Torotrak Group shared its vision for high-performance, low-emission hybrid powertrains that employ flywheel technology at the CENEX Low Carbon Vehicle event. Its idea involves a carbon-fibre and steel rotor spinning at high speeds in a vacuum to store kinetic energy. This energy is then extracted when vehicle acceleration is needed.
According to Torotrak chief engineer, Dr Andrew Deakin: “Using KERS [kinetic energy recovery system] power of 200 to 250 kW, we can deliver a hybrid vehicle that accelerates from 0-100 km/h in around four seconds, yet uses a downsized conventional engine with an output of as little as 30 kW to minimise carbon emissions.”
In terms of mass, flywheels are less energy dense than batteries, but have better power-to-mass properties. What this means is a lot of power can be made available in a short time – perfect for a boosting function. The other advantage is that the system costs a quarter of an equivalent conventional electric solution.