PV forecast.solar

The http request in this logic group uses the free but limited API access of "forecast.solar" for the solar forecast.
Thus, the expected yield for today and tomorrow can be queried in order to trigger actions.

Note: Use is possible without registration, but the number of daily calls is limited.
The http request for this query is structured as follows: https://api.forecast.solar/estimate/:lat/:lon/:dec/:az/:kwp

The following information must be provided for the public request:
- ":lat" is the "latitude of location" North-South position of your PV system; example 51.4905
- ":lon" is the "longitude of location" East-West position of the PV plant; example 7.511
- ":dec" is the "declination" installation angle or roof angle of the PV system; example 36grd
- ":az" is the "azimuth", installation direction of the PV with east=-90, south=0, west=90; example -10grd
- ":kwp" is the installed maximum power of the PV in kW; example 5kWp

Thus, an example query is: https://api.forecast.solar/estimate/51.4905/7.511/36/-10/5

The query in the example is made twice a day (11 am and 11 pm). These times are regulated via the two "value filters" after the timer element and can be adjusted if necessary.
The query can also be made manually via the corresponding input.

The response of the request is read out in the text processor and output as a single value. Since the position of the values in the response string are always in the same place, but have a changing identifier (current and tomorrow's date), a "regular expression" is required for reading out.
The regular expression for the two values "Forecast today Wh" and "Forecast tomorrow Wh" is:
- Forecast value today: \{„\d{4}-\d{2}-\d{2}\“:(\d*) und
- Forecast value tomorrow ,\"\d{4}-\d{2}-\d{2}\":(\d*)}

The values are passed to the output elements. The data point type used is DPT 14.*, In the unit Wh.
For an output in kWh, only a 1,000 divisor (using the calculator tool) has to be inserted between the text processor and output element.

This gives you PV forecast values, PV yield forecasts to guide further actions. The accuracy of these forecasts is equivalent to that of a weather app.

Uwe Müller
(235; 2023.04)

PV forecast.solar

This logic group is compatible with: EP, LOM
*With the download you accept the Notes on use for logic groups.