Brighter Sparks
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ELECTRICS AND HYBRIDS Brighter sparks Hybrids, range extenders and full-electric vehicles are getting a lot of airtime and attracting significant R&D dollars. But are some developers missing an engineering trick? Brian Tinham reports ybrids, range extenders generator – strictly speaking, making it a Nikola One this vehicle also runs under (series hybrids that relinquish range-extender hybrid). electric power, in this case harnessing diesels as part of the Also in North America, Mack is a 120kW/1,800Nm electric motor and drivetrain), full electrics… working on a range extender drivetrain a reduction gearbox to drive the back The look and feel not only – in its case a Wrightspeed Route axle. However, its 66kWh battery pack is Hof commercial vehicle powertrains but 1000 hybrid powertrain in place of augmented by a 100bhp 1.6-litre Ford also of their energy storage and delivery the conventional MP7 11-litre diesel engine, which provides charging on the technologies, as well as their associated engine on its LR RCV (refuse collection move – so boosting its electric-only 100 ‘refuelling’ infrastructures, is on the move. vehicles) chassis. Drive is all electric, with mile range to circa 370. And it’s no longer just about buses Wrightspeed’s 80kW Fulcrum multi-fuel Critical to this innovative little truck’s and a few vans and lightweight chassis turbine generator and its 730kW KERS likely acceptance, however, is its PREMS cabs – the former driven by subsidies, delivering the recharge. (predictive range-extender management the latter riding on the coat-tails of Coming down the weight range, in system), which harnesses GPS to accelerating take-up in the automotive the UK there is Tevva Motors’ 7.5-tonne determine when to fire-up the diesel sector. Mid to heavyweight trucks are range-extender truck, based on the and when not. For example, not in urban also now seeing significant engineering Chinese JAC N series chassis. Like the areas where zero emissions matter. innovation, if not yet much uptake. Look at Mercedes-Benz’s 26-tonne all- electric rigid – a revolutionary truck that TIME FOR A CHANGE? has already moved beyond last year’s IAA Hanover Show prototype into small Why the scale of activity now on electric and hybrid commercial vehicles? Partly it’s because vehicle series production, and trials with major manufacturers are alive to growing environmental pressures (regulatory and political) nudging the operators across Europe (see panel). industry towards cleaner and quieter trucks. Partly – and there is some causality here – high-profile Look also at US-based Nikola Motor fleets are concerned about their brands’ green credentials and the increasingly damaging impact of Company’s Nikola One full-electric long- diesel-driven transport. haul 6x6 tractor unit, which famously Full-electrics and intelligent range extenders, such as Tevva’s, ostensibly solve both problems while boasts 1,000bhp and 2,700Nm torque also enabling night-time deliveries, with their obvious potential to bear down on equally important traffic delivered via six wheel motors. Still congestion. And as the charging infrastructure improves, so the feasibility index looks more attractive. at prototype stage, this leviathan is However, technology too is on the move, with both the energy density and price per kWh of powered by a 320kW/h lithium-ion battery packs of all flavours looking increasingly favourable. Together, these mean that current payload battery pack, in turn charged via a penalties and the considerable on-costs of hybrids and full electric vehicles alike are set to diminish – hydrogen-electric 800V fuel cell (or, and quite rapidly, capitalising on developments in the consumer and automotive markets. optimally, a 400kW gas turbine-driven 14 www.transportengineer.org.uk April 2017 ELECTRICS AND HYBRIDS MERCEDES-BENZ ALL-ELECTRIC URBAN E-TRUCK STARTS OPERATOR TRIALS parallel hybrids – why, they say, do so few Following the launch of its all-electric 26-tonne implement automated disconnect-clutch gvw Urban eTruck – the first and with a range of technology? 200km – at last year’s IAA commercial vehicle KERS first, and one company show, in Hanover, Mercedes-Benz is now starting suggesting there’s a better way than customer trials across Europe. Initially, a “low two- the current (primarily flywheel and figure number” of Mercedes’ new zero-emission supercapacitor) options already in use trucks will go to customers in Germany, with is Lightning Hybrids International. CEO more to follow elsewhere in Europe later this year, Tim Reeser is a strong advocate of KERS according to Stefan Buchner, head of Mercedes- as an enabler not only for reducing Benz Trucks worldwide. emissions and fuel (diesel or otherwise) The vehicles – each initially offering a payload consumption, but also powertrain and of 18 tonnes – will be deployed in real transport braking wear. However, he believes operations, with a goal of optimising the electric existing approaches don’t have the truck’s concept and systems configuration, he capacity to expand adoption beyond, for says. “We are currently talking to around 20 example, buses and RCVs. potential customers from the waste, food and Hence his enthusiasm for a hydraulic logistics sectors,” states Buchner. “With this small Then Mercedes and Iveco offer all- alternative: “By using composite carbon series, we are now rapidly taking the next step electric variants of their established fibre accumulators for high-pressure towards a series product. By 2020 we want to be Fuso Canter (up to 6 tonnes) and Daily storage, our system is one sixth the on the market.” (3.5—5.6 tonnes) light commercials weight of an equivalent battery pack yet Details released so far are that 18- and respectively. Although both have been delivers six times the power density. It’s 26-tonne gvw models will be available, and around for a while, it’s still early days virtually an order of magnitude more will be equipped with refrigerated, dry box and for full-scale operations as the ROI and powerful.” And he suggests that means platform bodies. They will be handed over to payload equations don’t yet balance. more opportunities either for downsizing customer-operators for 12 months. Each will That may change, particularly in the existing engines in new vehicle designs, come with charging facilities appropriate to the lower gvw ranges, when (not if) the or retrofitting equipment to existing customer’s likely demand, and will be supported UK concedes a 4.25-tonne car driving trucks and buses to slash emissions. by Mercedes-Benz Trucks’ road testing department. licence derogation for alternatively “2017 will be our year of implementation: fuelled vehicles. UNIVERSAL BOOST step by step we are developing the vehicles and And there are diesel-electric hybrids, “Other than first start, our KERS offers systems to achieve market maturity,” insists such as the Fuso Canter Eco Hybrid (up massive acceleration support for Buchner. And he adds that Daimler Trucks’ analysis to 7.5 tonnes), with its 150bhp diesel launches, which are responsible for 80% reveals that battery costs will have fallen by a engine working in parallel with a 40kW of a truck’s pollution output, as well as factor of 2.5 between 1997 and 2025, with energy electric motor. Organic food producer a powerful built-in retarder for braking,” density increasing at the same rate – together Soyfoods is operating one, citing its insists Reeser. And that’s not all. “Our changing the landscape for all-electric heavy trucks. fuel-saving (up to 23% compared to the innovation has been in making this straight diesel equivalent) and green technology applicable across the market credentials as key to its selection. for every [parallel hybrid] platform, They all sound promising and the truck type and vehicle size. We’ve also list goes on. But, according to some in made it universal for drivers: there is the advanced driveline development no requirement for specialist training community, many may be missing because it is fully automatic.” potentially important tricks. In particular, Reeser claims several existing although KERS (kinetic energy recovery applications for Lightning Hybrids’ KERS systems) is used in practically all electrics – including in the UK on a DAF 18-tonner and hybrids to harness otherwise wasted operated by TradeTeam on DHL’s braking energy, insiders challenge the beverage distribution side. “That’s been underlying technologies. Equally – and running for one year,” he says, adding this criticism applies specifically to that the vehicle in question came with April 2017 www.transportengineer.org.uk 15 ELECTRICS AND HYBRIDS an unmodifi ed drivetrain, comprising a Paccar Cummins engine driving through a standard AMT (automated manual transmission). “We simply replaced the drive PPark.ark. ““MiraMira iiss vvalidatingalidating oourur ttechnologyechnology mmachineachine ssoo tthathat ddriverive ccanan bbee ffullull eelectric.lectric. shaft with two prop shafts, one for the for the European market, both from the ““LookLook aatt tthehe FFusouso CCanteranter EEcoco HHybrid.ybrid. TThehe conventional drive and the other for emissions reduction and vehicle integrity electric machine augments the diesel our system. Then we installed our high- perspectives.” engine but it can’t drive on electric alone. pressure energy storage and reservoir Meanwhile, turning to parallel hybrids Having spent all that money on the tanks – in this case behind the rear axle. for mid- to heavyweight vehicles, diesel, the Duonic dual-clutch AMT, the Electronically, the system integrates with Mike Savage, chief engineer at hybrid electric machine and battery pack, why the truck’s Wabco EBS so that when powertrains developer Drive System not spend a little more on an automated the driver brakes, it sees the signal and Design, wonders about their long-term disconnect-clutch?” captures energy hydraulically, via a high- viability. He points to the sheer cost For him, until Mercedes, Nikola and pressure pump, until the vehicle stops, and complexity of implementing both the handful of others pursuing heavy- when it reverts to the foundation brakes.” conventional and electric powertrains.