The HYDROSOL-Plant project was the continuation of a series of successful research projects (HYDROSOL, HYDROSOL-II and HYDROSOL-3D) focusing on the production of H₂ from the two-step solar thermochemical water splitting based on redox structured reactors. The principal objective of HYDROSOL‐PLANT was the development and operation of a plant for solar thermo‐chemical hydrogen production from water in a 0.750 MWth scale on a solar tower, based on the HYDROSOL technology.

The predecessor projects HYDROSOL and HYDROSOL-II have introduced the concept of redox structured monolithic solar reactors for the production of solar H2 from water. The proof of concept at lab-scale was presented in the first HYDROSOL project, while the feasibility of the main principles of the process for longer-term cyclic operation at a pilot reactor set-up in a scale of 100 kWth at the Plataforma Solar de Almeria (PSA) was proven in HYDROSOL-II project. In the third project of the series, HYDROSOL-3D, the relevant design aspects necessary to prepare the erection of a solar demonstration plant at the 1 MWth scale were addressed. However, the actual realization of a solar demonstration plant near the MW scale (0.75MWth) was achieved in the HYDROSOL-Plant project. In the HYDROSOL-Plant project several advancements were introduced related to large scale redox materials’ synthesis, shaping into porous structures, reactor design, etc. The ultimate objective was to achieve the production of H2 at a level of 3 kg/week. The HYDROSOL-Plant is the largest demonstration facility of its kind, worldwide.

The specific Scientific and Technical Objectives of HYDROSOL-3D were:

  • Define all key components and aspects necessary for the erection and operation of a 750 kWth solar plant for H2O splitting (heliostat field, solar reactors, overall process monitoring and control, feedstock conditioning, etc.)
  • Develop tailored heliostat field technology (field layout, aiming strategies, monitoring and control software) that enables accurate temperature control of the solar reactors.
  • Scale-up the HYDROSOL reactor while advancing the state-of-the-art (redox materials, monolithic honeycomb fabrication and functionalization) for optimum hydrogen yield.
  • Design the overall chemical process, covering reactants and products conditioning, heat exchange/recovery, use of excess/waste heat, monitoring and control.
  • Construct a solar hydrogen production demonstration plant in the 750 kWth range to verify the developed technologies for solar H2O splitting.
  • Operate the plant and demonstrate hydrogen production and storage on site (at levels > 3 kg/week).
Title of Programme FCH-JU-2012-1
Financing Code for Project 325361
Project start year - end year 2013 - 2016
Financing organisation SP1-JTI-FCH.2012.2.5: Thermo-electrical-chemicalprocesses with solar heat sources
Coordinator Aerosol and Particle Technology Laboratory (APTL)


Deutsches Zentrum Fuer Luft - Und Raumfahrt EV (DLR)

Centro de Investigaciones Energeticas, Medioambientalesy Technologicas (CIEMAT-PSA)

HyGear B.V. (HYG)


Budget  3,480,806 €