This chapter will summarize the successful practices for PCF assessment for Kongs-berg’s propulsion products. Following guidelines are built based on LCA and PCF liter-ature review, making use of findings from case study. Guideline is built in 5 following steps:
1. First and perhaps the most important step is similar than in LCA framework fo-cusing also to very fundamental questions, which are normally discussed before launching the LCA project.
- What is the goal of the project and how the results are going to be utilized? Is company ready to communicate these externally or will it be only as an informa-tive result for further sustainability decision making? What is the role of LCA and PCF in company’s sustainability strategy? Answers will affect directly to PCF standard selection and further processes.
2. After this, the decisions related to scope & goal definition may start. This part follows the question presented in every PCF standard. The functional unit will be presented and if project is conducted in accordance with ISO 14067, identifi-cation of included system components can be done. For component identifica-tion, cut-off rule can be applied, including 95 % of the total emissions but not excluding the components that are more than 1 %. At this stage, emission amounts are not known so cut-off can be conducted in mass basis. On case study waterjet cut-off rule were introduced with a simple list but in case of pro-pellers and thrusters, it requires more work to go through part list and compo-nent masses as there are thousands of compocompo-nents.
Geographic cut-off rule is not recommended to use as propulsion product value chain is widely spread out across the world and this can of limitations would lead to biases result. It is also essential to remember that cut-off is not mandatory to use but it gives room for leaving out the components, which emission contribution are insignificant.
At case study LCA approach was chosen to be cradle to gate as the target was only cli-mate change impact category. If all stages will be under study (cradle to grave), follow-ing assumptions must considered:
- What is the lifetime of product and hours of use annually? Will it be measured from one product or average time?
- How maintenance activities and amount of spare parts will be allocated during use stage?
- For full LCA assessment, how to evaluate the amount of sever particles from product to water?
- How product is assumed to recycle? Will it be melted or if any level of circular economy applies at the end of life cycle?
At the beginning of the first stage, it should be clear what resources are available and how the LCA team is built. Work group should include participant(s) from designing, procurement, and manufacturing. Members are chosen based on the LCA stages, where designers can create system boundaries, purchaser contacts and motivates suppliers and manufacturing will identify the processes done indoors. For the last one, operations manager would be also relevant resource. LCA team should also include project manager who is responsible for the whole assessment implementation. Per-haps the most important role is the one whole will conduct LCA calculations in real.
3. Third step is called Inventory Analysis and at the beginning of this, data quality should be discussed before data collection is started. At this, the amount of pri-mary data and sources of secondary data can be decided. Data quality is rele-vant to the question what is the level of uncertainty that can be tolerated on re-sults? According to the case study, following information should be collected to decrease the uncertainty level:
- Suppliers energy sources
- The ratio of primary and secondary material used on raw material production - Primary data from internal operation
Before data collection may start, all the processes for components under evaluation should identified by creating system- and component level process flows. Process flow creation will go through the operations for components step by step in a systematic way. Already on this stage, suppliers must be included or consulted to have detailed knowledge how the components are manufactured and where the raw material is origi-nated. If supplier is not able to offer primary data, secondary data must be collected from databases or literature when the knowledge of implemented processes is essen-tial. For secondary data, following requirements can be set to lower the uncertainty level:
- Steel and stainless-steel manufacturing data should be based on similar manu-facturing methods than reality and should be as new as possible but not older than 5 years due to development of the processes’ emission efficiency.
- Freight data should be addressed to correct ship type as emitted emissions var-ies between container ship size and speed. Data age should be maximum 3 years because of increased emission efficiency. Between 2007-2012 shipping emissions decreased 10 % even cargo amount increased, and ships built after 2013 are 30-40 % more carbon efficient than the replaced ships.
The most recent data can be found from Ecoinvent v3.7- or GaBi database. Data han-dling and recording is highly dependent which LCA software is in use. With OpenLCA, new processes will be manually created, and relevant emissions added to input/output system. There are variations between software and functionalities so coherent guide-line cannot be applied. It is thought highly recommended to supply one of the commer-cially available software due to a reason explained in chapter 3.3. Impact category se-lection for PCF analysis is quite optional as the analysis is limited to climate change midpoint category. For this, only requirement is to apply GWP for 100 years.
4. As LCA and PCF are iterative processes, after first result, it is recommended to conduct steps 2 and 3 again to find possible mistakes on system boundaries settings, process flows and eventually on data collection.
5. The last step is result interpretation and presentation. If official report will be made, it should follow PCF standard report guidance. Only PAS 2050 does not include this section.
The results calculated for particular unit size can be scaled to other sizes only if com-ponent masses are scalable and follows exactly similar process flows. If only process flows and system boundaries are similar, it is rather effortless to change the masses and other dimensions to LCA software. The most time-consuming stage is data collec-tion, but ones it is done, it can be applied across the whole product family.