# SolarForecast Binding
This binding provides data from Solar Forecast services. Use it to estimate your daily production, plan electric consumers like Electric Vehicle charging, heating or HVAC. Look ahead the next days in order to identify surplus / shortages in your energy planning.
Supported Services
- Solcast (opens new window)
- Free Hobbyist Plan (opens new window) with registration
- Forecast.Solar (opens new window)
- Public, Personal and Professional plans (opens new window) available
Display Power values of Forecast and PV Inverter items
Display Energy values of Forecast and PV inverter items Yellow line shows Daily Total Forecast.
# Supported Things
Each service needs one xx-site
for your location and at least one photovoltaic xx-plane
.
Name | Thing Type ID |
---|---|
Solcast service site definition | sc-site |
Solcast PV Plane | sc-plane |
Forecast Solar site location | fs-site |
Forecast Solar PV Plane | fs-plane |
# Solcast Configuration
Solcast service (opens new window) requires a personal registration with an e-mail address.
A free version for your personal home PV system is available in Hobbyist Plan (opens new window)
You need to configure your home photovoltaic system within the web interface.
The resourceId
for each PV plane is provided afterwards.
In order to receive proper timestamps double check your time zone in openHAB - Settings - Regional Settings. Correct time zone is necessary to show correct forecast times in UI.
# Solcast Bridge Configuration
Name | Type | Description | Default | Required | Advanced |
---|---|---|---|---|---|
apiKey | text | API Key | N/A | yes | no |
timeZone | text | Time Zone of forecast location | empty | no | yes |
apiKey
can be obtained in your Account Settings (opens new window)
timeZone
can be left empty to evaluate Regional Settings of your openHAB installation.
See DateTime section for more information.
# Solcast Plane Configuration
Name | Type | Description | Default | Required | Advanced |
---|---|---|---|---|---|
resourceId | text | Resource Id of Solcast rooftop site | N/A | yes | no |
refreshInterval | integer | Forecast Refresh Interval in minutes | 120 | yes | no |
resourceId
for each plane can be obtained in your Rooftop Sites (opens new window)
refreshInterval
of forecast data needs to respect the throttling of the Solcast service.
If you have 25 free calls per day, each plane needs 2 calls per update a refresh interval of 120 minutes will result in 24 calls per day.
# Solcast Channels
Each sc-plane
reports its own values including a json
channel holding JSON content.
The sc-site
bridge sums up all attached sc-plane
values and provides total forecast for your home location.
Channels are covering today's actual data with current, remaining and today's total prediction. Forecasts are delivered up to 6 days in advance. Scenarios are clustered in groups:
average
scenariopessimistic
scenario: 10th percentileoptimistic
scenario: 90th percentile
Channel | Type | Unit | Description | Advanced |
---|---|---|---|---|
power-estimate | Number:Power | W | Power forecast for next hours/days | no |
energy-estimate | Number:Energy | kWh | Energy forecast for next hours/days | no |
power-actual | Number:Power | W | Power prediction for this moment | no |
energy-actual | Number:Energy | kWh | Today's forecast till now | no |
energy-remain | Number:Energy | kWh | Today's remaining forecast till sunset | no |
energy-today | Number:Energy | kWh | Today's forecast in total | no |
json | String | - | Plain JSON response without conversions | yes |
# ForecastSolar Configuration
ForecastSolar service (opens new window) provides a public free (opens new window) plan. You can try it without any registration or other preconditions.
# ForecastSolar Bridge Configuration
Name | Type | Description | Default | Required |
---|---|---|---|---|
location | text | Location of Photovoltaic system. | empty | no |
apiKey | text | API Key | N/A | no |
location
defines latitude, longitude values of your PV system.
In case of empty the location configured in openHAB is obtained.
apiKey
can be given in case you subscribed to a paid plan.
# ForecastSolar Plane Configuration
Name | Type | Description | Default | Required | Advanced |
---|---|---|---|---|---|
refreshInterval | integer | Forecast Refresh Interval in minutes | 30 | yes | false |
declination | integer | Plane Declination: 0 for horizontal till 90 for vertical declination | N/A | yes | false |
azimuth | integer | Plane Azimuth: -180 = north, -90 = east, 0 = south, 90 = west, 180 = north | N/A | yes | false |
kwp | decimal | Installed Kilowatt Peak | N/A | yes | false |
dampAM | decimal | Damping factor of morning hours | 0 | no | true |
dampPM | decimal | Damping factor of evening hours | 0 | no | true |
horizon | text | Horizon definition as comma separated integer values | N/A | no | true |
refreshInterval
of forecast data needs to respect the throttling of the ForecastSolar service.
12 calls per hour allowed from your caller IP address so for 2 planes lowest possible refresh rate is 10 minutes.
# Advanced Configuration
Advanced configuration parameters are available to fine tune your forecast data. Read linked documentation in order to know what you're doing.
Damping factors (opens new window) for morning and evening.
Horizon information (opens new window) as comma-separated integer list. This configuration item is aimed to expert users. You need to understand the horizon concept (opens new window). Shadow obstacles like mountains, hills, buildings can be expressed here. First step can be a download from PVGIS tool (opens new window) and downloading the terrain shadows. But it doesn't fit 100% to the required configuration. Currently there's no tool available which is providing the configuration information 1 to 1. So you need to know what you're doing.
# ForecastSolar Channels
Each fs-plane
reports its own values including a json
channel holding JSON content.
The fs-site
bridge sums up all attached fs-plane
values and provides the total forecast for your home location.
Channels are covering today's actual data with current, remaining and total prediction. Forecasts are delivered up to 3 days for paid personal plans.
Channel | Type | Unit | Description | Advanced |
---|---|---|---|---|
power-estimate | Number:Power | W | Power forecast for next hours/days | no |
energy-estimate | Number:Energy | kWh | Energy forecast for next hours/days | no |
power-actual | Number:Power | W | Power prediction for this moment | no |
energy-actual | Number:Energy | kWh | Today's forecast till now | no |
energy-remain | Number:Energy | kWh | Today's remaining forecast till sunset | no |
energy-today | Number:Energy | kWh | Today's forecast in total | no |
json | String | - | Plain JSON response without conversions | yes |
# Thing Actions
All things sc-site
, sc-plane
, fs-site
and fs-plane
are providing the same Actions.
Channels are providing actual forecast data and daily forecasts in future.
Actions provides an interface to execute more sophisticated handling in rules.
You can execute this for each xx-plane
for specific plane values or xx-site
to sum up all attached planes.
See Date Time section for more information. Double check your time zone in openHAB - Settings - Regional Settings which is crucial for calculation.
# getForecastBegin
Returns Instant
of the earliest possible forecast data available.
It's located in the past, e.g. Solcast provides data from the last 7 days.
Instant.MAX
is returned in case of no forecast data is available.
# getForecastEnd
Returns Instant
of the latest possible forecast data available.
Instant.MIN
is returned in case of no forecast data is available.
# getPower
Parameter | Type | Description |
---|---|---|
timestamp | Instant | Timestamp of power query |
mode | String | Choose average , optimistic or pessimistic to select forecast scenario. Only Solcast. |
Returns QuantityType<Power>
at the given Instant
timestamp.
Respect getForecastBegin
and getForecastEnd
to get a valid value.
Check log or catch exceptions for error handling
IllegalArgumentException
thrown in case of problems with call argumentsSolarForecastException
thrown in case of problems with timestamp and available forecast data
# getDay
Parameter | Type | Description |
---|---|---|
date | LocalDate | Date of the day |
mode | String | Choose average , optimistic or pessimistic to select forecast scenario. Only Solcast. |
Returns QuantityType<Energy>
at the given localDate
.
Respect getForecastBegin
and getForecastEnd
to avoid ambiguous values.
Check log or catch exceptions for error handling
IllegalArgumentException
thrown in case of problems with call argumentsSolarForecastException
thrown in case of problems with timestamp and available forecast data
# getEnergy
Parameter | Type | Description |
---|---|---|
startTimestamp | Instant | Start timestamp of energy query |
endTimestamp | Instant | End timestamp of energy query |
mode | String | Choose optimistic or pessimistic to get values for a positive or negative future scenario. Only Solcast. |
Returns QuantityType<Energy>
between the timestamps startTimestamp
and endTimestamp
.
Respect getForecastBegin
and getForecastEnd
to avoid ambiguous values.
Check log or catch exceptions for error handling
IllegalArgumentException
thrown in case of problems with call argumentsSolarForecastException
thrown in case of problems with timestamp and available forecast data
# Date Time
Each forecast is bound to a certain location which automatically defines the time zone.
Most common use case is forecast and your location are matching the same time zone.
Action interface is using Instant
as timestamps which enables you translating to any time zone.
This allows you with an easy conversion to query also foreign forecast locations.
Examples are showing
- how to translate
Instant
toZonedDateTime
objects and - how to translate
ZonedDateTime
toInstant
objects
# Example
Example is based on Forecast.Solar service without any registration. Exchange the configuration data in thing file and you're ready to go.
# Thing file
Bridge solarforecast:fs-site:homeSite "ForecastSolar Home" [ location="54.321,8.976"] {
Thing fs-plane homeSouthWest "ForecastSolar Home South-West" [ refreshInterval=15, azimuth=45, declination=35, kwp=5.5]
Thing fs-plane homeNorthEast "ForecastSolar Home North-East" [ refreshInterval=15, azimuth=-145, declination=35, kwp=4.425]
}
# Items file
// channel items
Number:Power ForecastSolarHome_Actual_Power "Power prediction for this moment" { channel="solarforecast:fs-site:homeSite:power-actual", stateDescription=" "[ pattern="%.0f %unit%" ], unit="W" }
Number:Energy ForecastSolarHome_Actual "Today's forecast till now" { channel="solarforecast:fs-site:homeSite:energy-actual", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Energy ForecastSolarHome_Remaining "Today's remaining forecast till sunset" { channel="solarforecast:fs-site:homeSite:energy-remain", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Energy ForecastSolarHome_Today "Today's total energy forecast" { channel="solarforecast:fs-site:homeSite:energy-today", stateDescription=" "[ pattern="%.1f %unit%" ], unit="kWh" }
// calculated by rule
Number:Energy ForecastSolarHome_Tomorrow "Tomorrow's total energy forecast" { stateDescription=" "[ pattern="%.1f %unit%" ], unit="kWh" }
Number:Power ForecastSolarHome_Actual_Power_NE "NE Power prediction for this moment" { channel="solarforecast:fs-plane:homeSite:homeNorthEast:power-actual", stateDescription=" "[ pattern="%.0f %unit%" ], unit="W" }
Number:Energy ForecastSolarHome_Actual_NE "NE Today's forecast till now" { channel="solarforecast:fs-plane:homeSite:homeNorthEast:energy-actual", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Energy ForecastSolarHome_Remaining_NE "NE Today's remaining forecast till sunset" { channel="solarforecast:fs-plane:homeSite:homeNorthEast:energy-remain", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Energy ForecastSolarHome_Today_NE "NE Today's total energy forecast" { channel="solarforecast:fs-plane:homeSite:homeNorthEast:energy-today", stateDescription=" "[ pattern="%.1f %unit%" ], unit="kWh" }
Number:Power ForecastSolarHome_Actual_Power_SW "SW Power prediction for this moment" { channel="solarforecast:fs-plane:homeSite:homeSouthWest:power-actual", stateDescription=" "[ pattern="%.0f %unit%" ], unit="W" }
Number:Energy ForecastSolarHome_Actual_SW "SW Today's forecast till now" { channel="solarforecast:fs-plane:homeSite:homeSouthWest:energy-actual", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Energy ForecastSolarHome_Remaining_SW "SW Today's remaining forecast till sunset" { channel="solarforecast:fs-plane:homeSite:homeSouthWest:energy-remain", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Energy ForecastSolarHome_Today_SW "SW Today's total energy forecast" { channel="solarforecast:fs-plane:homeSite:homeSouthWest:energy-today", stateDescription=" "[ pattern="%.1f %unit%" ], unit="kWh" }
// estimation items
Group influxdb
Number:Power ForecastSolarHome_Power_Estimate "Power estimations" (influxdb) { channel="solarforecast:fs-site:homeSite:power-estimate", stateDescription=" "[ pattern="%.0f %unit%" ], unit="W" }
Number:Energy ForecastSolarHome_Energy_Estimate "Energy estimations" (influxdb) { channel="solarforecast:fs-site:homeSite:energy-estimate", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
Number:Power ForecastSolarHome_Power_Estimate_SW "SW Power estimations" (influxdb) { channel="solarforecast:fs-plane:homeSite:homeSouthWest:power-estimate", stateDescription=" "[ pattern="%.0f %unit%" ], unit="W" }
Number:Energy ForecastSolarHome_Energy_Estimate_SW "SW Energy estimations" (influxdb) { channel="solarforecast:fs-plane:homeSite:homeSouthWest:energy-estimate", stateDescription=" "[ pattern="%.3f %unit%" ], unit="kWh" }
# Persistence file
// persistence strategies have a name and definition and are referred to in the "Items" section
Strategies {
everyHour : "0 0 * * * ?"
everyDay : "0 0 0 * * ?"
}
/*
* Each line in this section defines for which Item(s) which strategy(ies) should be applied.
* You can list single items, use "*" for all items or "groupitem*" for all members of a group
* Item (excl. the group Item itself).
*/
Items {
influxdb* : strategy = restoreOnStartup, forecast
}
# Actions rule
rule "Tomorrow Forecast Calculation"
when
Item ForecastSolarHome_Today received update
then
val solarforecastActions = getActions("solarforecast","solarforecast:fs-site:homeSite")
val energyState = solarforecastActions.getDay(LocalDate.now.plusDays(1))
logInfo("SF Tests","{}",energyState)
ForecastSolarHome_Tomorrow.postUpdate(energyState)
end
# Handle exceptions
import java.time.temporal.ChronoUnit
rule "Exception Handling"
when
System started
then
val solcastActions = getActions("solarforecast","solarforecast:sc-site:3cadcde4dc")
try {
val forecast = solcastActions.getPower(solcastActions.getForecastEnd.plus(30,ChronoUnit.MINUTES))
} catch(RuntimeException e) {
logError("Exception","Handle {}",e.getMessage)
}
end
# Actions rule with Arguments
import java.time.temporal.ChronoUnit
rule "Solcast Actions"
when
Time cron "0 0 23 * * ?" // trigger whatever you like
then
// Query forecast via Actions
val solarforecastActions = getActions("solarforecast","solarforecast:sc-site:homeSite")
val startTimestamp = Instant.now
val endTimestamp = Instant.now.plus(6, ChronoUnit.DAYS)
val sixDayForecast = solarforecastActions.getEnergy(startTimestamp,endTimestamp)
logInfo("SF Tests","Forecast Average 6 days "+ sixDayForecast)
val sixDayOptimistic = solarforecastActions.getEnergy(startTimestamp,endTimestamp, "optimistic")
logInfo("SF Tests","Forecast Optimist 6 days "+ sixDayOptimistic)
val sixDayPessimistic = solarforecastActions.getEnergy(startTimestamp,endTimestamp, "pessimistic")
logInfo("SF Tests","Forecast Pessimist 6 days "+ sixDayPessimistic)
// Query forecast TimesSeries Items via historicStata
val energyAverage = (Solcast_Site_Average_Energyestimate.historicState(now.plusDays(1)).state as Number)
logInfo("SF Tests","Average energy {}",energyAverage)
val energyOptimistic = (Solcast_Site_Optimistic_Energyestimate.historicState(now.plusDays(1)).state as Number)
logInfo("SF Tests","Optimist energy {}",energyOptimistic)
end