Forty Years of Wind Energy Development - Wind Power for the World: The Rise of Modern Wind Energy - page 20

Figure 2.2 The 25mHAT experimental wind turbine at the premises of

ECN, Petten, the Netherlands, equipped with the FLEXTEETER
rotor, 1992 (Photo: Jos Beurskens ©).

Figure 2.3 The FLEXTEETER experimental rotor and hub structure, 1992

(Photo: Jos Beurskens ©).

The tests on the FLEXTEETER showed promising results with
respect to the decrease of the fatigue load spectrum by introducing
flexibility in the rotor concept (Fig. 2.4).