Hybrid cars can be nearly five times dirtier than battery electric cars, new report finds

A new assessment of lifecycle emissions of four common passenger vehicle powertrains in the United States has found that battery electric vehicles (BEVs) have considerably lower lifecycle greenhouse gas (GHG) emissions than all other power trains.

The new detailed assessment of vehicle lifecycle emissions was carried out by the International Council on Clean Transportation (ICCT) as an update to a 2021 analysis, which concluded at the time that “the life-cycle emissions over the lifetime of BEVs … are already lower than a comparable gasoline car” in Europe, the United States, China, and India.

The new analysis estimates the life-cycle emissions of internal combustion engine (ICE) vehicles, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and BEVs – for both sedans and SUVs, and it finds that the advantage of BEVs has increased.

The ICCT’s 2021 study found that the lifecycle greenhouse gas emissions of the average battery electric mid-size cars sold in the United States in 2021 were between 57 to 68 per cent lower than ICE vehicles – depending on the average carbon intensity of the electricity grid.

The latest assessment finds that the lifecycle emissions of model year 2024 BEV sedans in the United States are between 66 to 70 per cent lower than conventional ICE vehicles (depending on the average carbon intensity of the grid), while the lifecycle emissions for model year 2024 BEV SUVs is between 71 and 74 per cent lower than their ICE competitors (depending on the same conditions).

This number gets even higher when the grid is powered by 100 per cent renewable electricity, up to 83 and 85 per cent, respectively.

And while both hybrid electrics and plug-in hybrid electrics both outperform ICE vehicles, they are nevertheless significantly behind the performance of a BEV.

The ICCT’s assessment found that the lifecycle emissions of model year 2024 PHEV sedans are 40 per cent lower than ICE models, while SUVs are 44 per cent lower than conventional ICE models, and HEV SUVs reduce emissions by only 27 per cent.

This means that 2024 PHEV sedans and SUVs are roughly two-times higher than BEVs powered by an average grid mix, and HEVs estimate 2.2 times higher for sedans and 2.5 times higher for SUVs.

The news is even more grim for hybrids when the grid is powered by 100 per cent renewable electricity, increasing the lifecycle emissions for HEV over BEVs to 4.9 times higher.

The ICCT expects new vehicles sold in 2030 to demonstrate an even larger gap. Conventional SUVs are estimated to have 7.5 times higher lifecycle greenhouse gas emissions than BEVs powered by 100 per cent renewable electricity.

And while PHEVs and HEVs will have a lower GHG footprint than ICE vehicles, the ICCT concludes that “their emissions reduction potential is more limited than for BEVs, which not only deliver emissions reduction at the tailpipe, but across the entire vehicle lifetime for representative sedans and SUVs sold in the United States.”