Optimised management of blade erosion

Introduction

Erosion of leading edges of wind turbine blades is a widespread issue, with potential for significant cost impact, particularly offshore. The ORE Catapult has developed the blade leading edge erosion programme (BLEEP) focussing in this area.
We present the results of a field study completed as part of BLEEP to measure impact on turbine performance of leading edge erosion at a commercial offshore wind farm. We describe the methodology used to quantify the performance impact of leading edge erosion and how improved understanding can be applied to improve financial yield by optimising the timing of maintenance interventions.

Approach

It is possible to measure the performance impact of erosion by conducting power performance assessments. The ORE Catapult, working with the operator of a UK offshore site have completed a measurement campaign to quantify the impact of blade erosion on turbine performance by completing power performance assessments using a turbine mounted lidar.

Main body of abstract

Based on extensive industry engagement ORE Catapult has developed the Blade Leading Edge Erosion Programme (BLEEP) to focus on this phenomena. Blade erosion is a significant issue, and has been experienced throughout the wind industry. It can be particularly costly to deal with offshore, but also affects onshore turbines. The whole industry is currently exposed to the issue of erosion, and an improved understanding of how erosion impacts turbine performance is a commonly described need.
In this presentation we will describe the results of a robust power performance assessment using lidar, carried out to quantify the impact of leading edge erosion on turbine performance. We will describe the methodology used to deliver this result and give insight using a real world case study.
This type of assessment can be used to optimise wind farm O&M and as a result reduce the cost of energy. An increased understanding of the performance impact of blade erosion is required and the results of this measurement campaign represent a first step on the journey to full understanding of how varying levels of blade erosion impact energy yield.
The ORE Catapult has convened a group of wind farm operators in a joint industry project to conduct further study of how erosion is impacting energy yield. This project will repeat the described measurement methodology and use other techniques to establish a better understanding of how varying levels of blade erosion will impact the yield of operational projects.


Conclusion

An organisation seeking to proactively manage blade maintenance needs to understand both the cost of interventions and the cost of lost yield that they will mitigate. Operators already have a good understanding of the costs of blade inspection and repair. Conversely there is not at present any accurate understanding of how different levels of blade erosion will reduce yield. By using the described and other types of turbine power performance assessment operators can expect to improve the financial yield of their projects by taking a better informed approach to blade erosion maintenance interventions. Having accurate information on which to base cost versus benefit decisions around blade maintenance is an achievable goal.


Learning objectives
Delegates can expect an introduction to the concept of the issue of blade leading edge erosion and the widespread nature of the issue. We will show how the yield impact of leading edge erosion can be assessed. This will introduce power performance assessment and turbine mounted lidar. Delegates will see what impact leading edge erosion was shown to have on energy yield from our test case and will be introduced to subsequent work that ORE Catapult is conducting in this area with a particular focus on optimising blade O&M expenditure.