2017-09 / Trading / 2017-09 / A portfolio of photovoltaic solar plants in Italy


7 September 2017

A portfolio of photovoltaic solar plants in Italy

If we consider the same prevision quality, the size and compositions of a portfolio have an impact on the variances between planned and actual power generation.

The case of September 7th related to a portfolio of about 20 plants illustrates this point.  This is a rather chaotic day from a meteorological perspective. Here, the forecast are delivered the day before, for the next day.

For plant number 1, production shows a dramatic drop around midday, and then an encrease around 1 pm.

For the portfolio as a whole,  no similar event can be observed in terms of intensity. Variances between the planned and actual generation remain comparatively low with a MAE –mean absolute error – twice or three times below the MAE reported for plant number 1 and plant number 2: 2.58% vs 6.66% and 4.92%.

 

Figure 1: actual production (in blue) vs production forecast of the day before (in red) – plant number 1

 

Figure 2: actual production (in blue) vs production forecast of the day before (in red) – plant number 2

 

Figure 3: actual production (in blue) vs production forecast of the day before (in red) – portfolio