Alkaline fuel cells (AFCs), although known to have a high efficiency, were considered to be only useful for space applications due to their high price, their low lifetime and their high carbon dioxide sensitivity. In fact, AFCs can be built low-cost and CO2 reconcilable with sufficient lifetimes for vehicles and backup systems. The key is a liquid circulating electrolyte which avoids many problems membrane systems have, like the water and the heat management. The drawbacks of AFCs diminishing the lifetime were also discussed, whereby solutions to overcome these problems were given.Finally, ammonia (NH3) as alternate fuel for an 300 W alkaline fuel cell system was introduced. (C) 2003 Elsevier B.V All rights reserved.