Case study: modeling the sustainability of EBS for battery management
In previous insights we discussed why we should evaluate the impact of products, and how. In this case study we benchmark five commercial electronic products for battery management, to see what we learn from an impact analysis and which method is best suited for that.
Battery management for hybrid and electric vehicles consists in an electronic based system (EBS) able to monitor and balance the charge in Li-ion batteries, in order to improve battery efficiency and lifetime. Life-cycle analysis of electric or hybrid vehicles are getting popular in the latest years, as they aid as a means to argument against the allegation of shifting the pollution problems from the use phase to car and electricity production phases (manufacturing of battery), partly to really support the environmentally friendliest solutions.
The product system includes the PCB and the electronic components and analyzes the impact of manufacturing and use (cradle to gate study). Further components of the battery block and other life-cycle phases do not change among the benchmarked products, and were not considered.
Scope of the study is to calculate the global warming potential (GWP) in manufacturing and use phases, where the impacts due to raw materials, energy and manufacturing are estimated through input-output data (EIO-LCA), and the use phase is based on datasheets.
The EIO data deliver energy consumption and GWP related to manufacturing, while the energy consumption during the use phase is a direct outcome of the use profile defined in the study.
The two main contributions to energy consumption are use and chip manufacturing. The manufacturing emissions are almost completely due to chip manufacturing, by far the most complex and energy demanding process in the supply chain, thus products with bigger IC show higher impact. Power consumption and thus emissions in the use phase are very different from product to product.
Following conclusions can be drawn from the impact assessment:
- Some products use more discrete devices, others have larger IC chips. The short Bill of Materials has almost no impact on energy and GWP because discrete devices are simple technologies if compared to IC manufacturing.
- Energy consumption is mainly due to chip manufacturing and use. In some products energy efficiency has been already optimized, but the chip contribution is high, in others the focus was set on small area, but the energy consumption during use is high.
- The impact of discrete devices on other environmental categories, here not considered, is expected to be important: in particular, the use of heavy metals and rare earths make these devices relevant in categories related to water or land pollution.
- End-of-life was not included in the analysis. But the different architectures could lead to different recyclability of the components. Being battery and electronics end-of-life a sensitive topic, this phase should be included wherever possible in such studies.
- EIO-LCA is a good workaround to proceed fast in the study, but a more accurate description of the system and the use of databases to improve the inventory would improve the quality of the assessment and lead to a fairer comparison.
Studies like this can be employed in further product development, to improve the environmental performance. The results can also be disclosed to stakeholders, to customers for marketing purposes in a first place, but also to policy makers: the European and the national authorities, in fact, which promote and subsidize developments linked to e-mobility, encourage the use of a life cycle approach and value the integration of LCA in such developments.
The end-of-life phase is for both batteries and electronic systems a critical one, therefore it is certainly interesting to highlight the use of recycled materials or the possibility of reuse some parts. One way to do that is the Material Circularity Indicator (MCI) developed by the EllenMcArthur Foundations with partners from the manufacturing world.
To calculate the MCI you must know the fraction of virgin feedstock employed in each component, the waste generated and the recycling rate at the end-of-life, and the utility of the product (i.e. durability or intensity of use). While the content of recycled material is usually known to the manufacturer, the final destination or the recycling rate of the product are usually unknown, and different from region to region. Here some streamlined models and indicators can help, similarly to what happened already with the GWP intensity of electricity. You could take for example the local recycling rate of the relevant materials from waste statistics.
The MCI takes into account the whole life-cycle of the product, but it contains no information about the climate impact, the use of critical materials, or the energy consumption: for this reason, it should not be used stand-alone to make claims on sustainability. Still it's an excellent indicator to support other methods or internal goals on circularity.
As already discussed in a previous blog, the Agenda 2030 with its SDGs offer an excellent framework to capture all sustainability aspects and the interplay between them. However, they are conceived for full organizations, more than for products, and are too generic to benchmarking.
can do is to show how battery management in itself is related to the SDGs, and
estimate what this means to the contribution of your whole organization to the
SDGs. Few example:
- having efficient battery management EBS in your product portfolio will affect target 7.3 (By 2030, double the global rate of improvement in energy efficiency), which can be measure as "reduction in energy requirements of products and services" (GRI standard);
- increasing the amount of recycled inputs improves target 8.4 (resource efficiency of products and services), and can be measured as "Extent of impact mitigation of environmental impacts of products and services" or as "Percentage of materials used that are recycled input materials" (GRI standard).
In this way you correlate not only your operations and practices to the SDG, but also your products.
Want to hear more about this topic! Get in touch with us!