Carbon Trust Offshore Wind Accelerator (OWA) Designing an Offshore Wind Measurement Campaign to Promote the Development of Wake Effects Models

Transcription

1 Carbon Trust Offshore Wind Accelerator (OWA) Designing an Offshore Wind Measurement Campaign to Promote the Development of Wake Effects Models Brian Gribben and Breanne Gellatly 13 June 2012, London 1

2 Proposed agenda Introduction Overview of the Offshore Wind Accelerator The Measured Data Shortage Measurement Campaign 2

3 Offshore Wind Accelerator Objective: Reduce cost of energy by 10% in time for Round 3 Joint industry project involving 8 developers + Carbon Trust 45m programme 10m for collaborative R&D Up to 35m for demonstrations DECC funds 1/3 Commitment to 30 June 2014 Launched 2009 Option for two 1-year extensions Offshore Wind Accelerator OWA members have licenses to develop 30GW in UK waters (60% market share) 3

4 The Measured Data Shortage Only a small number of met mast and turbine power datasets are available publically There is a concern that this data scarcity had led to wake effects models being tuned to the datasets available We need more benchmarking and validation from a variety of wind farms in order to differentiate between wake effects models There is limited value in more accurate wake effects models if they are not bankable OWA s aim is to reduce the cost of financing by validating wake effects models using measured data 4

5 Measurement Campaign Overview A measurement campaign is planned for the Rødsand II offshore wind farm, which is owned and operated by E.On The major elements of the campaign are as follows: Element Additional Equipment 1. Unsteady Inflow 3D sonic anemometers Data loggers 2. Bulk Flow 2x scanning pulsed LIDAR 3. Turbulence 4x short-range nacelle-mounted LIDARs 5

6 Measurement Campaign Elements 3 campaign Elements presented: Element 1: Unsteady Inflow Element 2: Bulk Flow Element 3: Turbulence Increasing depth of physical insight Increasing universality of results Increasing cost Increasing risk 6

7 Element 1: Unsteady Inflow 7

8 Element 1: Unsteady Inflow Objective: Understand how unsteadiness in the inflow affects power production to understand why the agreement between models and measurements deteriorates at small bin sizes 8

9 Northing Thousands Element 1: Unsteady Inflow Upgrade existing met mast (1Hz, velocity components 6054 and temperature profiles) 6053 Rodsand II Layout with Instrumentation Turbines MetMast Trafo Potential 6044 upgrades of turbine SCADA systems (higher frequency data) Thousands Easting 9

10 Element 1: Unsteady Inflow Benefits: Understand how unsteadiness in the inflow affects power production Understand why the agreement between models and measurements deteriorates at small bin sizes Increase the validation database for wake effects models by taking data at another farm Increase understanding of the link between atmospheric stability, turbulence and wake losses Increase understanding of the bulk flow and turbulence characteristics of the flow exiting at a large wind farm, which drives farm-on-farm interactions 10

11 Element 2: Bulk Flow 11

12 Element 2: Bulk Flow Objective: Measure steady and unsteady bulk velocities across a wind farm to validate models of how wakes develop, merge and dissipate Investigate the interaction with the upper atmosphere, which dominates wake recovery for very large wind farms 12

13 Northing Thousands Element 2: Bulk Flow Long-range scanning pulsed LIDAR unit mounted on the substation Rodsand II Layout with Instrumentation Good coverage across much of the farm Detailed view of wake development from SW Investigate interaction with upper atmosphere Turbines MetMast Trafo LIDAR 1 Range LIDAR 2 Range 6046 Long-range scanning pulsed LIDAR unit mounted on the 6045 met mast 6044 Gives true 2D information in regions of overlap 6043 Allows cross-validation with met mast data Thousands Allows cross-validation of LIDARs on line-of-sight between units Investigate interaction with upper atmosphere Easting NB Indicative LIDAR only unit selection has not been made SGURR Galion Leosphere Windcube 13

14 Element 2: Bulk Flow Benefits: Step-change in the ability to identify the source of discrepancies between modelled and measured production data Step-change in empirical evidence on interaction between large wind farms and the upper atmosphere Improve understanding of how wakes spread, merge and dissipate in large wind farms Understand spatial variation of flow across a large swathe of the farm, allowing direct validation of CFD-predicted flowfields Understand how unsteadiness propagates through the farm and identify any unsteady features arising from flow instability 14

15 Element 3: Turbulence 15

16 Element 3: Turbulence Objective: Understand the underlying physical processes that cause wakes to develop, merge and dissipate as they do, enabling development of models that better characterise these phenomena 16

17 Northing Thousands Element 3: Turbulence Rodsand II Layout with Instrumentation Forward- and aft-looking nacelle-mounted LIDAR units on 2 turbines Can cross-validate with met mast and scanning LIDAR Turbines exposed to free-stream, and wide Turbines variety MetMast of wake conditions Trafo including deep array LIDAR 1 Range LIDAR 2 Range Thousands Leosphere Easting Natural Power ControlZephir NB Indicative LIDAR only unit selection has not been made 17

18 Element 3: Turbulence Benefits: Elements 1 and 2 help a lot with the what Element 3 is the why Turbulence is behind the key processes of wake dissipation and merging. We need to understand wake turbulence better Without Element 3, we will have excellent pictures of the wind speed through the farm allowing validation of next generation wake effects methods, much better than today But, we need to validate the turbulence in the methods too to make sure we are getting the right answer by modelling the physics correctly otherwise we have little confidence in applying wakes methods generally (i.e. to any wind farm) 18

19 Other Measurement projects WakeBench FP7 US Offshore Wind Advanced Technology Demonstration Projects Funding Opportunity Announcement 19

20 Questions Brian Gribben Technical Manager - Modelling, Frazer-Nash Consultancy Ltd b.gribben@fnc.co.uk Breanne Gellatly Offshore Wind Accelerator Delivery Manager, Carbon Trust breanne.gellatly@carbontrust.com