Hiiumaa offshore wind Park EIA: Main EIA results and description of the required supplementary environmental investigations

The Nelja Energia OU (LLC) initiated the project of an offshore wind park in coastal waters of Hiiumaa Island within Estonian EEZ (Baltic Sea) in 2006. Altogether 200 wind turbines with total output about 1000 MW are planned to build in five sections, located in the shallow water at the depth of 15-20 meters. Environmental Impact Assessment (EIA) was initiated in June 2006. However during the scoping of the EIA and the public hearing of the EIA Programme, the lack of essential environmental information was revealed. Because of that, several special studies were performed in 2006-2008. In parallel, a number of technical amendments to the project were made. The paper is focusing on the results of EIA and of related environmental studies. The possible environmental and socio-economical impacts and necessary mitigation measures are discussed. As a result, the two of the initially proposed five sections were excluded from the wind park, whereas the rest three of them were suggested to be moved into deeper and more distant locations. These implemented amendments would decrease the total output of Hiiumaa offshore wind park up to 594-730 MW. As probably the only important environmental factor the wind turbines impact on migrant birds should be highlighted. The visual pollution effects of wind turbines were found to be more problematic from the socio-economic point of view.