In what might be obvious news, your brakes are one of the most important components on your vehicle.
However, what many people don’t realize is that your brake system is the biggest energy waster on a conventional vehicle. When you push the brake pedal, you’re essentially converting your vehicle’s hard-earned kinetic energy into heat, which is then dissipated into the air and lost forever…hardly the picture of efficiency.
While hybrid vehicles have used regenerative brakes for years, new fuel economy rules and regulations are forcing automakers to consider the benefits of regenerative brakes on ALL vehicles. Here’s what that means to you.
What are Regenerative Brakes?
The name “regenerative” may be a bit misleading considering that regenerative brakes cannot actually “regenrate” themselves when they are damaged.
Instead, “regenerative” refers to re-capturing energy from the engine. Typically, regenerative brakes are used in fully-electric or hybrid motors. This is because of a unique feature of electric motors: When run forward, electric motors convert electrical energy into mechanical energy; when run in the opposite direction, an electric motor becomes a generator and captures energy.
Regenerative brakes work by using the motor as a generator when the brakes are applied, putting energy back into the battery pack and slowing your vehcile down at the same time.
The trick of regenerative braking is getting the motor to run backward and to do only do so when the motor can handle the energy. This task is handled by the most important piece of regenerative braking’s sophisticated electronic circuitry: the braking controller. When you brake, the braking controller diverts the kinetic energy that would have normally been lost back to the battery.
More importantly, the brake controller decides whether the motor is capable of handling the force necessary to stop the car. If the force would damage the motor or inhibit the vehicle’s ability to stop in time, traditional friction brakes (regnerative systems feature both regenerative braking and traditional friction brakes) take over.
While we’re talking about innovations in vehicle brake technology, it’s important to note that pending regulation in California will eliminate both the presences of heavy metals like copper in ceramic pads, as well as asbestos (that’s right, some brand new after-market brake pads contain asbestos).
How Efficient are Regenerative Brakes?
Hybrid vehicles with regenerative braking will typically see a 10-25% improvement in fuel economy, but the efficiency of regenerative brakes on a conventional gas only vehicle are to be determined, mostly because the system is still being perfected.
The most current iteration of regenerative braking systems on gas-only vehicles will likely boost fuel economy 5-10%, which isn’t bad considering that conventional vehicles will not use an electric motor to recapture braking energy. Instead, conventional vehicles will use capacitors or hydraulics to “store” energy re-captured from braking, which in turn will be used later (either as electricity or hydraulic pressure).
Mazda, using a system of capacitors, promises that regenerative braking on a non-hybrid can improve fuel economy as much as 10%, but real-world feedback indicates this estimate is a bit generous.
Still, when it comes down to it, automakers have to meet some very tough fuel economy requirements in the next decade. Regenerative braking systems – even if they can “only” improve fuel economy 5% – will absolutely be evaluated. It just might be that the next new car you buy – hybrid or non-hybrid – will feature regenerative brakes.