Backup power applications

Proton exchange membrane fuel cells (PEMFCs) do not have the problems associated with batteries and diesel generators, and are believed to be the ideal backup power. The following discussion will focus on telecommunications backup power applications. 

Stationary fuel cells include backup and primary power generation systems for various applications. For backup power applications, it is best to use pure H2 as the fuel for instant startup, but the supply of H2 is not convenient at the moment. For continuous primary power applications, it is best to use the existing fuel infrastructure for natural gas or propane, but the fuel cell... 

Wuhan Intepower Fuel Cells Co., Ltd. A Chinese company aimed at developing, manufacturing, and marketing PEMFCs for telecommunications backup power applications. It was founded in 2008 with headquarters located in Wuhan, Hubei, China. Company website http //www.intepower.com. 

Fuel Cells in Backup Power Applications , Federal Energy Management Programme... 

Potential disadvantages of using SOFC technology in backup power applications... 

Federal Energy Management Programme, (2005) Fuel Cells in Backup Power Applications , US Department of Energy, DOE/EE-0310, available from http //www. osti. go v/bridge/... 

This particular battery was originally developed for backup power applications. The latest research and development activities seem to indicate that the battery design architecture can be modified to meet its application to EVs and HEVs. The battery uses lithium as a negative electrode, vanadium oxide as a positive electrode, and polymeric solution as electrolyte. The conductivity of the electrolyte is less than O.OOOl/O-cm at temperatures greater than 40°C, which offers the most satisfactory battery performance as backup power source for telecommunications applications. The cells can be connected to a bus bar to supply a voltage of 24 V or 48 V, which is most ideal for telecommunications applications. The battery loses only 1% per year of its capacity and offers a battery life in excess of 10 years even at an ambient or storage temperature as high as 60°C. Battery tests indicate that... 

Backup Power Applications of Lead-Acid Batteries.328... 

The three major types of nonautomobile applications in which lead-acid batteries play important and necessary roles are (1) stationary applications for large-scale electricity storage (2) standby applications for UPS, telecommunications, and emergency lighting and (3) backup power applications. 

Fuel cell system requirements for backup power applications significantly differ from requirements for such systems in automotive and stationary (primary) power generation markets. As Table 10-4 shows, there are only a few common characteristics between the backup power on one side and automotive and stationary (primary) power on the other. 

The operational lifetime requirement for a fuel cell in backup power application is less than 2000 hours. Such a fuel cell operates with continuous load requirements during the power outage, but never longer than 8 hours. This duty cycle is achievable with today s fuel cell technology. Operational lifetimes of several thousand hours have been demonstrated by almost all the major membrane electrode assembly (MEA) suppliers/ developers. 

One of the most important system requirements for backup power applications (especially for telecommunications) is ability to start instantly upon power outage. The required response time is in the order of milliseconds. The fuel cell itself can meet this requirement, as long as the supply of reactants is uninterrupted, otherwise a bridge power may be needed (such as batteries or ultracapacitors). System engineering solutions could significantly reduce or even eliminate the need for bridge power. For example, the fuel cell may be kept in a "ready" mode. Most of the time the backup power system is in the "idle" or "ready" mode and the operation is highly intermittent. It may only operate up to 50-200 hours per year. 

Clearly, the fuel cells designed for automotive or stationary power application do not meet existing backup power requirements. In some cases they indeed exceed the requirements, but some of the system features that drive these designs to exceed current requirements often negatively affect system cost and complexity. Therefore, a fuel cell stack and system specifically designed for backup power applications is more likely to meet the requirements at minimum cost. 

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