Make electric vehicles lighter to maximize climate and safety benefits [octobre 2021]
▻https://www.nature.com/articles/d41586-021-02760-8
One issue that has received too little attention, in our view, is the increasing weight of vehicles. Pick-up trucks and sport utility vehicles (SUVs) now account for 57% of US sales, compared with 30% in 1990. The mass of a new vehicle sold in the United States has also risen — cars, SUVs and pick-up trucks have gained 12% (173 kilograms), 7% (136 kg) and 32% (573 kg), respectively, since 1990. That’s equivalent to hauling around a grand piano and pianist. Similar trends are seen elsewhere in the world.
Electrifying vehicles adds yet more weight. Combustible, energy-dense petroleum is replaced by bulky batteries. And the rest of the vehicle must get heavier to provide the necessary structural support1. The electric F-150 weighs 700 kg more than its petrol-powered predecessor. Smaller electric cars are heavier than their petrol equivalents, too.
Why does this matter? First and foremost is safety. The likelihood of passengers being killed in a collision with another vehicle increases by 12% for every 500-kg difference between vehicles. [...] Pedestrians will also be at risk. If US residents who switched to SUVs over the past 20 years had stuck with smaller cars, more than 1,000 pedestrian deaths might have been averted, according to one study.
Heavier vehicles also generate more particulate pollution from tyre wear. They require more materials and energy to build and propel them, adding to emissions and energy use.
How big a problem is this extra weight? A rough comparison between mortality costs and climate benefits shows that it is significant. Under the energy systems operating in most countries today, the cost of extra lives lost from a 700-kg increase in the weight of an electrified truck rivals the climate benefits of avoided greenhouse-gas emissions.
Parmi les solutions proposées : taxer les véhicules en fonction de leur poid et faire en sorte que les gains d’efficacité des batteries servent à réduire leur taille plutôt qu’à en augmenter la puissance et l’autonomie.
#transport #voitures_électriques