PATH™ Toroidal Heliostat

Passive Adjustment Toroidal Heliostat Specification
Reflective Surface
  • Glass
  • Independent Static and Dynamic
  • In Orthogonal Directions
  • According to requirement
Tracking Mechanism
  • Spinning Elevation with rotation axis adjustment
Motion Control
  • Two High Precision Slewing Drives
  • 24V BLDC motors (or custom) + solid state limit switches
Range of Motion
  • Horizon to Horizon Tracking
Pier and Footing
  • 1 post and two light stays
  • Footing dependent on application

The Passive Adjustment Toroidal Heliostat (PATH™) is the latest in advanced heliostat design. It delivers unprecedented performance and flexibility, as well as real cost-effectiveness. That's our vision for affordable solar energy for the future.

Why Toroidal?

Astigmatism and image broadening is a significant energy loss mechanism in solar concentrator installations. This causes under performance of the heliostat when the sun is not in the 'ideal' position in the sky.

The toroidal heliostat mitigates these loss mechanisms by using a smarter reflector shape. The toroidal heliostat delivers higher concentration ratios for longer periods of operation than other types of heliostat.

Why Passive Adjustment?

Passive adjustment is the ultimate efficiency winner for heliostats. It adds the possibility of dynamic variation of the curvature of the heliostat reflector to further enhance the heliostat's performance. This is achieved with no additional complicated framing; it's simply a matter of putting things in the right place.

The PATH™ is an innovative solution to improving the concentration ratio of the heliostat. The size of the concentrated image from the heliostat is smaller, allowing it to be more easily captured by a receiver. The flexibility of the design also allows it to be customised to any receiver aperture, providing good control over energy delivery rates as well as compensation for seasonal insolation variation. A great achievement for solar energy!

Graph of Image dimension at reciever versus time of day
Simulation result shows a comparison between concentrated images from a spherical heliostat, a toroidal heliostat and a Passive Adjustment Toroidal Heliostat (PATH™). The PATH™ consistently shows the best concentration and smallest image

The PATH™ is the subject of a current Australian Patent Application.