1 IRENA – M ARTINIQUE C ONFERENCE ON ISLAND ENERGY TRANSITIONS Workshop C : Wind resources and technologies for islands W IND MEASUREMENTS ON I SLANDS : T HE BENEFITS OF USING LIDARS Martinique, 22 th June 2015

2 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS  Eoltech short presentation  Wind resource assessment, background and state of the art  Wind measurements with LiDARs  Specificities of the wind resource on tropical islands  Main conclusions Summary

3 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Eoltech at a glance 1st French independent expert in wind resource assessment Pre and post construction wind potentiel assessments 13 years of expertise, more than 7 GW of projects analyzed

4 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Wind resource assessment, background and state of the art - 1/3 Main characteristics of the wind resource High temporal variability Order of magnitude ± 10 % on wind speed from one year to another over 15 years High spatial variability Depending on the complexity of the topography and the landscape H igh sensitivity wind speed versus production 3 % variation on wind speed could lead to 6 % to 9 % of variation in production Wind resource assessment subject to high level of uncertainty without measurement on site +11 % - 9%

5 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Wind resource assessment, background and state of the art - 2/3 On site measurements, the starting point of a standard process Spatial extrapolation State of the art : 1 year of measurement on a representative point of the site at a height the closest to the hub height (2/3 minimum) Wind measurement 1 year on site & Data analysis Long term prediction +11 % - 9% Long term energy output

6 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Wind resource assessment, background and state of the art - 3/3 On site measurements with met mast Met mast equipped with sensors (Cup anemometers, Wind vanes…) Height between 50 m and 80 m The most recognized process for wind measurements

The fequency of the reflected signal is modified (Doppler effect) o Difference of frequency o Signal return time 7 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS The LiDAR - Operating principle A laser beam is pulsed by the LiDAR (Light Detection and Ranging), and reflected by the suspended particles Wind speed Height of measurement Different heights of measurement possible Usually between 40 m and 200 m Aerosol speed LiDAR Aerosol Speed = Wind speed f1 f2 Height

8 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS The LiDAR - Who uses it ? The LiDAR - Accuracy Well-proven technology on a non complex area Recognized by industry for wind resource assessment On going IEC standard for power curve measurement (started in 2014) We are talking about the technology, not the product itself Used by developers, manufacturers, consultants and research institutes More than 400 Lidar Windcube by Leosphere have been deployed

9 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS The LiDAR - Advantages Easy to install and remove No building permit required Satisfactory measurement quality up to 200 m Low risk of wear due to climatic conditions (especially corrosion) But keep in mind…. Precautions of installation are required (flat terrain, avoid obstacle in the volume of the cone) The technology is proven, not each device Conclusions : The LiDAR is an alternative technology to masts for wind measurements, recognized and easy to implement

10 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Specificities of wind climate on tropical islands (1/3) Usually, one year of measurement is strongly recommended to take into account the seasonality effect of wind resource Per seasonMain impact on Different wind regimePrevailing wind direction Different landscape (crops or forests summer versus winter)Vertical wind shear Atmospheric stability conditionsVertical wind shear In tropical areas, especially on islands, the wind climate is a result of stable trade winds and temperature variation

11 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Specificities of wind climates on tropical islands (2/3) Seasonality effect on wind resource Per seasonNorthern FranceIsland on a tropical area Wind roses m Q Q – Q – Q4 m Q Q – Q – Q4

12 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Specificities of wind climates on tropical islands (2/3) Seasonality effect on wind resource Per seasonNorthern FranceIsland on a tropical area Wind roses x Not stable Stable Landscape (farmland / forests) Atmospheric stability conditions (temperature)

13 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Specificities of wind climates on tropical islands (2/3) Seasonality effect on wind resource Per seasonNorthern FranceIsland on a tropical area Wind roses x Not stable Stable Landscape (farmland / forests) Atmospheric stability conditions Summerwinter

14 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Specificities of wind climates on tropical islands (2/3) Seasonality effect on wind resource Per seasonNorthern FranceIsland on a tropical area Wind rose x Not stable Stable Landscape (farmland / forests) x Not stable Stable Atmospheric stability conditions x Not stable Stable Seasonality effect on wind resource is relatively low on islands in tropical areas

15 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Specificities of wind climates on tropical islands (3/3) 12 months of measurement is always better than 8 or 10 months for exemple But... 8 or 10 months of measurement on such area should be enough To estimate accurately the wind resource To allow to get bankable wind resource assessments

16 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Conclusions – 1/2 On the one hand…. … A reliable and easy to install (or move) device for wind measurement On the other hand… … A wind climate on tropical islands allowing to perform an estimate (or a 1st estimate) with less than 12 months of measurements on site

17 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Conclusions – 2/2 Main applications for using LiDARS on tropical islands Standard wind resource assessment studies Resource mapping Move one LiDAR on several locations during few years to carry out a first estimate of wind resource map Adjusting meso-cale model on strategic locations First estimate of the wind resource on several islands in the same area

18 W IND MEASUREMENTS ON ISLANDS : THE BENEFITS OF USING LIDARS Thank you for your attention