Trackers
Trackers are an unavoidable aspect of any high concentration photovoltaic system. This is because the Laws of Physics dictate that the more one concentrates sunlight, the narrower must be the acceptance angle of the solar concentrator. Hence, in order to get the sunlight into a high concentration lens system either the concentrator must be turned to always face the Sun (the approach used by most HCPV companies) or the sunlight must be steered into the concentrator (the approach used by XE).
The Objective
FIG 3.1 Concentrating solar arrays waste a huge amount of the incident solar energy. To create a practical renewable energy system such waste is not possible and needs to be eliminated. To appreciate why land area is so important to a sustainable energy future see Land Requirements.
Our objective is to flatten the design, and revolutionize the actuation mechanism, of solar trackers so that they may be incorporated into every XE-CPV solar panel inexpensively. Ultimately, this will allow us deploy ultra-high efficiency concentrating photovoltaic solar panels, in area-filling geometries, on the roofs and facades of commercial buildings, and across huge swathes of desert land in low-profile, flat, central utility solar power stations. Furthermore, we seek to lower the costs of solar trackers by basing our actuation mechanism on printable electronics, obtained under a Technology Collaboration and Licensing Agreement with Hewlett Packard, rather than on traditional geared motors.
Some consequences of meeting these objectives are:
- A 100% increase in the area-efficiency of HCPV power plants.
- Elimination of almost all the “dead space” between trackers.
- Reduction in the shadowing of one tracker on another.
- Miniaturization of the large-scale mechanical trackers using micro-electronics and optics.
- Lowering of the manufacturing costs of solar trackers.
- Trackers that steer the sunlight rather than steer the panel.
- Exponential decrease in tracker costs due to the economies-of-scale that electronics fabrication provides in comparison to large mechanical systems.