Optimization of a thermal storage system with integrated steam generator
Overall Cost
European Commission, 7th FP
Project Description

Project Summary
OPTS project aimed at developing a new Thermal Energy Storage (TES) system based on single tank configuration using stratifying Molten Salts (MS, Sodium / Potassium Nitrates 60/40 w/w) as heat storage medium at 550°C maximum temperature, integrated with a Steam Generator (SG), to provide efficient, reliable and economic energy storage for the next generation of trough and tower plants.
Thermal Storage Group’s Role
CIEMAT gained valuable experience in integrating thermocline storage tanks in CSP simulation models as well as definition of efficient operation strategies for this type of storage systems.
Technical Approach and Resources Used
The research team is engaged in
  • Analysis, modelling and simulation of thermocline storage tanks with internal filler.
  • Implementation of TES systems in CSP performance models.
  • Analysis and optimization of control strategies for thermocline storage systems in CSP plants.
  • Experimental design and test matrix for a TES-SG prototype of 12.5 MWth.
  • Experimental evaluation of equipment for molten salt loops.
  • Heat transfer coefficient for molten salt-SG.
Project Results (including any commercial outcomes)
Key Staff
The project aimed at the full development of the integrated system (TES-SG) up to demonstration level. The SG, with natural recirculation of the MS, can be either positioned directly into the tank (Pool-type) or as an external shell-and-tube once-through SG (Loop-type) with thermocline storage tank.
  • Dr. Mª Esther Rojas
  • Dr. Rocío Bayón
  • Mario Biencinto
  • Margarita Rodriguez
  • Esther Rivas