Thermodynamic studies of a novel heat pipe evacuated tube solar collectors based integrated process for hydrogen production Vahit Corumlu a , Ahmet Ozsoy a , Murat Ozturk b,* a Suleyman Demirel University, Faculty of Technology, Department of Energy Systems Engineering, 32260, Isparta, Turkey b Suleyman Demirel University, Faculty of Technology, Department of Mechatronic Engineering, 32260, Isparta, Turkey article info Article history: Received 13 April 2017 Received in revised form 12 October 2017 Accepted 16 October 2017 Available online xxx Keywords: Solar energy Hydrogen Energy Exergy Integrated system abstract In this study, the detailed thermodynamic assessment of an integrated process based on heat pipe evacuated tube solar collectors for hydrogen production is provided for more efficiently process designs. An integrated process consists of the solar heat pipe collector, photovoltaic panels, PEM electrolyzer and Linde-Hampson hydrogen liquefaction process are considered and analyzed thermodynamically for hydrogen production and liquefaction aims. The energetic and exergetic efficiencies of this integrated process are calculated as 0.2297 and 0.1955, respectively. Based on the parametric study, the effectiveness of the solar energy based integrated process is also highly dependent on the solar flux and ambient conditions. © 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction The energy need of world increases with increasing living standard, industrialization, quality of life and population. Nowadays, a greater part of energy requirements is supplied by using the fossil fuels i.e. coal, natural gas and petroleum. The fossil fuel utilization for energy generation has negative effects on the environment and on health of human beings. Meeting the importantly escalating global energy needs with no or minimal environmental damage and fossil fuel depen- dence can only be achieved by utilizing clean energy processes. These renewable energy based processes have considerable environmental, energetic, financial, and societal benefits [1]. The solar energy is a reliable and sustainable en- ergy resource. Based on the environmental view-point, the solar energy processes do not have negative effects and harmful emission to the environment compared to the fossil energy sources, which continuously increase the earth's average ambient temperature and pollution [2]. In order to decrease fossil fuel consumption, the solar energy assisted integrated systems, which make use of the renewable and clean solar energy, should be designed for power, heating, cooling, hydrogen, hot and clean water production aims. Also, * Corresponding author. E-mail addresses: vahitcorumlu@hotmail.com (V. Corumlu), ahmetozsoy@sdu.edu.tr (A. Ozsoy), muratozturk@sdu.edu.tr (M. Ozturk). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (2017) 1 e11 https://doi.org/10.1016/j.ijhydene.2017.10.107 0360-3199/© 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article in press as: Corumlu V, et al., Thermodynamic studies of a novel heat pipe evacuated tube solar collectors based integrated process for hydrogen production, International Journal of Hydrogen Energy (2017), https://doi.org/10.1016/ j.ijhydene.2017.10.107