The Solar Thermal Applications Unit (USTA) is devoted to the development and evaluation of solar thermal technology applications in industrial processes, including desalination and brine concentration. The main objective is to generate new scientific and technological knowledge in the field of thermal applications of solar energy, seeking approaches that take into account circular economy and the water-energy-food nexus.
Main current research lines are the following:

  • Application of solar thermal energy to large capacity distillation processes, with special emphasis on multi-effect distillation (LT-MED, TVC-MED, ABS-MED).
  • Application of solar thermal energy to small capacity distillation processes, with special emphasis on membrane distillation (MD) and forward osmosis (FO).
  • Solar thermal plants for cogeneration of water and electricity (CSP+D).
  • Electricity generation through saline gradient processes regenerated with thermal solar energy: reverse electrodialysis (RED) and pressure retarded osmosis (PRO).
  • Application of solar thermal energy to separation processes for brine concentration and treatment of industrial effluents.
  • Dynamic modelling, process optimization and advanced control strategies in solar thermal applications.

During 2021, the Unit has continued its relevant R&D activities within the framework of national and international projects. Remote work has practically mitigated the effects of the pandemic and even all the installations can be operated remotely. Most notable is the participation in H2020 projects with a strong participation in the industry sector: WATER MINING, EERES4WATER and INTELWATT. In particular, the first one implies the creation of a Living Lab at PSA, involving a Community of Practice on solar desalination with zero liquid discharge and the production of high-quality salts and water suitable for agriculture. Two new PhDs have started in 2021, one devoted to the application of solar-powered MD for brine concentration and another to the development of advanced control techniques for solar desalination.
The international relevance of the activities carried out in the Unit is clearly supported by the participation in EU projects and the following positions currently held:

  • Coordination of the Renewable Energy and Desalination Working Group of the Platform Water Europe.
  • CIEMAT’s representative in the “Modularisation” subtask of Task 64 of IEA SHC Solar Process Heat.
  • CIEMAT’s representative in the EERA Joint Digitalization Program for Energy.