The main aim of this study is to investigate the possibility of producing hydrogen gas from water by electrolysis as renewable source of energy. To achieve that, a simplified unit of water electrolysis was developed and evaluated.  Five types of water (4000 ppm, 6000 ppm, 8000 ppm, alkaline water (10% wt KOH) and seawater) were used, three distance between electrodes namely 6, 4 and 2 mm were also investigated. Hydrogen yield, energy requirements, and energy output were studied.  Unit efficiency and cost of hydrogen production was also determined. The obtained results indicate that the energy requirements for hydrogen production increases with decreasing distance between electrodes and increasing operating time. The hydrogen yield increases with decreasing distance between electrodes and increases with increasing operating time, where it ranged from 1.977 to 36.997 L h^-1 for all treatments. The energy output increases with decreasing distance between electrodes and increases with increasing operating time which ranged from 0.007 to 0.180 kWh for all treatments. The hydrogen production unit efficiency ranged from 25.36 to 80.32 % for all treatments. The total costs of hydrogen production unit ranged from 0.040 to 0.069 LE kg^-1 of hydrogen.