Gemasolar is the world’s first commercial-scale plant that applies the technology of a central tower receiver and thermal storage with a single thermal fluid (molten salts).
The relevance of this plant resides in its technological uniqueness, as it paved the way towards a new, more efficient technology for thermosolar power generation, providing greater prospects for reducing prices in the future. It also provides significant environmental benefits thanks to its use of a single thermal fluid, with an inorganic basis that is harmless to the environment, and whose handling is restricted to a minimum portion of the area occupied by the plant.
Characteristics of Gemasolar:
- Registered electrical power: 17 MW
- Net electric production typically yielded to the grid: 80 GWh/year
- Solar field: with 2,650 heliostats over 195 hectares
- Thermal storage system: the storage tank of hot salts allows for power generation autonomy for up to 15 hours without sunlight.
The extended time during which the plant can run without solar radiation and the improved efficiency of using solar heat mean that Gemasolar’s production is much greater than that which can be achieved with other technologies in an equally powerful facility.
The remarkable increase in the plant’s energy efficiency ensures power production for 4,565 hours per year, 1.5-2 times higher than other renewable energies. This way, it will supply clean and safe energy to 25,000 homes, and reduce CO2 emissions by more than 27,000 tonnes per year.
The energy generated by Gemasolar is sent to the Villanueva del Rey substation (Andalusia, Spain) via a high-voltage line, where it is fed into the electric grid to be distributed to consumers.
Central tower technology
The heat collected by the salts in a collector located in a tower (capable of reaching temperatures higher than 500ºC) works to generate steam, and uses this to produce electric power. The surplus of heat accumulated during hours of sun is stored in a tank of hot salts.
Thus, Gemasolar has the capacity to produce electric power 24 hours a day throughout many months of the year. Its continual operation record is 36 consecutive days without halting electricity production.
Heat storage also allows for an extremely high predictability of production, with a precision of more than 90%, and deviations (between real vs. expected production) that are 50% lower than the average of the CSP sector.
For all of these reasons, Gemasolar was selected as a representative project for Spain in the COP 21 conference in Paris.
The main technological contribution in Gemasolar – the central receiver and the design of the heliostats – was produced by SENER, with its own solutions.