Daimler engines as Wrightbus targets Euro growth

Flybrid technology

The flywheel in the new Flybrid mild hybrid solution

For an on-cost of £22,000 the flywheel hybrid option being offere in the Streetlite offered a fuel saving of 15%

Wrightbus is part of a team that, with the help of funding from the Technology Strategy Board (TSB), has developed a mechanical KERS (Kinetic Energy Recovery System) flywheel system capable of saving 15% on fuel consumption.

This mild hybrid system is capable of contributing to the propulsion of the bus but not fully driving it or powering ancillaries. The system alone is sufficient to take a bus from rest up to around 20mph.

At the heart of the system is a flywheel spinning at up to 40,000rpm/2,000mph in a vacuum within an immensely strong aluminium housing designed to contain all parts in the unlikely event of the flywheel disintegrating. This stores kinetic energy and then uses it to contribute to powering the bus.

The unit is designed to operate for the life of the bus with only a mid life service to change the oil and bearings, a task that will be completed on a service repair basis. It can be disconnected from the bus and it will run perfectly well without it in place, it will just use more fuel.

An attraction is that it can be used in conjunction with the Micro Hybrid technology to gain both sets of savings as each does a different job. This equates to a saving of over 24%.

At £22,000 per bus, the pricing is such that you could buy four Flybrid hybrids for the additional cost of one HEV full hybrid and buying the flybrids would save more fuel.

The Flywheel Hybrid ‘Flybrid’ project has already been running for a year and the first production vehicle is scheduled to go to Arriva for evaluation. By the end of 2014 it is planned that 25 units will be in operation with a variety of operators.

Streetlite EV

Wrightbus first showed the EV electric Streetlite at the NEC in 2012. It carries 150kWh of Lithium batteries on its roof and has a range of 76 miles on a SORT2 drive cycle until the batteries are run down to 30%.

A further fuel saving avenue down which Wrightbus is going with the EV is that of adding Induction Power Transfer (IPT). Backed by Green Bus Fund support, the first examples are to run in Milton Keynes where the buses will recharge at the end of each route via a contactless IPT system that boasts 95% transfer efficiency. Twelve minutes charging will give them the capability to run for 54 minutes on a high capacity 14.4 mile route through the city centre.

The first examples have already been delivered to Milton Keynes for driver training and are scheduled to go into service in the New Year, running from 07.00-23.00 and covering 56,000 miles annually. An example, with its distinctive front roof mounted pod, was present in Antrim.

Citea MLE

Occupying a prominent position on the VDL stand at the Busworld exhibition in Kortrijk, the VDL Citea MLE is the latest addition to the VDL product range. Based on the Streetlite, it is manufactured in Northern Ireland and sold in Europe by VDL. Slightly different in appearance to the UK Streetlite because it has been remodelled to reflect the styling of the rest of the Citea bus range, it also has a number of other specification changes introduced as a result of discussions with VDL. The steering has been redesigned so that it now returns to the centre, the lock is five degrees better and the turning circle is reduced. Two bevel boxes have been removed along with an intermediate shaft and the system has gone from a twin bearing system to a single hammerhead bearing system. These changes will come to the UK version towards the end of 2014. Also new on the Citea MLE was a redesigned cab area with a continental style dash arrangement with four dials instead of two and an additional child mirror on the nearside. Full air conditioning was also fitted.

Mark Nodder pointed out that the relationship with VDL went back over 15 years. One of VDL’s strengths was that it had a good sales and distribution network, which is an attraction to Wrightbus because it would be difficult to cover the Continent from Ballymena. Reaction at Busworld had been positive and VDL was now pursuing leads and tender opportunities with the model.

He said of the Citea MLE, ‘This is an important step in our strategy of expanding the reach of Wrightbus in key overseas markets. Europe is a priority target for us, and we know from operator feedback that there is significant potential for a high quality midibus that delivers exceptional passenger-carrying capacity in a highly fuel-efficient package.’