5 Things you Should Know About Solar Tracking Systems As a result of the green energy movement and increased renewable sources of power, like wind energy, biomass and hydroelectricity, solar power systems have gained more demand. One way to become more efficient when running a solar energy program is to use a tracking base. Here is an in-depth look at a few things you should know about running a PV system:
1. Tracking Pros
Because tracking arrays receive more peak sun-hours, energy production can be improved with them. This allows a smaller array to be installed, shrinking the required array footprint - a benefit for sites with limited space.
Kits with wide-open solar access (shade-free from dawn to dusk with low horizons) can benefit the most from a tracking array, wringing every last electron from the sun as the year progresses.
The energy gained during early morning and late evening hours can be significant - especially during long summer days - when, at many northern latitudes, the sun rises in the northeast and sets in the northwest.
2. Best Applications
Extra power is only beneficial if you can use it, sell it, or store it as it is produced. A grid-corrected system with a wide open sun window can be a good candidate for a tracked array since every kilowatt-hour gets used. In net-metered situations this home kit grid is credited to your utility bill.
Another good candidate for a tracking array is an off-grid system that has daytime summer-dominated loads. Water-pumping systems are also ideal candidates for PV-direct tracked arrays.
3. Basic Installation of Solar Power Kit
Tracking arrays, like all pole-mounted arrays, are like big sails: Set several feet above the ground, they can experience significant wind-loading. To keep them in place, arrays are usually mounted on large poles (6 to 8 inches in diameter, or even bigger for taller poles) which must be set in large concrete footers. Tracker components can be heavy, often tipping the scales at more than 200 pounds. Often, they'll need to be placed with a crane, backhoe bucket, or some other mechanical means.
When installing module home-run wiring, leave lots of wire length from the modules to the junction box on the pole. This will ensure that when the tracker is in its furthest positions, the cables are not pulled too tight.
4. Installation Options
Electronically controlled trackers have an optical sensor that needs to be mounted at the top of the array. Also, a tracker controller needs to be mounted on the drive and powered either by the battery bank or AC power (if available).
In either case, a power line needs to be appropriately planned for and run from the power source to the controller. Although the controller can be powered directly from the PV system (PV array), this option is discouraged because there's no power available from the PV array after sunset. This means that the tracker must wait until the next morning to turn back to face the sun.
During the summer months, the optical photovoltaic sensor can get confused as to which direction it should return, since it will end up pointing northwest in the evening. Tracker rotation must be limited to 180 degrees to avoid this confusion. However, this does limit the energy gain the tracker can yield in the summer months, since the suns azimuth angle exceeds 180 degrees.
5. Green Money
The decision to invest in tracking solar power systems is a personal one based on your budget and your willingness to deal with possible maintenance and repair issues. In the right circumstances, a solar power tracking systems can save you money up-front and keep you on track to greater energy production and efficiency.