Large Gaps in Belgian Photovoltaic Power Production Over 3 Days

August 12th, 2016

Belgium reaches 3,2 GWc of installed PV power. Photovoltaic power covers close to 4% of the country’s total electricity needs. The solar output may show strong variations from one day to the next.

As a result, on August 11th, 2016 at midday, the production was around 500 MWh while two days later, it was approaching 2 000 MWh (see figure 1).

These changes, if not anticipated, may have a significant negative impact on the production-consumption balance.

The most obvious solution is a good forecast!



Figure 1: photovoltaic production in Belgium (from August 11th to 13th)


Figure 2 shows that the forecasts made the day before the given day with the different confidence intervals. August 11th, was expected to be a day with a low production and a limited uncertainty.

An important production was announced for the 13th, also with a limited uncertainty. By contrast, the confidence intervals are much wider for August 12th and the expected production is modest.



Figure 2: Actual (in blue) vs SteadyMet Forecast of the day before (in red / orange for the quantiles)


In figure 3, we can see the solar power predictions supplied in the early hours of the given days. They confirm the trends announced the day before.



Figure 3: Actual (in blue) vs SteadyMet Forecast of the early morning (in red / orange for the quantiles)