Weather prediction in Node Red

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62

Agreed. I have set my NodeRED flow to get the prediction and email it to me at 1 minute past midnight (00:01) Reason being is that my cheap rate electricity tariff starts at 00:30 (to 05:30) so what % to charge the batteries to will be decided (as sent to Schedule 1)

Absolutely awful weather here. The API (vrm solar irradiance fc:) predicted a value of 0, yes Zero for today. Fingers crossed for some sun tomorrow but again it looks like a grid charge tomorrow morning :grimacing:

63

Well here’s an update. I’ve been logging data and I have to say that I’m getting back from the API call is absolute rubbish! …

15/2/25 - 139.67 - Overcast all day.
16/2/25 - 69.33 - Cloudy a.m., sunny p.m.
17/2/25 - 97.13 - Full sun all day.
18/2/25 - 110.45 - Full sun all day.

Here’s the flow that emails me the ‘prediction’ at 15 minutes past midnight.

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Any thoughts out there???

64

Hi Diedrick,

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Using the above I get a return of ‘solar yield forecast: false’

Here’s the flow…

image

What on earth am I missing here?

Best regards

Paul

65

You didn’t make a typo in your VRM token?

66

A good question. The token I created in ‘Active API access tokens >Add’ does actually facilitate the return of data when I use the Attribute ‘PV Solar Irradiance Forecast’ but not if I request ‘PV Solar Charge Yield Forecast’.
I’m using a EpEver solar charge controller but surely this has nothing to do with the error.

I’m proper stuck here

67

Further…
PV Inverter Yield Forecast - false
PV Solar Charger Yield Forecast - false
Solar Irradiance Forecast -114.9
Solar Yield Forecast - false

68

Hi Paul,

I write data from

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to a file and this are the results

3:47:57 PM
5986
4:47:57 PM
5995
7:20:33 PM
6087
9:08:15 PM
6033
10:08:15 PM
6053
11:08:15 PM
6053
12:08:15 AM
2682
1:08:15 AM
2688
2:08:15 AM
2688
3:08:15 AM
2584
4:08:15 AM
2584
5:08:15 AM
2584
6:08:15 AM
2766
7:08:15 AM
2807
8:08:15 AM
2916
9:08:15 AM
2985
10:57:07 AM
3205
11:09:02 AM
3561

I wonder how many hours in advance the prediction is made of how i have to interprete this
if you look at
11:08:15 PM
6053

69

Hi, rz7k91

Here’s my test flow…

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and here’s the properties for the VRM API Node …
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Here’s the email I get sent at 10 mins passed midnight (forecast for the next 24 hours hopefully)
Thu Mar 13 2025 : Solar Irradiance for today : 108.45833333333333
Wed Mar 12 2025 : Solar Irradiance for today : 143.375
Tue Mar 11 2025 : Solar Irradiance for today : 104.45833333333333

It is starting to look like a fairly good prediction. I’ll have it update the battery charge levels soon)

70

Hi Paul,

thx for the information. looks good.

regards,
Koen

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