A solar PV powered electrolyser with a DC-DC buck converter interface to help regulate hydrogen generation is presented. The converter serving as a current regulator maintains a constant direct current through the electrolyser. Field and laboratory based experimental studies are used to obtain the characteristics of both PV panel and electrolyser. Flow rate characteristics and electrical equivalent circuit of the electrolyser besides I-V characteristics of the solar panel yielded the parameters required for the current regulator design. The regulator when tested in the closed loop control mode, with a 68 Wp rooftop installed PV panel and a laboratory scale 30 W electrolyser, maintained a constant current in turn producing hydrogen at a constant rate over a range of solar irradiance from 440 to 975 W/m(2). (C) 2015 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.