Portable Power System

Idatech Advanced Fuel Cell Solutions of the United States has developed a 250 W Portable Power System that can provide 4h of backup power with 2 liters of a methanol and water mixture as fuel. The system uses a PEM fuel cell and includes a fuel processor in the module (Idatech 2005a). Idatech initially is marketing 1 kW Modular Fuel Cell Systems to the military. These systems are scalable and able to use a variety of fuel sources (Idatech 2005b). 

Small- to medium-sized PEM fuel cells are liable to be an important market for fuel cells in portable power systems. A problem with these cells is the pumps for circulating the reactant air, and the hydrogen fuel, if not dead-ended. In compact designs of, say, 200 W to 2kW, the back pressure of the reactant air is liable to be around lOkPa, equivalent... 

In conclusion, it can be said regarding the battery selection process, whether primary or secondary batteries are being considered, that the design engineer is faced with many commercial portable power systems in a wide variety of models. The battery selection process cannot therefore be reduced to an exact science. Seldom does any one battery system meet all the requirements Ta a given application. The selec-lion of a battery is further complicated by the fact that the performance characteristics of battery systems vary with temperature, current drain, service schedules, etc. Consequently the selection process usually involves a trade-off or compromise between battery requirements and battery system characteristics. 

The term "portable power system" is not sharply defined. Hoogers (34] attempted to define it as "a small grid-independent electric power unit ranging from a few watts to roughly one kilowatt, which serves mainly a purpose of convenience rather than being a primarily a result of environ-... 

The second example describes distributed, mobile and portable power-generation systems for proton-exchange membrane (PEM) fuel cells [106]. A main application is fuel processing units for fuel cell-powered automobiles it is hoped that such processing units may be achieved with a volume of less than 8 1. 

Fig. 4.7.7 A portable NMR system for measuring freeze damage in Navel oranges. The Halbach magnet is shown above the completed system with two Navel oranges for comparison. The complete system has the battery powered spectrometer electronics housed in a metal box and the system is run by a portable computer.

The modular design of the HyPM fuel cells allows scaling for higher power requirements using a variety of configurations, such as series and parallel systems. Potential applications for the technology include vehicle propulsion, auxiliary power units (APU), stationary applications including backup and standby power units, combined heat and power units and portable power applications for the construction industry and the military. 

Portable power and stationary or transport systems are validated infrastructure investment begins with governmental policies. 

Canadian interests span into hydrogen production, delivery and utilization, primarily in fuel cell applications in transportation, stationary and portable systems. Furthermore, codes and standards for hydrogen systems are an important area of activity. The range of future electrical requirements for early adopters, such as the military, is very wide with numerous applications for various electrically powered systems. The introduction of hydrogen as an energy carrier into the commercial and military sector offer similar and sometimes unique challenges in all the areas discussed. 

Dahm, W. J. A., Ni, J., Mijit, K., Mayor, R., Qiao, G., Benjamin, A., Gu, Y., Lei, Y., and Papke, M., Micro internal combustion swing engine (MICSE) for portable power generation systems. In the 40th AIAA Aerospace Sciences Meeting and Exhibit, Reno, 2002. 

Therefore, methanol is the top candidate because of its low price, less toxicity, high energy density and easy handling. Although direct methanol fuel cells may need an auxiliary system to treat unoxidized or partially oxidized fuel in the exhaust gas, direct methanol fuel cells are still a very attractive system as a portable power source. 

Because of the modular nature of fuel cells, they are attractive for use in small portable units, ranging in size from 5 W or smaller to 100 W power levels. Examples of uses include the Ballard fuel cell, demonstrating 20 hour operation of a portable power unit (32), and an IFC military backpack. There has also been technology transfer from fuel cell system components. The best example is a joint IFC and Praxair, Inc., venture to develop a unit that converts natural gas to 99.999% pure hydrogen based on using fuel cell reformer technology and pressure swing adsorption process. 

Prior to this appointment. Dr. Wilkinson was the director, and then vice president of research and development at Ballard Power Systems and involved with the research, development, and application of fuel cell technology for transportation, stationary power, and portable applications. Until 2003, Dr. Wilkinson was the leading all-time fuel cell inventor by number of issued US. patents. Dr. Wilkinson s main research interest is in electrochemical power sources and processes to create clean and sustainable energy. He is an active member of the Electrochemical Society, the International Society of Electrochemistry, the Chemical Institute of Canada, and the American Chemical Society. 

Fuel cells are electrochemical devices that convert the chemical energy of the fuels directly into electrical energy, and are considered to be the key technology for power generation in stationary, automotive, portable and even microscale systems. Among all kinds of fuel cells, direct methanol fuel cells have really exhibited the potential to replace current portable power sources and micropower sources in the market (Yao et al., 2006). 

A fuel cell that has desirable features for transportation and portable power is the polymer electrolyte membrane (PEM) system. The core of this technology is a polymer membrane that conducts... 

Finally, in order for PEM fuel cell systems to be affordable for portable power applications, a source... 

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