This paper presents the results of a study on the frequency deviation of the utility grid due to wind power fluctuations. The deviation is estimated by a deterministic method based on the transfer functions of system components. As the grid frequency is regulated, the deviation can limit high wind power penetration. The research identifies speed governors as one key component in enabling high wind penetration and there is need to factor their increased wear and tear into the ancillary services cost. It also raises the question as to whether the existing standards, set for frequency deviation, which have to be complied at the points of connection of wind energy providers, are adequate to promote high wind penetration.