Type Approval according to DIBt
Since 2004 TÜV NORD has issued more than 1200 reports on type approvals (“Typenprüfungen”) based on the DIBt Guideline for Wind Turbines. In each of the 16 German federal states wind turbines are treated as buildings, which require a building permit according to the local LBO ("Landesbauordnung“ = local building regulations). The type approval is a tool defined by the BauPrüfVO (“Verordnung über bautechnische Prüfungen“) - substituting the required individual approval in case of multiple buildings that are constructed in the same way. The type approval covers the structural design of the tower and - if requested – of the foundation as well. All other components – such as load assumptions, safety system, manuals, rotor blade, machinery components, nacelle cover, electrical equipment and lightning protection – are evaluated in form of a GS (“Gutachtliche Stellungnahme” = evaluation report in german language) issued by any certification body with a notification for Germany.
One alternative to a type approval is the single approval (“Einzelprüfung”). The single approval is always a site-specific approval, e.g. for a certain wind farm. For a single approval an inspection order by the local authorities (“Prüfauftrag”) is required. The single approval may include the check of the site-suitability, the geotechnical report and the construction supervision, if requested by the local authorities.