Invention:
This invention is an apparatus and method for controlling the motion of heliostats, which are mirrors that reflect sunlight towards a common target. For heliostats to be maximally efficient, they must be able to shift in orientation precisely as the Sun’s relative position to the Earth changes. This technology utilizes a beamsplitter perpendicular to a heliostat reflector surface and to the incident and reflected rays of sunlight, as well as a camera that views both the sunlight transmitted through the beamsplitter and the sunlight reflected from the beamsplitter. By applying the law of reflection, the system ensures that the images of the sun and the target captured by the camera share a common center when the heliostat is correctly oriented. A computer processes these images to continuously adjust the heliostat’s orientation, maintaining accurate targeting of the reflected sunlight. The integrated dual-axis mount and automatic mechanical shape adjustment significantly enhance the precision and efficiency of solar energy collection.
Background:
Numerous heliostat tracking and orientation correction methods currently exist, including open loop methods, which calculate the necessary orientations of each heliostat in a tower or field based on relative positions of the Earth and Sun and the precise location of the heliostat. However, these methods are imprecise and cannot account for irregularities or imperfections in the heliostat, or for uneven or rocky ground beneath a heliostat tower or field. Closed loop methods of heliostat control, in which the heliostat’s degree of unalignment is continuously calculated using sensors and cameras and then corrected, are more effective and precise than open loop methods, but many current methods require cameras with very wide fields of view, which have relatively low resolution and high distortion. This limits the accuracy of most current closed loop heliostat orientation control to greater than 1 milliradian milliseconds. This technology, using a camera in conjunction with a beamsplitter on the heliostat reflector, can achieve an accuracy of less than 0.5 milliradian milliseconds.
Applications:
- Heliostats
- Power generation
- Renewable energy
- Industrial heating
- Agriculture
Advantages:
- Highly accurate
- Continuously adjusts heliostat orientation
- Increased efficiency
- Cost-effective
