Tuesday, 27 September 2016
14:30 - 16:00 LIDARs - the zapping competition
Resource assessment  
          

In this highly interactive quick-fire session, participants will scan through 14 LIDAR-related presentations and vote to select the three contributions they would like to hear in full. Presentations will cover a wide range of possible LIDAR applications, both offshore and onshore, such as power-curve validation, resource assessment in complex terrain, turbulence intensity measurements, and more.

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Learning objectives

Get a wide overview of the latest research and field work involving LIDARs, both onshore and offshore.

 

This session will be chaired by:
Co-chair(s):

Alex Clerc RES Ltd, United Kingdom
Co-authors:
Megan Smith (1) ^F
(1) Carbon Trust, London, United Kingdom (2) RES Offshore, London, United Kingdom

Scanning LIDAR in Offshore Wind

Introduction

Scanning LIDAR is not a new technology – it has been used in a variety of ways for decades – however it is only relatively recently that it has been used in offshore wind. While there is broad acceptance across the industry that the technology could be very useful, it is not yet clear what are the most valuable ways for the technology to be applied. To address this challenge, the Offshore Wind Accelerator programme launched the world's largest offshore trial of scanning LIDAR systems in January 2016. This presentation will present the results from the trial and discuss the impact on the industry.

Approach

The OWA has launched a scanning LIDAR campaign in Dublin Bay to validate devices for prescribed use cases. There are a variety of potential uses of scanning LIDAR, including:
- Understanding the spatial variation across a wind farm site
- Met mast replacement
- Power performance measurements
- Wake measurements
- Turbulence and boundary layer studies
- Wind power forecasting and turbine control

Scanning LIDAR can be used in all of the above applications, at least in theory. What remains is understanding the relative costs and benefits of installing and using SL equipment in such ways, and also analysing what real cost savings could result from these applications.


Main body of abstract

In order to best inform investment decisions and reduce risk when developing wind farms, the available wind resource needs to be fully and accurately understood.
The conventional solution (met masts) for measuring potential offshore wind fields is becoming prohibitively expensive as wind farms move further out to sea into deeper and rougher waters so a cheaper alternative could significantly reduce costs for developers.
Studies have shown that there could be significant benefit to be realised through the use of scanning LIDAR technology which could provide a low cost alternative to fixed foundation met masts. This technology brings the added advantage of being able to characterise long-range wake effects over a wide area from a single fixed location.
One area in which this technology may be able to reduce uncertainties for wind resource measurement campaigns is through the assessment of spatial variation over a wind farm zone. This would reduce the uncertainty of the predicted wind resource at a proposed wind turbine location, by verifying the models used for the extrapolation of the wind speed from measurement points to wind turbine locations.
In 2014 the OWA launched a project which aims to fully evaluate the capabilities and potential of scanning LIDAR systems for offshore wind measurements, assess all the possible applications of the technology and provide insight into the benefits and limitations of the system over the conventional met mast method of measurement. In January 2016, the scanning lidar trial itself commenced. Consisting of four scanning systems from two manufacturers as well as a range of validation devices, the project will conclude in May 2016 and no results have been published to date.

This campaign is a key element of that project, designed to best validate and demonstrate the capabilities of this technology as well as further understand the potential uses in an offshore wind context. The results will be significant in utilising this technology to reduce uncertainty, optimise offshore operations and maximise turbine output.


Conclusion

Interim results are very encouraging but full trial conclusions will not be complete until May. The data will be complied with full results being shared at the WindEnergy conference.


Learning objectives
Delegates will learn about the operational capability of a range of scanning lidar devices offshore. the presentation will discuss practical lessons and considerations, data capture and analysis and potential future applications that delegates will be able to apply directly to their own projects.