High-purity hydrogen gas was generated from the chemical reaction of aluminum with sodium hydroxide. Several molar relations of sodium hydroxide/aluminum were investigated in this study. The experimental results showed that hydrogen yields are acceptable and its purity was good enough to be used in a proton exchange membrane (PEM) fuel cell to produce electricity. An estimation of the amount of energy produced from the reaction of 100 aluminum cans with caustic soda showed that the hydrogen production is feasible to be scaled up to reach up to 5 kWh in a few hours. This study is environmentally friendly and also shows that green energy can be produced from aluminum waste at a low cost. (c) 2004 Elsevier B.V. All rights reserved.