These requirements are differing from Grid Code to Grid Code. Revisions change frequently and even new Grid Codes are issued from time to time. GL is always keeping track, collecting Grid Code revisions, drafts and corresponding information in order to extract requirements relevant for wind turbines. This is even offered by GL as a special update service, called IGCC (International Grid Code Comparison).

In some countries system operators require to establish evidence that wind turbines are compatible with the requirements of their Grid Codes in order to be connected to the grid. In most countries only wind farms can be compliant with Grid Codes. Types of wind turbines can show Grid Code Compliance by defining assumptions which have to be implemented on wind farm level. Showing compliance with Grid Codes can be done best by certification (GCC).

This will be done in two steps. First a type of a wind turbine will get a Type Certificate (GCC) based on one ore more Grid Codes according to the relevant certification procedure. In a second step a site specific Project Certificate (GCC) will be issued for each wind farm, based on site specific data and the Type Certificate (GCC). GL Renewables Certification's intention is to facilitate the process of Grid Code Compliance (GCC) for all parties involved by offering such certification (GCC) saving valuable resources.