# Tracker Configuration

pvnode supports fixed, single-axis, and dual-axis tracker systems. Set `tracker_system_type` to choose:

| Value | System |
|---|---|
| `0` | No tracking (fixed mount, default) |
| `1` | Single-axis tracker |
| `2` | Dual-axis tracker |

Tracking only applies to the first PV array.

## Single-Axis Tracker

When `tracker_system_type=1`, use `single_axis_tracker_config` to define the tracker geometry. The format is four values separated by colons:

```
single_axis_tracker_config=axis_azimuth:axis_tilt:max_rotation:backward_tracking
```

| Value | Description | Range |
|---|---|---|
| Axis azimuth | Compass direction of the rotation axis | 0–360° (180 = south) |
| Axis tilt | Tilt of the rotation axis from horizontal | 0–90° |
| Max rotation | Maximum rotation angle from center | 0–90° |
| Backward tracking | Enable backward tracking to prevent row shading | `T` or `F` |

**Example:**

```
single_axis_tracker_config=180:0:90:T
```

This configures a tracker with:
- Axis oriented south (180°)
- No axis tilt (0°)
- Full rotation range (±90°)
- Backward tracking enabled to reduce row shading at low sun angles

## Dual-Axis Tracker

Set `tracker_system_type=2`. No additional configuration needed — the system automatically optimizes for maximum irradiance at every timestep.

## Comparing Fixed vs. Tracked

To quantify the yield gain from tracking, run two requests for the same location — one with `tracker_system_type=0` and one with your desired tracker configuration. Compare the `spec_watts` or `pv_watts` output.