Introduction

The invention describes an innovative concept of a thermionic conversion stage of concentrated solar energy for the production of electrical energy, combinable in cascade with a thermoelectric stage or a thermodynamic stage, and fabricated with a series of manufacturing processes by using a wide set of materials.

Technical features

Device for converting energy from concentrated solar radiation into electrical power, comprising a thermionic emitter and a radiation absorber configured to transform radiation energy into thermal energy, having an external surface provided with a periodic sub-micrometric structure and an internal surface on which the thermionic emitter is monolithically integrated.
The conversion efficiency of the device, which combines the scalability of solid state technology, typical of photovoltaic cells, with the high operating temperatures of thermal solar technologies (up to about 1000 ° C), can exceed 30% for the thermionic stage as well as it can reach efficiency values around 40% and 50% by combining it with thermoelectric generators and heat engines, respectively.The system is perfectly compatible with thermal  energy storage systems (e.g., based on molten salts).

 

Possible Applications

• Concentrated solar energy conversion;
• Thermal energy conversion from energy storage systems at high temperature;
• Space propulsion systems;
• Thermal energy conversion from nuclear and industrial processes;
• Geothermal energy conversion;
• Electron emitters.

Advantages

• Solid-state converter;
• High-temperature converter;
• High conversion efficiency;
• Compatibility with thermodynamic cycles and related thermomechanical cycles;
• Compatibility with energy storage systems;
• Compatibility with co-generation systems;
• Scalability.