Wind Index

Wind Index (WI) aims to quantify the monthly fluctuations on electricity production by wind farms over the average historical value. It is based upon real wind farm production results, properly corrected in order to dissipate any operational unavailability effects.


More than represent the produced wind resource variation on the produced electricity, it is intended to describe regional patterns. It is a very useful analysis tool for all the players in the wind energy market, allowing them to properly evaluate their monthly results regarding the long term patterns of fluctuation.


The WI is published every trimester by MEGAJOULE, together with APREN, and with the support of a great number of some of the larger promoters at national level.

Wind Index - 1st Quarter 2015
Wind Index - 2nd Quarter 2015
Wind Index - 3rd Quarter 2015
Wind Index - 4th Quarter 2015
Wind Index - 1st Quarter 2016
Wind Index - 2st Quarter 2016
Wind Index - 3rd Quarter 2016
Wind Index - 4th Quarter 2016
Wind Index - 1st Quarter 2017
Wind Index - 2st Quarter 2017
Wind Index - 3rd Quarter 2017
Wind Index - 4th Quarter 2017
Wind Index - 1st Quarter 2018
Wind Index - 2nd Quarter 2018
Wind Index - 3rd Quarter 2018
Wind Index - 4th Quarter 2018
Eolicity index for Continental Portugal - Q3 2020
Eolicity Index for Continental Portugal - Q2 2020