Flywheel Hybrid System for Premium Vehicles

The FHSPV (Flywheel Hybrid System for Premium Vehicles) project which bought together some of the UK’s most respected names in automotive engineering under the TSB umbrella has concluded its work to determine the viability of flywheel hybrids as a cost-effective and modular solution for production vehicle applications.
The consortium, comprising Jaguar Land Rover, Flybrid Systems, Ford, engineering consultancies Prodrive and Ricardo, and transmission experts Torotrak and Xtrac investigated the benefits of flywheel hybrids in a number of applications. Compared to conventional electric hybrid systems, mechanical flywheel hybrids reduce the number of inefficient conversions during the recovery and re-use of braking energy. Instead of converting kinetic energy into electricity, energy is stored in a high-speed flywheel with power transfer controlled by a compact continuously variable transmission (CVT). The Jaguar XF premium saloon used as the research vehicle has the flywheel hybrid system integrated into the rear axle, occupying part of the space normally used by the spare wheel.
Following conclusion of the programme the consortium has made the following statements with respect to outcomes:
• The development vehicle has demonstrated that this technology can deliver significant CO2 reductions in real world conditions, building on established stop-start gains
• In the industry-standard NEDC cycle, the flywheel hybrid and stop-start combined achieved an 11.9% percent benefit, a 6.4% improvement over start-stop alone.
• In the new ARTEMIS test cycle, which represents typical real-world usage, the flywheel hybrid system yields an 11% improvement over stop-start only.
• The system can be realised at significantly lower cost and weight than a typical HEV application.
This is a positive outcome for an early development system. Further refinements and related optimisation of other vehicle systems are expected to yield additional gains.