The idea of using fuel cells for uninterrupted power supply is being put into practice by P 21 GmbH, of Brunnthal near Munich. They develop, manufacture, and market high-quality fuel-cell systems. The hydrogen and the necessary peripheral equipment are supplied exclusively by the Linde AG’s Linde Gas Division. With their years of skill and experience in hydrogen technology, Linde are a competent partner in this project. 

A forward-looking project

P 21 GmbH – Power for the 21st Century – was founded at the end of 2001 as a spin-off of the Vodafone/Mannesmann concern, and develops, manufactures and markets PEM (Polymer Electrolyte Membrane) fuel-cell systems and the associated components. Development and manufacturing focus particularly on PEM fuel-cell stacks providing between 1 kW and 21 kW of power. The goal is to quickly open up the market in the segment of uninterrupted power supply (UPS) – first and foremost in the area of emergency power supply of mobile telecommunications base stations, because today’s fuel-cell technology already meets the requirements of this market segment. Long term, it is intended to open up other stationary and mobile areas of application in other strategic markets. 

Environmentally responsible and highly effective
The P21 fuel-cell systems aim to assure uninterrupted power supply for mobile telecommunications base stations, replacing and even outstripping the capabilities of conventional solutions. The fuel-cell systems are considerably lighter, durable, robust, low in maintenance, and environmentally responsible, because they do without lead and acids. They permit significantly longer interruptions, have a longer lifetime and an electrical efficiency of over 50 percent, and as a future replacement for the battery systems used hitherto, can even make a considerable contribution to savings. The P21 fuel-cell system is modular, so its output power and voltage level can be adapted very easily to a wide range of different power demands or application environments. It is conceivable that it will even be used as a primary power-supply unit in future. Work is currently in progress on perfecting a pilot production line. This means that fuel-cell systems can be manufactured in high volume, and, according to plan, can be offered at considerably more attractive prices by 2005 than today. The benefits of using fuel cells have already been proven in practice. At the end of 2003, P21 employees simulated more than 400 power cuts during actual operation at a mobile telecommunications base station in Bavaria, with a total down time of 2 hours 45 minutes. The customer did not notice anything. Comprehensive skill and years of experience 

Linde AG, Linde Gas Division, is the technological leader in establishing an innovative hydrogen infrastructure for the mobile sector. Another of the many facets of the introduction of hydrogen as an alternative energy source is the cooperation with P21. In this project, Linde are the exclusive suppliers of gas-supply equipment for the fuel cells on the transmitter masts, contributing both years of experience and seamless, reliable distribution. A cooperation contract to this effect was signed on December 4, 2003. Cooperation with P21 involves both the development and manufacturing of the hydrogen supply systems, and the provision of the gas. Linde are working on innovative solutions for tailor-made supply of the fuel cells with hydrogen. This necessitates new developments in the area of fittings. The aim is to produce cost-effective, compact units. As early as the middle of the year, Linde will present a typical sample supply system that can be cost-effectively manufactured in series. The smallest supply unit consists of one hydrogen pressure cylinder and a pressure-reduction unit. This supply unit can be varied by adding more cylinders, and adapted to the individual needs of a particular custome