Every month we take a look at the irradiation on the European and African continent with the help of our latest solar data tool: The Solar Index Maps. The Solar Index Map uses 3E’s Solar Data Services and generates detailed maps showing the percentage difference between the solar resource during the period of interest (in this case, the month of April 2018), compared with the long-term average solar resource since 2004.
Last month was again a very dark month in western Europe with 8% to 30% less sunshine than the average (P50). However, Central and Eastern Europe had a much better scenario with higher irradiation values than the P50.
How did this impact the production of thousands of solar plants across Europe?
A decrease in solar index also corresponds to a decrease of the solar parks production for the considered period with respect to the expected P50 values as calculated in the business models. Such variations over time must be correctly accounted for when assessing the long-term yield of PV assets. 3E’s uncertainty analysis, which is part of a standard P90 calculation, accounts for this concept through a detailed solar resource assessment.
The story was actually the opposite last year when Western Europe enjoyed a much sunnier April in 2017, while western Europe had a darker month: