The development of the first retro-fit system is accelerating the drive to the conversion of thousands of existing vehicles. This includes large vans and buses, into fuel-saving and less polluting electric hybrids.
The result of collaboration between leading automotive engineering organisations is designed to operate as a simple plug-in development. The new technology is said to have performed well in final testing at the Millbrook national automotive proving ground in the UK.
And Transport Minister Andrew Adonis said the aim is for such low-carbon vehicles to become an everyday feature of life on roads in fewer than five years and for the UK to be at the forefront of the technology.
He added: “This research shows we can do that not only by producing new, more environmentally friendly electric cars, but by modifying existing vehicles. The technology could even be applied to buses which will help us to cut carbon emissions by even more.” Cranfield University
The development of what is known as the Addzev (affordable add-on zero emissions vehicle) is the work of experts from Cranfield University in southern England, the Millbrook Proving Ground, the Provector hybrid vehicle company and Oxford University, with specialist advice and financial backing from Europe’s Advanced Lead Acid Battery Consortium and the UK Department of Transport.
As part of the low-carbon research and development programme run by the UK’s Energy Savings Trust, the five-partner consortium has overcome many technical challenges to demonstrate how it is possible to convert much of the country’s vehicle fleet into hybrids. There are 30 million cars and vans on UK roads.
Using a standard Vauxhall Combo light delivery van, the development team retained the existing conventional front-wheel-drive diesel engine but added an electric drive powered by low-cost, advanced, lead acid batteries to the rear wheels.
roject leader Professor Nick Vaughan, head of automotive engineering at Cranfield University, explained: “This means you can operate the vehicle so that the back wheels free-wheel as it would have operated before the modification, or you can leave the front part non-operational and just work with the electrical system at the back.”
This transformed the van into a hybrid vehicle capable of achieving an all-electric range of more than 20 kilometres (12 miles) from one charge. New control software
Powered through twin liquid-cooled electric motors, with maximum power of up to 100 kilowatt and mounted in a sub-frame under the rear floor of the Combo, the retro-fit system provides zero-emission urban speeds of up to 60 kilometres (36 miles) an hour while the vehicle’s normal front-wheel-drive diesel produces power for out-of-town driving or higher speeds. Drivers can manually switch between electric or diesel modes of travel to achieve the best overall ultra-low emissions.
Lead acid batteries were chosen over the latest nickel metal hydride or lithium ion batteries because they are much cheaper, can be more readily recycled and their extra weight does not pose a problem in commercial vehicles.
For their Addzev role, they have already completed more than 161,000 km (100,000 miles) service on the Combo test vehicle without problem. Specially devised control software and power management systems - created by Cranfield University and the Provector company - provide the option of recharging by connection to the electricity grid or via the diesel engine that generates and stores energy when the vehicle is in motion. New potential
The head of transport advice at the Energy Savings Trust, Nigel Underdown, added: “With CO2 emissions caused by production, driving and disposal, swapping your old vehicle for a new electric or hybrid is not always the most sustainable solution. To be able to retrofit, so that the vehicle becomes more efficient and emits less carbon, is a wonderful solution.”
Professor Vaughan continued: “The project has shown the untapped environmental potential of modifying existing urban vehicle designs to hybrid. In the current economic climate, relying on the gradual penetration of newly built vehicles to reduce carbon emissions will not deliver much-needed carbon savings in the short term. Our target for Addzev was to demonstrate what could be achieved with the existing urban fleet.”