Background Report: The market - Yardstick for fuel-cell plants

• mtu Friedrichhafen's 'HotModule': cost efficient through simple construction
• Potential for further cost reduction

Friedrichshafen - So far, the fuel-cell technology has not been able to prevail in the mass market. The reason: In comparison to traditional methods of generating electricity, high-performance fuel-cell plants are still too expensive; either because they are complex plants with extensive peripheral equipment, or because they require very expensive materials such as platinum. For some technologies, the manufacturer's cost for the equipment to produce each kilowatt of output is 20,000 Euro or even more.

The HotModule fuel-cell system of MTU Friedrichshafen is much less expensive, even today. At the same time, the costs must be reduced even further according to Michael Bode, head of "New Technologies" at mtu: "The market sets strict demands. Today, gas-engine plants are available for less than 1000 Euro per kilowatt output; they have a considerably lower efficiency than our HotModule, but they set the standard."

Record-breaking results in efficiency achieved

An initial, customer-operated HotModule field test system has been in operation for over two years at the University of Bielefeld. It feeds its electrical energy into the local town network and supplies the university with heat and steam. Valuable experience was gained during this continuous operation, which has contributed towards further optimization of the technology. During its total running time of 16,000 operating hours, the system achieved record figures: It ran longer than any other previous carbonate fuel cell and achieved an electrical efficiency of 47 percent; a value unachieved by any conventional technology in the 250 kilowatt class. In comparison: Modern gas engines of the same size work with a mechanical efficiency of maximum 41 percent, which does not even include the conversion of the mechanical energy into electrical power.

The world's first high-temperature fuel cell in the clinical sector was commissioned at the Rhön clinic in Bad Neustadt/Saale in 2001where it supplies energy and heat for part of the clinic. As well as the electrical energy, the medical section of the Rhön clinic uses the high-pressure water steam produced with the hot waste air for air conditioning and sterilizing purposes.

Besides the HotModule in the Rhön clinic, two further systems were commissioned in 2001. The HotModules were manufactured under license by Fuel Cell Energy Inc. (Danbury, Connecticut), an American cooperative partner of which the mtu is the largest shareholder with seven percent of the shares, and were then delivered in the USA. These were provided for applications in the automotive and energy supply industries. As well as licensed manufacturing, mtu and FCE are also working together in the cell manufacture field. The cells for the HotModules, the central components of the system, originate from FCE.

High potential for further cost reduction

Even though today the HotModule can already be produced at much lower cost than other fuel-cell systems, mtu is aiming at 1100 Euro to 1500 Euro per kilowatt output over the medium term to make the HotModule interesting also from an economic perspective. To reach this target, mtu's engineers are set to lower the production cost by one-third in the future through technical simplification. Even the cell itself will again be subject to scrupelous examination. It is planned to further simplify its construction, reduce superfluous material and cut the cost of the core component to one-half of its present figure. The greatest potential for savings, however, lies in manufacturing. Today, each HotModule is a unique, hand-made piece, which makes it impossible to compare it with standard products such as engines. When the HotModule reaches production maturity, Michael Bode believes that another 50% can be saved, making it possible to reach the target costs.