During braking, the kinetic energy is transformed into heat, which is then uselessly radiated into the environment. To help you get part of this energy back, we’ve developed the brake energy recuperation system, which uses intelligent alternator to store the energy in battery during deceleration and then uses it to lower the engine load by alternator, reducing the fuel consumption.
How does it work? When you brake with the engine, alternator increases its output to use engine’s kinetic energy, which would otherwise be wasted uselessly. Conversely, when engine power is needed, the alternator can lower its output and thus also its resistance to the engine. This helps to lower the fuel consumption in this mode and basically “recycle” the energy recovered during braking.
Article source: www.skoda.co.uk