Parabolic trough technology
Torresol Energy builds plants with parabolic trough technology which include a molten-salt heat storage system, enabling a very high annual coefficient of use.
How the technology works
These plants are comprised of loops (or arrays) of parabolic mirrors that concentrate solar radiation in a central collector pipe through which thermal oil circulates and is heated to almost 400ºC.
This oil is transferred to a heat exchanger, where:
- It vaporizes water which, in a steam turbine, drives a generator that injects electrical power into the grid
- Surplus power can be used to heat liquid nitrate salts and store the heat in a hot tank, making it possible to generate electricity even in the absence of sunlight.
Torresol Energy operates two parabolic trough collectors plants in the south of Spain, Valle 1 and Valle 2.
These plants each have:
- 50 MW of power
- One solar field of 510,000 m2 of SENERtrough®-type collectors
- A molten-salt heat storage system, supplying electrical power for up to seven hours without solar radiation.
The system of SENER-patented SENERtrough® parabolic trough collectors includes design enhancements that make it possible to reduce both the assembly time and the weight of the collector structure versus other similar ones.
This is no small achievement, since a standard 50-MW solar plant includes 90 km of parabolic trough collectors.
The use of these collectors in the Torresol Energy plants helps to reduce the costs of power-plant construction and of energy collection, thus improving performance, both technically and economically.