Electrification specialist Equipmake showed its latest pure-electric bus technology in the shape of a “repowered” version of the New Routemaster double-decker bus at the Euro Bus Expo held at the NEC in Birmingham England. The company’s process sees the hybrid drivetrain of the bus replaced with a ZED (zero-emission drivetrain) that uses 95% British-built component content.

With pre-service trials operated by Metroline already started in London, the electric bus is being assessed over the next six months to deliver valuable test data as Transport for London (TfL) as it continues to evaluate a range of clean technologies—including state-of-the-art repower systems such as Equipmake’s ZED. Charging infrastructure at Metroline’s Holloway depot, alongside battery data analytics for the bus, is being provided by EV fleet and battery storage specialist Zenobē.

“Repowering is a vital, cost-effective transitionary technology that can bridge the gap between diesel and a new electric bus fleet,” said Ian Foley, CEO of Equipmake. “London is leading the way in the adoption of green technologies for large commercial vehicles and as TfL continues to evaluate a range of clean technologies, we are confident our repower systems can play a rapid role in accelerating any zero-emission vehicle strategy.”

“Repowering technology has huge potential in enabling operators to accelerate the transition of fleets to zero emissions and we look forward to further evaluating this test vehicle over the coming six months,” added Adrian Jones, Engineering Director, Metroline.

The repowered bus, developed by Equipmake at its base in Snetterton, Norfolk, features a 400-kW·h battery enabling an expected in-service range of 150 mi (241 km)—said to be more than enough for a day’s running. Development was funded by the Advanced Propulsion Centre (APC).

The New Routemaster features Equipmake’s HTM 3500 electric motor. Seamlessly integrated into the prop shaft without the need for a separate transmission, the motor is engineered to meet the demanding requirements of a fully laden double-decker bus by producing 3500 N·m (2580 lbf·t) torque at a motor speed of just 1000 rpm and delivering 400-kW maximum power.

One of the ZED’s most important features is a patented ultra-efficient thermal management system, which maintains all three of the ZED’s key components—the battery pack, motor, and inverter—at an optimum operating temperature to maximize vehicle range. Featuring an advanced water-glycol cooling circuit, the system has the added benefit of providing interior heating during cold conditions with captured thermal energy.

When the battery is depleted at the end of a complete duty cycle, it can be recharged at the depot overnight via a CSS DC charging point.

The ZED can be applied to any existing hybrid or diesel bus, quickly upgrading the vehicle with a state-of-the-art battery drivetrain. A repower technology program involves an inspection of a bus to ensure its adaptability to Equipmake’s scalable modular electric chassis. Once verified, the process is quick, with up to five repowers a week being able to be completed, ensuring buses are off the road for as little time as possible.

Each repower is tailored to specific operator requirements, with service routes simulated to ensure the correct battery power level is selected for optimum performance and efficiency and a guaranteed driving range of 150-250 mi (241-402 km) is achievable. This is more than sufficient for a complete duty cycle, allowing buses to be recharged overnight.

Repowering buses with Equipmake’s technology also means a new lease on life for internal combustion engine vehicles that might otherwise be scrapped as operators transition to emissions-free driving. Instead of writing off a whole vehicle, repowering means the body and systems are effectively recycled—bringing huge environmental gains given that the manufacturing of a vehicle is one of the more polluting and energy-intensive parts of its lifecycle.

In addition to the environmental benefits, Equipmake says its repower program makes sense from a cost perspective, with each conversion coming in at less than half the price of a new electric bus. With most buses expected to remain in service for 14 years or more, operators can still make significant efficiencies by repowering a bus halfway through its working life.

“We know there is a clear appetite for repowering technology, with strong demand from operators, which is leading to the expansion of our facilities in Norfolk,” Foley continued. “Changes to grants for bus operators mean repowering is encouraged, and the DfT’s consultation on proposals to end the sale of new non-zero emission buses means demand for our technology will only increase. Add in the associated financial benefits of a repowered bus, and it’s easy to see why such vehicles can very quickly bring cleaner air to every town and city in the UK.”

Earlier this year, Equipmake was awarded a contract by First Bus to convert 12 Optare Versa buses from existing EV Generation One systems to Equipmake’s ZED. Conversion work has been carried out on the first Versa bus at Equipmake’s Snetterton headquarters, with the first of the buses expected to be back in operation on York’s roads this month.

In the coming months, Equipmake will be trialing additional repowered buses with other bus operators across the UK.