Abstract: A wind turbine generator (1) is disclosed comprising a nacelle (7) and rotor (8), and a tower (2, 3, 5) between said nacelle and a foundation (4), wherein said tower comprises an ultra-high performance fiber reinforced composite (UHPFRC) tower part (3) extending from the foundation (4) and including at least four tower segments (13, 14, 15, 16) arranged on top of each other to form a column, and pre-tensioning steel strands or bars (22) for pre-tensioning said tower segments (13, 14, 15, 16) in a vertical direction, wherein said UHPFRC tower part (3) is made in a UHPFRC with a percentage of steel fibers per volume in the range of 0.5 to 9, such as 1 to 6, and preferably in the range of 2 to 4.