Hydrogen, which can be produced by water electrolysis, can play an important role as an alternative to conventional fuels. It is regarded as a potential future energy carrier. Photovoltaic arrays can be used in supplying the water electrolysis systems by their energy requirements. The use of photovoltaic energy in such systems is very suitable where the solar hydrogen energy systems are considered one of the cleanest hydrogen production technologies, where the hydrogen is obtained from sunlight by directly connecting the photovoltaic arrays and the hydrogen generator. This paper presents a small PV power system for hydrogen production using the photovoltaic module connected to the hydrogen electrolyzer with and without maximum power point tracker. The experimental results developed good results for hydrogen production flow rates, in the case of using maximum power point tracker with respect to the directly connected electrolyzer to the photovoltaic modules. (c) 2005 Elsevier Ltd. All rights reserved.