Why the flywheel hybrid could beat battery power

摘要

Flywheel energy storage has proven itself in F1 and will soon feature on road cars. Mention hybrids and most of us think of petrol or diesel-electric hybrids epitomised by the Toyota Prius. But a new breed of hybrid car - equipped with a very different form of energy storage to a battery pack - will be in the showrooms and on the roads in a few years, using a technology which is, quite literally, a spin-off from Formula 1. It's called Flywheel Energy Storage, or FES for short, Flywheels have been used since the steam age as a means of smoothing the rotation of reciprocating engines. Every car with a piston engine has one, at the clutch end of the crankshaft, where it stores and releases energy through its rotational inertia to calm the pulsed torque from successive cylinder firings. Using flywheels as energy storage for vehicle propulsion is nothing new; the famous Gyrobus buses exploited the principle when they went into service in Switzerland in 1953. The same principle, albeit in refined form, is at the heart of FES.