Wind Energy Projects Evolution

In order to assess how the wind resources have been utilized  historically, we use a global wind project database with access provided by the International Renewable Energy Agency \cite{markets2017}.  The database is the most comprehensive listing of individual wind projects. Comparing the database entries to country statistics we find that it covers 50XXX% of the global installed capacity and the way this breaks down by country is shown in Table XXX. It provides information on installed capacities of the projects and their locations using geographic coordinates.   Due to winds dependence on geographical morphology, wind resource quality is very localized as shown in Fig.  \ref{957922}. At the same time, the database reported coordinates are not accurate but are given with a precision of ±1km. It therefore requires some additional assumptions to reconcile the project location data (which are not always accurate) with the resource distribution. To do so, we split the region of analysis into a one km2 grid. If one or more wind projects are reported inside the area of a given square, all projects are correlated with the best wind resource quality in all of the eight adjacent squares excepting areas with terrain that exceeds a slope of XXX.
In addition, it does not make sense to include countries with very limited capacity for exploring technology diffusion trends. Therefore, we filter the dataset based on two criteria: