Waste Management World was the first magazine to try out the new heavy-duty Volvo diesel-electric hybrid truck chassis on waste collection duties. A trial vehicle has been in service in Gothenburg, Sweden, with Renova since last year. Malcolm Bates was the first journalist to drive it, and here he tells all ...
In the last couple of years, the word ‘hybrid’ has slipped into polite social conversation at the first opportunity; every film star or minor celebrity living in California seems to own a hybrid car and more recently, a number of manufacturers of light duty trucks – such as Isuzu, Mitsubishi-Fuso and Hino – have added diesel-electric hybrids to their respective product range catalogues.
From the conservationists point of view all that is to be welcomed, but getting beyond the ‘positive spin stories’ we get in the media, even a quick look at the lines of traffic trying to get into any of the world’s larger and more congested cities will confirm that many of the more essential tasks are not undertaken by cars, SUVs or light duty trucks. The real jobs, such as transporting fuel supplies, foodstuffs and consumer items into the city, and collecting and taking away waste materials and recyclables from it, tend to be handled by trucks upwards of 18 tonnes gross weight – and in the case of waste from commercial and retail premises 30+ tonnes gross weight. In other words ‘big trucks’, and these are still powered by diesel engines.
The solution? There are sure to be those who advocate the greater use of rail, or waterway barge traffic for transporting domestic and commercial waste out of inner city areas – after all, many of the world’s great cities are centred on navigable rivers. And rail lines are often under-utilized outside of peak commuter rush hour periods. The issues involved with the design and production of a true ‘multi-modal’ system are not to be underestimated however, and although the author has seen the multi-modal system designed by HN Logistic in Germany, the reality is: neither has it gone into full-scale production, nor has London – or any other major city authority – yet ordered a new fleet of multi-modal refuse collection vehicles.
But even if orders did start flowing, that still leaves the issue of what type of truck chassis should pick up waste in the inner city areas. Any notion of a dedicated electric battery chassis, even on the inner city operations, would still be a challenge in terms of vehicle utilization. To say nothing of the fact that a large part of the total gross weight would be battery packs – the highway authorities may have something to say on the subject of increased wear to city streets per tonne collected!
So just what is the future going to look like? A trip to Gothenburg, Sweden, might help put it all into some sort of perspective. There are a couple of good reasons: firstly, Renova, the commune-owned company charged with collecting all the household waste (not only in the Gothenburg, but in five neighbouring communes) has a history of innovation and of setting high environmental standards. And secondly? I’m sitting in it.
Two in one
The ‘it’ in question is a 26-tonne gross weight Volvo Hybrid 6x2 rear steer truck chassis, fitted with the very latest Geesink Norba ‘plug-in’ hybrid compaction refuse collection equipment; which means, in effect, we have two hybrid systems in one vehicle!
Of course the other thing Gothenburg is famous for, is for being the headquarters of Volvo Truck & Bus, so perhaps it’s not surprising that Renova was chosen to trial the Volvo diesel-electric hybrid concept last year.
At the time of my visit, the unit had been at work for several months around the downtown area. At first glance there’s very little – aside from the bold graphics on each side of the vehicle – to give the game away. It just looks like any other RCV working in Gothenburg. So what’s the attraction?
Lars Thulin has welcomed me to Gothenburg so I can see for myself. ‘See for myself’ is actually a pretty good description because as he introduces me to the crew just off the main downtown shopping area, I’m short of the usual aural references that accompany most refuse collection vehicles working in a city street; in other words, aside from the muffled sounds of waste materials being compacted and the bin-lifters doing their stuff, there is virtually no noise coming from the hybrid above the sound of passing traffic. I double-check by standing right up close at the back of the Volvo FM cab. Yes, actually the Euro-5 diesel engine is running, but only at tick-over speed, and it is very quiet.
Impressive noise reduction
How can this be? The packing system is still packing, and both bin-lifters are in constant use, so what is powering the hydraulics? This is where it gets a touch more complicated… because on this truck, the Geesink Norba body/hopper hydraulics are themselves powered by another hybrid system – whereby the truck engine charges an independent battery pack which then powers the hydraulics.
The pack is primarily charged overnight, so when stopped in downtown areas, up to 1000 container lift movements can be undertaken, plus enough compaction cycles to last an eight hour shift (or a combination of the two) can be accomplished without the truck engine having to be revved to provide the hydraulic power. That might not sound revolutionary, but I suspect if you were a downtown resident and your waste bins were emptied early in the morning, any such reduction in noise would be very welcome!
But while the advantages of the Geesink Norba plug-in system (which can also be fitted to existing conventional diesel truck chassis) are impressive enough, it is only half the story. The other half of this hybrid story is related to the chassis drivetrain. Just to recap on the principal already found in hybrid cars like the Toyota Prius: the internal combustion engine is there to do two things – drive the road wheels through a conventional propshaft and charge the hybrid battery pack. In most cases, at normal highway speeds, the internal combustion engine will be doing most of the work, except when full power is needed. In which case, the battery pack is capable of introducing an extra power boost into the driveline via an electric motor.
Stop/start technology
But where the hybrid really comes into its own is in congested city streets. In slow speed stop/start situations, the internal combustion engine is automatically shut down, and the drive comes from the electric motor powered by the battery pack. Should the traffic start to move off more quickly, further pressure on the accelerator will automatically start the internal combustion engine and engage drive.
That same principal seems to work equally well on light duty trucks – such as the Isuzu previously tested on behalf of Waste Management World. But surely the added weight naturally limits the environmental advantages of the battery-only mode on a heavy truck?
Having previously driven a number of hybrid cars and SUVs, it is clearly advantageous if a heavy-duty hybrid truck chassis designed for waste collection operations could have the same attributes. But how could that be engineered? After all, a distribution truck only needs to stop/start in city traffic and then provide auxiliary power for either a hydraulic tail lift, or perhaps a refrigeration unit in the body.
An RCV needs to power the compaction system, the bin-lifters, plus a considerable number of extra work lamps and other systems throughout the shift. And at the same time it has to work at up to 26 tonnes gross weight, sometimes stopping and starting on steep grades. How can all that be incorporated into such a chassis – especially without using up valuable payload capacity?
Well, thanks to the hospitality of Lars Thulin and his team at Renova those questions can be answered. Firstly, although essentially a ‘prototype’, the Renova trials vehicle is built to factory production standards in all respects. While a wider series of trial vehicles is due to go into service in other cities (initially around Europe, with London and Paris high on the list) others will follow.
Volvo is close to production, and Renault – and more recently Mercedes-Benz – have applied the same sort of technology to heavy duty chassis, so the opportunity to switch to a hybrid waste collection fleet is probably closer than you might think. It could be as close as your next fleet replacement. So a closer look at the costs produced by Renova are sure to make useful reading (see www.renova.se for the latest news) but the target of a 30% saving in running costs together with a ‘significant reduction’ in CO2 is achievable, I’m told.
Yes, there is a slight weight disadvantage, but with all the hybrid components contained within the chassis rails, a standard design of compaction body can still be mounted. There are still some details to sort out; Renova had previously experimented with stop/start technology, and indeed, Lars Thulin and his colleagues have also looked at replacing oil hydraulics with water hydraulic systems, with mixed success. It could also be the case that ‘pure’ electric bin-lifters – like those designed and produced by Icelandic manufacturer Ecoprocess – could be a part of a hybrid future as they reduce the quantity of hydraulic oil required. In the case of the trial Renova unit, a further body battery pack is located between the rear of the cab and the front of the body, combining this with the chassis battery pack could reduce weight by another 200 kg.
Fail-safe option
Yes, there is a considerable first cost disadvantage in considering hybrid truck chassis at this level. But according to Lars Martensson, director of environmental affairs at Volvo, this looks set to become less of an issue as greater numbers are built. In fact, he suggests that within five years, all new heavy truck chassis used for distribution could be specified with hybrid drivetrains as standard. Both he and Lars Thulin underline that one of the big advantages of this technology is that even if the high-tech electric systems fail, chances are the diesel engine (and its gearbox and propshaft) will probably still function and enable the truck to keep working.
But having looked at the other revolution contained within the cab of this trial unit – a state-of-the-art flatscreen TV screen with multi-function touch displays and full diagnostics reporting – I’d suggest that the next generation of hybrid RCV will in any event probably fix itself while out on the highway with little more than some remote input from an engineer sitting behind a computer screen back in the office! In fact, we’re about there already.
In electric mode
But the team at Renova had one last treat in store. On the pretext that we needed more photographs at the end of the working shift, Lars Thulin suggested we take the unit down to the historic dockside at Gothenburg where there was more space. By then I’d ridden in the hybrid while collecting in the downtown area and on a run to the waste transfer facility out of town.
On the highway, it performed much like any other RCV, and while working in the city the diesel engine sometimes cuts out completely, with the batteries alone providing drive. I was anxious to try this for myself, so it was with some mixed feelings that I took the driver’s seat. This is after all, a very expensive pre-production prototype and there was some very deep and cold water at the end of the dock!
The diesel engine did indeed shut down while I was driving the truck – the colour TV screen graphics informing me that the battery pack was fully charged. With Lars Thulin acting as ‘banksman’, I was able to turn the truck around in complete silence. I could hear exactly what Lars had to say (mostly jokes along the lines of ‘was I aware Sweden drives on the other side of the road to England?’) but had there been an emergency I would have been able to hear him easily.
True, while modern trucks with automatic gearboxes and power steering are far easier to drive than older designs, the total lack of mechanical noise really was a trip into the future.
Malcolm Bates is Transport Correspondent for Waste Management World
e-mail: wmw@pennwell.com
Information on the hybrid chassis: www.volvo.com
Geesink Norba plug-in compaction system: www.geesinknorba.com
MORE HYBRID WASTE TRUCK NEWS…
Four hybrid-powered Volvo trucks have been leased by Veolia Propreté for use in London and Paris from autumn this year. The vehicles are based on Volvo Trucks heavy-duty FE model but have some important differences from normal refuse trucks …
They operate using both a diesel engine and an electric motor and can alternate between using one or the other or use them in tandem. The electric motor is designed to be used when the vehicle is going slow or accelerating and is said to cut fuel consumption by 15-20%. An extra battery with a plug-in recharging facility to power the ancillaries also cuts an extra 10-15% off the fuel consumption.
Carbon dioxide emissions are low on these trucks and the electric power source enables them to give an exhaust-free and almost silent operation.
Tests on these hybrid vehicles took place throughout 2008 and series production has been scheduled for 2009. But the interest shown from Veolia is a good indicator that there will be a large demand for these trucks.
‘It is particularly gratifying that Veolia Propreté, an international company renowned for its dedication to green development, wants to be among the very first to harness the benefits of hybrid technology,’ said Claes Nilsson, President of the Europe division at Volvo Trucks.
Volvo will deliver the four vehicles to Veolia with all the necessary bodywork and they will be leased on a 24-month contract that covers service, maintenance and software upgrades.
‘We will carefully monitor how the trucks are used and how they are perceived by the drivers. This will provide us with vital information for the ongoing development of our hybrid vehicles,’ said Claes Nilsson.
