fronius.py

# -*- coding: utf-8 -*-
#    See the file LICENSE.txt for your rights.
#    Author: Michael Kainzbauer (github: mkainzbauer)

"""How to read data from your Fronius device and store it as as selected value in weewx archive data

*******************************************************************************

To use this extension, add the following somewhere in your configuration file
weewx.conf:

[Fronius]
    api_url = http://IP_ADRESS.OF_YOUR.DEVICE.HERE/solar_api/v1/GetArchiveData.cgi?
    timeZone = Z # use the timeZone of your device 
    installedWP = 3000 # installed Watts peak
    archive_column = signal1 #optional, "radiation" is default
    

*******************************************************************************

To enable this service:

1) copy this file to the user directory

2) modify the weewx configuration file by adding this service to the option
"report_services", located in section [Engine][[Services]].

[Engine]
  [[Services]]
    ...
    data_services = user.fronius.AddElectricity # other services can be appended separated with a comma

*******************************************************************************
"""

import weewx, json, urllib.request, urllib.error, weeutil.weeutil, logging
from weeutil.weeutil import timestamp_to_string
from weewx.engine import StdService
from datetime import datetime

log = logging.getLogger(__name__)

class AddElectricity(StdService):
      
    def __init__(self, engine, config_dict):

      # Initialize my superclass first:
      super(AddElectricity, self).__init__(engine, config_dict)

      # Bind to any new archive record events:
      self.bind(weewx.NEW_ARCHIVE_RECORD, self.new_archive_record)

    def new_archive_record(self, event):
      value = self.getValue(event)
      log.debug("Inverter Value: %s at %s" % (value, (weeutil.weeutil.timestamp_to_string(event.record['dateTime']))))
      
      archive_column = "radiation"
      if 'archive_column' in self.config_dict['Fronius']:
        archive_column = self.config_dict['Fronius']['archive_column']
      
      event.record[archive_column] = value

    def getValue(self, event):
      timeZone = "Z"
      if 'timeZone' in self.config_dict['Fronius']:
        timeZone = self.config_dict['Fronius']['timeZone']
        log.debug("Fronius timeZone: %s"  % timeZone)
      installedWP = float(self.config_dict['Fronius']['installedWP'])
      log.debug("Installed Watt peak: %s"  % installedWP)
      startDateTime = int(event.record['dateTime'])
      endDateTime = startDateTime + int(self.config_dict['StdArchive']['archive_interval'])
      endDate = datetime.utcfromtimestamp(endDateTime).isoformat() + timeZone
      startDate = datetime.utcfromtimestamp(startDateTime).isoformat() + timeZone
      url = self.config_dict['Fronius']['api_url'] + 'Scope=System&StartDate=' + startDate + '&EndDate=' + endDate + '&Channel=EnergyReal_WAC_Sum_Produced&Channel=TimeSpanInSec'
      log.info(url)
      try:
        response = urllib.request.urlopen(url)
        data = json.loads(response.read())
        work = data["Body"]["Data"]["inverter/1"]["Data"]["EnergyReal_WAC_Sum_Produced"]["Values"]["0"]
        timeSpan = data["Body"]["Data"]["inverter/1"]["Data"]["TimeSpanInSec"]["Values"]["0"]
        averagePower = work / (timeSpan / float(3600))
        log.info("Avg Power: %s at %s" % (averagePower, (weeutil.weeutil.timestamp_to_string(event.record['dateTime']))))
        normalizedOutput = averagePower / installedWP
        log.debug("Normalized Output: %s at %s" % (normalizedOutput, (weeutil.weeutil.timestamp_to_string(event.record['dateTime']))))
        return normalizedOutput
      except urllib.error.URLError as e:
        log.error("Error getting inverter data: %r" % e)
      except:
        log.error("Unexpected error:")