Maps with wind speed, wind rose and wind power density potential in Poland. The GIS data stems from the Global Wind Atlas (http://globalwindatlas.info/). GIS data is available as JSON and CSV. The second link provides poster size (.pdf) and midsize maps (.png).
Poland - Wind Speed and Wind Power Potential Maps
Poland - Wind Speed and Wind Power Potential Maps - Posters
Poland - Wind Speed and Wind Power Potential Maps - GIS