At Autarco, we continuously monitor solar irradiation levels for locations where our PV systems are installed. By doing so, we are able to analyze whether the yields of these systems are as expected and all components work as they should. The collected data leads to interesting results when comparing one year with another or looking for differences between various locations around the globe.

It’s not uncommon that a months irradiation levels may change from year to year by up to 20%. This is one more reason an intelligent monitoring system that tracks your systems actual performance against actual weather conditions is so important.

See how Autarco can offer you this here.

Last winter was quite dark...

For example in the Netherlands, irradiance levels last December and January have been lower than the long term average. On top of that, snowfall led to small decreases in yield, mostly for flat-roof systems. However, since average yields in these winter months account for only a small part of the yearly total, the impact of an incidental snow cover is minimal. The Royal Dutch Meteorological Institute (KNMI) measured that the number of sun hours in December and January were both far below average, this had a big influence on irradiation levels in this period, as we saw in our satellite data as well. The winter months were truly dark this year!

... but February made up for it!

Fortunately, February 2018 showed an entirely different image. Sun hours are far above average values, even so that it is the second highest number since the KNMI start monitoring these data back in 1909. On our satellite data we see this resulting in irradiation levels that are indeed above average, up to 30%, depending on the location within the Netherlands. Together with the low temperatures and the days lengthening again, this boosts the overall performance of PV systems, resulting in good yields for this time of the year.