Infrastructure Access Report

Infrastructure: ECN Hydrodynamic and Ocean Engineering Tank

User-Project: FPPHybVal

Joint Wind Wave Testing and Validation of Floating Power Plant’s Renewable Hybrid

Sarah Bellew, Anders Køhler, Anders Juliussen and Pierre Le Faucheux: Floating Power Plant A/S

Anders Yde, David Verelst: DTU Wind Energy

Marine Renewables Infrastructure Network

Status: Draft Version: 01 Date: 20-Jan-2015

EC FP7 “Capacities” Specific Programme Research Infrastructure Action

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ABOUT MARINET MARINET (Marine Renewables Infrastructure Network for emerging Energy Technologies) is an EC-funded network of research centres and organisations that are working together to accelerate the development of marine renewable energy - wave, tidal & offshore-wind. The initiative is funded through the EC's Seventh Framework Programme (FP7) and runs for four years until 2015. The network of 29 partners with 42 specialist marine research facilities is spread across 11 EU countries and 1 International Cooperation Partner Country (Brazil). MARINET offers periods of free-of-charge access to test facilities at a range of world-class research centres. Companies and research groups can avail of this Transnational Access (TA) to test devices at any scale in areas such as wave energy, tidal energy, offshore-wind energy and environmental data or to conduct tests on cross-cutting areas such as power take-off systems, grid integration, materials or moorings. In total, over 700 weeks of access is available to an estimated 300 projects and 800 external users, with at least four calls for access applications over the 4-year initiative. MARINET partners are also working to implement common standards for testing in order to streamline the development process, conducting research to improve testing capabilities across the network, providing training at various facilities in the network in order to enhance personnel expertise and organising industry networking events in order to facilitate partnerships and knowledge exchange. The aim of the initiative is to streamline the capabilities of test infrastructures in order to enhance their impact and accelerate the commercialisation of marine renewable energy. See www.fp7-marinet.eu for more details.

Partners

Ireland

University College Cork, HMRC (UCC_HMRC) Coordinator

Sustainable Energy Authority of Ireland (SEAI_OEDU)

Denmark

Aalborg Universitet (AAU)

Danmarks Tekniske Universitet (RISOE)

France

Ecole Centrale de Nantes (ECN)

Institut Français de Recherche Pour l'Exploitation de la Mer (IFREMER)

United Kingdom

National Renewable Energy Centre Ltd. (NAREC)

The University of Exeter (UNEXE)

European Marine Energy Centre Ltd. (EMEC)

University of Strathclyde (UNI_STRATH)

The University of Edinburgh (UEDIN)

Queen’s University Belfast (QUB)

Plymouth University(PU)

Spain

Ente Vasco de la Energía (EVE)

Tecnalia Research & Innovation Foundation (TECNALIA)

Belgium

1-Tech (1_TECH)

Netherlands

Stichting Tidal Testing Centre (TTC)

Stichting Energieonderzoek Centrum Nederland (ECNeth)

Germany

Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V (Fh_IWES)

Gottfried Wilhelm Leibniz Universität Hannover (LUH)

Universitaet Stuttgart (USTUTT)

Portugal

Wave Energy Centre – Centro de Energia das Ondas (WavEC)

Italy

Università degli Studi di Firenze (UNIFI-CRIACIV)

Università degli Studi di Firenze (UNIFI-PIN)

Università degli Studi della Tuscia (UNI_TUS)

Consiglio Nazionale delle Ricerche (CNR-INSEAN)

Brazil

Instituto de Pesquisas Tecnológicas do Estado de São Paulo S.A. (IPT)

Norway

Sintef Energi AS (SINTEF)

Norges Teknisk-Naturvitenskapelige Universitet (NTNU)

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DOCUMENT INFORMATION Title Joint Wind Wave Testing and Validation of Floating Power Plant’s Renewable Hybrid

Distribution Public

Document Reference MARINET-TA1-FPPHybVal

User-Group Leader, Lead

Author

Sarah Bellew Floating Power Plant A/S Henningsens Allé 53, DK-2900 Hellerup Denmark

User-Group Members,

Contributing Authors

Anders Køhler Floating Power Plant A/S Anders Juliussen Floating Power Plant A/S Pierre Le F Faucheux Floating Power Plant A/S Anders Yde DTU Wind Energy David Verelst DTU Wind Energy

Infrastructure Accessed: ECN Hydrodynamic and Ocean Engineering Tank

Infrastructure Manager

(or Main Contact)

Jean-Marc Rousset

REVISION HISTORY Rev. Date Description Prepared by

(Name)

Approved By

Infrastructure

Manager

Status

(Draft/Final)

01 28/01/15 First Draft Sarah Bellew

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ABOUT THIS REPORT One of the requirements of the EC in enabling a user group to benefit from free-of-charge access to an infrastructure is that the user group must be entitled to disseminate the foreground (information and results) that they have generated under the project in order to progress the state-of-the-art of the sector. Notwithstanding this, the EC also state that dissemination activities shall be compatible with the protection of intellectual property rights, confidentiality obligations and the legitimate interests of the owner(s) of the foreground. The aim of this report is therefore to meet the first requirement of publicly disseminating the knowledge generated through this MARINET infrastructure access project in an accessible format in order to:

• progress the state-of-the-art

• publicise resulting progress made for the technology/industry

• provide evidence of progress made along the Structured Development Plan

• provide due diligence material for potential future investment and financing

• share lessons learned

• avoid potential future replication by others

• provide opportunities for future collaboration

• etc. In some cases, the user group may wish to protect some of this information which they deem commercially sensitive, and so may choose to present results in a normalised (non-dimensional) format or withhold certain design data – this is acceptable and allowed for in the second requirement outlined above.

ACKNOWLEDGEMENT The work described in this publication has received support from MARINET, a European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme.

LEGAL DISCLAIMER The views expressed, and responsibility for the content of this publication, lie solely with the authors. The European Commission is not liable for any use that may be made of the information contained herein. This work may rely on data from sources external to the MARINET project Consortium. Members of the Consortium do not accept liability for loss or damage suffered by any third party as a result of errors or inaccuracies in such data. The information in this document is provided “as is” and no guarantee or warranty is given that the information is fit for any particular purpose. The user thereof uses the information at its sole risk and neither the European Commission nor any member of the MARINET Consortium is liable for any use that may be made of the information.

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Executive Summary

Floating Power Plant is a Danish company that develops the world's only offshore proven combined wind

and wave system with the goal of producing competitive power at water depths over 45 meters. At this

depth, the wind industry today cannot develop profitable projects. The patented technology is developed in

technical collaboration with industrial leaders including (amongst others) Siemens Industry, Fritz Schur

Energy, Risø and Dong Energy. The technology has been developed over the last 8 years and is documented

via 4 scaled grid connected offshore tests as well as wave basin testing, dry tests and, last but not least, in-

depth mathematical modelling and engineering. The unique and patented combination of technologies

results in numerous synergies including a reduced LCOE, increased O&M capabilities due to the safe boat

harbour in the wake of the WECs, and smoothed power output.

Having successfully completed over 2 years of offshore tests of the P37 test device in Denmark, FPP is now

moving fast towards the construction and deployment of its first commercial device. FPP is finalising the

details of the first international consortium agreement as technology provider for commercial offshore wind

farms, with negotiations regarding further European commercial deployment projects underway.

The tests performed at ECN were combined wind and wave testing of the commercial P80 design, at a scale

of 1:50. Wave regimes were designed according to real site data, with wind speeds chosen to achieve the

rated thrust for the 5MW turbine.

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CONTENTS

1 INTRODUCTION & BACKGROUND ...................................................................................................................7

1.1 INTRODUCTION .................................................................................................................................................... 7 1.2 DEVELOPMENT SO FAR .......................................................................................................................................... 7 1.2.1 Stage Gate Progress .................................................................................................................................... 7 1.2.2 Plan For This Access ..................................................................................................................................... 8

2 OUTLINE OF WORK CARRIED OUT ................................................................................................................. 13

2.1 SETUP ............................................................................................................................................................... 13 2.2 TESTS ............................................................................................................................................................... 13 2.2.1 Test Plan ........................................................................................................ Error! Bookmark not defined.

2.3 RESULTS ............................................................................................................................................................ 14 2.4 ANALYSIS & CONCLUSIONS...................................................................................... ERROR! BOOKMARK NOT DEFINED.

3 MAIN LEARNING OUTCOMES ...................................................................... ERROR! BOOKMARK NOT DEFINED.

3.1 PROGRESS MADE ............................................................................................................................................... 14 3.1.1 Progress Made: For This User-Group or Technology ................................................................................. 14 3.1.2 Progress Made: For Marine Renewable Energy Industry .......................................................................... 14

3.2 KEY LESSONS LEARNED ........................................................................................................................................ 15

4 FURTHER INFORMATION .............................................................................................................................. 15

4.1 SCIENTIFIC PUBLICATIONS ....................................................................................... ERROR! BOOKMARK NOT DEFINED. 4.2 WEBSITE & SOCIAL MEDIA ................................................................................................................................... 15

5 REFERENCES ................................................................................................................................................ 15

6 APPENDICES ................................................................................................................................................ 16

6.1 STAGE DEVELOPMENT SUMMARY TABLE ................................................................................................................ 16 6.2 ANY OTHER APPENDICES ........................................................................................ ERROR! BOOKMARK NOT DEFINED.

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1 INTRODUCTION & BACKGROUND

1.1 INTRODUCTION

Floating power plant is the developer of Poseidon, a hybrid wind- and wave-energy device. Since the conception of the device, it has undergone many testing stages including wave flume, 3D basin, dry and offshore tests. A scaled version of the device called P37 (due to its 37 m platform width) has undergone a total of two years offshore testing and is currently about to be redeployed for its fourth (and final) test-phase. The full-scale device, P80, will be 80 m platform width with an installed wind capacity of 5 MW from wind and 1.6 MW from wave.

We are currently developing advanced numerical models, together with amongst other the Technological University of Denmark (DTU-wind), for the complete device including the wind turbines, platforms and Wave Energy Convertors, which are due to be ready for validation by the end of 2013. The models are to be validated against the previous tests which were carried out on the P37 design, and used to optimise the design of the full-scale P80 device. In order validate the results of the numerical modelling, we require a large amount of new test data, particularly combined wind and wave testing, which is the purpose of our MARINET testing in ECN.

1.2 DEVELOPMENT SO FAR

1.2.1 Stage Gate Progress

Previously completed: � Planned for this project: �

STAGE GATE CRITERIA Status

Stage 1 – Concept Validation

• Linear monochromatic waves to validate or calibrate numerical models of the system (25 – 100 waves) �

• Finite monochromatic waves to include higher order effects (25 –100 waves)

• Hull(s) sea worthiness in real seas (scaled duration at 3 hours) �

• Restricted degrees of freedom (DofF) if required by the early mathematical models

• Provide the empirical hydrodynamic co-efficient associated with the device (for mathematical modelling tuning)

• Investigate physical process governing device response. May not be well defined theoretically or numerically solvable

�

• Real seaway productivity (scaled duration at 20-30 minutes) �

• Initially 2-D (flume) test programme �

• Short crested seas need only be run at this early stage if the devices anticipated performance would be significantly affected by them

• Evidence of the device seaworthiness �

• Initial indication of the full system load regimes �

Stage 2 – Design Validation

• Accurately simulated PTO characteristics �

• Performance in real seaways (long and short crested) �

• Survival loading and extreme motion behaviour. �

• Active damping control (may be deferred to Stage 3) �

• Device design changes and modifications �

• Mooring arrangements and effects on motion �

• Data for proposed PTO design and bench testing (Stage 3) �

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STAGE GATE CRITERIA Status

• Engineering Design (Prototype), feasibility and costing �

• Site Review for Stage 3 and Stage 4 deployments �

• Over topping rates

Stage 3 – Sub-Systems Validation

• To investigate physical properties not well scaled & validate performance figures �

• To employ a realistic/actual PTO and generating system & develop control strategies �

• To qualify environmental factors (i.e. the device on the environment and vice versa) e.g. marine growth, corrosion, windage and current drag

�

• To validate electrical supply quality and power electronic requirements. �

• To quantify survival conditions, mooring behaviour and hull seaworthiness �

• Manufacturing, deployment, recovery and O&M (component reliability) �

• Project planning and management, including licensing, certification, insurance etc.

Stage 4 – Solo Device Validation

• Hull seaworthiness and survival strategies �

• Mooring and cable connection issues, including failure modes �

• PTO performance and reliability �

• Component and assembly longevity

• Electricity supply quality (absorbed/pneumatic power-converted/electrical power) �

• Application in local wave climate conditions �

• Project management, manufacturing, deployment, recovery, etc �

• Service, maintenance and operational experience [O&M] �

• Accepted EIA

Stage 5 – Multi-Device Demonstration

• Economic Feasibility/Profitability

• Multiple units performance

• Device array interactions

• Power supply interaction & quality

• Environmental impact issues

• Full technical and economic due diligence

• Compliance of all operations with existing legal requirements

1.2.2 Plan For This Access

Background

The tests described in this report were on a 1:50 scale model of the P80 device. Previous tests have been performed on the same platform during August 2013. The previous tests were performed in a wave only basin however (HMRC in Cork, Ireland), hence they included only a wooden mast and nacelle replica with representative masses. One of the key purposes of the ECN tests is to include the effects of wind on the platform. In order to implement this, a 1:50 scaled version of the NREL 5MW wind turbine was attached to the platform in place of the previously used wooden mast. Another key aim for the ECN tests is to determine design loads for a catenary mooring system for the P80 device. Although FPP has extensive mooring data from its P37 offshore tests (1:2,3 scale), the P37 test device is not an exact

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scaled version of the P80, as it was specifically designed for a shallow Danish test site with the main purpose of testing and gathering key components of the design and understanding their interactions with other. Further to this, the site was more benign than a directly scaled commercial site for a P80 device, and the water much shallower. The design loads for a catenary mooring system for a P80 commercial device are therefore not clearly derivable from the P37 offshore data.

Mooring

Floating Power Plant’s full scale commercial device, P80, will have a three-spread catenary mooring system, and will be in waters of 45 to 250 m (with initial devices likely to be closer to 45 m). The ECN wave basin is 5 m deep, corresponding to 250 m depth at full scale (assuming the test device to be 1:50 scale). Scaling the catenary mooring system is further complicated by the desire to maintain the both the mass and the diameter through the same scaling law. For example, a chain with a diameter of 60 mm and a dry weight of 72 kg /m would scale at 1:50 scale to a chain of diameter 1.2 mm and dry weight of 0.5 g/ m, which is unrealistic.

Further to the difficulties with scaling a known catenary mooring system, is the unknowns in the design of the full-scale mooring system. Floating Power Plant has extensive operational mooring data for their test platform P37, however at 37 m long it is 1:2.2 scale of the P80. The P37 contains the key components of the P80 platform, but the configuration is different as it was specifically designed for the shallow Danish site at which it operated, which was on 7 m deep (corresponding to only 15 m at 2.2 scale, far short of the minimum P80 depth of 45 m). As a result, it is difficult to determine the operational and extreme load cases of a P80 in potential test sites.

The mooring during the ECN tests was therefore designed to obtain characteristics of an appropriate catenary mooring system whilst ensuring the repeatability of the setup and the ability to model it in future simulations. For these reasons the catenary mooring system was replaced with a horizontal and vertical mooring line, each with a spring of known stiffness (see Figure 1.)

Extreme Waves

In order to determine the most appropriate horizontal stiffness component of the mooring system, waves representative of a potential deployment site in the Atlantic Ocean are applied. The peak waves have a very long period, which results in the greatest test of the mooring forces in surge.

Figure 1: Diagram of mooring system including a horizontal and vertical mooring line representative of a catenary system, and a light rear line to ensure the platform cannot hit the wind generator

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Linear Monochromatic Waves

A small range of linear waves will be tested both without and with the wind generator in operation. Their purpose is some controlled validation data for numerical models, so only a small amount of different linear waves are deemed necessary. Regular waves will be tested to offer a fair representation of the waves that the P80 is likely to experience. The waves are selected so that comparisons are always available to other waves of the same wave height of wave period (Table 1). This means that the wave steepness, �, varies from wave to wave, where

� =��������( )

���������(�).

Irregular Sea States

A range of irregular wave regimes will be tested both without and with the wind generator in operation. The following table indicates discrete combinations of Hs and Te, which cover the wave regimes experienced at the three sites that are relevant to FPP. A letter is used in each combination to show that it is relevant to one of these sites. A red letter indicates this is one of the most common wave regimes experienced at that site.

Table 2: The wave regimes experienced at three sites relevant to FPP, indicated by the letters W, B,and P (at basin scale), Hs = significant wave height and Te = energy period

Table 1: Linear waves to be tested at P80 scale and 1:50 scale, H = waveheight and T = period

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As

Table 2 indicates 80 wave regimes of interest, the highlighted regimes have been selected for use in the wave basin as a

selection of wave regimes which spans the spectra experienced most commonly at all three sites. These are shown in

Table 3.

Table 3: Irregular wave regimes to be tested at ECN, the red writing indicates the peak at a site of interest to FPP, Hs = significant wave height and Te = energy period

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Directional Wave Spreading

Experience from previous tests has shown that the wave energy convertors on Floating Power Plant’s platform are more

efficient when the wave regime includes directional spreading. Further to this, many offshore locations experience directional

spreading. Some of the irregular wave regimes shown in

Table 3 will therefore be further tested with directional spreading.

Wind

The wind turbine was designed, built and tested at ECN as part of a PhD (Courbois, 2013; Philippe, et al., 2013). It is a 1:50 scale of the NREL 5 MW theoretical wind turbine (Martin, et al., 2012), modified to include a blade twist. The turbine is scaled to maintain aerodynamic loads as opposed to the wind speed, since this is the main aerodynamic force in the wind direction, and the thrust will directly influence the mean pitch of the platform. As the rotation of the blades induces loads that are transverse to the wind flow, the rotational speed is also scaled, using Froude scaling to maintain the gyroscopic moment. An engine is placed in the nacelle to maintain constant rotation, which is measured with a counter. The tip speed ratio is not scaled accurately, hence the wakes and other aerodynamic phenomena will not be scaled correctly. The wind generator was designed specifically for this wind turbine, with an optimal window which almost exactly fits the swept area of the blades. The platform used in the current tests has a lower height above the water compared to the platform that the turbine was previously tested on. As a result, Floating Power Plant built a tower extension piece to attach the tower bottom to the top of the main hull (Error! Reference source not found.). The extension piece was designed to have an inner tube within an outer tube locked into place with screws once the correct height is determined. Once the correct height was determined, a hole was drilled by ECN staff through the inner and outer tubes to allow the electrical cables to pass through the side wall (Figure 3). on Day 6, the ECN staff corrected the height of the extension piece from 320 mm to 213 mm, so that the height of the centre of the hub from the waterline was 1800 mm.

Figure 3: Wind turbine tower extension

piece after ECN staff made a hole near the

bottom for the cables to pass through.

z

Figure 2: Tower extension piece to be placed

between the bottom of the wind turbine tower

and the top of the main hull, in order to correct

the height of the turbine to coincide with the

wind generator

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2 OUTLINE OF WORK CARRIED OUT

2.1 SETUP The floating platform is mostly constructed of wood, except with aluminium used for the heave plates, along the top edges of the hull and the upper cross-bridge. The platform was originally designed for a previous set of tests in which variations of the overall geometry were tested in a wave basin. It is therefore possible to vary the position of the cross-bridge and the turbine along the hull, and the length of the legs (by constructing them out of combinations of different size leg-blocks, and the size of the heave plates (small or large). The design selected for use within the ECN basin was, however, fixed. The wind turbine was the 1:50 scale 5MW NREL turbine, owned by ECN. The platform can be seen in operation in

The following tests were performed:

Subject Desctription

Wave Calibration All waves to be calibrated to ensure that the programmed wave is the wave experienced at the device location

Mooring Tests Horizontal spring to be determined first, beginning with the lightest option for spring stiffness, then increasing to a spring with higher spring stiffness value if the spring extends greater than the calculated value under extreme (long) wave conditions. Once the horizontal spring is determined, the corresponding vertical spring is deployed (to represent a catenary system).

Wind Calibration For several different rotational speeds, the wind is increased until the measured thrust is greater than rated. The wind speed that results in the rated thrust is then known for several rotational speeds.

Drop and drag tests The platform is (in still waters) pushed/pulled at one point in order to measure the decay in a single mode of motion (e.g. heave)

Regular waves Each regular wave is applied

Regular waves plus rated wind thrust Each regular wave is applied with the rated wind

Figure 4: The 1:50 scale model of the P80, complete with the

scaled 5 MW NREL turbine, in operation wihth wind and wave s

at the ECN wave basin

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thrust also applied

Irregular waves Each regular wave regime is applied

Irregular waves plus rated wind thrust Each regular wave regime is applied with the rated wind thrust also applied

Irregular waves plus directional spreading Each regular wave regime is applied with 30 degrees directional spreading

Irregular wave plus directional spreading plus

rated wind thrust

Each regular wave regime is applied with 30 degrees directional spreading and the rated wind thrust

Table 2.1 List of tests performed at ECN by FPP on the 1:50 scale version of their P80 device with a scaled 5MW NREL turbine

from ECN

2.2 RESULTS For all of the tests, data was obtained from wave gauges, deployed in a configuration around the device, motion of the overall platform in 6 degrees of freedom, motion of each individual wave energy floater, mooring loads, thrust on the turbine and tower bending moments. Of key interest to FPP, was the pitch motion of the platform, as this must meet the design requirements of the turbine. The pitch amplitude of motion was found to be well within the design criteria.

2.3 PROGRESS MADE The two week test period proved a great success for Floating Power Plant, with a total of 100 separate tests to analyse.

2.3.1 Progress Made: For This User-Group or Technology

The test results contain enough information to validate and further advance the user groups numerical models. Further to this, the design of the P80 has been validated to keep platform motions minimal in all relevant sea states, whilst operating a 5 MW wind turbine. The required mooring loads have been obtained under extreme conditions in order to develop appropriate catenary mooring systems for the P80 in specific sites of interest (some of which are already under negotiations).

Next Steps for Research or Staged Development Plan – Exit/Change & Retest/Proceed?

The HAWC2-WAMIT coupling is further being developed by DTU using the motion and wind turbine sensors from these tests. This model is one of the most advanced in existence, and once confidence has been built with this, through validation, it can be used to perform site specific optimisation of the device and give accurate predictions of the platform’s behaviour over a life cycle. The mooring data is currently being used to develop an optimised mooring system together with Aalborg University. Floating Power Plant is in negotiation for several commercial contracts, for which the proof of platform stability arising from these scaled tests has been useful.

2.3.2 Progress Made: For Marine Renewable Energy Industry

Floating Power Plant develop one of the only offshore proven floating wind technologies. It is made stable by its unique design by incorporating wave energy into the platform. After 12 years of research and development, and over 2 years offshore operation of the test device, FPP is close to commercialisation. The results from these tests are being used to validate the numerical models which are essential to close the commercial contracts currently under negotiation. Further to that, the mooring design for the commercial test sites is relying on the data from these tests, and the stability of the platform when coupled with a 5 MW turbine, proven in these tests, ensures further confidence from the customers and partners involved in the commercial contracts that are under negotiation.

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These tests have therefore taken the industry one step closer to making floating wind a key player in meeting the energy targets across Europe.

2.4 KEY LESSONS LEARNED • An appropriate representation of a catenary mooring system (that is repeatable with the key characteristics

preserved) can be attained using a horizontal and vertical mooring line, each combined with a spring of the appropriate stiffness. Care must be taken, however, to remove the pretension from the spring, in order for the force-extension relationship of the springs to remain linear throughout the tests.

• The wind generator at ECN is only able to generate wind within an exact window. Care must be taken when using the generator to keep the turbine facing the generator and within the correct window. Care must therefore also be taken to ensure the hub of the turbine is at the correct height (which required FPP to add a tower extension piece, since the turbine was originally built for a different platform).

• A certain amount of mass is added to the device due to the cables, although measures can be taken to keep this amount to a minimum.

• Although it may seem like wasting time, it is a good idea to calibrate the waves, as some of the waves that we originally requested required some adjustments, and some even resulted in a transverse standing wave due to the dimensions of the wave basin.

• The staff at ECN are incredibly helpful, and show a lot of initiative as they clearly have a lot of experience with testing issues from previous clients. It is not as complicated as we expected to adjust the device in situ using one of the rafts available (just a few minutes to paddle out).

• When working with two resources instead of wind, i.e. by using wind together with the wave, one should expect twice the number of issues and corrections that need to be made to the plan and/ or device.

3 FURTHER INFORMATION

3.1 WEBSITE & SOCIAL MEDIA Website: www.floatingpowerplant.com YouTube Link(s): LinkedIn/Twitter/Facebook Links: www.facebook.com/floatingpowerplant/ Online Photographs Link:

4 REFERENCES Further information on the Floating Power Plant concept can be found on the website given above. Information on the turbine (owned by ECN) that was used for these tests can be found at the following references: Courbois, A. (2013). Étude expérimentale du comportement dynamique d’une éolienne offshore flottante soumise à

l’action conjuguée de la houle et du vent. Nantes: l’École Centrale de Nantes. Martin, H. R., Kimball, R. W., Viselli, A. M., & Goupee, A. J. (2012). METHODOLOGY FOR WIND/WAVE BASIN TESTING

OF FLOATING OFFSHORE WIND TURBINES. Rio de Janeiro: Proceedings of the ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering .

Philippe, M., Courbois, A., Babarit, A., Bonnefoy, F., Rousset, J.-M., & Ferrant, P. (2013). COMPARISON OF SIMULATION AND TANK TEST RESULTS OF A SEMI-SUBMERSIBLE FLOATING WIND TURBINE UNDER WIND AND WAVE LOADS. Proceedings of the ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. Nantes: Proceedings of the ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering.

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5 APPENDICES

5.1 STAGE DEVELOPMENT SUMMARY TABLE The table following offers an overview of the test programmes recommended by IEA-OES for each Technology Readiness Level. This is only offered as a guide and is in no way extensive of the full test programme that should be committed to at each TRL.