Thursday, 20 November 2014

Fuel cell: "engine" of the future?

Audi is calling the fuel cell “the power source of the future”.

In this “engine”, in which hydrogen and oxygen are combined to form pure water., the Powertrain of the future?  In the fuel cell, Energy is released in a "cold combustion" process to provide the drive energy for an electric motor that turns with zero emissions.

Audi has installed fuel cell technology in the front-wheel drive Golf SportWagen HyMotion which can accelerate to 62 mile/h in 10s. The hydrogen is stored safely in four high-technology carbon-fibre tanks located in a space-saving manner in the underbody. Their fuel capacity enables a driving range of 310 miles. Refilling the fuel tank of the concept car takes three minutes.

The key drive components of the Golf SportWagen HyMotion were developed by Volkswagen’s group research team in Germany. The concept of the fuel cell system, which has a driving power of 100kW (134bhp), was devised at the Volkswagen Technology Centre for Electric Traction.

In addition, the concept car has a high-voltage lithium-ion battery, which stores the kinetic energy recovered from regenerative braking, assists in the starting phase of the fuel cell and adds a dynamic boost to the maximum acceleration of the vehicle. Fuel cell and battery together drive an electric motor adapted from the e-Golf.

The mechanical design for this innovative car build is based on the modular transverse matrix (MQB) developed by Volkswagen and used throughout the Group. Thanks to use of MQB, the current Golf hatchback versions and the new Golf SportWagen have become the world's first vehicle model series that can host all conceivable drive types.

Today, the Golf is already offered with petrol engines (TSI), diesel engines (TDI), a natural gas drive (TGI)1, an electric drive (e-Golf)2 and a plug-in hybrid drive (Golf GTE)3. Volkswagen claims no other car offers such a variety of drive types.

Volkswagen is showing the Golf SportWagen HyMotion to demonstrate for the first time how a hydrogen fuel cell could be implemented based on the MQB as soon as research and development work has been completed and “a solution developed such that price would be acceptable to new car buyers”.

However, and this is crucial to the whole development of fuel cell technology, before market launch, a hydrogen infrastructure must first be created. This means not only a broad network of hydrogen fuel stations, but also the production of the hydrogen. Hydrogen only makes sense as a source of drive energy if the primary energy used to produce it is derived from renewable energy sources.

Unlike many of its competitors, Volkswagen is following the strategy of implementing its alternative drives in high-volume production vehicles. Just as the all-electric e-Golf and the Golf GTE that is equipped with a plug-in hybrid drive are integrated in a production model that has everyday practicality, so future fuel cell drives would also be integrated into production models that have been optimally engineered and are offered at an attractive price.

It was with this objective in mind that several research vehicles were built based on the North American Passat, in which the same drive components from the Golf SportWagen HyMotion are used. The fleet of Passat HyMotion vehicles is currently being tested on the streets of California.

And, finally, how several questions remain: Is hydrogen the fuel of the future? If it is, will the infrastructure be put in place to sustain coast-to-coast availability? Is such an infrastructure sustainable if only 20 per cent of vehicles are fuel cell powered? And will the cost of the fuel match or improve on the cost of gasoline and diesel? Finally, from a design and manufacturing viewpoint, how does the cost of manufacture of the complete fuel cell drive line compare with that of a present-day four-wheel drive passenger vehicle of comparable size?

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