docs(solis): default the FB00 template's grid_power to the Solis meter

sensor.solis_meter_active_power (Modbus 33130) reads import as negative and
export as positive, which is Predbat's convention, so it needs no
grid_power_invert. Confirmed against a grid CT on a live FB00 system. It is
now the template default, and the comments and docs cover what to do when the
Solis meter is not at the grid connection.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Author: CI

docs/inverter-setup.md

@@ -2698,7 +2698,7 @@ To run PredBat with Solis hybrid inverters with firmware level FB00 or later (yo
 
 - Check that each entity name matches the ones your Solax Modbus integration created, as the prefixes depend on the name you gave the integration
 
-- Optionally set **grid_power** to a sensor that measures your grid connection (see the comments in the template)
+- **grid_power** uses the Solis meter (`sensor.solis_meter_active_power`), which already reports import as negative so no invert is needed. If your Solis meter is not at the grid connection, point it at another grid sensor instead (see the comments in the template)
 
 - Lastly you will need to comment out or delete the **template** line to enable the configuration
 

templates/ginlong_solis_fb00.yaml

@@ -63,11 +63,11 @@ pred_bat:
   pv_power:
     - sensor.solis_pv_total_power
 
-  # Grid power in W - should be negative for import and positive for export, set grid_power_invert to true if yours is the other way around
-  # Point this at whichever sensor measures your grid connection, e.g. the Solis meter (sensor.solis_meter_active_power) or another CT clamp
-  # If no single sensor reports it in that form, create a Home Assistant template sensor that does and use that here
-  #grid_power:
-  #  - sensor.solis_meter_active_power
+  # Grid power from the Solis meter - negative for import and positive for export, which is what Predbat expects so no invert is needed
+  # This assumes the Solis meter/CT is at your grid connection. If it isn't, point this at another sensor that measures the grid
+  # (e.g. a CT clamp), set grid_power_invert to true if it reports import as positive, or create a Home Assistant template sensor that does
+  grid_power:
+    - sensor.solis_meter_active_power
   #grid_power_invert:
   #  - true