*Article* **Techno-Economic Assessment of Solar Hydrogen Production by Means of Thermo-Chemical Cycles**

**Massimo Moser 1,\*, Matteo Pecchi 1,2 and Thomas Fend <sup>3</sup>**


Received: 20 December 2018; Accepted: 22 January 2019; Published: 23 January 2019

**Abstract:** This paper presents the system analysis and the techno-economic assessment of selected solar hydrogen production paths based on thermochemical cycles. The analyzed solar technology is Concentrated Solar Power (CSP). Solar energy is used in order to run a two-step thermochemical cycle based on two different red-ox materials, namely nickel-ferrite and cerium dioxide (ceria). Firstly, a flexible mathematical model has been implemented to design and to operate the system. The tool is able to perform annual yield calculations based on hourly meteorological data. Secondly, a sensitivity analysis over key-design and operational techno-economic parameters has been carried out. The main outcomes are presented and critically discussed. The technical comparison of nickel-ferrite and ceria cycles showed that the integration of a large number of reactors can be optimized by considering a suitable time displacement among the activation of the single reactors working in parallel. In addition the comparison demonstrated that ceria achieves higher efficiency than nickel-ferrite (13.4% instead 6.4%), mainly because of the different kinetics. This difference leads to a lower LCOH for ceria (13.06 €/kg and 6.68 €/kg in the base case and in the best case scenario, respectively).

**Keywords:** solar hydrogen; concentrated solar power (CSP); two-step thermochemical cycles; simulation; techno-economic assessment
