Linear Fresnel Reflectors
In the Fresnel plants linear reflectors concentrate the sun into an absorber tube quite similar to the parabolic trough plants. As the concentration factor is smaller than in parabolic trough plants lower temperatures are normally achieved in the heat transfer fluid. That is why most of the plants which have been designed until know has chosen saturated steam as the only working fluid in both the solar field and the turbine. This concept claims to be cheaper than the parabolic trough, but it has lower optical and thermodynamic efficiency and it is not so suitable for storing energy in molten salt tanks. In Europe, 2 plant based on the Fresnel principle is currently operating (in total 31.4 MW) and another one have been announced (12 MW).
Uses flat mirror design to concentrate sun, enabling simpler production and installation
Enables other industrial uses such as steam processing
Plant size between a couple MW to 200 MW.
Temperature of the working fluid: 300ºC. New plants that could reach up to 500ºC are been tested.
Heat storage capabilities are under investigation
Solar energy to electric power performance: Design point 14%. Annual 10%.
Prices of PPA that will make projects feasible: between 13 and 20 c€/kWh depending on the level of solar radiation, size of the plant, capacity factor, financial conditions, etc.