Pyramid lamp medallion control for solar thermal power generation system

A heliostat mirror alignment calibration system, comprising:

• a heliostat including a first drive mechanism rotating a mirror about a first axis and a second drive mechanism rotating the mirror about a second axis extending perpendicular to the first axis;
• an artificial light source adapted to be coupled to the heliostat mirror;
• photovoltaic sensors adapted to be mounted to a solar tower, the sensors outputting signals indicative of the intensity of artificial light striking the sensor;
• first and second mirror position sensors operable to output signals indicative of the mirror position along the first and second axes;
• a control module in receipt of the photovoltaic sensor signals and the position sensor signals, the control module correlating a first set of photovoltaic sensor signals with a first set of position sensor signals when the mirror is at a first orientation, the control module correlating a second set of photovoltaic sensor signals with a second set of position sensor signals when the mirror is at a second orientation and calibrating the heliostat alignment system based on the photovoltaic sensor signals and the position sensor signals.

A method of calibrating a mirror orientation system of a heliostat, the method comprising:

• providing a calibration zone on a solar thermal tower;
• moving a mirror of a heliostat to a first orientation to reflect solar light on a calibration zone;
• determining an energy distribution across the calibration zone based on the first orientation;
• moving the mirror a predetermined amount to a second orientation to reflect solar light on the calibration zone;
• determining an energy distribution across the calibration zone based on the second mirror orientation;
• determining an alignment accuracy of the heliostat based on a comparison of the energy distributions;
• and
• calibrating the heliostat to increase the alignment accuracy.

A heliostat mirror positioning system, comprising:

• a plurality of sensors adapted to be mounted to a solar tower about its circumference, the sensors being in receipt of solar light reflected by a heliostat mirror and providing signals indicative of the solar energy at the respective sensor positions;
• a central control module in receipt of the signals provided by the sensors, the control module determining an energy distribution associated with a mirror position;
• a heliostat mirror position sensor providing a signal indicative of the mirror position;
• a heliostat control module in receipt of the mirror position signal and being in communication with the central control module to associate the energy distribution with the mirror position, the heliostat control module being adapted to actuate a drive mechanism, wherein the central control module commands the heliostat control module to move the mirror to another position, determines another energy distribution, and associates another energy distribution with the another mirror position, the central control module determining an alignment accuracy based on a comparison of the energy distributions, and calibrating the positioning system to increase the mirror alignment accuracy.