Impact of the use of intraday forecasts on the accuracy of the solar power prediction

4 marzo 2015

Updated forecasts for a group of plants in Lombardy (Italy) :

The day before at 8 a.m. o’clock (SteadyMet):

Day-ahead forecast - Italy multi plants 1

then about 8 p.m.:

Day-ahead forecast - Italy multi plants 2

SteadySat 3 hours before:

3h-ahead forecast - Italy multi plants

PV-production seems to reach a maximum level, higher than announced the day before

SteadySat: 1.30 hours before:

1h30-ahead forecast - Italy multi plants

The forecast confirms the level of the peak of production, on the other side it may occur earlier than previously expected 1:30 before.

The two forecasts, provided the day before (at 8 a.m. and 8 p.m.), are different, nevertheless in both cases they underestimate the future solar power production. The profit on the day-ahead market is not optimum.

During the day, every 15 minutes a new forecast is provided using the Satellite technology. An hour before, we anticipate a more important forecast than expected the day before, it can still be time to change the positions on the intraday market.