# \[APP\]\[Pro\] Solar Forecasts (SolCast + Forecast.Solar)

**URL:** <https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842>\
**Category:** Apps\
**Created:** [April 29, 2021, 7:25am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842 "2021-04-29T07:25:41Z")\
**Posts on this page:** 20\
**Page:** 10

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**Author:** ![Torch1969](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/torch1969/32/33305_2.png) [@Torch1969](https://community.homey.app/u/Torch1969)\
**Post date:** [April 28, 2024, 6:49am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/182 "2024-04-28T06:49:44Z")

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> [@Pieterv123](#):
>
> it is a strange bug, maybe observe if it still happens today.  
> I think it will only happen when you first set up the app

You’re correct it looks like the counter is behaving ok now. Only the first update after first setup gave this error.

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**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 9:28am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/183 "2024-05-09T09:28:55Z")

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Hi @Pieterv123, I just realized strange behavior of Forecast TODAY - updated last time 24 days ago 😉

 ![solcast](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/d/d/dd53ffe68a6f0928830829a0c9184b95cf43f941.png)

Just in case you see anything in the logs - 0953c047-308a-418d-a5d4-6d51d782c49a

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**Author:** ![Pieterv123](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pieterv123/32/13353_2.png) [@Pieterv123](https://community.homey.app/u/Pieterv123)\
**Post date:** [May 9, 2024, 10:34am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/184 "2024-05-09T10:34:07Z")

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Did you make a flow for the midnight fetch at 02 AM as described in the first post?

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**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 10:51am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/185 "2024-05-09T10:51:57Z")

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I actually use your integration for maybe more then year and never used automatic polling, have so far set only midnight fetch and not 02AM fetch (+ several others within API limit). So that’s the cause, missing manual fetch at 02AM, later fetch will not update it ?

_Maybe to prevent misunderstanding - all values get updated except of Forecast TODAY_

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**Author:** ![Torch1969](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/torch1969/32/33305_2.png) [@Torch1969](https://community.homey.app/u/Torch1969)\
**Post date:** [May 9, 2024, 10:54am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/186 "2024-05-09T10:54:11Z")

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> [@Sharkys](#):
>
> Just FYI, I asked SolCast support, if there is some solution for me to increase API calls in case I have 2 strings - surprisingly they replied by increasing API calls to 20, which is great and sufficient for me as home-hobby user. So seems to be pretty good service 😉

Based on this experience I also asked (begged) support for some extra api calls for a second string. Unfortunately they didn’t want to raise it. There are many free users and server load is getting to high… 😒  
They are thinking about a subscription model for extra calls. To investigate if users are interested they have a [form](https://docs.google.com/forms/d/e/1FAIpQLSefZqRZ9z2f9pjl4Tc3zpscPVSBzhsPbErdyAwzui2xXqRz4A/viewform?usp=sf_link)

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**Author:** ![RonnyW](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/ronnyw/32/10879_2.png) [@RonnyW](https://community.homey.app/u/RonnyW)\
**Post date:** [May 9, 2024, 10:56am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/187 "2024-05-09T10:56:02Z")

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As example:

 ![grafik](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/1/e/1e7a8862f0a499bba46ce03553ec28fd846adfaa.png)

The “Fetch midnight” is used once in the morning to get the daily forecast (I think ist must be later than 2am CET).  
The other Fetch is used to update today remaining forecast.

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**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 10:59am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/188 "2024-05-09T10:59:30Z")

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Thanks Ronny - even at midnight, I used only Solcast update, never called Midnight update, will update the flows then.

**update** indeed Midnight update fetch (action card) updated the forecast TODAY (even when I launched it now 1PM…)

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**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 11:13am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/189 "2024-05-09T11:13:01Z")

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> [@Torch1969](#):
>
> To investigate if users are interested they have a [form](https://docs.google.com/forms/d/e/1FAIpQLSefZqRZ9z2f9pjl4Tc3zpscPVSBzhsPbErdyAwzui2xXqRz4A/viewform?usp=sf_link)

Thanks, answered - not sure if it’s right strategy to target hobbyist though…

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**Author:** ![Pieterv123](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pieterv123/32/13353_2.png) [@Pieterv123](https://community.homey.app/u/Pieterv123)\
**Post date:** [May 9, 2024, 11:16am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/190 "2024-05-09T11:16:11Z")

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Yes you can use it during the day, but the values are not correct then. (only once per day)  
Forecast today should be triggered before sunrise, to have a good comparison with your actual solar data. By experience in Europe 0200 AM is a good time.

I disabled the automatic update because for people in different timezones and daylight savings, it is more complicated to make an accurate update.

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<div class="post-metadata">

**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 11:19am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/191 "2024-05-09T11:19:57Z")

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> [@Pieterv123](#):
>
> I disabled the automatic update because for people in different timezones and daylight savings, it is more complicated to make an accurate update.

Yep, as I mentioned, I never used it, just missed the point with new Action card (Fetch midnight data) required when updated to new version v3.5.0

I’m using it to calculate values from both strings and based on this triggering actions - so sort of manage effective expected solar energy vs. expected consumption vs trying to minimize battery cycle, the rest is for me only kind of FYI. So eg. in case of sufficient solar power, I start water heating sooner to use directly the energy for the heating instead of taking power from battery… later for car charging and during night maximise use of battery and to have sort of backup / battery fully charged…

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**Author:** ![CaptainVoni](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/captainvoni/32/3549_2.png) [@CaptainVoni](https://community.homey.app/u/CaptainVoni)\
**Post date:** [May 9, 2024, 12:28pm UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/192 "2024-05-09T12:28:34Z")

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> [@Torch1969](#):
>
> Based on this experience I also asked (begged) support for some extra api calls for a second string.

Somehow OT, but there is a solution for solar forecasts of multiple strings: you could request global tilted radiation data from open meteo and simply multiply it by your panel area and panel efficiency. Use of the open meteo api is free for up to 10,000 calls a day (in words: ten thousand) and totally straight forward. I use it to calculate predictions for my two strings for the upcoming days. Let me know if you are interested in some details.

Example: Prognosis for the remaining yield of the current day (“Prognose Restertrag”)

 !["Prognose Restertrag" - prognosis for the remaining day](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/1/2/123edfcc60a7d9e093bbd01696fa42be5cf4b2ce.jpeg)

Example: Prognosis of the next three days

 ![Three day prognosis](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/9/2/9274825b2bc72565840854e80c7435fb851981d7.jpeg)

Example: Prognosis for the next 24 hours

 ![24 hour prognosis](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/0/3/03fe9df9298d3966bbfb1a5f43d420f67152f3fb.jpeg)

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<div class="post-metadata">

**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 12:53pm UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/193 "2024-05-09T12:53:01Z")

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> [@CaptainVoni](#):
>
> you could request global tilted radiation data from open meteo

Can you elaborate on this one please ? It’s like UVI index, or ?

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**Author:** ![CaptainVoni](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/captainvoni/32/3549_2.png) [@CaptainVoni](https://community.homey.app/u/CaptainVoni)\
**Post date:** [May 9, 2024, 1:01pm UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/194 "2024-05-09T13:01:06Z")

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It’s just that: global tilted radiation. See [here](https://open-meteo.com/en/docs#latitude=45&longitude=15&minutely_15=&hourly=global_tilted_irradiance&timezone=Europe%2FBerlin&forecast_days=3&tilt=35&azimuth=150). You have to enter your latitude, longitude and the tilt and azimuth of your panels (at the top of the page).

 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/6/9/691dc2de19607da108054727defae3fd70bd7c2a.png)

API URL is below the chart.

Once you got the values, just multiply by your panel area and efficiency and you’re done. If you have multiple strings, just make one request per string, multiply by the respective area and efficiency and add all up.

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**Author:** ![Sharkys](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sharkys/32/54029_2.png) [@Sharkys](https://community.homey.app/u/Sharkys)\
**Post date:** [May 9, 2024, 1:03pm UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/195 "2024-05-09T13:03:01Z")

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Might be clearly solution if the “hobbyist” part of SolCast will be paid … thank you for sharing !

Maybe method to think about for @Pieterv123 ? 😀

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**Author:** ![RonnyW](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/ronnyw/32/10879_2.png) [@RonnyW](https://community.homey.app/u/RonnyW)\
**Post date:** [May 15, 2024, 5:17am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/196 "2024-05-15T05:17:49Z")

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This prognosis would give the ability to calculate max. PV production during noon. This would allow an easy check if you should stop battery charging in the morning to charge over noon to collect production from the panels that the inverter is not able to convert.

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**Author:** ![CaptainVoni](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/captainvoni/32/3549_2.png) [@CaptainVoni](https://community.homey.app/u/CaptainVoni)\
**Post date:** [May 15, 2024, 6:40am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/197 "2024-05-15T06:40:49Z")

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> [@RonnyW](#):
>
> This prognosis would give the ability to calculate max. PV production during noon.

Kind of. Those GTI values are average values over a given time over a given area. Especially on days with a few clouds your actual values vary A LOT. On the other hand, your average actual values will fit quite nicely the average prognosed values even on those days.

> [@RonnyW](#):
>
> This would allow an easy check if you should stop battery charging in the morning to charge over noon to collect production from the panels that the inverter is not able to convert.

I have this implemented here already, but it’s not that straight forward and you should never delay battery charging until the last moment. My battery level of the last seven days looks like this:

 ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/1/3/134eec3de58050671ee54e7433eb61026d702316.png)

You see it discharging during the night, then staying the same for a few hours until early afternoon, and finally quickly charging up to the max level necessary (currently around 80%) before discharging starts again 1-2 hours later.

If you want to manually activate/deactivate something like this during certain seasons, it’s easy to implement. If you want it fully automated throughout the year, it’s really challenging. I’m planning on sharing my code, but right now it’s not yet feature complete, especially during the winter time (prioritised charging is missing, house consumption is necessary without heat pump consumption, etc.).

When I find the time I’ll start with a How-to for the visualisation of the PV yield prognosis on one of the upcoming weekends. It’s one of the two major requisites for a sophisticated battery dis-/charging strategy. The other is house consumption and prediction thereof, which I haven’t completely solved yet.

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**Author:** ![Pieterv123](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pieterv123/32/13353_2.png) [@Pieterv123](https://community.homey.app/u/Pieterv123)\
**Post date:** [May 15, 2024, 6:55am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/198 "2024-05-15T06:55:16Z")

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You should have a look at EMHASS

[https://emhass.readthedocs.io/en/latest/](https://emhass.readthedocs.io/en/latest/)

Makes a forecast of your consumption, uses solar data and dynamic prices to make a plan on how to use the battery

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**Author:** ![TheSource](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/thesource/32/53900_2.png) [@TheSource](https://community.homey.app/u/TheSource)\
**Post date:** [May 28, 2024, 3:08pm UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/199 "2024-05-28T15:08:00Z")

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Can you please share advanced flows making use of this? I’m trying to make optimal use of my solar power by swithing on devices based on solar over production based on load & priority (like pool pump, warm water, washing machine, etc). On Facebook they pointed me to this script which can for sure help, but some examples would be really usefull.

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**Author:** ![Sanderv123](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/sanderv123/32/79673_2.png) [@Sanderv123](https://community.homey.app/u/Sanderv123)\
**Post date:** [May 29, 2024, 10:32am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/200 "2024-05-29T10:32:30Z")

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I installed Solcast today, added my API and Resource Key but get an API error in Homey. I have removed the app, reinstalled it, added API and Resource Key and rebooted Homey but I keep getting the API error. Am I missing something, new to Homey.

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**Author:** ![Pieterv123](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/pieterv123/32/13353_2.png) [@Pieterv123](https://community.homey.app/u/Pieterv123)\
**Post date:** [May 29, 2024, 10:43am UTC](https://community.homey.app/t/app-pro-solar-forecasts-solcast-forecast-solar/46842/201 "2024-05-29T10:43:38Z")

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I have no examples for an advanced flow

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