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History of fuel cell development at Mercedes-Benz
In 1994, the Mercedes-Benz NECAR proves that the fuel cell is suitable for driving vehicles
Continuous further development on the way to large-scale production
Field testing with over 100 vehicles supplies important data and experience from everyday operation
The surprise presentation of a Mercedes-Benz research vehicle with fuel cell drive was like the spark that starts a prairie fire. The proof that the fuel cell, the electrochemical power plant invented by Sir William Robert Grove in 1839, was suited to drive vehicles has been manifest to the whole world since April 13, 1994, the day on which “NECAR” (New Electric Car) captured public attention.
Since that memorable day, the sustained commitment and untiring activities of Daimler AG in matters of vehicular fuel cell drives, including the alternative fuels needed to operate them and the basic conditions which follow from them, have gained worldwide attention and respect down to the very present.
The topic of alternative propulsion systems was nothing new for the company, however. Time and again, it had engaged in research activities in this field. Precursors with respect to the use of hydrogen in the NECAR project were, above all, the sedans and vans which had been set up in the early 1980s on the basis of complex fundamental research: their piston engines burnt pure hydrogen rather than gasoline.
The idea is as simple as it is ingenious: when the elements of hydrogen and oxygen are permitted to react with each other under controlled conditions, this process generates electric energy – in a direct, chemical reaction which is also referred to as “cold combustion” by the experts.
It was to last over 120 years before Grove’s invention was revived. In the 1960s, the American National Aeronautics and Space Administration (NASA) was looking for an efficient energy system for its manned Gemini and Apollo missions. This technology also passed the practical test in submarines.
It was only on land that there was seemingly no use for this source of electricity. Too large, too heavy and too expensive – this was the verdict with respect to the direct conversion of chemical energy into electricity. It is therefore not surprising that professional circles pricked their ears when Daimler-Benz announced its plans to continue research into fuel cell technology and test its use as a source of energy for motor vehicles in 1993. Just one year late, in April 1994, the project was presented to the public.
Into the future with NECAR and NEBUS
NECAR 1, 1994: Laboratory-like van
On April 13, 1994, Daimler-Benz invited the international press to come to Eselsberg hill in Ulm, Germany, site of Ulm University and the new Daimler-Benz Research Center. The arriving journalists knew that something special was in the air since Edzard Reuter, chairman of the Board of Management of the integrated technology group, was scheduled to open the press conference and not, as originally expected, the host of the Ulm facility, Prof. Hartmut Weule, Board of Management member responsible for Research.
They were not disappointed because, to their astonishment, what Reuter and Weule introduced to them was not the new Research Center but the first vehicle in Europe featuring fuel cells capable of operating under workaday conditions. The vehicle was christened NECAR (New Electric Car). To distinguish it from subsequently introduced, further developed vehicles, it was eventually named NECAR 1.
NECAR 1, a Mercedes-Benz MB 100 van model, had already run up several thousand miles by the time of its presentation, operating on German roads with its revolutionary electric drive trouble-free since December 1993.
The research vehicle was more like a mobile laboratory than an automobile suited for daily use. The 800 kilograms (1,800 lbs) of the quite compact, though still voluminous, fuel cell power generation system, with hydrogen as fuel, including electronic controls, compressor, cooling system and hydrogen tank, plus a number of measuring instruments, filled the entire cargo space.
The output of the total twelve fuel cell stacks from Ballard Power Systems Inc., Canada, was 50 kilowatts (kW). The tank held 150 liters (40 gallons) of compressed gas (300 bars), adequate for a range of about 130 km (80 miles). The electric motor developed 30 kW/41 hp, giving NECAR 1 a top speed of 90 km/h (56 mph).
With this vehicle, Daimler-Benz proved to a worldwide audience beyond all doubt the basic suitability of the fuel cell technology as an electric vehicle propulsion system and, at the same time, highlighted its biggest advantages: its energy converting efficiency, appreciably higher than that of all drive systems previously used for automobiles employing internal combustion engines; its highest levels of environmental friendliness; and the fact that it used resources sparingly.
The range and speed of NECAR 1, though still modest, encouraged all interested parties. The next objectives were to reduce the size of the system, put more efficiency into it and, of course, take weight out of it. In addition, future fuel-cell-powered vehicles from Daimler-Benz had to permit operation on methanol, a liquid fuel that can be handled almost like gasoline.
Prof. Weule could be proud of what had been achieved in only three years. After all, he was the man who had unflaggingly been pushing ahead the development of the fuel cell vehicle drive since 1991.
NECAR 2, 1996: V-Class, six-seater
A Mercedes-Benz V-Class, a multipurpose vehicle with up to three rows of seats, which was just in the making at the time, was chosen as component carrier for the next research vehicle. On May 14, 1996, Daimler-Benz presented to the public the world’s first passenger car with fuel cell drive – NECAR 2. The V-Class – officially, the model did not begin selling until September – featured a 45-kW/62-hp electric motor under the short hood and an integrated 50-kilowatt fuel cell power plant.
The two hydrogen tanks, each holding 140 liters (37 gallons), were located under a dome on the roof which emphasized the body lines. The maximum speed was 110 km/h (68 mph) and the range a good 250 kilometers (155 miles). The six seats were available to the occupants with no restrictions.
In place of the twelve fuel cell stacks of NECAR 1, total output 50 kW, NECAR 2 now had only two stacks consisting of 150 cells each but the same overall output. First and foremost, this was achieved with completely newly developed fuel cells with more effective power output and higher operational reliability. The waste air from the fuel cells was used for energy recovery and optimal air supply to the fuel cells.
All in all, the fuel cell system in NECAR 2, reduced in size and volume, weighed only about 270 kilograms (600 lbs) or one third of its predecessor. The scaling down of the system and the enhancement of efficiency were accomplished. The future of the fuel-cell-powered vehicle had been brought a little closer.
“The Group,” said Daimler-Benz Research Chief Prof. Weule on the occasion of the presentation of NECAR 2, “continues traveling in the fast lane worldwide with this revolutionary technology. No other company in the automotive industry in Europe, the U.S.A. or the Far East has attained our level in research activities regarding the fuel cell.”
The presentation of NECAR 2 caused a sensation throughout the world: “The Times” called NECAR 2 “a breakthrough in exhaust-free driving.” “Reuters” called it a “a giant step forward for Daimler and Ballard, who have reduced the cells to less than one fifth of their original mass without sacrificing power.” The specialized “Hydrogen & Fuel Cell Letter” pointed out that the U.S. Energy Department’s timetable did not provide for a fuel cell energy system before 1998, a concept car before 2000, or a prototype before 2004. The Letter estimated that “Daimler’s announced schedule is at least four years ahead of the U.S. plans.”
NEBUS, 1997: Environmentally compatible city bus
Thought was first given to a bus with a fuel cell drive in March 1994, even prior to the presentation of NECAR 1. On May 26, 1997, Daimler-Benz finally presented the NEBUS (New Electric Bus) in Stuttgart. It was the product of the collaboration of Daimler-Benz Research, EvoBus GmbH, the Group’s Competence Center for Emission-free Commercial Vehicles (KEN) and Zahnradfabrik Friedrichshafen.
The basis of the NEBUS was the Mercedes-Benz O 405 OH standard city bus. It used hydrogen as source of energy and was therefore a genuine “Zero Emission Vehicle”. Thanks to electric drive it was extremely quiet; one could merely hear the low hum of the wheel hub motors, the air compressor and the tire noises. The practical bus, licensed by the German Technical Inspection Association, was 2.50 meters (8ft 2 in) wide, 3.50 meters (11 ft 6 in) tall and 12 meters (39 ft 4 in) long, had a curb weight of 14 tons and accommodated 34 seated and 24 standing passengers. The entrances were only about 34 centimeters (13 inches) above the ground. This low-floor design was made possible by the wheel hub drive developed by ZF Friedrichshafen in which electric motors close to the wheels directly transmitted the current from the fuel cells to the wheels.
During braking, the wheel hub motors acted as “engine brakes,” producing excess current in the process which was converted into heat on the roof in water-cooled brake resistors and escaped into the atmosphere. The transmission and drive shaft required by a diesel bus were dispensed with.
NEBUS had a range of 250 kilometers (155 miles) on one tank filling, easily enough to handle the average daily distance covered by a regular service bus, 140 to 170 kilometers (87 to 106 miles). Its top speed was around 80 km/h (50 mph).
Owing to the powerful wheel hub motors, shifting was unnecessary; the bus’s gentle, continuously variable acceleration scored well with passengers. The reaction time of the fuel cells was very dynamic: when the accelerator was depressed, the power was available in less than one second and proved to be entirely comparable to that of a good diesel engine. Air-cooled 75 kW/102 hp three-phase asynchronous motors were fitted – one each on the right and left of the rear axle. The total output of 150 kW/204 hp matched that of a good diesel drive. There were additional supply systems and reserves for the on-board electric power supply with power steering, compressed air, brakes and door controls.
Ten stacks with 150 fuel cells each fitted in the rear of the NEBUS delivered a total output of 250 kilowatts and 720 volts of electricity. 21 kilograms (46.25 lbs) of hydrogen were stored in seven roof-mounted fiberglass-wrapped pressurized aluminum tanks at a pressure of 300 bars.
The NEBUS was about 3.5 tons heavier than a conventional diesel bus and had a relatively high center of gravity. To prevent the roof load of some 1,900 kilograms (4,185 lbs) from amplifying any pitch and roll especially during cornering, specially developed sensor-controlled adaptive shock absorbers suppressed these tendencies by adjusting the tension and compression stages of the shock absorbers to the different loads and permitting only slight tilt, much to the benefit of the passengers and their safety.
The on-board electric system featured three distinct voltage levels: 600 volts for driving and for the ZF axle with the wheel hub motors; 380 volts for the power steering pump and the air compressor, and finally 24 volts for the vehicle power supply and the reserve power steering pump. Another environment-friendly detail were the solar roof hatches with the aid of which the electric current generated by solar cells was converted to operate the air-conditioning and ventilation ducts independently of the rest of the electric system.
The NEBUS proved its workaday suitability in real-world operation in Mannheim; further demonstrations in various locations around the world followed.
In 1998 the Daimler-Benz partner Ballard Power Systems Inc. delivered three American “P3” prototype buses with fuel cell drive as test vehicles to the Chicago Transit Authority and three to BC Transit, Vancouver.
NECAR 3, 1997: A-Class with methanol reformer in the trunk
At a Board of Management meeting in April 1996 Dr. Dieter Zetsche, head of Development at the time, emphatically spoke out in favor of getting the next fuel cell concept car – it was planned to build a Mercedes-Benz A-Class to run on methanol – on its wheels as quickly as possible, even if the methanol reformer that was undergoing development was not yet minimized in volume to an extent that it could be fitted into the sandwich floor of the A-Class.
With this car, Prof. Weule saw his vision of 1991 fulfilled: within five years, he had imagined traveling in a vehicle that uses easy-to-handle methanol as a fuel, which is reformed into hydrogen on board the vehicle.
September 10, 1997, thus rang in a new era of alternative vehicle propulsion systems with the showing of the NECAR 3 in Frankfurt am Main, a car based on the A-Class, the compact Mercedes-Benz with the double floor and the modest length of 3.60 meters (11 ft 10 in). The pioneering innovation in this car was the world’s first fuel cell system incorporating the on-board production of hydrogen. Methanol served as fuel; the hydrogen needed to operate the fuel cell was generated from it with the aid of a reformer.
The reformer – a complex in-house development of Daimler-Benz, still in its early stages –used in the NECAR 3 had the character of a laboratory model. It needed a great deal of space in the rear passenger compartment and definitely required further reduction in size. The “rest” of the fuel cell system was already working “underfloor.” When the gas pedal – a gas pedal it was, indeed – was depressed, the system responded, delivering 90 percent of its maximum output in just two seconds – a fuel cell car with the dynamic power of an automobile with combustion engine.
This sedan was the first of a new generation of fuel cell cars equally suitable for use in heavily populated downtown areas as they were for long-distance journeys, because refueling with methanol – every filling station could offer this fuel in future – would be a familiar exercise for the owner of such a vehicle.
As in NECAR 2, in NECAR 3 two stacks with 150 fuel cells each sufficed to generate 50 kilowatts output. They worked at a temperature of about 80°C (176°F). The water produced during operation of the fuel cells was reused to reform the methanol into hydrogen.
A tank filling of 38 liters (10 gallons) of methanol provided a range of easily 300 kilometers (186 miles), and the electric motor developing 45 kW/61 hp permitted a top speed – intentionally limited – of 120 km/h (almost 75 mph).
NECAR 4, 1999: Emission-free driving pleasure
NECAR 4, also based on the Mercedes-Benz A-Class, was a “ZEV,” a Zero Emission Vehicle with pure hydrogen operation, and was presented to the world on March 17, 1999, in Washington, D.C., by Jürgen E. Schrempp and Robert J. Eaton, then CEOs of DaimlerChrysler.
Outstanding features were the space for five passengers plus luggage, the range of over 450 kilometers (280 miles), and the driving pleasure afforded by a top speed of 145 km/h (90 mph). In short: emotions instead of emissions.
The two stacks in NECAR 4 each consisted of 160 individual, tightly packed fuel cells which together attained an output of 70 kilowatts, about 40 percent more than the predecessor, NECAR 3. They fitted together into a suitcase-sized box and thus all found room in the underfloor of the A-Class.
The fine touches to the cell components resulted in a clear-cut improvement in power generation and current intensity, which was now around 340 amperes – in contrast to the 260 amperes of NECAR 3 – with no impairment of efficiency. In this case efficiency means: of the chemical energy contained in the hydrogen, as much as 80 percent is converted into electric energy at part load, and still a good 50 percent at full load.
In NECAR 4 the electric motor and transmission also were of new design: the transversely installed asynchronous motor in the nose of the A-Class with an output of 55 kW/75 hp embodied a new design principle in which the motor enclosed the drive axle. The transmission was integrated in the right side of the motor to save space. From there one half-shaft led directly to the right front wheel; the other ran through the motor to the left wheel. Moreover, this motor attained its maximum torque as early as the car moved off, a decisive characteristic for very dynamic driving performance.
The cold liquid hydrogen (-253°C or -423°F) was located in the rear in a cylindrical tank of 100 liters (26.5 gallons) or five kilograms (11 lbs) capacity; it extended slightly into the trunk from below. To maintain the extremely low temperature, it was made up of two steel capsules, one inside the other, so that it looked like an oversized thermos flask.
But since the fuel cells required gaseous hydrogen to operate, the ice-cold liquid fuel passed into the gaseous state on the way to them. This was achieved by means of two heating elements integrated in the tank; they ensured that the stacks were supplied with hydrogen gas immediately upon starting and allowed them to supply electricity instantaneously. The result was starting behavior which easily compared with that of conventional vehicles.
NECAR 4 was a vehicle which was very well suited for fleet use, for delivery services, and for taxis operating in a defined region. The quiet and emission-free vehicles can return to their fleet headquarters and be supplied again with new energy at a central hydrogen filling station. Refueling hardly takes any longer than for a gasoline- or diesel-engined vehicle.
NECAR 4a (advanced) 2000: Practical testing with hydrogen
The NECAR 4a version served practical testing. Introduced on November 1, 2000, NECAR 4a became the basis, already prepared for small series, of further planned A-Class cars of the same design, intended to undergo intensive field and road tests in California until 2003 under everyday conditions in the California Fuel Cell Partnership.
In contrast to the NECAR 4 introduced in 1999, the “California” NECAR 4 operated on compressed hydrogen. It also attained a top speed of 145 km/h (90 mph), but additionally featured better driving dynamics owing to the optimized 55 kW/75 hp electric motor.
In the compact fuel cell system, the core of which was now made up only of a single Ballard Mark 900 stack with 75 kilowatts output, the volume could be halved and the weight reduced by another third. The three hydrogen tanks in the underfloor, with a volume of 140 liters (37 gallons) each, were pressurized to 350 bars. The approximately two kilograms of hydrogen sufficed for a range of 200 kilometers (over 120 miles). The use of components of lightweight design both in the passenger compartment and the body additionally reduced weight.
NECAR 5, 2000: A milestone on the way to production standards
NECAR 5, after NECAR 4a actually the sixth version in the line of NECAR concept cars, was presented on November 7, 2000, in Berlin by Jürgen E. Schrempp, then Chairman of the Board of Management of DaimlerChrysler, in the presence of then German Chancellor Gerhard Schröder.
NECAR 5 was the world’s most advanced fuel cell car and the mature successor to NECAR 3, with which the Group first demonstrated in 1997 that hydrogen for the fuel cell can be obtained from methanol with the aid of a reformer on board the vehicle.
The still quite voluminous reformer of NECAR 3 was halved in size in only three years, and its weight was reduced appreciably. So for the first time, NECAR 5 housed the entire fuel cell system including reformer in the sandwich floor of the Mercedes-Benz A-Class, whose interior now belonged entirely to the passengers and their luggage. The top speed was over 145 km/h (90 mph), and the car was capable of covering a distance of more than 400 kilometers (250 miles) before refueling – thanks to the 45-liter (12-gallon) tank.
Also due to measures designed to reduce body weight, NECAR 5 was about 300 kilograms (660 lbs) lighter altogether than its direct predecessor, NECAR 3. Driving dynamics and acceleration benefited from this, as they did from the more powerful 55 kW/75 hp electric motor and the higher output of the fuel cell, whose sole stack module delivered 75 kilowatts as in NECAR 4a. This module, together with the sensors, the humidifiers and the electronics, fitted into a vibration- and shock-resistant container with compact dimensions (80 x 40 x 25 centimeters or 32 x 16 x 10 inches).
The Ballard Mark 900 stack was already designed for large-scale production. Owing to a newly developed coolant on ethylene-glycol basis, the drive system was now frost-resistant and ready to start even in icy winter weather. Like the diesel engine of former days, the system required a warm-up time before reaching working temperature.
1,111-kilometer record run with NECAR 5
For the Mercedes-Benz research cars of the NECAR series it has always been: drive, drive, drive – as much and as far and as long as possible. To demonstrate the performance of NECAR 5, the car was put through a first long-distance test in December 2001 on highways No. 1 and 101 in California. It ended with a new record: 1,111 kilometers (690 miles) in two days. During this record run the car managed about 13 hours of daily operation with no problems worth mentioning. It was the longest test drive of a methanol-powered fuel cell vehicle until then. Thus, the propulsion technology of NECAR 5, with fuel refilled the conventional way, fulfilled the hopes placed in it on its first major attempt. Further long-distance trials were scheduled in which the main concern was coping with difficult topographic and climatic conditions.
Fuel cell testing under normal operating conditions
Fuel Cell Sprinter, 2001: Van tested by customer
The commitment of DaimlerChrysler to commercial vehicles with fuel cell drives deepened. On July 26, 2001, the first cooperation with a customer, the Hamburg-based distribution company Hermes Versand Service, was sealed. The deal was for Hermes to test the world’s first van featuring a fuel cell drive system, a Mercedes-Benz Sprinter, under everyday conditions over a two-year period. In a first test phase the prototype was initially deployed in the Stuttgart metropolitan region, and then, after the Hermes drivers were instructed, in Hamburg.
The basis of the fuel-cell Sprinter was an all-wheel-drive version, though reduced to pure front-wheel drive. Instead of the standard combustion engine it had a 75 kW/102 hp electric motor coupled to a six-speed semiautomatic transmission. The current of this motor was supplied by a single compact fuel cell stack. The underfloor configuration of drive technology and tank system permitted full use to be made of the cargo space. Front-wheel drive and power steering went a long way toward ensuring good handling. The top speed was about 120 km/h (75 mph).
In the first twelve months of operation, the realistic testing, scheduled for two years, already confirmed the ambitious expectations regarding the fuel cell van’s suitability for everyday use. Up to that point the van had traveled over 16,000 kilometers (10,000 miles) without serious snags. Modifications to the system based on the knowledge gained in the course of the testing improved operational reliability, range and economy.
The fuel consumption about equaled that of the diesel-engined Sprinter available at the time – an outstanding result for this still young technology, particularly seeing as parts of the drive train were not up to the now possible standard. Filling up with hydrogen hardly took longer than with diesel fuel.
Its drivers, trained merely to deal with certain peculiarities of the hydrogen technology, were captivated by the ease of operation, the maneuverability, the quietness and the range of easily 150 kilometers (well over 90 miles).
Test under practical conditions
In October 2002, DaimlerChrysler presented the A-Class F-Cell and announced production of a small series of 60 cars. From 2003, these were tested in everyday operation in small fleets of customers in Europe, the U.S.A., Japan and Singapore within the framework of government-subsidized international cooperative ventures. The scope of delivery in each case also included a hydrogen filling station.
At the same time, the first of 33 Mercedes-Benz Citaro city buses with zero-emission fuel cell drive was presented; also from 2003, they were operated in demanding line service by the local public transport authorities of ten cities in a two-year test.
The cities involved in the project were Amsterdam, Barcelona, Hamburg, London, Luxembourg, Madrid, Porto, Stockholm, Stuttgart, Reykjavik und Perth/Australia. In Europe, this field test formed part of the CUTE (Clean Urban Transport for Europe) hydrogen project. In November 2005, another three buses were supplied to Beijing. In March 2006, the European CUTE project was extended by one year with the aim of incorporating more practical experience in fuel cell research.
The Citaro fuel cell bus was the successor to the NEBUS. It had a range of some 200 kilometers (125 miles) and, depending on its equipment, capacity for up to 70 passengers. The fuel cell module with an output of over 200 kW/272 hp and the compressed-gas containers holding the hydrogen compressed to 350 bars were accommodated on the roof of the bus. As in the production bus with diesel engine, the electric motor, transmission, propeller shaft and rear axle were installed in the rear. The bus reached a top speed of 80 km/h (50 mph).
Environment-friendly Sprinter in commercial delivery service
On May 19, 2003, a cooperative venture of DaimlerChrysler, the U.S. Environmental Protection Agency (EPA) and United Parcel Service (UPS) was announced. This meant that the first nation-wide large-scale demonstration project for the practical testing of fuel cell vehicles in everyday commercial delivery service was launched in North America. The project was headquartered at the EPA in Ann Arbor.
For express deliveries, a Mercedes-Benz A-Class Fuel Cell was entered into everyday service. Two Dodge Sprinters were the first commercial vehicles powered by fuel cells to be used in commercial delivery service in North America – with the cargo space of the panel van being in no way restricted by the on-board equipment.
The U.S. administration showed great interest in this technology. On August 12, 2003, for instance, the then Secretary of Energy Spencer Abraham visited the development center in Kirchheim/Teck-Nabern, Germany, to inform himself about the status of fuel cell activities at DaimlerChrysler.
A major challenge in fuel cell development was the improvement of cold-start ability. In the early stages, the water responsible for carrying the protons in the fuel cell froze at temperatures below freezing point. In the spring of 2004, the corporate Research Center in Ulm presented the crucial breakthrough: a cell in which water can no longer freeze thanks to high-precision water-supply management and heat management. They modified the structure of the MEA (Membrane Electrode Assembly) in such a way that the water is kept where it is required for ensuring the fuel cell’s high performance. At the same time, water quantities were reduced to a minimum in areas where freezing may cause damage. Based on this research work, the fuel cell can now be started at temperatures as low as minus 20°C (minus 4°F).
The A-Class F-Cell proves itself
During the Frankfurt International Motor Show in 2003,
Mercedes-Benz made three A-Class F-Cell cars available for the press shuttle service. These cars were used to take journalists to the individual trade fair halls.
On June 18, 2004, the first passenger cars powered by fuel cells were handed over to German customers in Berlin. Partners Deutsche Telekom and BEWAG/Vattenfall Europe took delivery of four A-Class
F-Cell cars for their fleets. “With the delivery of the cars for everyday operation, we are entering a new stage in Germany in that the fuel cell technology has left the research status behind,” said Dr. Thomas Weber, member of the Board of Management with responsibility for Research and Technology as well as for Development at
The German chancellor also had the opportunity to gain hands-on experience with this advanced technology: in August 2004 the chancellery’s fleet was extended by the addition of an F-Cell car of which the then Chancellor Gerhard Schröder personally took delivery, saying: “The fuel cell is an important contribution toward ensuring sustainable mobility and making it economically and ecologically acceptable - especially against the background of present-day oil prices.”
It went without saying that the cars in Berlin had to be capable of obtaining hydrogen for refueling. Therefore, Europe’s first regular service station for fuel-cell-powered passenger cars started operating here in early 2005. In March 2007 the German Federal Ministry of Transport also took delivery of an A-Class F-Cell vehicle.
Record: Reliable 24-hour operation
On the road for 24 hours with stops just for refueling – this was achieved with an A-Class F-Cell on the test track in Idiada near Barcelona, Spain, in late November 2004. It was the first time a fuel cell car proved itself in endurance testing. The car covered just under 8,500 kilometers (5,300 miles) at an average speed of around 120 km/h (75 mph) – without a hitch.
B-Class with fuel cell drive
In March 2005, the fuel cell drive advanced to the sports tourer category when Mercedes-Benz presented a B-Class car with this progressive propulsion system at the Geneva Motor Show. Its electric motor developed over 100 kW. Thanks to the fuel cell’s reduced hydrogen consumption and improved efficiency, the range doubled to almost 400 kilometers (250 miles).
Practical testing with more than 100 fuel cell vehicles
The largest practical test of fuel cells to date was started in 2003 and involved over 100 fuel cell vehicles of the company, operated throughout the world under the most diverse conditions. The fleet of passenger cars, buses and vans supplied valuable findings for the ongoing development of this promising technology.
On September 1, 2005, DaimlerChrysler and Ford took over the fuel cell business unit from Ballard, Ballard Power Systems AG headquartered in Nabern. The two equal-status partners founded a joint venture, NuCellSys GmbH, which is equally headquartered in Nabern. The company closely cooperates with Ballard in pushing ahead with the development of the fuel cell technology. DaimlerChrysler and Ford concentrate on the integration of fuel cell drive in vehicles, while Ballard engages in the further development and manufacture of fuel cells and electric drive systems for fuel cell vehicles.
The Tokyo Motor Show in October 2005 was the venue for a premiere in progressive technology: Mercedes-Benz presented the F 600 HYGENIUS research car. With this car, the company took a significant step forward in that it not only incorporated a further developed fuel cell drive system but was also a car specially designed for the fuel cell, rather than being installed in the existing bodywork of a large-scale production vehicle. Dr. Thomas Weber: “We are thus taking a big step ahead on the way to a fuel cell system that is ready for the market. This is a goal we are set to reach between 2012 and 2015.” The F 600 HYGENIUS sounds a clear signal.
The engineers have reduced the size of the fuel cell by some 40 percent; in spite of this it operates more efficiently today and boasts good cold-start ability. This is achieved with newly developed fuel cell stacks, an electric turbocharger and a new humidifying and dehumidifying system. With a peak output of 86 kW, the F 600 HYGENIUS develops a maximum torque of 350 Newton meters. The continuous output of the fuel cell drive is 60 kW at a torque of 250 Newton meters. Energy not required is stored in a lithium-ion battery. Energy consumption is equivalent to 2.9 liters of diesel fuel per 100 kilometers (81.11 mpg). When required, the F 600 HYGENIUS can also be used as a mobile power generator: its electric output of 66 kW would suffice to supply several detached houses with electricity.
Important experiences on the way to production standards
In May 2006, the test fleet of over 100 fuel cell vehicles beat the magic mark of two million kilometers (1.24 million miles) covered overall. The 60 A-Class F-Cell cars accumulated over 705,000 kilometers (437,800 miles) in 21,600 operating hours. The fleet of 36 buses covered 1.25 million kilometers (776,250 miles) in just under 86,000 operating hours, and the fuel-cell-powered Sprinter vans had clocked up 58,000 kilometers (36,000 miles) in almost 2,200 operating hours. “Worldwide fleet testing is in full swing and with two million kilometers covered supplies valuable experience and findings for the ongoing development of the zero-emission fuel cell drive,” says Prof. Dr. Herbert Kohler, head of Group Research and Advanced Vehicle and Powertrain Engineering, as well as the Group’s Chief Environmental Officer.
Fire-fighting and police cars with fuel cell drive
The first fuel-cell-powered car for use in fire-fighting was put into service in January 2007 when DaimlerChrysler handed over a Mercedes-Benz A-Class F-Cell car to the fire brigade of Sacramento, California, where it will be used as an operations control car. A little earlier, DaimlerChrysler had already made a fuel cell patrol car available to the police of Wayne State University in Michigan. These two cars are thus the world’s first special-service vehicles with the future-oriented fuel cell technology.
From the very start of development work, Daimler AG has invested almost one billion euros in the research into, and development of, fuel cell vehicles. No other manufacturer has been able to collect more data and experience from some three million kilometers (1.8 million miles) covered with zero emissions to date. The company is thus coming closer and closer to its goal of large-scale production of fuel cell vehicles. When will the fuel cell be ready for production? A precise point in time has not yet been defined but each research car of Daimler AG and each development in this field are steps in this direction.
Further information from Daimler is available on the internet at: www.media.daimler.com