Life Cycle Assessment, or LCA, is the method that estimates these individual contributions to all processes, flows of resources, and energy associated with the car’s production, usage, and recycling to predict the car’s environmental impact over its entire lifetime ‘from cradle to grave’. Green NCAP is an independent initiative in Europe that promotes the development of cars that are clean, energy-efficient, and not harmful to the environment. The organization recently announced its first Life Cycle Assessment (LCA) to judge the real environmental impact of some of Europe’s most popular cars to help car buyers make more informed and sustainable choices.
The LCA involves estimates based on the available data and a methodology, developed by JOANNEUM RESEARCH and peer-reviewed by the PAUL SCHERRER INSTITUTE. According to information provided by Green NCAP, one unique feature of the 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.
To obtain the results, Green NCAP has calculated the estimated total life cycle greenhouse gas emissions and primary energy demand for the 61 recent cars tested in the program from the period from 2019 through 2021. The data includes vehicles of all sizes and types, including conventional gasoline and diesel, full-electric, and hybrid-electric cars. A vehicle lifetime of 16 years and a total driven mileage of 240,000 km (150,000 miles) were assumed.
The calculations are based on the current forecast about the average energy mix of the 27 European Union member states and the United Kingdom, canceling out the effect that local energy supply has on the cars’ LCA values.
From the information from Green NCAP, the results show that total estimated greenhouse gas emissions and primary energy demand, and the respective contributions at different phases and times 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 fuels 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.
The full result of the Green NCAP study can be found in the organization’s press release, however, comparing vehicles of similar mass/size and body shape but with a different powertrain is particularly interesting. While electric vehicles do not produce any local emissions while in use, the production of an EV – including all the electrical and electronic components and the high voltage battery that went into it – is projected to generate a significant quantity of greenhouse gases (GHG). Adding the estimated GHG emitted in supplying the electrical energy over its lifetime brings the life cycle emissions closer to some of the internal combustion engine (ICE) vehicles. Nevertheless, the electric car still shows the best overall result, especially when the benefit of recycling electric components is added.
The Green NCAP comparison of cars also confirms that the petrol vehicle has a slight disadvantage compared to the diesel one, due to its higher fuel consumption. Overall, the CNG and the plug-in hybrid cars give similar life cycle results of around 40 tons CO2-equivalent. The report concludes that despite the relatively low GHG emissions from fuel production, all vehicles with a combustion engine experience a drawback due to the CO2 that is being released when the fossil fuel is combusted.
Kevin Clemens is a Senior Editor with Battery Technology.