Drop time-of-day tag which makes data difficult to use with victoria-metrics/promql

SMETS2 gas meter consumption is measured in m3 rather than kWh, so conversion
from one unit to the other is required.
Algorithm and description of terms is taken from:
https://www.theenergyshop.com/guides/how-to-convert-gas-units-to-kwh

This commit adds additional config file options to the `gas` section:
- `meter_type` (default `1` for backward compatibility)
  Enables unit conversion from m3 to kWh before reporting metrics to influxdb
- `volume_correction_factor` (default `1.02264`)
- `calorific_value` (default `40`)

app/octopus_to_influxdb.py

@@ -71,6 +71,9 @@ def store_series(connection, series, metrics, rate_data):
 
     def fields_for_measurement(measurement):
         consumption = measurement['consumption']
+        conversion_factor = rate_data.get('conversion_factor', None)
+        if conversion_factor:
+            consumption *= conversion_factor
         rate = active_rate_field(measurement)
         rate_cost = rate_data[rate]
         cost = consumption * rate_cost
@@ -99,7 +102,7 @@ def store_series(connection, series, metrics, rate_data):
         time = period.datetime().strftime('%H:%M')
         return {
             'active_rate': active_rate_field(measurement),
-            'time_of_day': time,
+            #'time_of_day': time,
         }
 
     measurements = [
@@ -149,6 +152,9 @@ def cmd(config_file, from_date, to_date):
 
     g_mpan = config.get('gas', 'mpan', fallback=None)
     g_serial = config.get('gas', 'serial_number', fallback=None)
+    g_meter_type = config.get('gas', 'meter_type', fallback=1)
+    g_vcf = config.get('gas', 'volume_correction_factor', fallback=1.02264)
+    g_cv = config.get('gas', 'calorific_value', fallback=40)
     if not g_mpan or not g_serial:
         raise click.ClickException('No gas meter identifiers')
     g_url = 'https://api.octopus.energy/v1/gas-meter-points/' \
@@ -184,6 +190,8 @@ def cmd(config_file, from_date, to_date):
                 'gas', 'standing_charge', fallback=0.0
             ),
             'unit_rate': config.getfloat('gas', 'unit_rate', fallback=0.0),
+            # SMETS1 meters report kWh, SMET2 report m^3 and need converting to kWh first
+            'conversion_factor': (float(g_vcf) * float(g_cv)) / 3.6 if int(g_meter_type) > 1 else None,
         }
     }
 

example-octograph.ini

@@ -25,3 +25,9 @@ mpan = 12345
 serial_number = 12A3456
 standing_charge = 16.80
 unit_rate = 3.03
+# 1 for SMETS1 meters, 2 for SMETS2 meters
+meter_type = 1
+# volume correction factor, and calorific values used to convert SMETS2 consumption from m^3 to kWh
+# Defaults are typically used values. Your energy bill will show you the values used for your supply.
+volume_correction_factor = 1.02264
+calorific_value = 40