Hydrogen holds out great promise as an energy source whose use does not pollute the environment. In this context, methods of hydrogen production which do not involve formation of carbon dioxide are especially attractive. The present work describes a cheap and versatile prototype of an alkaline hydrolyser which efficiently produces hydrogen from aluminum scrap and aqueous sodium hydroxide, the hydrogen produced being used directly to energize, by combustion, a refrigerator working on the ammonia-water principle, which was also designed and developed in our laboratory. A direct comparison of the system when energized by liquid-propane flame and by hydrogen flame shows a clearly better performance in the latter case, which produces a temperature of -20 degrees C after about 2 h of operation. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.