Backtracking

Backtracking is a tracker operating mode used at dawn and dusk, when the sun is low and tracker rows would otherwise shade each other. In this mode the tracker control unit calculates a tilt angle that keeps adjacent rows from shading each other's panels, then moves the tracker to that angle. It is worth doing when the loss from pointing the panels away from the sun is smaller than the loss shading would cause. The calculation relies on geometry: row pitch, tracker angle, module plane and the horizon formed by the neighboring row. On site, row spacing and panel width must be set for each tracker. Backtracking only stops east-west shading between rows. It does not prevent north-south shading. On rolling terrain, a row that backtracks correctly for a flat-ground assumption can still shade its neighbor or be turned further off the sun than needed. Large motor blocks make this worse because they force one angle onto rows that need different ones. To find these losses, compare backtracking settings, motor block boundaries, shade-model output and row-level production in the morning and afternoon. Then tune the backtracking parameters for each terrain zone. During commissioning, check and adjust the backtracking shadow status. Changing backtracking parameters requires a login on the handheld terminal or the computer app.

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• sentence 1: support check: partial - u4 gives dawn/dusk substate, but 'sun is low' and 'rows would otherwise shade' are only implied, not stated.
• sentence 8: support check: partial - u9 and u5/u16 support the commissioning check and login requirement, but the handheld terminal login path only shows a LOGIN step, not an explicit requirement statement, though it is implied. -->