Learnings

Outcomes

The project has produced:

An extensive literature review into the different ways of investigating the impact of a wind turbine on an overhead line, with recommendations on how to approach this project and generate guidance material or to create a tool to help assess the impact of a turbine on an overhead line. 

A ‘Tool’ based upon the wind flow modelling effects of a wind turbine in close proximity to an overhead line conductor, which can be used to provide a basis for appropriate recommendations and guidance for future proposed wind turbine installations.

Lessons Learnt

The learning captured during this project is outlined below: 

The vibration information collected from the first installation has enabled a picture to be formed of the movement that the overhead line conductor experiences without the wind turbine installed. The four monitoring devices were placed on each of the phase conductors and the earthwire (in a vertical line, separated by approximately 5 meters). The field data has shown that each of the phase conductors and earthwire experience different movement patterns. The difference in movement patterns is believed to be due to the height above ground of the conductors and earthwire, and that the strength of the wind is not uniform 
as it crosses the landscape. 

The vibration monitors need to be carefully installed, the older models have exposed wiring which needs to be checked to ensure it’s not been nipped or is in a position to rub against fixing attachments.

There are a vast number of factors, such as the roughness of the ground, the localised wind rose, the gradient of the site, times of the year, average wind speeds and temperatures, which influence the behaviour of the wind flow beyond the turbine. Modelling is an aid to predicting the likely impact, validating the modelling via field results provides more certainty, the ‘Tool’ 
created still needs to be treated with respect and caution. Going forwards additional field monitoring is advisable, this would be at the generators cost.