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I have updated the flow with an example showing how to combine different solar arrays into a single graph.

I've just updated the subflow to make it easy to generate a graph from it. All that is needed is to connect a line or bar chart to the second output of the subflow.

Thanks for sharing this - obvs, forecasting is an important part of optimising self-consumption. First thing for me is exploring accuracy - yesterday's forecast accurately predicted the likely low yield today, given unrelenting rain (UK Midlands).

I have a 1770Wp free-standing, facing due south, array - will write a bit of python to collect the day's forecast at 1am (when E7 cheap rate starts) and, that evening, compare with the actual yield for the day. Will report back in a week.

Edit: sorry, should have said, going to use Solcast data as the forecasts are based on location, declination, azimuth/orientation AND weather (essential for the UK!). It seems the 'forecast solar' data is only based on location, declination, azimuth/orientation??

Collecting hourly forecast.solar data in a db, but seeing big variation when doing an estimate/watthours/day/ call for my location and my little 45/0/1.77 array. In the last 3 hours:

{'2023-01-11': 3068, '2023-01-12': 829, '2023-01-13': 1472, '2023-01-14': 967}

{'2023-01-11': 2609, '2023-01-12': 824, '2023-01-13': 962, '2023-01-14': 1132}

{'2023-01-11': 1781, '2023-01-12': 946, '2023-01-13': 2230, '2023-01-14': 1051}

Yesterday the forecast for today went as high as 3303W - was wondering if I'd need sun cream, but no it's partly cloudy with rain on the way! Anyone else seeing this level of variation? Have I gotten something wrong??

For the graph output there are some extra settings available:

• Output in kWh - when checked output can be set to kWh instead of Wh
• Show todays forecast - whether or not to include todays forecast
• Days to forecast - the number of days to forecast (excluding today). Note that you can not get more days forecasted than your API key allows.
• Widen graph - widen the graph to only show non-zero values

Quick update on accuracy/reliability of forecast data. It's a good time to gauge accuracy as in the UK this morning there's a bog-standard Atlantic jet-stream produced weather system which has been accurately forecast - over the last 3-4 days - to arrive overnight. Currently, in the Midlands at 52 deg North it's overcast but clearing. Given yields over the last few weeks - with max sun altitude of 15deg, now 16 deg in mid-January - harvesting 1kW today looks very optimistic. Following data gathered by python script into a db:
Time of forecast / yield-for-the-day forecast for 1.77kWp free-standing, south facing array
Solcast
21:02 2448W
00:02 2783W
03:02 2794W
06:02 977W
forecast.solar
21:02 4196W
00:02 5112W
03:02 4129W
06:02 1501W

EDIT: actual yield for today: 960Wh (Pmax 1076W). Snowing at midday. Yes, Solcast was very accurate at 6:02 - of course, though, that's way too late for deciding whether or not to fully charge the battery in cheap rate period. 6:02 is more of an observation than a forecast!

Another big clue to the inaccuracy - today is sunny (not cloudless, and started out misty). Max sun altitude for my location (52 deg N) today is 17 deg. Expected max yield for the 1.77kWp array is around 2.5kWh. Forecasts:
Solcast
21:02 6785Wh
00:02 7066Wh
03:02 7124Wh
06:02 6416Wh

forecast.solar

21:02 6398Wh
00:02 6417Wh
03:02 5905Wh
06:02 5645Wh

You'd have thought they would use the easily available 'clear-sky irradiance' data as a baseline, then factor in the weather. Here's a January daily 'average daily irradiance' graph for my location from PVGIS.

Clearly, 6-7kWh for my 1.77kWp array is simply not anywhere near possible in January - why don't the APIs use PVGIS data?

Dirk Thanks for the ideas, I've now got your bit and a Solcast one averaging and setting the charge levels each night for my kit dependant on the forecasts. It also emails the figures used each day... Cheers

Hi, thanks for sharing.

Im relativly new to node red. Ist there a way to get the estimated production from doing the request to the end of the day?

If not I want to suggest it :)

Why im asking is, I try to consume as most as possible with different loads directly wihout touching the battery but still want to get the battery full at the end of the day.

So I need to know when to stop direct consumpten to get enough to get the battery full.

I know I could charge the battery first and start direct consumption after its full but my heat pump has high load from 4-6kw/h and Im running it whern sun deliveres enough to not touch the battery and in most cases the battery is not full when this period starts. I hope you understand what im trying to say achieve :D