I recently signed up to solcast to predict the output of my 4kW home solar array so that my Home Energy Management System could establish when it needed to charge our storage battery from the grid. We have a dynamic smart tariff where the price changes each half hour, and the battery helps to minimise our cost by charging when the price is lowest and discharging when the price is highest.
About 2 weeks ago I started to upload generation data from the panels every 5 minutes. The generation data is measured by my ImmerSUN as part of an optional monitoring add-on and automatically uploaded to the cloud by the ImmerSUN. I use a modified version of this script to collect the data from the cloud which is then uploaded to solcast.
Initially there were some discrepancies between estimates and actuals where the orientation of the roof seemed a little out, and the periods of peak production over-estimated (although my system peaks at 4 kW it rarely sustains 4 kW and certainly not in March). However after 2 weeks the tuning routine ran automatically last night, and now these concerns appear to have been eliminated. Prior estimates now seem to have been revised to reflect the new tuning giving these results for the last 7 days…
There is a period yesterday morning when the ImmerSUN cloud went down so the uploaded measurements are wrong being all zeros, but otherwise the projections now look very good.
My system actually takes the estimates from the evening before, not an hour before, and so there is more uncertainty in the data that I actually use; but all the same I am quite impressed by the accuracy here.