The present invention allows increasing the net electric power supplied to the network by the solar thermal power plants of the cylindrical parabolic collector type by using the solar field in a more efficient manner, generating steam to drive the main ancillaries by means of steam turbines (turbo pumps), reducing electric consumption of the ancillary services and therefore increasing the net electric power of the plant.
On days when the solar radiation is greater than the designed radiation, part of the solar field must stop being used since the generator and the turbine would exceed its designated power. The present system proposes harnessing the unused portion of the solar field for generating steam to drive the main ancillaries of the plant, energy which would otherwise not be harnessed.
In addition, the overall operating performance of the ancillary service pumps is better when using steam to drive the pumps through a steam turbine (turbo pumps) instead of driving them with electric motors (motor pumps).