Regulatory studies related to wind farm facilities are constituted of environmental impact studies in pre-implantation step and post-implantation monitoring. The aim of these studies is to assess local impact of these facilities on the flora and fauna, but these studies and their data could also potentially contribute to a better understanding of global conservation issues. To test this, we collected regulatory reports of these studies from administrative services. We then conducted an analysis on the «bat» component, focusing on information availability according to the inventory methods (acoustic point counts, ground records, altitude records, transects and mortality monitoring), assessing the level of documentation, and on the format of data presentation. Concerning collected reports (since August 2011, when studies and availability rules were reinforced in France), only 5.5% (impacts studies) and 6.8% (monitoring) were accessible from French environmental authorities. Our analysis shows that the proportion of reports with a complete level of documentation was 30% for the point count method and for ground records, 60% for altitude records and nothing for others methods. Moreover, the average level of documentation of transects and mortality monitoring is significantly lower than others methods. There is an important organisation effect concerning the level of documentation of methods, but not on the organisation type (public or private sectors, associations). The level of documentation consists in various metadata about context, materials and methods, and sampling design information. However, basic and essential informations concerning some metadata are often missing, such as the duration of acoustic records (this prevents an assessment of the sampling effort). Finally, based on our sample of 48 impact studies and 52 post implantation monitoring reports, we demonstrated that the level of documentation of reports has not progressed significantly over time despite publication of European and French technical guidelines (2008 and 2012, respectively) and despite the evolution of French laws (2011). However, the mortality monitoring is close to significance concerning a progress of level of documentation for before compared to after the evolution of French laws. Our results raise questions about the quality of method used in studies and the reliability of conclusions for the wind farm facilities. We advocate for improved and standardized methods in future studies, as well as the availability of inventory data and their metadata following the SINP (Information System on Nature and Landscapes) model.