Solcast Forecast - How is dotted line calculated

Hi. I’ve created a Solcast account with two roofs defined, and installed the Solcast integration, and I’m wondering (and puzzled) how the dotted line is calculated from the api data.

I’ve downloaded the diagnostics via the Solcast API Forecast device, but no matter how I slice and dice it I can’t seem to marry it up to the dotted line displayed in Energy => Solar Production

Here’s the Solar Production chart, showing a peak of 1.58 kWh between 10:00 and 11:00

and here’s a screenshot of the JSON folded up in Notepad++ to show the various “categories” in the api data structure

No matter what I’ve tried, I’ve not been able to calculate a value of 1.58 corresponding to the peak on the Forecast.

Can anyone tell me how the GUI does it?

I should add that I don’t have any Solar PV yet, so the bar chart is using my Smart Meter Electricity Import, so I’m not expecting the bar chart and Forecast to line up in any way. Just interested in how the Forecast is determined from the api data

I don’t know about Solcast, but with (the default provider for the built in forecast data) the GUI calculates nothing. It just plots the data that is supplied as an array from the API call.

By GUI, I suppose I really mean Home Assistant. I thought it would have to at least add the data from each of the roofs I have set up in Solcast. I’ll keep digging.

OK, I think I’ve stumbled on the answer for myself! The data used to plot the dotted lines for the solar forecast is stored in the solcast.json configuration file, which obviously (now) gets populated when the Solcast PV Solar automation runs. Obvious now!