Fix grid meter sign: positive reading is export

The assumption meter1_power positive = import was wrong. Evidence
from the recorded data: sustained +2kW meter readings at high PV
with a full battery in maximize-self-consumption mode (exports,
not imports), and a single -2.5kW sample at 17:54 with only 600W
PV - a kettle import, physically impossible as an export under
the old assumption. house_load was inflated by adding export on
top of production, which made PV and consumption look swapped.

All derived flow fields follow the single METER_IMPORT_POSITIVE
constant; tests now describe the observed kettle/export patterns.

solaredge_modbus_mqtt/__init__.py

@@ -86,10 +86,12 @@ storage_mode_map = [
     "Remote Control"
 ]
 
-# Observed on the probed system: meter1_power positive = grid import,
+# Observed on the probed system: meter1_power positive = grid EXPORT
+# (verified against a full-battery self-consumption system: sustained +2kW
+# readings at high PV were exports; a kettle appears as a negative spike).
 # battery1_power positive = discharge. If day-one graphs disagree, flip here -
 # all derived flow fields (house_load, grid_import, ...) follow.
-METER_IMPORT_POSITIVE = True
+METER_IMPORT_POSITIVE = False
 BATTERY_DISCHARGE_POSITIVE = True
 
 

solaredge_modbus_mqtt/test_SolarData.py

@@ -210,8 +210,8 @@ class TestSolarData(unittest.TestCase):
         self.assertAlmostEqual(597.0, solarData.data['power_ac'])
 
     def testFlowsImport(self):
-        # probed live values: PV 861.2 W, grid +689.5 (import), battery idle
+        # kettle: PV 861.2 W, grid meter reads -689.5 (import), battery idle
-        solarData = SolarData(probe_data(power_ac=8612, m1_power=6895, b1_power=0.0))
+        solarData = SolarData(probe_data(power_ac=8612, m1_power=-6895, b1_power=0.0))
 
         self.assertAlmostEqual(1550.7, solarData.data['house_load'])
         self.assertAlmostEqual(689.5, solarData.data['grid_import'])
@@ -220,9 +220,9 @@ class TestSolarData(unittest.TestCase):
         self.assertAlmostEqual(0.0, solarData.data['battery_discharge'])
         self.assertAlmostEqual(861.2, solarData.data['solar_to_house'])
 
-    def testFlowsSurplus(self):
+    def testFlowsExport(self):
-        # PV 5000, exporting 2000, charging battery with 1000
+        # observed afternoon: PV 5000, exporting 2000, charging battery with 1000
-        solarData = SolarData(probe_data(power_ac=50000, m1_power=-20000, b1_power=-1000.0))
+        solarData = SolarData(probe_data(power_ac=50000, m1_power=20000, b1_power=-1000.0))
 
         self.assertAlmostEqual(2000.0, solarData.data['house_load'])
         self.assertAlmostEqual(0.0, solarData.data['grid_import'])