Hydrogen production probability distributions for a PV-electrolyser system E. Akyuz a , C. Coskun a , Z. Oktay a, *, I. Dincer b a Mechanical Engineering Department, Faculty of Engineering, Balikesir University, 10110 Balikesir, Turkey b Faculty of Engineering and Applied Science, University of Ontario Institute of Technology (UOIT), 2000 Simcoe St. N., Oshawa, ON L1H 7K4, Canada article info Article history: Received 20 August 2010 Received in revised form 12 November 2010 Accepted 26 November 2010 Available online 5 January 2011 Keywords: Hydrogen production Efficiency Solar energy Photovoltaics PEM electrolyser abstract In this study, we comprehensively analyze the probability distribution of the hydrogen production for PV assisted PEM electrolyser system. A case study is conducted using the experimental data taken from a recently installed system in Balikesir University, Turkey. A novel computational tool is developed in Matlab-Simulink for analyzing the data. The concept of probability density frequency is successfully applied in the analyses of the wind speed and the solar energy in literature. This study presents a method of applying this knowledge to solar energy assisted hydrogen production. The change in the probability distribution of the hydrogen production with the solar irradiation throughout a year is studied and illustrated. It is found that the maximum amount of hydrogen production occurs at between 600 and 650 W/m 2 of solar radiation. Annual hydrogen production is determined as 2.97 kg for per m 2 of PV system. Average hydrogen production efficiency of the studied PEM electrolyser is found to be 60.5% with 0.48 A/cm 2 of current density. The presented results of this study are expected to be valuable for the researchers working on renewable hydrogen production systems. Copyright ª 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. 1. Introduction Hydrogen is a sustainable option as a fuel and it is regarded as one of the potential solutions for the current energy and environmental problems present on Earth. Its eco-friendly production is one of the key features on the road for a better environment as well as for the success of sustainable devel- opment [1]. Implementing sustainable energy strategies for creating a sustainable living space is important for combating against climate change and global warming. Hydrogen energy and production of hydrogen from renewable energy sources is important for the solution of these problems. Many scientists have focused on the feasibility and the system performance of hybrid renewable energy systems for the production of hydrogen, mainly concentrating on solar, wind, geothermal and the nuclear energy options [2e12]. Several methods have been and are being developed for the production of hydrogen from solar energy; the only one that is currently practical is through the electrolysis of water. The water electrolysis is considered a technology that has solid grounds and has been widely used for a long time [1]. In this regard, the performance of proton exchange membrane (PEM) electrolyser systems has been investigated from different perspectives by many researchers [13e19]. Knowledge of global solar radiation distribution is needed for design and analysis of solar energy systems. Many parameters affect the energy and exergy efficiencies or working conditions of PV arrays. One of the most important * Corresponding author. E-mail addresses: akyuz11@gmail.com (E. Akyuz), canco82@yahoo.com (C. Coskun), zuhal.oktay@gmail.com (Z. Oktay), ibrahim.dincer@uoit.ca (I. Dincer). Available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy 36 (2011) 11292 e11299 0360-3199/$ e see front matter Copyright ª 2010, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2010.11.125