Case Study - Wind Resource Assessment


Inverbervie, Aberdeenshire

Green Cat Renewables, (GCR) was appointed as wind resource consultants with a view to providing a bankable assessment for the energy generation potential of the site.

The original consent for the development consisted of 3 2.5MW wind turbines, with a tip height of up to 100m.

The initial layout was designed on the basis of a turbine model that had become obsolete, thus GCR considered three alternative compliant models from various manufacturers as requested by the client, each with identical 2MW capacity and dimensions.

In addition to this, a fourth model identified and suggested by GCR was included in the assessment, with a higher 2.3MW capacity.

Whilst this model had a marginally larger rotor diameter, and increase on wake losses, the higher yield benefits outweighed the increased capital costs.

A comprehensive wind resource model of the site was developed based on metrological mast. As well as wind data, the model incorporated terrain data and neighbouring operational and consented wind projects.


The results provided by GCR enabled the client to progress to discussions with the local planning authority and the turbine manufacturers.

The estimated yield figures were used by the client as part of project cost models, allowing the client to select the most profitable scheme under the current consent.

The project progressed with a 2.3MW wind turbine. This delivered an improved capacity factor of around 31%, compared to around 27 – 28% for the other models.

Key Data
  • 6.9MW Wind Farm
  • 3 wind turbines, 100m to tip height
  • Capable of providing enough electricity to power over 5,600 homes
  • GCR provided technical support for a bankable wind resource assessment
  • Detailed yield to inform turbine selection
  • GCR identified a more suitable model leading to an improved energy yield prediction
  • Wake loss modelling due to nearby sites at Tullo and Twinshiels
  • Commercial operation achieved February 2017