Analysing the performance, fuel cost and emission parameters of the 50 MW simple and recuperative gas turbine cycles using natural gas and hydrogen as fuel Yıldız Koc ¸ a , Hu ¨ seyin Ya  glı a , Adnan G € orgu ¨ lu ¨ b , Ali Koc ¸ a,* a Iskenderun Technical University, Faculty of Engineering and Natural Sciences Department of Mechanical Engineering, 31200, Iskenderun, Hatay, Turkey b Siemens Energy, Gas and Power, Hydrogen Sales, Duisburg, Germany highlights graphical abstract  Analysing the using pure hydrogen and natural gas as fuel for gas turbines  Assessing the effect of fuels on performance for simple and recu- perative gas turbine systems  Applying the performance, cost and environmental analyses together for simple and recupera- tive gas turbines  Evaluating the best-performing cycle parameters for different working conditions article info Article history: Received 7 April 2020 Received in revised form 17 May 2020 Accepted 29 May 2020 Available online xxx Keywords: Gas turbine Recuperator Hydrogen Natural gas abstract In the present study, firstly, the power production, thermal and exergy efficiencies were calculated for the simple and recuperative gas turbine cycles at constant power production (50 MW) and turbine outlet temperature (450  C). The system was analysed for the cases of using both natural gas and pure hydrogen as a fuel for simple and recuperative gas turbine systems. After analyses, the efficiencies of the recuperative gas turbine cycle were higher than the simple gas turbine cycle up to 18 bar pressure for both natural gas and H 2 . At the pressure of 18 bar and above, the efficiency of the simple gas turbine cycle found higher than the recuperative gas turbine cycle since the compressor outlet temperature is higher than the turbine outlet temperature. Despite the higher cost of H 2 for unit power pro- duction, the H 2 used gas turbine cycles has more advantageous than natural gas in terms of performance, environment and CO 2 emission. For the cases of using H 2 and natural gas as fuel, the minimum fuel cost was calculated as 0.345 $/kWh and 0.075 $/kWh at 20 bar for simple gas turbine cycle, while they were found as 0.322 $/kWh and 0.071 $/kWh at 4 bar * Corresponding author. E-mail address: ali.koc@iste.edu.tr (A. Koc ¸). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (xxxx) xxx https://doi.org/10.1016/j.ijhydene.2020.05.267 0360-3199/© 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article as: Koc ¸ Y et al., Analysing the performance, fuel cost and emission parameters of the 50 MW simple and recu- perative gas turbine cycles using natural gas and hydrogen as fuel, International Journal of Hydrogen Energy, https://doi.org/10.1016/ j.ijhydene.2020.05.267