Green NCAP: diesel more sustainable than EVs?

In its first study on life cycle assessment, Green NCAP, the sustainability branch of safety organization Euro NCAP, has examined the environmental impact of 61 popular models on the European market. Though the electric Fiat 500 showed the smallest carbon footprint, the Skoda Octavia 2.0 TDI made a case for the combustion engine.

Life cycle assessments (LCA) address the environmental impact of a car on a cradle-to-grave basis, taking into account all processes and flows of resources needed to make, use and scrap a car. Over three years, Green NCAP has analyzed vehicles of all sizes and drivelines, ranging from models with an internal combustion engine to electrified vehicles and battery-powered cars.

Primary Energy Demand

Green NCAP has investigated the carbon footprint and the primary energy demand (PED) of the listed vehicles. According to the organization, “PED represents the sum of all primary energy extracted from nature to provide the transportation, including coal, oil, natural gas, hydropower, wind, waste, solar, and nuclear power.

As energy supplies are scarce and valuable, they should be utilized wisely, and the efficiency of all processes in a vehicle’s life cycle maximized.” The total energy demand of a car’s life is equally essential for the customer adds the organization that assumed a vehicle lifetime of 16 years or 240 000 kilometers for its study.

On top of that, environmental impact strongly depends on how much stress a driver puts on his car, leading to lower or higher consumption, and whether energy sources come from renewables. So, green NCAP calculated a best and worst case for each vehicle and then an average to cope with these different scenarios.

Not a wide gap

With usage eating away the most considerable portion of carbon emission and primary energy demand, it comes as no surprise that an electric powertrain has a lower impact than a combustion engine. But don’t expect a wide gap between similarly sized models. For example, the Skoda Octavia Combi 2.0 TDI (42 tons) sits slightly above 40 tons CO2 equivalent, a VW ID.3 Pro 150 kW(35 tons) slightly under.

As the graphs show, in a worst-case scenario (e.g., a country dependent on brown coal production for electricity), a frugally driven diesel of the same size outperforms its electric equivalent. This contradicts an earlier study by Transport & Environment, claiming that even in countries with heavily polluting electricity production, like Poland, an electric car still emits less than a diesel. That study uses official consumption figures.

Fiat 500e first

A similar statistic favoring small or efficient combustion engines arises if one filters out the primary energy demand for different vehicle types. For example, unbothered by the energy used for producing a battery, the Skoda Octavia 2.0 TDI (first with 164 MWh) outperforms the tiny Fiat 500 e (171 MWh), which comes in at fourth place after the Toyota Prius PHEV (167 MWh) and Peugeot 208 1.5 BlueHDI (169 MWh) also with combustion engines.

But if you zoom in on nothing but the average CO2 emissions, the first four places are occupied by BEVs: Fiat 500e (31 tons), VW ID.3 Pro 150 kW (35 tons), Lexus UX300e (38 tons), and then the Nissan Leaf E+ (38 tons). The complete list can be found here. So the overall conclusion is that while EVs do have an edge on LCA, it is not a big lead.

What about pollutants?

In a second phase, Green NCAP wants to make the LCA board interactive so that customers can figure out how sustainable their next car purchase is depending on their driver profile and where they live.

Finally, Green NCAP points out that its LCA ranking isn’t exhaustive since it excludes toxic emissions like NOx, SO2, or particulate matter, which profoundly affect the environment and health. Though electric cars emit some of these pollutants locally, vehicles with combustion engines score higher on the pollutant list.