Dual-axis tracking allows solar panels and heliostats to spend the whole day directly facing the sun. This allows a pv panel to harvest more of the sun's energy and can generate as much 40+% more electricity than a fixed panel.
As the sun moves through the sky up/down and East/West the tracker positions the PV panels to directly face the sun so that they can absorb the maximum amount of sunligh. This allows them to make the most of the energy that the sun has to offer.
Some trackers use optical sensors to follow the sunlight and others use an algorithm calculated ahead of time based upon geopositioning coordinates.
The use of trackers is becoming more and more common. Issues that have delayed even more widespread use have revolved around the duo of reliability and cost. Traditional tracker designs require substantial amounts of raw materials (primarily steel and cement) to allow them to be rugged enough to function reliably. This has made them expensive. The mechanical components are sometimes unreliable or require considerable maintenance as they typically rely on actuators and custom-engineered components.
The Eternegy ETracker doesn't require custom components and uses simple robust mechanicals that are already available and tested across a range of applications.
At Eternegy we have developed a much lighter (more affordable) yet also more rugged dual-axis tracker. We use a geolocation driven algorithm to ensure that the PV panels are on track throughout the day and employ steel cables rather than actuators to move the PV panels. This is by far the most material efficient tracker design available. As a result it is the best tracker investment that a large-scale PV project can make.