For the full picture on CO2 emissions, we need to assess the vehicle lifecycle. SSAB’s Jonas Adolfsson explains how tier suppliers can help to make significant reductions at the manufacturing stage
Carbon dioxide is a key subject for many people, especially in the automotive industry. Most talk, however, is about CO2 from the tailpipe and not what happens before or after the car is produced. To get the full picture of how much CO2 is being produced from raw material to recycling we have to perform a lifecycle assessment (LCA).
LCA is a technique to assess environmental impacts associated with all the stages of a product’s life from raw material extraction through materials processing, manufacture, distribution, use, repair and maintenance, and disposal or recycling.
How should we look at this from a manufacturing perspective?
Everything counts If we are to reduce the total greenhouse gas emissions (GHG) we must look at everything and make the right and sustainable choices. Making a lifecycle assessment can help us get the full scope.
However, an LCA is only as valid as its data. Therefore, it is crucial that the data used for the completion of a LCA is accurate and current. When comparing different LCAs with one another, it is crucial that equivalent data are available for both products and processes in question. If one product has a much higher availability of data, it cannot be justly compared to another product which has less detailed data.
There are two basic types of LCA data – unit process data and environmental input-output data (EIO). The latter is based on national economic input-output data. Unit process data on the other side, are derived from direct surveys of companies or plants producing the product of interest, carried out at a unit process level defined by the system boundaries for the study.
The lifecycle considered usually consists of several stages including: materials extraction, processing and manufacturing, product use, and product disposal. If the most environmentally harmful of these stages can be determined, then impact on the environment can be efficiently reduced by focusing on making changes for that particular phase.
For example, the most energy-intensive life phase of a car is during use due to fuel consumption. One of the most effective ways to increase fuel efficiency is to decrease vehicle weight.
Analysis toolIf, as an automotive engineer, you are interested in the full lifecycle of a vehicle you can use an excellent tool called Automotive Energy & GHG Model (“UCSB Model”). The model, developed by the University of California at Santa Barbara, helps users to analyse the environmental impact of new vehicle design using LCA.
“The UCSB Model looks specifically at material substitution, but its data and parameters capture around 99% of the energy and GHG impacts of the studied automotive material substitutions,” said Russ Balzer, technical director at WorldAutoSteel.
[Download the UCSB Model from www.worldautosteel.org]
Difference between materialsIf we take a deep dive into producing material, we can have a look at the graph below. This picture shows that steel has an advantage compared to some other lightweight materials as it emits less CO2 when being produced. Steel has good numbers here, but there are also differences between the steels as such. By using advanced or ultra high-strength steel, you can further reduce the emissions as you will be using less steel. All in all, we need to start reducing the total Greenhouse Gas Emission today . There is no Planet B – so how are you planning on contributing?