Worrying failure (Angela Hunt)
John Robertson’s report of a windmill rotor head becoming detached from its mounting and travelling a considerable distance due to a weld failure raises important considerations around the safety of placement of on-land wind turbines in Shetland.
Fortunately in this case the turbine head did not hit a human being or an animal and its displacement has been attributed to a manufacturing defect, an accident which could occur with a turbine placed anywhere in the world. However, the potential for public harm from faulty and damaged turbines is higher in Shetland than elsewhere.
Shetland’s unique atmospheric conditions caused by narrow landmass and sea fogs give all metal parts a regular bath in salt water and the speed of advanced metal corrosion is a well-known aspect of living here; from the quickening rust on car bodies, the seizure of locks to the beautiful colours of rusting tin sheds.
Manufacturers of offshore wind turbines manage seawater corrosion through the application of protective coatings and regular checks for metal fatigue on turbine fixings, rotor blades and seams.
Development proposal details which have been shared with the public too date for large scale on land wind turbines in Shetland do not evidence consideration of the cost of protection in atmospheric conditions which could considerably shorten the working life of the turbines, or the cost of substantial public liability insurance for the compensation of employees and members of the public where metal corrosion leads to an accident.
Primary school children have been taken up to see the Burradale turbines while they are shiny and new and we are informed of regular checks on the turbines profitability.
It would be reassuring to hear that there are also to be regular checks by an independent metallurgist for any signs of wear or corrosion on the rotor blade mountings as the turbines age and the extent of the public liability insurance in place, both here and in the Viking Energy proposal.