New research suggests some electric vehicles aren’t as green as they seem

·2-min read

Some electric vehicles consume more energy across their life cycle than petrol and diesel vehicles, according to new research.

Green NCAP, an offshoot of road safety specialist Euro NCAP, has released its first Life Cycle Assessment results. This indicates the total life cycle greenhouse gas emissions and primary energy demand of 61 recent cars.

The batch includes vehicles of all shapes and sizes, with full combustion engines, hybrids and all-electric powertrains. It factors in changing energy sources and assumes a vehicle life of 16 years or about 150,000 miles.

When comparing similar vehicle types with different powertrains, it was found that although electric vehicles do not emit any tailpipe emissions, their production is much more energy intensive than petrol and diesel cars.

Fiat 500

Despite this, they still had the best result, especially once recycling was taken into account. Petrol models struggled compared with diesel because of their higher fuel consumption.

Vehicle mass had a big impact on emissions, with large electric vehicles emitting more over their lifetime than smaller combustion vehicles. For example, Green NCAP showed a graph where the electric Ford Mustang Mach-E had larger emissions than a diesel Peugeot 208.

However, a smaller EV emitted even less, with the example being the Fiat 500, which had the lowest emissions footprint of all the cars tested.

Another example of how emissions can be affected is in the ‘usage conditions’ tests. Here, a best and worst case scenario is offered, based on optimal ambient conditions and driving style.

Electric vehicles perform poorly in cold weather, because battery capacity is negatively affected by this. As such, there was quite a large difference between the scenarios, with the EV consuming twice as much energy at -7°C than at its optimal temperature.

It wasn’t quite as extreme in the diesel, but there was a huge difference for plug-in hybrid models. This is because the best case scenario is based on the battery being kept topped up, whereas the worst case looks at an empty battery in cold weather.

Based on the tests, it is clear that these models have some of the lowest lifetime emissions when topped up, but the worst when left uncharged.

Green NCAP says the next stage of its life cycle assessment system is to create a platform where consumers can compare results based on their own local parameters and car use.