How Sustainable is Your Car?

Green NCAP announces its first Life Cycle Assessment (LCA) results, examining the real environmental impact of some of Europe’s most popular cars in order to help car buyers make more informed and   sustainable choices.

To understand the true ecological impact and sustainability of a car, it must be viewed in the context of its whole life cycle.  This means that all processes and flows of resources and energy associated with the car’s production, usage, and recycling must be considered.  Life Cycle Assessment, or LCA, is the method that estimates these individual contributions to predict the car’s environmental impact over its entire lifetime ‘from cradle to grave’.

Green NCAP’s Life Cycle Assessment involves estimations based on the available data and state-of-the-art scientific methodology, developed by JOANNEUM RESEARCH and peer-reviewed by the PAUL SCHERRER INSTITUTE.  A unique feature of our approach is the use of realistic, comprehensive, and precise vehicle measurements to estimate the impact of the vehicle’s use phase.  The average, best and worst measured fuel and energy consumptions from Green NCAP's tests serve as input data for the LCA calculations, revealing the potential effect of driving style and ambient conditions on the LCA results.  Beside vehicle test data, the LCA methodology includes the forecast about changing electricity mix in various countries and the estimated evolution of the energy supply for the next two decades. Green NCAP’s Life Cycle Assessment hence sets the stage for the first true long-term harmonised vehicle LCA platform for the European market.

To demonstrate the value of the LCA approach, Green NCAP has calculated the estimated total life cycle greenhouse gas emissions and primary energy demand for the 61 recent cars tested in the programme in the period 2019-2021.  This batch includes vehicles of all sizes and types, including conventional petrol and diesel, full-electric and hybrid-electric cars.  For the comparative analysis, a nominal vehicle lifetime of 16 years and a total driven mileage of 240,000 km are assumed.  The calculations are based on the current forecast about average energy mix of the 27 European Union member states and the United Kingdom, cancelling out the effect that local energy supply has on the cars’ LCA values.  For each model, the transportation process flow and the output are summarised in a LCA factsheet.

Overall, the results show that total estimated greenhouse gas emissions and primary energy demand, and the respective contributions at different phases and time in the life cycle, may vary significantly depending on the propulsion system, the energy carrier and other factors.  For conventional vehicles, the burning of fossil fuel during the operational phase accounts for most of the life cycle emissions and energy demand. This is different for electric cars for which the production phase on average accounts for a larger share of the total, while emissions in usage can vary depending on the portion of energy from non-renewable sources in the electricity used for charging.  Electric cars have zero local greenhouse gas emissions and show overall the best LCA numbers in the European average. Not every car of the same powertrain type is equal too: the LCA analysis clearly shows that the impact of vehicle mass and size remains significant for all vehicle types.  The same can be said about how cars are driven – relaxed or sporty. Additionally to optimizing their driving style, consumers that chose plug-in hybrid cars can help reduce the impact on the climate by making sure their cars are always fully charged.

While it is still too early to consider an all-encompassing star rating system based on LCA, the information provided underlines the importance of adopting a holistic approach towards the real life cycle environmental impact of modern cars and the role LCA will play in consumer information programmes.

Green NCAP makes its life cycle assessment details available for information purposes only, without ranking of better or worse cars.  The next step, coming soon, is the launch of an interactive LCA platform, allowing consumers to examine LCA results based on their own local parameters and car use.

Finally, like any other LCA method, there are limitations to consider.  With the impact on global warming and total primary energy demand, Green NCAP’s LCA accounts for the most relevant environmental aspects. However, other environmental effects of pollutant emissions like NOx, SO2, particulate matter and their consequential impacts like acidification, ozone formation, and toxicity to humans are not considered. The life cycle impact of a transport system on water demand, pollution of water or soil are also not included in the assessment yet.

SOURCE: LCA Results: A Closer Look