domoticz_energy_prices v0.3b

Jeroen Gouma

Domoticz_Energy_Prices (aka DEP) is a small set of scripts to perform a hourly update of the electricity prices used for costcalculation in Domoticz.

Scripts are intended for and tested on a Raspberry Pi or other linux environment.

Sometimes one has to reconsider the plans and go back to the drawingboard. After the previous version I found out it was released a bit to early. I did not take into account the fact that on end of day some counters where reset to 0. Thanks to other scripts I could make a better solution (I think).

In the new setup the collection of prices is unchanged, but calculation of the costs is moved inside Domoticz in a dzvents script. The svript now also takes into account the other costs you have to incorporate (netbeheer, teruggave energiebelasting en leveringskosten)

Improvements can (and will) be made. Suggestions are welcome!

To Do:

• Finetuning and cleanup
• Implement error handling on price collecting

Scripts

• collect_prices.sh Collects the prices for tomorrow and saves them for future use by the other scripts
• show_prices.sh Script to check what the actual prices are that would be send to Domoticz
• update_domoticz_prices.sh Performs the actual update of the dummy-device in Domoticz every hour with the actual price.
• electricity_costs.dzvents Calculates the electricity costs per hour based on variable pricing

Installation part 1 (price gathering)

• Go to https://enever.nl and create a token (it's free).
• Edit the script collect_prices.sh and add your token on line 3.
• Create a dummy sensor in Domoticz of type "Custom Sensor" and take a note of the index number. Give it a proper name indicating it's holding the actual price of electricity.
• Create a folder on your domoticz environment and put all files in there. I use /home/pi/domoticz/scripts/energy_prices/
• Make the scripts executable (chmod 755 *.sh)
• Execute the command below in the same folder to collect today's pricing (replace the XXXXXX string with your token): wget -O $(date +'%Y%m%d').json2 https://enever.nl/feed/stroomprijs_vandaag.php?token=XXXXXXXXX
• Execute the show_prices script to validate the output: ./show_prices.sh
• If all looks fine open the script update_domoticz_prices.sh and make the following modifcations:

- on line 8:     change the URL to your own Domoticz IP
- on line 14-25: change the idx number of the used energy provider to the idx of the sensor created in Domoticz
- on line 50-61: remove the # in front of the line which mentions our energy provider

• Save the file and close it.
• The moment of truth: Run the update_domoticz_prices.sh script and check the results: ./update_domotiz_prices.sh
• If the feedback contains "status": "OK" everything works as designed.

Automation

Of course nobody want to run these scripts manually, that's why we have crontab at our disposal. Add the following lines to the crontab the user running domoticz (and change the path to your environment):

   # Collect variable electricity prices for tomorrow
      30    19    *    *    *     /home/pi/domoticz/scripts/energy_prices/collect_prices.sh >/dev/null 2>&1
   # Update variable electricity prices in Domoticz
       0     *     *    *     *   /home/pi/domoticz/scripts/energy_prices/update_domoticz_prices.sh  >/dev/null 2>&1

The update script is scheduled on minut 0 of every hour to ensure the dashboard always shows the actual price.

Installation part 2 (Cost calculation)

• Create a dummy sensor in Domoticz of type "Custom Sensor" and take a note of the index number. Give it a proper name indicating it's holding the costs of electricity. You can create multiple for multiple providers if required.

• Create 3 user variables in Domoticz:

  • fixed daily delivery costs incl BTW (DailyFixedFee)
  • fixed daily "netbeheer" costs incl BTW (DailyFixedCosts)
  • fixed daily "vermindering energiebelasting" incl BTW (negative value as it is a return) (EnergyTaxReturn)

• In Domoticz, create a new dzvents script. Paste the content of the file electricity_costs.dzvents and make the following modifcations:

- on line 2: change the idx number you use in Domoticz to read data from your meter (aka "Power")
- on line 3: change the idx number you use in Domoticz which holds the dynamic electricity price (created in part 1)
- on line 3: change the idx number you use in Domoticz which holds the cumulative electricity cost (created step 1 of this part)
- on line 7: change the idx number of the user variable you created for DailyFixedFee
- on line 8: change the idx number of the user variable you created for DailyFixedCosts
- on line 9: change the idx number of the user variable you created for EnergyTaxReturn

Save the file and be patient. The script is scheduled on minute 59 of every (clock)hour because it needs to total usage of the past hour to enable proper calculation. The first (partial) day will have incorrect values, but starting of the next day is should be correct.

Every hour you will also find the relevant data in the Domoticz logfile.