Wind turbines contribute significantly to the production of renewable energy. In order to minimize the Levelized Cost of Energy (LCOE) the cost of the wind turbine incl. tower and the foundation should be as low as possible but at the same time have a sufficient reliability. In this paper, focus is on wind turbine components which may be made of concrete such as tower and foundation. In traditional deterministic design based on design standards, partial safety factors are applied to obtain the design values. Improved design with a consistent reliability level for all components can be obtained by use of probabilistic design methods with explicit consideration of uncertainties connected to loads, strengths and numerical models / calculation methods. Wind turbines are basically designed based on IEC 61400-1:2019 which indicates a target reliability level that can be used for probabilistic design. In this paper, probabilistic fatigue models for concrete are presented based on the fatigue models in fib Model Code 2010, but extended within a stochastic modelling using a large dataset of fatigue tests. Generic uncertainty models for the fatigue load are applied. It is illustrated how reliability analyses can be performed within a probabilistic design framework.