Forecast.Solar - How to Compare Daily Forecast To Actual Solar Production?

Third party integrations
1

Has anyone figured out a way to map tomorrow’s predicted solar production forecast from forecast.solar to the actuals the next day?

I created as sensor to show me the diff between the forecast for TODAY minus the actual production from today about 1.5 hours after sunset, but I noticed that the forecast changes throughout the day. I’m thinking I need to snag the forecast the day before and then get the difference between that and today’s actual production to see the accuracy, but I haven’t figured out how to extract thta one data point into a sensor.

My goal here is to easily track how accurate forecast.solar is in my configuration so I can tweak it appropriately.

2

I do a similar thing with my temperature forecasts.
Every night I copy the forecast sensor (data via api) to a separately entity with which I then construct graphs, this allows me to find out which forecast provider (I have 3) is better. The main reason here is to not (!) have 3 forecast providers in the end and taking the best one. My automation uses the hacs automation script hass_entities for that

3

Interesting. Could you share more specifically about what you have set up and how it looks?

Is it this hass_entities script? I’d be interested to see how your automation is setup and how it’s useful. Appreciate it!

4

I used the gui for this but in the end the automation looks like this, it triggers at 6 and also when I restart the machine…else it will remain empty.
Again…it copies the weather forecast attribs …but this is imilar as to what you can do

alias: Set forecast at 06:00
description: fix forecast at 06:00 to compare with actual
trigger:
  - platform: time
    at: "06:00:00"
  - platform: homeassistant
    event: start
condition: []
action:
  - service: python_script.hass_entities
    data:
      action: set_state_attributes
      entity_id: input_text.forecast_owm_hourly_0600
      state: "{{ 'Switched on at '~ now().strftime('%H.%M') }}"
      attributes:
        - icon: mdi:home
        - forecast: "{{ state_attr('weather.openweathermap','forecast') }}"
  - service: python_script.hass_entities
    data:
      action: set_state_attributes
      entity_id: input_text.forecast_meteof_hourly_0600
      state: "{{ 'Switched on at '~ now().strftime('%H.%M') }}"
      attributes:
        - icon: mdi:home
        - forecast: "{{ state_attr('weather.mougins','forecast') }}"
mode: single
5

ahhh, thank you.

So it’s an input_text entity that’s recording the values - makes sense!

6

And then I have this graph to compare actual with fc…for today not too far off :slight_smile:
image

7

that looks great and exactly what I’d like to see with my solar forecast vs production.

What does the hass_entities script do for you more than just having an automation set the value of the input_text entity directly at a certain time daily? Is it something to do with your desire to see comparisons hourly?

Since forecast.solar updates regularly throughout the day, the diff calculation I have changes as well. So I’d like to know after sunset the night before - what did they predict versus what I actually produced at the end of the next day.

8

The hass script allows to update states and attribs of existing sensors, e.g. if you cannot get those values through the sensor/template itself…esp. updatinf attribs is quite a challenge wihtout it