EON has commissioned the €100m ($139m) large wind farm, Wielkopolska, with a generating capacity of 52.5MW near Poznan in Poland.
About 21 turbines located at seven sites around Poznan will be capable of delivering wind energy to 45,000 households.
The new wind farm is part of EON's plan to increase the renewables share in its generation portfolio to 10GW by 2015.
EON will invest €8bn ($11bn) in renewable energies between 2007 and 2012.
The company has increased its renewables capacities from 400MW to 3,500MW since 2007 and aims to have 4GW by the end of 2010.