Many companies offer products with different tracking possibilities, varying from single-axis to dual-axis. Dual-axis solar tracking is known to harvest significantly more energy from the sun compared to other PV module mounting structures. For mass deployment of dual-axis tracking system into the market place, two conditions need to be met: simplifying the hardware structures in order to lower the capital and O&M costs, and also to guarantee stability and reliability against the weather elements.
Generally, solar tracking systems use linear actuators, ball screw or slew wheel drive systems. To lower costs, BIG SUN Group has developed a commercial dual axis tracker unit called iPV Solar Tracker (3 kW and 6 kW) which uses simple hardware configurations and control systems. The key feature of the iPV Solar Tracker that differentiates it from other solar tracking devices is the steel cable drive mechanism.
The iPV Solar Tracker drive mechanism consists primarily of electronic control unit, two electric motors, shafts, ball bearings, cable reels, pulleys, shackles, anchoring bolts, springs and steel cables. The two motors are attached to a central pole and positioned perpendicular to each other. Each motor has a two-slot cable reel fitted on a rotation shaft. Steel cables attached to the diagonal corners of the module frame are wound on the reel slots—one in clockwise direction and the other in anti-clockwise direction.
When the electric motor rotates the cable reels, the winding and unwinding of the steel cables pulls the module mounting frame into a rotational motion. The pulley connecting the anchor bolt diverts the horizontal force into vertical motion so that less force is used to pull the module mounting frame downwards. The springs connecting the middle anchor bolts help to modulate the tension of the steel cables so they will not be too tight or too loose. Once the frame moves to the target position, all four steel cables will be tightened, hence providing four anchoring strengths to the mounting frame. The steel cables anchors also provide additional stability to the tracker in the event of gusty wind of up to 220 km/h.
The tracking accuracy of the iPV Solar Tracker is managed by an electronic control unit based on astronomical algorithm. This enables a full 360° azimuth rotation and altitude tilt of -40° to 40° (0 = horizontal). The tracking position moves every five minutes along the sun’s path, requiring as few as 30 motions per day with a consequential low power consumption, less wear and tear and low O&M costs. The controller algorithm also includes backtracking capability which allows optimization of the ground cover ratio. The performance evaluation of iPV Solar Tracker power plants in Taiwan (23∘N) shows an average of annual energy gain of 30% compared to a fixed-tilted PV system. This result bares a testament to the high accuracy of the sun tracking capability of the iPV tracker using simple cable drive mechanism.
Kal K says
I am interested. Can you please send me the information.
Thomas Chen says
can you leave your e-mail?
Lightfoot says
I am interested, and would like to see an installation using this type of dual-axis tracking. Currently working on a 54MW single axis tracking solar farm, that has predictions of 20% more energy compared to fixed panels, there is a high cost to get this extra 20% energy, which is approx double the installation costs, of a fixed panel system, plus higher maintenance costs. It uses nextracker independant rows that can move to 60 degrees altitude tilt, which is significantly more flexible than 40 degrees above. I accept the 30% extra energy figure given in the article for this dual-axis tracking, as other dual axis systems have closer to 25% and would like to see maintenance costs and install costs to obtain that extra energy, as those details become available.
When I build my solar farm, I’m tempted to stay with fixed panels, and a lot of them…
Thomas Chen says
Dear Lightfoot,
Can you leave your e-mail or contact phone number, I’ll send you some information about this amazing dual-axis soar tracker.
Lightfoot says
Hi Thomas, apologies for not replying sooner! my email is lightfoot222@gmail.com
Thomas Chen says
No comments?!
How can you people not like this technology?