Solar Forecast PV

Tnx for the reply, i’ll take it from the Marketplace then :slightly_smiling_face:

Jar is for a standalone binding. Kar if you binding needs to be packaged with dependencies


I’ve upgraded my openHAB from a nodeRED Flow to this Binding and it works great :slight_smile:

Are you planning to integrate the Tuning-Function for Solcast? Here i am still using my nodeRED Flow atm.

Yes, test version is already running in my system and as soon as it’s stable enough on my side it’ll be part in an upcoming version update in the Marketplace.


Thanks Bernd for sharing this binding. I’m about to try it once being back from vacation :wink:

Happy, that you took the effort for simplifying this solar prediction stuff. I did something similar just by using the http binding getting the Solcast json and calculate the predicted solar production by a rule.

Your approach simplifies this a lot. And according to the other posts here and in other threads, there seems to be some demand for such a binding.

Mind raising a pull request for it to get it merged as official binding once you are convinced by your code’s maturity?

One additional thing: Would you add a channel for predicted “current solar power” which should provide the average power for the current time.

Example for Solcast (as they provide the prediction in 30 mins resolution):

<Solar yield for current half hour> * 2 = <current predicted power>

Bonus: You could even interpolate values by considering last+current+next half hour to provide intermediate values as you already seem to do for some of your existing channels.

Thanks for this binding. I was already looking for a way to do some solar predictions.
Grabbing the json via http binding was offcourse also an option, but this simplifies the whole process.

I created a rule which is triggered when the jsonraw channel changes to create some graphs (inspired by this post)

// import ForecastSolarPV_RawJSONResponse
val forecastJSON = ForecastSolarPV_RawJSONResponse.state.toString
//logInfo("ForecastSolar", forecastJSON)
// influx uri
val String influxdb_uri = ""

// ZonedDateTime
val ZonedDateTime todayStart = now.withHour(0).withMinute(0).withSecond(0).withNano(0)
val today = now.getDayOfMonth()
val month = now.getMonthValue()
val year = now.getYear()
val hour = now.getHour()
//logInfo("ForecastSolar", "currentHour " + currentHour)
// json parse
var String watts = transform("JSONPATH", "$.result.watt_hours", forecastJSON) //watts or watt_hours
//logInfo("ForecastSolar", "-" + watts.toString + "-")

// loop over entries
var Integer x = 0
var influx_content = ""
while (x < watts.split(",").length() ) {
  val entry = watts.split(", ").get(x).replace("{","").replace("}","")
  val time = entry.split("=").get(0).toString
  val value = (Double::parseDouble(entry.split("=").get(1)))/1000 // watts to kWh
  val formatter = java.time.format.DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")
  val dateTime = LocalDateTime.parse(time, formatter).atZone(ZoneId.systemDefault())
  val dateTime_seconds = (dateTime.toEpochSecond)
  val dateHour = dateTime.getHour()
  val dateDay = dateTime.getDayOfMonth()
  //logInfo("ForecastSolar", "-" + dateTime_seconds.toString + "-")
  // filter 0 values & hours in the past
  if ((value != 0 && dateHour > hour && dateDay == today) || (value != 0 && dateDay > today)) {
    //logInfo("ForecastSolar", "-" + dateTime.toString + "-")
    influx_content = influx_content + "solarforecast watt_hours=" + value + " " + dateTime_seconds.toString +"\n"

// send to influx
influx_content = influx_content.substring(0, influx_content.length()-2)
//logInfo("ForecastSolar", influx_content.toString)
var responds = sendHttpPostRequest(influxdb_uri, "--data-binary", influx_content, 3000)
logInfo("test", "Influx responds {}", responds)

in Grafana ot looks like this

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Solcast tuning is now available in v0.2-alpha in advanced configuration and channels.
Please check in readme solcast tuning section the correct configuration with

  • powerItem - delivering the correct values
  • powerUnit - delivering values with the correct unit
  • DateTime - check openHAB region settings for right time zone

and advanced channels raw-tuning to verify sent data.

Thanks very much for this binding - it has greatly simplified one of my setups, and allowed me to get rid of poorly written spaghetti-code rules!

One minor bit of feedback: in the README, at the Channels sections, the first column is called Channel. However, the values in these cells are not the Channel name - to derive the name one must remove the -channel from the cell value.

So for example:


is not how this Channel should be referred to. It should just be


This confused me for a second when trying to create links in Items files from the Solcast Thing.

Note that the example at the end of the README is correct, omitting the -channel from the Channel names.

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I think this is a good idea - looks pretty neat in the graph and can be used e.g. to calculate accuracy values using your pv inverter items.

For those who already installed the binding: Things needs to be re-created otherwise the channel won’t appear.

Please check the Thing Actions from version 0.3. You can query kW values at any point of time. Also kW/h values can be queried between two timestamps.
Note: I needed one reboot after exchanging the bundle in addons folder to be able to access the Actions

You’re right - readme is corrected.


Perfect, exactly this was the intention while asking for it. Many thanks :+1:

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@weymann : There seems to be a conflict between the Solar Forcast PV Binding and the openHAB cloud connector (see openHAB Cloud "class org.json.JSONObject cannot be cast to class org.json.JSONObject")
I had the same behaviour on my system running on openHAB 3.3.0. I just uninstalled Solar Forecast PV and immediately the cloud connector worked again.

I’m not a programmer, but maybe a dependency issue.
This is the stacktrace when the binding is installed:
2022-08-17 22:06:11.977 [ERROR] [io.socket.thread.EventThread ] - Task threw exception
java.lang.ClassCastException: class org.json.JSONObject cannot be cast to class org.json.JSONObject (org.json.JSONObject is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader ; org.json.JSONObject is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader )
at$ ~[?:?]
at io.socket.emitter.Emitter.emit( ~[bundleFile:?]
at io.socket.client.Socket.onevent( ~[?:?]
at io.socket.client.Socket.onpacket( ~[?:?]
at io.socket.client.Socket.access$100( ~[?:?]
at io.socket.client.Socket$2$ ~[?:?]
at io.socket.emitter.Emitter.emit( ~[bundleFile:?]
at io.socket.client.Manager.ondecoded( ~[?:?]
at io.socket.client.Manager.access$1600( ~[?:?]
at io.socket.client.Manager$ ~[?:?]
at io.socket.parser.IOParser$Decoder.add( ~[?:?]
at io.socket.client.Manager.ondata( ~[?:?]
at io.socket.client.Manager.access$1000( ~[?:?]
at io.socket.client.Manager$ ~[?:?]
at io.socket.emitter.Emitter.emit( ~[bundleFile:?]
at io.socket.engineio.client.Socket.onPacket( ~[bundleFile:?]
at io.socket.engineio.client.Socket.access$1000( ~[bundleFile:?]
at io.socket.engineio.client.Socket$ ~[bundleFile:?]
at io.socket.emitter.Emitter.emit( ~[bundleFile:?]
at io.socket.engineio.client.Transport.onPacket( ~[bundleFile:?]
at io.socket.engineio.client.Transport.onData( ~[bundleFile:?]
at io.socket.engineio.client.transports.WebSocket.access$100( ~[bundleFile:?]
at io.socket.engineio.client.transports.WebSocket$1$ ~[bundleFile:?]
at io.socket.thread.EventThread$ [bundleFile:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker( [?:?]
at java.util.concurrent.ThreadPoolExecutor$ [?:?]
at [?:?]

Would be great if you could resolve this. I liked the forecast, but remote control via app and Alexa is the more important feature :wink:


Thank you @weymann for this very helpful binding.

Unfortunately the binding doesn’t work anymore after upgrading to 3.4.0 M1.

If I try running your example script the following error shows up in openhab.log:

2022-08-19 16:37:01.755 [ERROR] [internal.handler.ScriptActionHandler] - Script execution of rule with UID ‘9bfc4b356f’ failed: class org.openhab.binding.solarforecast.internal.actions.SolarForecastActions cannot be cast to class org.openhab.binding.solarforecast.internal.actions.SolarForecastActions (org.openhab.binding.solarforecast.internal.actions.SolarForecastActions is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @127438b; org.openhab.binding.solarforecast.internal.actions.SolarForecastActions is in unnamed module of loader org.eclipse.osgi.internal.loader.EquinoxClassLoader @1d3ebce)

I tried to uninstall/install the bundle. During install openhab.log shows the following warning:

2022-08-19 16:35:31.319 [WARN ] [internal.service.FeaturesServiceImpl] - Can’t load features repository mvn:org.openhab.core.features.karaf/org.openhab.core.features.karaf.openhab-core/3.4.0-SNAPSHOT/xml/features
java.lang.RuntimeException: Error resolving artifact org.openhab.core.features.karaf:org.openhab.core.features.karaf.openhab-core:xml:features:3.4.0-SNAPSHOT: [Could not find artifact org.openhab.core.features.karaf:org.openhab.core.features.karaf.openhab-core:xml:features:3.4.0-SNAPSHOT] : mvn:org.openhab.core.features.karaf/org.openhab.core.features.karaf.openhab-core/3.4.0-SNAPSHOT/xml/features

Thank you very much.


Did you install the kar or jar file? In this topic both the kar and jar file are included, and given the tag kar I assume ithe marketplace addon will take the kar file. However kar files are version specific, which explains why it doesn’t work. Also the kar file is not needed as this binding doesn’t depend on additional libraries, therefore the jar file should be enough. You could try manually installing the jar version, by downloading it and dropping it in the add-ons directory.

Thanks, this fixed it as you expected.

Thank you very much.


Hi Bernd,

thanks for the binding. I’m playing around with it right now using the Forecast.Solar public service. They recently introduced an aditional parameter for damping - see link below. Any chance to get this supported by the binding?


… well, there are a few more API URL parameters I’d be interested to explore:

Any chance to provide a freeform edit field by the binding to manipulate the API call?

Thanks for the hint. These parameters are really new. I performed calls with each of them and checked the results.

  • time & time-tz
    are just delivering timestamps in different formats. This shouldn’t be changed by the user. The binding is handling current timestamps in the correct way and it shall not guess around which format is delivered

  • no sun
    Just delivering zero values before and after sunset / sundawn. Binding is already handling this properly

  • inverter
    For each plane you need to specify Kilowatt Peak kwp in configuration. Your inverter can’t handle that? Then please reduce what your inverter can handle or am I wrong?

  • start
    This will jeopardize the calculated values. I you start forecast from e.g. 12:00 the today channel, which shall deliver the total daily forecast, is missing the morning hours.

  • damping
    This parameter is valid! It really delivers different forecast values. Then you would have the possibility to tweak these parameters to get best possible forecast for your system.

My proposal is to add 2 config parameters for morning / evening damping.
The other options will result in errors in the binding calculations plus they don’t have any effect on the forecast values.

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Hi Bernd,

Yes, the damping parameter(s) are the most interesting ones. The inverter parameter is clipping the peak energy to the max inverter power. I have confirmed that the estimated peak values are reduced to the inverter value. So it might be useful for specific setups.


Hi Bernd,

first of all, thanks for your work at this and also your other bindings.

As Solcast has daily rate limits for the API, it is required to set the refresh interval to 120 min for two sites, which is quite a long time.
I just had a idea how the limited number of API requests might be used more efficient: don’t or far less request the API at night (at least one request during night to get todays forecast would be required) and use those „saved“ requests to refresh more often during day.

Please let me know what you think about that idea.