Experience and Results from the ReDAPT and PerAWaT Projects Marine Renewables Canada Ottawa, Ontario November 21 st Technical by Nature

Transcription

1 Experience and Results from the ReDAPT and PerAWaT Projects Marine Renewables Canada Ottawa, Ontario November 21 st 2013 Technical by Nature

2 Who is GL Garrad Hassan? Industry-leading, independent renewable energy consultancy Established in 1984 ~1000 full time staff, in 44 locations, across 26 countries worldwide Working in 5 continents Independent: No equity stake in any technology / project Part of the GL Group (Renewables, Oil & Gas, Maritime) As of September 2013, part of DNV GL Group (~16,000 employees Energy, Oil & Gas, Maritime) Onshore & Offshore Wind Wave & Tidal Solar PV & CSP

3 GL Garrad Hassan Wave & Tidal Tools WaveDyn Tidal Bladed WaveFarmer TidalFarmer Waves Tides O2M O2C GH SCADA Developer s Database Waves WaveDyn Tides Tidal Bladed WaveFarmer TidalFarmer

4 The ReDAPT Project GL Garrad Hassan is a contributor to the Reliable Data Acquisition Platform for Tidal (ReDAPT) project The ReDAPT Project is commissioned and co-funded by the ETI ( 12.4 million) 3-year project, expected completion: Summer 2014 Project Aims Install 500kW and 1MW tidal turbines in the European Marine Energy Centre in Orkney (Scotland). Test performance of tidal generator in operational conditions, and to increase confidence by providing wide range of environmental impact and performance information

5 The device Alstom/TGL 500kW prototype device and commercial scale 1MW device. Variable speed, pitch control device with gearbox. 20m

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7 ReDAPT: GH involvement Controller z x SCADA Tidal Bladed validation Standards & other working groups

8 Tidal Bladed Design software for loads and power performance analysis of tidal stream turbines Coupled multi-body modal structural dynamics, BEM hydrodynamics and control system dynamics Designed to produce fast time domain simulations Used by most major tidal turbine manufacturers

9 Data collection Upstream ADCP SBD mounted on back of turbine ~50m Flow speed and direction in water column Quality control parameters Strain gauge blade loads Controller and pitch system status Rotor torque, power, speed

10 Data collection Upstream ADCP SBD mounted on back of turbine Tidal Bladed inputs Shear profile Turbulence intensity Turbulence lengthscales Relative flow direction Wave conditions (Hs, Tp) Data for comparison Flapwise blade root load Rotor torque, power, speed minute samples

11 Power vs. flow speed Normalised Electrical Power TB simulation (mean) TB simulation (max) TB simulation (min) Measured Data (mean) Measured Data (max) Measured Data (min) Normalised Hub flow speed Range higher within each measured data sample Average power prediction within 1.5%

12 Mean loads and parameters summary Excellent match in mean values for Power Rotor Speed Pitch Angle Blade Root Flapwise Bending load Therefore time averaged behavior of turbine and mean interaction of flow with turbine are captured very well. Difference between max and min values is greater in simulations Why? thought to be higher turbulence intensity in simulations than reality + uncertainty in turbulence length scales.

13 Conclusions from GL GH ReDAPT involvement to date Tidal Bladed predicts mean load and operation parameters very well Simulation data is showing larger variation in load and operation parameters, leading to higher damage equivalent loads (and power production extreme loads) in Tidal Bladed simulations than in the measured data Turbulent length scales, turbulence intensity, tower shadow model and shear profile are key areas of uncertainty hindering accurate fatigue loading predictions

14 Understanding turbulent structure There is an industry-wide lack of understanding of tidal stream turbulence Next phase of ReDAPT project aims to better characterize the turbulence

15 ReDAPT Project Update The 1MW Alstom TGL tidal turbine (18m rotor diameter, hub height of 20m) was just deployed during June and July. Turbine data recorded using GL GH s WindHelm SCADA system. Turbine equipped with multiple ADPs Two ADP surveys conducted during turbine deployment to provide flow profile data upstream and downstream Data used to further validate Tidal Bladed and wake modeling in Tidal Farmer

16 The Performance Assessment of Wave and Tidal Array Systems (PerAWaT) Project Primary Goal: To establish and validate numerical models to predict the performance of wave & tidal energy converters (WECs and TECs) operating in arrays ETI Investment: 8 million Project led by GL Garrad Hassan Project Announced October 2009 Project Completion: End 2013 Four year 8m project bringing together key consortium of universities, utilities and an engineering consultancy.

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25 WaveFarmer Validation: PerAWaT experiments at QUB Baseline layout (Configuration A) Maximised interactions / minimised yield (Configuration C) Principal wave direction Maximised yield (Configuration B)

26 Large array of 1:80 scale point absorbers

27 PerAWaT WaveFarmer validation (summary) Difference in yield between spectral-domain and experimental results is between 2.2% and 13.5%, with the average being around 8.0%. Given the uncertainties inherent in the experimental results and the modeling methodology for an isolated WEC, this is a good level of correspondence.

28 Overview of PerAWaT (Tidal) work stream The overall objective of the Tidal work stream under PerAWaT is to: Establish and validate numerical models to predict the hydrodynamic performance of tidal energy converters (TECs) when operating in arrays.

29 Motivation for a Tidal array planning tool Developers need to understand the issues involved and be able to quantify their potential impacts Bathymetry, geotech, metocean Spatial and temporal variability of resource, Hydrodynamics wakes and blockage Installation and access for O&M Electrical cabling arrangements and grid connection Environmental impact and collision avoidance Efficient use of consented site To provide a robust & consistent method for energy yield prediction of tidal energy converter arrays. Accurate energy yield dependent on ability to model array interactions. enabling project developers have sufficient confidence in the return on their investment. Motivation

30 The tidal array modeling problem Coastal basin/regional scale hydrodynamics Temporal & spatial Array scale hydrodynamics free-surface / channel flow hydrodynamics boundary layer / shear profile Device scale hydrodynamics resource / device interaction device-device interaction device-resource interaction How can we capture all the relevant physical processes in a numerical model? Source: Andritz Hydro Hammerfest

31 The modeling problem Coastal basin/regional scale hydrodynamics Temporal & spatial Array scale hydrodynamics free-surface / channel flow hydrodynamics boundary layer / shear profile Device scale hydrodynamics resource / device interaction device-device interaction device-resource interaction We can t full NS solver not computationally feasible shallow water models don t model the physics at the array scale so need tuning Need to adopt a nested approach Answer the right question at the right time! Coastal basin scale Array scale Device scale Source: Andritz Hydro Hammerfest

32 GL GH TidalFarmer an array planning tool Planning Tool to aid the development of tidal stream arrays. Engineering models Evaluates energy yield Turbulence intensity for loads Validated models allow accurate predictions. Measurable levels of certainty for site developers and investors. Financial modelling Electrical/grid layout analysis TidalFarmer

33 Tidal Farmer methodology Pre-processing (Site specific tidal flow field prediction) Site data analysis and long term predictions Flow modeling Energy yield calculation (Array influenced flow field prediction) Device models Blockage modeling Wake modeling Converting power to energy Post processing (Array influenced flow field prediction) Global resource

34 3-d far wake model validation Validation against measured data through PerAWaT project. Experimental Data GH 3D Far Wake Eddy Model Downstream Prediction of the GH 3D Far Wake Eddy Model Downstream Position: 4D 6D 8D 10D 12D Three Rotor at x = 8D Three Rotor at x = 10D GH 3D Far Wake Model at x = 8D GH 3D Far Wake Model at x = 10D Three Rotor at x = 6D Lateral Position (D) GH 3D Far Wake Model at x = 6D 3 3 Three Rotor at x = 4D GH 3D Far Wake Model at x = 4D Normalised Velocity Deficit (Udefnor) Validation

35 3-d far wake model validation Multiple rows Row of Three then Row of Four Rotor Study of Three-Dimensional Wake Model 3 Row of Three then Row of Four Rotor at x = 4D Three-Dimensional Wake Model at x = 4D 2 Lateral Position (D) Normalised Velocity Deficit Validation

36 PerAWaT Tidal Summary TidalFarmer is an array planning tool. Engineering models for energy yield are a necessity Validation data essential PerAWaT is providing: Blockage, near wake and far wake data (numerical & physical) Traditional wake (merging) models are limited Development of an efficient 3-d model Ongoing validation work, preliminary results are encouraging. Measuring uncertainty in model predictions and experimental error.

37 Some Closing Thoughts Developers need to be able to depend on design tools to inform decisions, without the need to continuously conduct new tests. Learn-by-doing has value, but an approach entirely dependent on it is especially costly when approaching commercial scale and dealing with difficult environments. Verification and validation need to be incorporated into the tool development process from the beginning, so reliable design tools are created. Take advantage of work and investment already made in global projects/experience Developers should strive to collect data to validate whichever design tool they are using at an early stage, and continuously conduct checks throughout the development process. More complex and/or computationally intensive tools DO NOT necessarily mean more accurate or realistic results.

38 Further Information Visit our website: Contact me: Jarett Goldsmith Engineer/Project Manager Wave and Tidal Energy GL Garrad Hassan 9665 Chesapeake Drive, Suite 435 San Diego, CA Tel. +1 (858) , x132