You are here


The ALSOLEN company develops medium solar thermal plants (up to 100 MWth or 20 MWe) using the technology of Fresnel mirrors. These thermal plants called ALSOLEN use oil as heat transfer fluid. They also integrate a direct thermal storage using thermocline principle. This oil is heated at 300°Celsius and transfers its thermal energy to different applications which based on users requirement can combine between: electricity, industrial heat, cold and desalination. ALSOLEN solar thermal plants are typically designed to be operated in isolated areas where access to national grid is not or hardly possible, ALSOLEN plants do not require top qualified operation team.

The originality of ALSOLEN solar thermal plants consists, amongst other points, in a design that maximizes on site fabrication (thanks to a mobile plant), in a minimum maintenance, in an optimized performance and a long lifetime. ALSOLEN plants comprise a thermal storage in which the oil of the thermal fluid loop is directly flowing. The thermal storage ensures a high energy availability ratio that fits the consumption requirements, mainly after sunset, during several hours.

Each application uses a technology that fits ALSOLEN design strategy. The electricity is generated by an organic Rankine cycle (ORC). Cold is produced by using a two fluids absorption system able to reach temperatures below 0°Celsius. And pure water is produced with a multi effect distillation.

All the development work conducted for ALSOLEN power plants has been done in cooperation with the CEA LITEN and subsidiaries of ALCEN.

Development of high-power solar thermal plants (50 MWe and over) called ALSOLEN SUP is also close to completion. ALSOLEN SUP technology will directly generate superheated steam at 450°Celsius. ALSOLEN SUP plants will operate with a 3 stages thermal storage able to unstore superheated steam. ALSOLEN SUP technology will launch new innovations on the market and will also benefit from ALSOLEN innovations. 


7 rue Jean Mermoz
78000 Versailles

+33 (0)1 30 21 09 94
  • Thermodynamic solar power plants
  • Thermodynamic solar power plants
  • Thermal storage
  • Thermodynamic solar power plants: Alsolen Sup