This paper presents an experimental study for hydrogen production using alkaline water electrolysis operated by solar energy. Attempts to produce pure hydrogen as well as pure oxygen for commercial demands are introduced. Two methods are used and compared for separation between the cathode and anode, which are acrylic separator and polymeric membrane. Further, the effects of electrolyte concentration, solar insolation, and space between the pair of electrodes on the amount of hydrogen produced and consequently on the overall electrolysis efficiency are investigated. It is found that the efficiency of hydrogen production is higher when using the polymeric membrane between the electrodes, in comparison with the acrylic separator. The experimental results show also that, the performance of alkaline water electrolysis unit is dominated by the electrolyte concentration and the gap between the electrodes. The gap of 5 mm leads to a higher hydrogen production rate than the gap of 10 mm. (C) 2017 Elsevier Ltd. All rights reserved.