Flywheel technology featured on new generation ADL Enviro400s
Oxford Bus has received delivery of the first of 14 new ADL Enviro400s for its BROOKESbus network. They were presented to senior Oxford Brookes University directors and the media on 2 September, by Operations Director, Phil Southall.
The buses are the first of a new generation of Enviro400s by Alexander Dennis. They are the first Euro6 buses for service in Oxford, as well as the first with Gyrodrive hybrid power systems. This innovative system was developed in Oxfordshire by global engineering group, GKN and the Go-Ahead Group using F1 technology to improve fuel efficiency. The same equipment helped Audi’s R18 e-tron win at Le Mans last month.
It has a Kinetic Energy Recovery System (KERS), so that when the bus brakes, the technology harvests energy usually wasted as heat and stores it in a flywheel, which runs at up to 36,000rpm. When the driver accelerates, the system works in reverse, feeding energy into the traction motor. This reduces the work done by the engine, lowering fuel use by up to 25%. All of this means the power used and the exhaust emissions are at levels as good as the electric hybrids in the fleet but with a much lower add on cost.
GKN and Go-Ahead have agreed a deal that will help reduce emissions in cities by supplying electric flywheel systems to 500 of its buses over a two year period. The agreement covers the complete Gyrodrive system, including the innovative GKN Hybrid Power flywheel as well as GKN’s advanced EVO electric motor, a GKN designed and manufactured gearbox and installation. The system is designed to last for the life of the bus eliminating the need for any battery changes.
The Gyrodrive system uses a high speed flywheel made of carbon fibre to store the energy generated by the bus as it slows down to stop. It then uses the stored energy to power an electric motor which helps accelerate the bus back up to speed, generating fuel savings of more than 20% at a significantly lower cost than battery hybrid alternatives. Following successful trials on buses in London, Go-Ahead is now using the technology in the cities it serves across the UK, initially in London and Oxford.
The BROOKESbuses themselves are in an eye catching livery designed by the university, and the interiors too were specified as part of the contract. BROOKESbus is operated in partnership with Oxford Brookes University. New timetables are being launched on the network, which have seen the introduction of a few changes to services, as well as the addition of a new route. It will see the U1X become a fast service between Wheatley Campus and Harcourt Hill, serving only six bus stops along the route. The U5X will be extended to operate to and from Oxford City Centre. There will also be more journeys added to the Semester timetable. A new U4 service will commence from the start of the new Semester on 13 September, connecting Blackbird Leys and Cowley with Gipsy Lane and the John Radcliffe Hospital.
CEO GKN Land Systems, Philip Swash, said, ‘This is an important milestone for GKN Hybrid Power. We’ve worked in close partnership with Go-Ahead throughout the development of this innovative technology and it’s very exciting to move into the production phase. The fact that we are using the same groundbreaking technology that helped Audi win at Le Mans for the past three years to improve fuel efficiency in the public transport sector also shows what great innovation there is in the UK’s engineering sector.’
CEO of Go-Ahead, David Brown, said, ‘Our collaboration with GKN has been a most constructive one. We have a strong record in continually reducing our carbon emissions and flywheel technology will help us make buses an even more environmentally responsible choice and encourage more people to travel by public transport. The flywheel technology helps us to reduce our fuel consumption and C02 emissions so improving air quality for all those living in, working in and visiting the city.’
GKN Hybrid Power is based in Oxfordshire, with final assembly taking place in a new facility at GKN’s site in Telford. The Gyrodrive technology is being further developed for other mass transit markets including trams, construction and agricultural equipment. Earlier this year GKN announced the acquisition of Williams Hybrid Power from Williams Grand Prix Engineering Limited to form GKN Hybrid Power, which is focused on delivering complete hybrid solutions across multiple vehicle, power and industrial markets.