Hybrid research project for buses

A hybrid research programme is aiming for a twenty percent fuel saving for buses and commercial vehicles.

The government-backed Technology Strategy Board is to help fund the new £1-million British-led programme involving a flywheel-based mechanical hybrid Kinetic Energy Recovery System (KERS).

Whilst electric hybrid systems have already been developed for bus applications and have demonstrated useful fuel savings, such chemical battery-based solutions add considerable weight and complexity, lead to increased whole-life costs due to regular battery replacement and also raise associated environmental and disposal issues.

In contrast, mechanical hybrids have been shown to offer up to twice the efficiency of a typical battery-based electric hybrid system in a package that is half the size, half the weight and a quarter of the cost.

Transmission specialist Torotrak (Development) Ltd will head the new “Flybus” programme with two consortium partners: international automotive engineering and technology provider Ricardo UK and Optare plc, the country’s leading supplier of eco-friendly, integrated single- and double-deck buses.

Allison Transmission Inc., the world’s leading manufacturer of medium- and heavy-duty automatic transmissions for commercial vehicles will also be involved, supporting the project with hardware and integration expertise.

The Flybus consortium will utilise Torotrak’s patented Continuously Variable Transmission (CVT) technology together with a high-speed composite flywheel for energy storage which has been developed by Ricardo UK, and which is known as ‘Kinergy’.

Both technologies have already undergone development as part of a flywheel-based mechanical hybrid KERS which has been designed for use in motorsport. The innovative mechanical hybrid system will offer the commercial vehicle sector an opportunity to cut CO2 emissions and deliver fuel efficiency savings of 20 percent.

The Technology Strategy Board is to provide £0.5-million for the Flybus research programme as part of its Low Carbon Vehicles initiative, with the consortium partners jointly matching this investment. The aim is to demonstrate a flywheel-based mechanical hybrid system in an Optare Eco Drive Solo bus and to confirm the benefits of mechanical hybrid systems for fitment as original equipment in new commercial vehicles and also as a retrofit system for updating existing vehicles. The consortium plans to demonstrate the new low emissions, high fuel efficiency vehicle to bus companies, fleet operators and regulatory bodies both in the UK and beyond.

The successful development of a mechanical hybrid system suitable for commercial vehicle applications will provide UK industry with a significant opportunity to manufacture and sell ‘green hardware’ for both newly-built vehicles and existing bus and truck fleets across the world.