Double act of the future?
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With the cost of diesel soaring, the day of the hybrid electric truck could be closer than you think
Words: Colin Barnett UKoperators will soon have a choice of hybrid middleweight trucks, with DAF having been building up its launch stock over the past few months, and offerings from Iveco, Renault and Volvo on the way. However, it’s Mercedes-Benz that has led the way in getting drivable examples on the road, with more than 50 vehicles already in service in European LHD markets, and UK operators can now join the party.
Japan has been responsible for the rise of the petrol/ electric hybrid car, although overall fuel economy, and hence CO2 emissions, struggle to match a modern turbodiesel. Peugeot/Citroën and Volvo are just beginning to lead the sensible move to diesel/electric hybrid for cars and light vans, but in the world of trucks, Daimler is leading the way. Its global hybrid research is being carried out by the Fuso division in Japan and we are already familiar with the dozen or so hybrid 7.5-tonne Canters on operational trials in London.
The real volume, though, will come with the widespread arrival of its hybrid Atego. We’ve been able to drive the Atego BlueTec Hybrid, now available to order in the UK, which takes the concept on to the next generation, on public roads for the irst time.
There was a time though, when the UK led the world of hybrids. By the time the First World War started, a hundred-plus leet of petrol-electric hybrid omnibuses had already seen a few years of public service in Brighton. Built by Thomas Tilling, they carried on their duties until the early 1930s, when they were usurped by the newfangled diesel engine. It took the arrival of the £1 litre of derv for the obvious marriage of diesel engine and electric motor to happen. You can guarantee that if you operate distribution rigids, it won’t be long before a hybrid appears on your shortlist.
Why not an electric truck?
You may be thinking, “why not an electric truck?” and some igures from Mercedes might explain. While a van or small truck on limited range, return to base operation can get away with it, until there’s a revolution in battery storage density, the size of battery required to give a decent range is just too large. A 12-tonner would need a 2.6m3 battery weighing 5.2 tonnes to replace a 100-litre diesel tank, while a 40-tonne long distance artic would need a 52-tonne battery. One solution might come out of Southampton University, where a spin-off company has used nano-technology to create a battery the size of a paperback, which recharges in minutes, but can start a heavy truck engine. Although at least one major European truck manufacturer is likely to reveal its use of this technology in the near future, it’s going to be a while before it is commonplace.
Available only as a 12-tonner, the Atego Hybrid uses a parallel system with a four-cylinder OM924 engine producing 215hp and 810Nm working in conjunction with a 44Kw (59hp), 420Nm electric motor fed from energy stored in a 2kWh li-Ion battery operating at 340V. The two power sources are blended in the electric motor/ generator, which sits in the conventional clutch position, adding some 400mm to the power unit length. Although almost the full range of normal cab and chassis versions is available, packaging of the extra components, which reduce the Atego’s payload by around 300kg, means that the shortest wheelbase currently available is 4,700mm, with a 4,200mm option coming later in the year.
Fuel saving
In the urban distribution environment for which it is intended, the Atego shows an overall fuel saving of 10%-15%, according to Daimler. It admits that the concept is not yet cost-effective in comparison with diesel power, due to the high cost of components that are still at the expensive low-volume stage, so supply will only be on a full service contract basis. While UK costs were not available at the time of writing, igures from the European LHD markets indicate a premium of between 40% and 70% over a regular diesel Atego. The controls of the Atego BlueTec Hybrid will be familiar to anyone who has driven a Merc auto, with gears operated by a stubby central joystick, and the engine started by a normal key. The only major addition is an extra screen on a stand-alone sat-nav display, with a diagram of the power low and other related data. Provided the battery has retained enough charge from its previous journey, moving off is a weird sensation as you accelerate with the diesel engine still at tickover.
Unlike some hybrid cars, the diesel engine is always running when on the move, so that steering and brakes can be powered. It does, though, have the frst application in an automatic of the MSS S stop-start system.
Compared with the manual system, where neutral has to be selected, in the auto the engine stops after two seconds at standstill with the footbrake applied, a much more driver
friendly approach. ■