What is a “rail tracking system”?
Until 2010, photovoltaic (solar electric) panels were mounted three ways:
- On fixed racks – simple, solid and inexpensive. But fixed racks only allow each panel to capture about three-fifths of the available energy! So fixed-rack systems take the most land, labor and equipment – panels, inverters and other components – to meet your energy needs, and thus are the most expensive way to mount solar electric panels.
- One one-axis tracking systems – tracking the sun east/west through the day but not north/south through the seasons. One-axis tracking systems produce about 20% more energy (in kilowatt-hours) than fixed rack systems.
- On upright-pole two-axis tracking systems – tracking the sun east/west through the day and north/south through the seasons. They produce about 40% more energy (kWh) than fixed-rack systems (depending on latitude and other factors).
The most productive of these is the two-axis tracking systems, but these systems have several disadvantages which have prevented their widespread use:
- High winds cause problems, because panels on the edge of each system are not supported. Upright-pole two-axis tracking systems are generally rated for winds 90 miles per hour or lower.
- Stresses from the wind and from the weight of the panels are concentrated at the top and bottom of the pole. These concentrated stresses can lead to breakdowns.
- The mechanism for moving the panels is complex, with numerous moving parts, which can lead to failure.
- The weight of these systems requires a massive concrete foundation, which means excavation with heavy equipment. This adds significantly to the cost of upright-pole systems.
- Upright-pole trackers are not scalable; that is, there are no mechanical components which are shared between two or more trackers.
In 2010, Mark Scanlon, founder of Sedona Solar Technology, developed a new method for mounting PV panels: the rail tracking system.
A rail tracking system can move dozens of panels in synch, tracking the sun east/west through the day and north/south through the seasons, so energy production is maximized.
But unlike upright-pole systems, rail tracking systems are simple, durable and reliable:
- Rail tracking systems support the weight of each panel, so they can withstand high winds. Some rail tracking systems are rated up to 150 miles per hour.
- Rail tracking systems spread the weight of the panels over the area of the array, so the load is not concentrated on one spot.
- Rail tracking systems have only two moving parts – actuators that move the array and bearings that allow each panel to rock in each axis. Fewer moving parts means fewer things to go wrong.
- Rail tracking systems can be mounted without a concrete foundation, so there is no need for heavy equipment or excavation.
- Rail trackers are scalable: frames which hold a few panels can be coupled, so actuators which move the panels in both directions (tracking east/west and north/south) can be shared among the frames. The result is lower cost per panel.
The InteliTrack system tracks both east/west and north/south, has only two moving parts, and is rated for use in winds up to 150 miles per hour.
To find out if a rail tracking system can work at your site, go to the “Request Information” bar to the right and provide us with your contact information. A Sedona Solar Technology engineer will contact you soon.