the gross GHG removals, $R_{project}$.