Wind turbines are incredibly strong structures that have been designed to withstand severe weather variations and high winds in areas of the country often deemed too severe to live in.

And that means that wind turbines can tolerate various levels of damage while still being operational. The main purpose of drone inspection of wind turbines blades is to asses and evaluate the degree of damage and monitor it going forwards so that any required repair work can be scheduled in during ‘off peak’ times such as when wind levels are low.

drone inspection of a wind turbine

This means that a defect category system is a valuable reference guide that we can provide our wind farm customers and acts as a way of monitoring and evaluating when repair work should be conducted.

Defect Category 1

Severity: Very Low

Category 1 damage of a wind turbine blade is where the integrity and performance window of the turbine has not been affected and there is no risk of the issue developing into a more severe issue. Category 1 damage is generally only cosmetic issues with no impact on performance.

Generally, a category 1 issue with a wind turbine will be documented but no repairs are necessary.

Defect Category 2

Severity: Low

Category 2 damage of a wind turbine blade is when the integrity and performance window of the turbine has not been affected but there is a small risk of the issue developing and hindering normal operational conditions.

A category 2 issues with a wind turbine should be documented and repairs should be conducted during the next scheduled turbine maintenance plan.

Defect Category 3

Severity: Medium

Category 3 issues are where the integrity and/or performance of the turbine has been affected by damage. In this situation, we would document the issue and advise repairs to be completed within 6 to 12 months.

Defect Category 4

Severity: High

A category 4 issue is where the structural integrity and/or performance of the turbine has been affected. In this situation, we would document and provide notification of the issue with repairs to be completed within 3-6 months.

Defect Category 5

Severity: Very High

A category 5 rating is the highest and most severe rating. This is where there is a real safety risk. In this circumstance the wind turbine should be stopped and immediate repairs should be conducted.

Why drone inspection is so important

Blade erosion and general wear and tear can reduce a wind turbines energy generation potential by several % marks. With our increasing dependence on wind power energy, a drop of 2% on several turbines all at the same time can easily amount to a significant overall drop in energy production.

By using drone inspection services, we can monitor issues with wind turbines and schedule in required repairs far more effectively. This can reduce the operational downtime of a wind turbine during a standard year and reduce the chances of catastrophic category 5 level issues from developing.

Find out more

The significant cost and time savings of drone surveys means that they are a genuine alternative to conventional inspection methods and are fast becoming the preferred method of carrying out scheduled visual inspections on ind turbines (both land and off-sea).

defect inspection of wind turbines

If you would like to know more about the drone inspection work that we can provide for wind turbines, blades and wind farms both on land and off shore, please contact us today by calling 0141 370 4037 or email