Miguel Sainz Manas

I am a Postdoctoral Fellow in the Heat and Power Technology Division of the Department of Energy at KTH Royal Institute of Technology. My research is conducted within the FLUWS project, a Horizon Europe-funded initiative focused on developing a high-temperature, air-based structured packed-bed thermal energy storage (TES) system using recycled waste materials from the ceramic industry.

As part of this project, I lead the experimental campaign of a novel TES prototype at Technology Readiness Level 5 (TRL5). The system will be evaluated under three distinct charging configurations: (i) external electrical heating, (ii) immersed electrical heaters integrated within the storage tank, and (iii) concentrated solar energy. This work aims to provide key insights into the influence of operating parameters on TES performance and to assess the potential of such storage architectures for hybrid concentrated solar power (CSP) and photovoltaic (PV) energy systems.

Background

I graduated in 2021 with a Master's degree in Mechanical Engineering from the Institut National des Sciences Appliquées (INSA) Toulouse. Following my master's thesis, I began a PhD in 2022 at the PROcesses, Materials and Solar Energy (PROMES) laboratory of the Centre National de la Recherche Scientifique (CNRS).

My doctoral research focused on the modelling and experimental investigation of a graphene nanofluid-based volumetric solar absorber for linear concentrating solar collectors intended to supply industrial process heat. I studied the optical properties of graphene colloids in semi-transparent media using both discrete dipole approximation (DDA) simulations and spectrophotometric measurements. These optical models were coupled with Monte Carlo ray-tracing and computational fluid dynamics (CFD) simulations to improve the understanding of receiver behaviour under varying optical conditions and elevated operating temperatures. In parallel, I led the development of an innovative on-sun volumetric absorption parabolic trough collector, designed to experimentally evaluate graphene nanofluids under concentrated solar irradiation. The outcomes of this work provided valuable insights into the relationship between graphene morphology and optical response, as well as the key operating parameters governing the performance of these advanced solar thermal systems.

During my PhD, I was involved in teaching activities within the EUREC European Master in Renewable Energy programme, contributing to courses on computational fluid dynamics. I also supervised and mentored engineering students during their master's thesis projects. In addition, I have presented my research at several national (JNES, JNPV) and international conferences (EuroSUN, SolarPACES) and had the opportunity to lead the organization of the 1st EU-SOLARIS Doctoral Colloquium, held in Font-Romeu in 2024.