Single-axis tracker plant

A single-axis tracker plant mounts PV rows on structures that turn about one axis to follow the sun, changing either orientation or tilt but not both. The trackers are usually the only moving parts in the plant, and the axis may be horizontal, tilted or vertical depending on the design class. To keep controller and actuator cost low per watt, many tracker rows are mechanically ganged by a drive strut or pushrod to one gear motor and controller. One report says single-axis tracking can raise annual yield by up to 27 percent depending on site. It also gives a smoother afternoon output plateau. Fixed-tilt mounting is simpler, cheaper and needs less maintenance, so tracking makes most sense at sites with a high share of direct irradiation. Most tracker plants use crystalline silicon modules, though low-cost single-axis trackers have also been used with some thin-film modules. Rigid drive struts force all units into one plane and usually require site grading. The tilted T20 design uses articulated struts to follow rough terrain and to allow looser tolerances when placing foundations. Field risks include higher soiling rates than dual-axis trackers in dry seasons and storm damage when the tracker structure is poorly engineered.

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• sentence 3: support check: partial - The passages support ganging rows to one actuator and controller to cut per-watt cost, and they name a gear motor with pushrod/drive strut. They do not say many rows are ganged in general or that this is common practice.
• sentence 5: support check: partial - The passage states fixed tilt is simpler, cheaper and lower maintenance, and that tracking suits locations with high direct irradiation. It does not state the causal 'so' link between the two.
• sentence 8: support check: partial - The passage shows higher soiling on the single-axis tracker than on the dual-axis tracker in the 2017 dry season, and storm damage from a poorly engineered single-axis tracker. Presenting these as general field risks goes beyond a single-site figure and a cover caption. -->