Circularity assessment

Projects that reduce GHG emissions and are issued Riverse Carbon Credits typically also contribute to a circular economy. The assessment of a project's circularity is considered under the co-benefits criteria and represents the Sustainable Development Goal (SDG) number 12.2.

The Material Circularity Indicator (MCI) is the selected measure of circularity, due to its comprehensive assessment of material flows and alignment with global standards, notably established by The Ellen MacArthur Foundation.

The MCI examines the mass of material flows throughout a product's lifecycle. It evaluates how efficiently materials circulate within a closed-loop system, assigning “more circular” scores to systems that minimize waste and optimize resource reuse. The formula uses input parameters such as material feedstock amount and type (e.g. from recycled, reused, or biological sources), recycling rates, and lifespan extension potential to quantify a product's circularity.

in the dedicated methodology document, on pages 22 to 31, following the Product-level Methodology under the Whole product approach). Figure 3 modified from summarizes the MCI material flows.

The MCI is a unitless indicator that varies from 0 to 1, where 0 represents a fully linear product and 1 is fully circular. The project scenario MCI is compared to the baseline scenario MCI, measuring how much more circular the project scenario is than the baseline.

The MCI methodology has been applied to the battery's second life using the input data presented in Table 5.

Figure 3 Summarized representation of the MCI material flows. Modified from Cottafava, D. and Ritzen, M. (2021). * Only landfill is considered in the MCI for battery second life. Energy recovery as part of a circular strategy only applies to biological materials following the MCI's conditions.

Table 5 All variables needed to calculate the Material Circularity Indicator (MCI) for the Riverse Battery Second Life methodology are detailed below. The full methodology and equations can be found in the dedicated methodology document.

Symbol	Definition by the MCI	Guidelines for the project scenario	Guidelines for the baseline scenario
$M$	Mass of a product	Total mass (kg) of second life batteries in the project scenario. $M = N_{i_B.c.sold}*W_{i_B.c. sold}$ Where $N_{i_B.c.sold}$ and $W_{i_B.c. sold }$ are defined in $Eq.2$ in the Calculations project battery collection section.	Consider the same guidelines as for the baseline scenario
$Fr$	Fraction of mass of a product's feedstock from recycled sources	Assumed zero	Assumed zero
$Fu$	Fraction of mass of a product's feedstock from reused sources	Considers the mass of second life batteries ($M$) and the mass of new components acquired ($N_p$, in kg): $Fu = (M-N_p)/M$ $N_p$ is the sum of new Battery materials as described in $Eq.11$ and $Eq.16$ (for Pb-acid batteries)	Assumed zero
$Fs$	Fraction of a product's biological feedstock from Sustained production.	It is assumed that no biological feedstock is used in batteries.	Consider the same guidelines as for the project scenario
$V$	Material that is not from reuse, recycling or biological material from sustained production.	The amount of virgin materials used in the project scenario is the same as the Np when virgin material shall be extracted to produce new pieces.	All the input materials are considered virgin as no reuse or recycled materials are assumed in a status quo scenario.
$Cr$	Fraction of mass of a product being collected to go into a recycling process	Value is based on the collection rates from the baseline scenario as presented in Appendix 3. After the end of the battery's first and second life, the product is assumed to follow the country's recycling rates where waste is generated.	Consider the same guidelines as for the project scenario
$Cu$	Fraction of mass of a product going into component reuse	Fraction considered under the Cr variable, according to the baseline's rates.	Consider the same guidelines as for the project scenario
$Cc$	Fraction of mass of a product being collected to go into a composting process	As no biological feedstock is used in batteries, this value is assumed to be zero.	Consider the same guidelines as for the project scenario
$Ce$	Fraction of mass of a product being collected for energy recovery where the material satisfies the requirements for inclusion	Energy recovery as part of a circular strategy only applies to biological materials, according to the MCI methodology. This value is assumed to be zero.	Consider the same guidelines as for the project scenario
$Wo$	Mass of unrecoverable waste through a product's material going into landfill, waste to energy and any other type of process where the materials are no longer recoverable	Following the MCI calculation methodology, this value is the same for both scenarios. Due to the comparative approach, it can be excluded.	Consider the same guidelines as for the project scenario
$Ec$	Efficiency of the recycling process used for the portion of a product collected for recycling	According to the EU Regulation for batteries, recycling efficiencies are determined based on their chemical composition rather than their usage category: Li-ion: 65% Pb-acid: 75% NiMH (other): 50%	Consider the same guidelines as for the project scenario
$Wc$	Mass of unrecoverable waste generated in the process of recycling parts of a product	Following the MCI calculation methodology, this value is the same for both scenarios. Due to the comparative approach, it can be excluded.	Consider the same guidelines as for the project scenario
$Ef$	Efficiency of the recycling process used to produce recycled feedstock for a product	Assumed equal to Ec as no data are available specifically for batteries. Additionally, since Fr is considered zero, this variable is not impactful.	Consider the same guidelines as for the project scenario
$Wf$	Mass of unrecoverable waste generated when producing recycled feedstock for a product	Following the MCI calculation methodology, and considering Fr equal to zero, this value is zero.	Consider the same guidelines as for the project scenario
$W$	Mass of unrecoverable waste associated with a product	Following the MCI calculation methodology and Riverse's guidelines, this value is the same for both scenarios. Due to the comparative approach, it can be excluded.	Consider the same guidelines as for the project scenario
$LFI$	Linear flow index	Varies from 0 to 1, where 1 is a completely linear flow and 0 is a completely restorative flow. In a circular project, the LFI shall be closer to zero, while the baseline shall be closer to 1.	Consider the same guidelines as for the project scenario
$L$	Actual average lifetime of a product	Sum of the lifespan of the product's first and second life according to Appendix 2, using an average weighted across the battery types refurbished or regenerated by the project.	Assumed 1
$Lav$	Average lifetime of an industry-average product of the same type	Average lifespan of the product's first life, weighted across all battery types refurbished or regenerated by the project as presented in Appendix 2.	Assumed 1
$U$	achieved during the use phase of a product	Calculated based on the extended lifetime of the project's product.	Assumed 1
$Uav$	Average number of functional units achieved during the use phase of an industry-average product of the same type	Assumed 1	Assumed 1
$X$	Utility of a product (function of the product's lifespan and intensity of use)	In battery second life projects, X is higher in the project scenario, as the project extends the product's life (MCI methodology, p. 29)	Equal to 1 as the baseline scenario regards the status quo market (average industry scenario).
$MCI_p$	Material Circularity Indicator of a product	Varies from 0 to 1, where 0 represents a fully linear product and 1 is fully circular.	Consider the same guidelines as for the project scenario