Numerical and experimental analysis of a novel thermal energy storage for a small-scale concentrated solar power plant (Small-scale CSP)

The biggest challenge for renewable energy sources is to match the demand with the supply. By using thermal energy storage for concentrated solar power plants, the stability, reliability, and capacity factor of the plants are improved. Currently used concentrated solar power technologies (parabolic trough collector, solar power tower, linear Fresnel reflector) use heavy and very expensive glass mirrors and receivers. Apart from that, conventional thermal storages are also expensive as these are based on molten salts, which are expensive and their handling requires special materials. As a result, conventional concentrated solar power technologies are only suitable for large-scale installations in regions with high annual direct normal irradiance.

This project addresses the development of a cost-effective concentrated solar energy driven cogeneration system with thermal energy storage. To this end, the project addresses the investigation of a novel micro-structured polymer foil-based concentrated solar power system and investigations of a novel packed-bed rock thermal energy storage system. The micro-structured polymer foil-based concentrated solar power system has the advantages of a low installation cost and a low operation and maintenance cost. The thermal energy storage is based on a packed-bed rock with heat storage charging and discharging using evaporation and condensation of heat transfer fluid.

The results indicate that the micro-structured polymer foil-based concentrated solar power plant with packed-bed rock thermal energy storage is a promising alternative for cogeneration/multi-generation plants. The project contributes to the development of cost-efficient renewable energy systems, reducing the dependence on fossil fuels and reducing the carbon dioxide emissions of the heat and power generation sector, thus helping to attain socio-economic and environmental targets in the context of the EU 2020 vision.

Project Partners: Technical University of Denmark (Lead), Heliac Aps (Denmark), Alfa Laval (Sweden) and IMDEA Energy Institute (Spain)

Funding: The project "Small-scale CSP" received funding from the European Union’s Horizon 2020 research and innovation programme with a Marie Skłodowska-Curie Individual Fellowship under grant agreement no. 794562. The financial support is gratefully acknowledged.

The progress of the project beyond the state of the art include the following:

(1) The first analysis of a micro-structured polymer foil-based CSP system.
(2) Models for the analysis and optimization of foil-based CSP driven co-generation systems
(3) Experimental investigations of a proof of concept for a packed bed rock thermal energy storage system with heat storage charging using the evaporation of the heat transfer fluid
(4) Modelling and analysis of different thermal energy storage system and ORC power system working fluid options for the foil-based CSP plant.