On the startup reliability of fuel cell systems

In recent years, fuel cells have been discussed as a new source of backup power in telecom applications. Critical for the backup application is the ability to start every time there is a power need. A special case is the startup after long time of standstill. The more trivial case, startup of fuel cells that have been in standstill for a short time, has been investigated in three different tests. The special case, startup after long time standstill, has been investigated in three different tests. The fundamental impact of humidity on performance is discussed. It is necessary that there is a high water content (%RH) of the vital polymer membrane of the fuel cell - If high conductivity and high performance should be delivered. The results show reliable startup if the standstill time is short without any special actions taken. The results further show that it is possible to obtain a soft and reliable startup after long time of standstill. The Cellkraft startup algorithm has been gradually refined to make the fuel cell deliver full power in 15-30 seconds even when the fuel cell is started from an extremely dry state.