Regenerative brakes translate kinetic energy into stored potential energy, with marginal friction and resistive losses. Friction brakes translate 100% of the kinetic energy into waste heat, through abrasion.

While it's true that regenerative brakes are not frictionless, none that I'm aware of rely on friction. One could imagine using a clutch to controllably wind/unwind a spring, for example, but auto manufacturers aren't rinky-dink steampunkers and even so you'd still do everything you could to minimize clutch slippage.

> While it's true that regenerative brakes are not frictionless, none that I'm aware of rely on friction.

They rely on the friction between the tire and the road, wearing the tire down, releasing the microplastic particles.

> They rely on the friction between the tire and the road

I don't think the tire is what people mean when they talk about the brakes. They mean the brake pads and other brake components.

It's literally what the linked article talks about, tyre wear not break wear.

This thread started when someone said ‘both brakes and tyres emit pollution’. The point was the brakes don’t when they’re regenerative. I’m sure the tyres still do. But that wasn’t what the thread was about.

> Regenerative brakes rely on friction just like any other.

I thought the resistance was provided by magnets in the motor? How do you think they capturing energy from friction?

What friction? The "regenerative" part is from the motors being driven in reverse and returning power to the battery.

Rolling friction in the tires / the contact patch's static friction.

This variable is a constant between both types of brakes. How is this relevant when comparing brakes? They both need it, one puts energy into a battery, the other one just heats up air due to the friction created by the system.

It's relevant to the question of whether regenerative braking produces dust from tire wear.

As compared to just straight braking — hence it’s irrelevant

The whole thread started with this message:

> Regenerative brakes rely on friction just like any other. Pollution is a given.

The article is about pollution from tires. Regenerative breaking can't cheat the laws of physics. That force has to be applied to the road through tires, just like any other form of wheel braking. And tires have significantly more mass to shed over their lives than brake pads.