D+1 / D+2 Forecast for an 800KWp Solar Plant in Corsica

1 septiembre 2015

The solar power forecasting several days in advance are based on weather forecasts and a refined modelling of the power plant itself.

The figure 1 compare the actual production to the one forecast two days before. One can see gaps which correspond to cloudy spells that had not been anticipated. This type of rapid and local fluctuations of the cloud cover cannot be predicted by the weather models.

One can notice production drops of very short duration (at the end of the morning for instance) and others that last about two hours (in the afternoon).

The figure 2 shows the forecast produced one day in advance. The announced average level of production is lower. This significant difference with figure 1 is an indicator of an unstable meteorological situation. As a result one can expect, then, a lower level of accuracy.


2 Days-ahead forecast

Figure 1: Actual (in blue) vs Forecast (in red) – 2 days ahead, Time step: 5 minutes

Day-ahead forecast

Figure 2: Actual (in blue) vs Forecast (in red) – 1 days ahead, Time step: 5 minutes