The development of hybrid technology continues apace around the world as truck manufacturers try and stay ahead of the game and prepare for an increase in demand for trucks with lower fuel consumption profiles. Oil prices will continue to rise, putting pressure on fuel consumption and, when the global economy does finally get going again, demand for fuel will accelerate the price rises. At the same time, governments around the developed world are heading towards introducing some form of carbon tax or pricing to reduce their nation's carbon dioxide footprint.
Other alternative technologies and alternative fuels are being developed around the world but, judging by the level of development dollars being poured into their development, hybrid electric trucks are likely to make the quickest impact. Hybrids have been available for several years in the Australian market, being supplied by both Hino and Fuso. They have been sold into a number of fleets and have met with a certain amount of success but are hampered by the very high price of the technology.
The problem for the truck manufacturers is to try and overcome the impediment of such a high price premium for environmentally responsible product. The high cost of the technology development and the cost of vital components in a hybrid system, i.e. high-tech batteries, electric motors and sophisticated electronic control technologies creates a substantial premium.
In a catch 22 type situation, higher volumes of sales will allow the manufacturers to spread the expensive development costs across more vehicles and the higher numbers would also tend to drive the cost of individual components down. The introduction of a carbon tax and higher fuel prices should change the equation and bring technologies like hybrids more to the fore. At the same time, societal pressure in the more environmentally responsible countries, like Northern Europe, will see highly visible companies using more hybrids, and advertising their use, to improve their environmental credentials.
The big truck manufacturers clearly believe hybrid is one of the routes down which the truck market is likely to go. All of the major players have put considerable effort into hybrid development and getting trucks out on the roads in real-world trials. Hybrid vehicles are delivering freight, collecting garbage etc. in North America, Europe and Japan.
In 2008 Daimler Trucks decided to integrate all of the different hybrid operations it is developing around the world into a single Global Hybrid Centre, based in Japan as part of the Fuso operation. There are still teams working in both North America and Europe, with Freightliner and Mercedes-Benz, but their work is coordinated from the Japanese headquarters.
The company already has hybrid product on the roads in the developed world. Japan, and Australia have the Fuso Canter Eco-Hybrid and we will see a much improved model coming onto the Japanese domestic market later this year – and, potentially, arriving in Australia sometime later. In Europe, Mercedes-Benz sells the Atego Blue Tec Hybrid in the medium duty market. Meanwhile, Freightliner sells the M2e Hybrid on the North American market.
These trucks are in the lighter end of the truck market but Daimler is looking to develop solutions for heavy duty trucks as well. In the lead up to the Tokyo Motor Show, Fuso announced the introduction of a new heavy duty hybrid truck which uses hybrid technologies to reduce consumption for the Japanese long-haul truck market. The new technology is going on trial in Japanese fleets to demonstrate its effectiveness.
“Our evaluation, so far, shows that hybridisation can indeed benefit heavy duty trucks in typical long haul operations,” says Gustav Tuschen, Fuso's Vice President of Product Engineering. “The conventional thinking is that hybrids best fit light duty truck operations in urban areas, since such operations involve many stops and starts. While small truck operations in big cities do benefit from hybrid power trains, due to their ability to frequently recapture braking energy, heavy duty highway trucks clearly can benefit as well.”
The system being used by Daimler follows the design principles which have become the norm for most of the truck manufacturers around the world. The parallel hybrid system is the simplest, consisting of a diesel engine and a battery both capable of putting energy into the drive train via the transmission. The company is also fitting the electric motor between the clutch and transmission, and not in its alternative position between the clutch and the diesel engine. This reduces the loss of energy during deceleration to the innate inertia in the engine, the clutch is disengaged as energy from the drive train turns the electric motor, which in turn charges the battery.
The development of the Fuso Super Great (FV in Australia) HEV product in Japan has implications for all Daimler truck products around the world. The basic components included in the driveline will soon be the same in North America, Europe and Japan. The engine being used is the Fuso 6R10, a version of the Detroit Diesel DD 13, on sale in North America. This will be on sale through Mercedes-Benz, as a Mercedes-Benz engine, this year. The 12 speed automated manual transmission is also going global. Starting off as the Mercedes-Benz Powershift, it is also expected to appear in Freightliner and has already been sold as the Fuso INOMAT in Japan.
Fuso has been trialing a number of trucks on the Tomei Highway which runs for 340km between the major industrial centres of Tokyo and Nagoya. These have shown a 10 per cent decrease in fuel consumption when compared to an identical, conventionally powered truck.
“On heavy duty long haul the environmental improvement is quite large,” says Genichiro Ishii, Senior Manager at the Global Hybrid Centre. “A 10 per cent fuel saving on these trucks is equivalent to an 11 tonne carbon dioxide emission reduction. This is more than five times higher than the environmental impact and contribution of our light duty hybrids which are showing a 20% saving in fuel consumption.
“We, at the Global Hybrid Centre, are developing a future common hybrid system with a modular concept to be used across all Daimler brand trucks and buses. We are working for all the Daimler brands. So the Super Great Eco-Hybrid is just a representative prototype of our technology platform for the future and we can include all of the technologies of the hybrid heavy-duty truck to maximise transportation efficiency in the future.”
The overall aims of the heavy duty project include bringing the technology to the point where the extra upfront costs of buying a vehicle are returned to the buyer in a period of between three to five years, with an emphasis on getting as close to three years as possible. The company also expects improved efficiency in the diesel engines used in its heavy duty trucks to reduce engine weight enough so that the combination of the whole driveline, including the lithium ion batteries and electric motor, will be around 200kg lighter than its conventional counterpart.
The current strategy is purely concentrated on getting the most efficient use of each litre of fuel over a long distance for a heavy duty truck. This means the system is designed and controlled in such a way to minimise energy losses and maximise energy recovery. This is a different strategy to the one being developed in Europe by Volvo, where it is possible for the truck to run using only battery power, with the engine turned off. This is to enable vehicles like garbage trucks to work in areas where local authorities are looking for zero emission vehicles.
“It is possible to run a truck purely on the electric motor simply by increasing the capacity of the battery being used,” says Genichiro. “But our mission is to just look for fuel efficiency from the hybrid, we don't want to waste electricity on purely electric driving. However, it depends on customer demand, if they would like the vehicles to start off only on electric, then we can adapt the system to do that easily.”
The decision by Daimler to follow this development route and exclusively seek lower fuel consumption over long distances is at odds with much of the other work being done to develop hybrids around the world. All of the hybrid vehicles sold, or on trial, around the European truck market concentrate on electric only running. All of them take off without using the diesel engine and can function without the diesel engine being turned on, for a certain amount of time. Of course, this makes them ideal for stop/start type applications but means they are not optimised for highway operation.
The spotlight was turned on to hybrid technology in Europe, recently, by the chairman of the ‘International Truck of the Year’ jury which gives the annual award to the truck judged to be the best in Europe. Gianenrico Griffini, editor of the Italian trucking magazine ‘Tuttotrasporti’ got all of the hybrid vehicles on sale in the European market together during the recent Solutrans Truck Show in Lyon, France. They were test driven by the jury to assess their differences and effectiveness.
“During the past few years, the main European truck manufacturers have been busy developing hybrid drivetrain versions of the diesel engine distribution rigid trucks and a number of these hybrid models have already reached a ‘pre-series’ or ‘limited series’ production phase,” said Gianenrico at the event. “According to the 2011 European Union Transport Policy White Paper, it is estimated that heavy-duty vehicles account for about 26% of carbon dioxide emissions from road transport, which is about 5% of total carbon dioxide emissions. The EU aims to reduce greenhouse gas emissions by 80 to 95% by 2050. Indeed the White Paper assumes a 20% reduction in greenhouse gas emissions by 2030 and 60% by 2050 compared to 1990 levels.
“These ambitious targets require an integrated approach. Hybrid trucks can be part of the solution, since they are able to reduce fuel consumption by 15 to 20% or more and, therefore, reduce carbon dioxide emissions by the same amount. However it is clear that the best results are achieved in difficult operating conditions like inner-city multi-drop distribution where there is low traffic speed and frequent traffic jams causing stop-go conditions.
“This is where hybrids excel as the electric mode provides the initial powerful pulling away from rest, when truck diesel engines typically consume the most fuel. Back on the highway those same hybrid trucks show (more or less) the same fuel consumption figures as a regular diesel model. If the truck is operated in a pure electric mode though, consumption reductions can be even higher.”
Talking to those who have experienced hybrids on the ground in real-world situations, there are mixed messages. The hybrid technology is a good idea but influences like driver behaviour can negate the effect of very expensive technology.
However, the amount of development dollars going into this technology tells us the big truck manufacturers are convinced this technology is going to get up and have a significant role in the future of transport. The control technologies to maximise the effectiveness of the systems and minimise the influence of human error are likely to help make the sums add up for those looking at spending the extra dollars required to reduce fuel burn and carbon footprint.