Assessment of the cumulative probabilistic power output of existing wind farms in the Eskdalemuir Seismometer Array exclusion zone.
Issues surrounding the seismometer array at Eskdalemuir in the southern uplands of Scotland have delayed wind farm developments in the region for many years. The array is part of the UK’s contribution to an international network of over 300 stations that monitor nuclear weapon testing activity across the world.
To safeguard the array from interference resulting from seismic vibration due to wind turbines, an exclusion zone of 50 km was established in 2005 that limited wind farm development in the region.
Later studies indicated that the limits were based on an erroneous assumption. Consequently, Xi Engineering was commissioned to re-evaluate the impact of wind farms on vibration at the Eskdalemuir seismometer array.
Within a short timescale, we analysed wind measurement data from 34 masts across the Eskdalemuir exclusion zone to understand the probability of all wind farms across the zone operating at the same time.
A period of concurrent data from a subset of these masts was used to model the likely behaviour of both existing and proposed wind farms. Probability curves were derived to indicate the probability of 0-100% of the wind farm capacity being operational at any one time.
This valuable information was used by Xi Engineering as an input to their analysis to derive the maximum wind power capacity within the exclusion zone whilst maintaining vibration levels under a given threshold.
Following completion of Xi Engineering’s study, the MoD acknowledged that the original cap on wind farm capacity in the Eskdalemuir exclusion zone was too low and generally all wind farms proposed are now likely to have minimal impact on the seismometer array.