Final Report Summary - DEEPWIND (Future Deep Sea Wind Turbine Technologies)
Executive Summary:
DeepWind challenges the existing offshore wind turbine concepts on design, installation and O&M aspects for lesser cost of energy with a radical new and simple design. Design and optimisation works have been supported by development of wind turbine design tools for more efficient and cost-effective deep-sea use of the DeepWind concept, consisting of a 2-bladed Darrieus rotor and a long spar buoy extending subsea. An aero-elastic modelling suite has been developed in the project for full numerical simulation of the concept, and this design tool integrates results from investigations done on the concept and calculates the effects of external loads on the main components consisting of few parts: wind turbine rotor, floater, power transmission module, and loads transmitted to the sea bed via the mooring system. The team has also delivered computer code for the blade pultrusion manufacturing process, for the generator and wind turbine bearings design as well as a particular tool for turbine control simulation.
DeepWind developed a proof-of-principle prototype one kilowatt (kW) wind turbine to demonstrate the principle under near-to-realistic operating conditions with a 2-bladed rotor, as well to study floater kinematics under controlled conditions in an ocean laboratory and in a wind tunnel to study the performance of the inclined rotor with 3 blades. An inbuilt monitoring system has provided data on movements of the rotating components and submerged parts in floating conditions. In particular the physics of the Magnus force and interaction with waves have been experimentally investigated and numerically verified on a model scale floater in a towing tank. Researchers have achieved to analyse power transmission, mooring and torque absorption components relative to environmental conditions such as wind, waves and currents. In parallel, the team prepared an outlook for a 20 megawatt (MW) baseline design, based on upscaling the 5MW conceptual design.The project has achieved to contribute with high quality results: new promising high-performance airfoils were developed for the 2 bladed design with potential increase of rotor efficiency, to provide a design of a permanent magnetic generator and a magnetic bearings system for the 5 MW conceptual design with a laboratory facility testing the bearing, to provide the controls of the power at the different wind speeds with rotor speed limitation. Furthermore, the team has achieved to provide a simulation tool for the pultrusion manufacturing process of specimen up to 60mm shell thickness, and in the HAWC2 simulation tool to integrate an engineering formula of the Magnus forces exerted on the rotating floater in waves, and to develop an optimised floater and mooring system integrated with the 5 MW conceptual design. The commercialisation aspects and estimation for costs of parts to produce the 5 MW conceptual design are analysed, and the expected plant-level costs of electricity generation is estimated for a 100 MW plant to be in the same order of cost estimations for a land based wind power plant(based on 2013 values). Furthermore substantial cost reductions can be obtained with reinforced concrete materials for the floater part. It is found that a cost impact is also originating from the anchoring system made of conventional design. DeepWind results have been published in numerous scientific journals and conference proceedings and DeepWind has been presented in the news media and at various conferences. It has stimulated creation of a new theme on deep offshore and floating installations, such as at the conferences of the European Wind Energy Association. DeepWind results show that gusty winds far out at sea to produce electricity are better tolerated than existing horizontal-axis wind turbines, and that the concept falls within an important niche and increased momentum from public awareness, pushing technology one step closer to commercialisation.
Project Context and Objectives:
The hypothesis of this project is that a new wind turbine concept developed specifically for offshore application has potentials for better cost efficiency than existing offshore technology. Based on this hypothesis the objectives are: i)to explore the technologies needed for development of a new and simple floating offshore concept with a vertical axis rotor and a floating and rotating foundation, ii)to develop calculation and design tools for development and evaluation of very large wind turbines based on this concept and iii)evaluation of the overall concept with floating offshore horizontal axis wind turbines.
Upscaling of large rotors beyond 5MW has been expressed to have more cost potentials for vertical axis wind turbines than for horizontal axis wind turbines due to less influence of cyclic gravity loads. However, the technology behind the proposed concept presents extensive challenges needing explicit research, especially: dynamics of the system, pultruded blades with better material properties, sub-sea generator, mooring and torque absorption system, and torque, lift and drag on the rotating and floating shaft foundation. In order to be able in detail to evaluate the technologies behind the concept the project comprise: 1) numerical tools for prediction of energy production, dynamics, loads and fatigue, 2) tools for design production of blades 3) tools for design of generator and controls, 4) design of mooring and torque absorption systems, and 5) knowledge of friction torque and lift and drag on rotating tube. The technologies need verification, and in the project verification is made by: 6) proof-of concept testing of a small, kW sized technology demonstrator, partly under real conditions, partly under controlled laboratory conditions, 7) integration of all technologies in demonstration of the possibility of building a 5MW and an evaluation of the concept.
The new proposed simple floating offshore wind turbine concept consist of a long vertical tube that rotates in the water, a vertical axis rotor at the top, a bottom based generator and a sea-bed fixing system at the bottom. However, though being simple, the technology behind the concept presents extensive challenges needing explicit research, especially: dynamics of the system, pultruded blades with better material properties, sub-sea generator, mooring and torque absorption system, and torque, lift and drag on the rotating and floating shaft foundation.
In order to evaluate the concept against floating offshore horizontal axis wind turbines, exploration of new technologies was needed for development of the individual components, and for evaluation of the overall concept.
These technologies comprised:
1) numerical tools for prediction of energy production, dynamics, loads and fatigue,
2) tools for design and production of blades
3) tools for design of generator, magnetic bearing and controls,
4) design of mooring and torque absorption systems
5) knowledge of friction torque and lift and drag on rotating tube.
As the technologies needs verification, verification is made in the project by:
6) proof-of principles testing of components and a small kW sized technology demonstrator,
7) integration of all technologies in demonstration of the possibility of building a 5MW wind turbine based on the concept, and an evaluation of the perspectives for the concept.
Six work packages include research in key technologies, in which development of tools for optimization and design are substantial elements. One work package comprises demonstration of the concept feasibility with the demonstrator and dedicated experiments. One work package integrates all technologies in demonstration of the possibility of building a 5MW wind turbine based on the concept, and the outlook of a 20MW turbine. One work package associates dissemination and exploitation of the results, and one with management.
Project Results:
The project comprised research and laboratory testing on an emerging high risk energy technology. The project combined different technologies into answering how the proposed concept can emerge into MW size with likely uptake towards industrialized concepts. The project resulted in a range of tests of physical models, and development of two main toolboxes for designs and simulations. The concept has been presented at offshore and at European wind energy conferences, and in various papers for publication. In the first stage of the project, the question arose about Magnus forces might challenge the soundness of the concept, and during the project it was successfully answered with carrying out the exploration of torque, lift and drag experiments on a rotating tube in a water flume with waves. The works confirmed that the results do not call attention for unexpected Magnus forces. The team conducted a posteriori analysis of the effects and derived an engineering model of the Magnus force for integration with code. Proof-of-principle experiments were conducted on a 1kW wind turbine with 5m overall height, and rotor diameter 2m. This demonstrator was designed and purpose built by the consortium. A special designed and built watertight generator was mounted at the end of a flexible shaft on a 2-bladed Aluminium Darrieus rotor. The manufacture of the GRP blades was not finished at that time. It was deployed and tested August-November 2012 in the fjord at DTU Campus Risø(DK) under various near to real operating conditions. The fjord experiment was designed to explore on the overall system stability, and for validation with the modified simulation tool HAWC2 of important floater motions: heave, pitch, yaw and roll. The site has been approved by the National Danish Naval authorities as a temporary facility for testing the concept. Prior to deployment, the rotor and tube were structurally modelled and modal tested on resonance effects. The deployment was successfully carried out with help of a special built installation and maintenance barge; lessons were experienced on how to install and to service the installation. Fjord testing gave understanding in the effects of currents and large waves rolling over parts of the rotating spar buoy, and input on how to work further on a future safety system. Testing of the demonstrator was carried out under controlled conditions at the ocean laboratory testing facilities at MARIN(NL) in March 2013. A substantial set of test cases, matching the fjord conditions was made. The 3-bladed rotor configuration was tested along with the 2-bladed demonstrator for test cases of different combinations of waves, wind, and current. The data were post processed in a comparison with HAWC2 simulations. Upfront to testing the floating wind turbine, the laboratory wind conditions were improved for operating conditions in the ocean basin and scaled for matching the turbine and sea states in consideration. The wind turbine was instrumented for monitoring movements of the rotating structure and the moving submerged parts. Data analysis of the power transmission system, the mooring - and torque absorption system has been started to be analysed for relevant environmental conditions, including wind, current and waves and comparison with results from simulations at same conditions. Finally the demonstrator was modified for testing the 3-bladed glass fibre reinforced polyester (GRP) rotor in the wind tunnel of MILAN(I). I was instrumented for performance testing and for investigation of the tilted rotor.
The project progressed with establishment of an integrated aero-elastic design and simulation tool HAWC2 for floating VAWTs in dealing with simulation of performance, dynamics and loads. The tool is developed in particular to handle the aerodynamic induction models of VAWTs and the fluids motion on the rotating spar buoy in interaction with waves in an appropriate manner, and is well validated with high fidelity CFD tools supported by the consortium. This code is, except for the detailed generator model, ready as the basic calculation tool for simulation of the concept. The tools have been used for design of the Proof-of-Principle 1 kW wind turbine and the 5 MW conceptual design, and for iterations of the design towards optimisation. Simulations of the 20 MW wind turbine, up-scaled from the 5MW has been carried out. Major developments have been included: turbulent flow field, mooring lines dynamics, an engineering model of Magnus effect, an actuator disk refinement to existing momentum models, generator model with controls, different codes comparison with HAWC2, and lightweight blade design with stall regulated rotor and rotor blade optimisation. A detailed 5 MW conceptual design loads report has been published with results for the Hywind site, situated at the Western coast of Southern Norway.
Blade technology and blade design progressed with a full model description and simulation of pultruded profiles during the manufacture process, and has contributed in the design optimization of a 5 MW floating offshore vertical-axis wind turbine rotor. Furthermore the development of a high efficiency airfoil for the 5 MW DeepWind concept has been developed and tested in the TUDelft(NL) wind tunnel. Two sets of 3 GRP blades for the demonstrator have been manufactured by NENUPHAR(F) for testing the demonstrator in the ocean laboratory and for wind tunnel testing of the rotor.
In the works dealing with the concepts of the generator and the intersection with the floater, the 1kW wind turbine electrical design, and generator built and control made the testing possible. Furthermore major contributions have been achieved on design rules and tools:
• A basic design of submersible 5 MW and 20 MW generator platforms
• Assessment and analysis of the coupling between generator and wind turbine rotor, including tools to design magnetic bearings and to perform testing in a test rig
• Computer code implementing design rules and optimisation for PM generators and magnetic bearing systems design
Within turbine operational control we developed a simplified simulation model of the DeepWind concept suitable for investigation of control strategies. The model takes into account a reduced-order mooring system, double disk BEM rotor aerodynamics that captures dynamic stall effect, and a simple representation of the tower tilt motion (yaw, roll and pitch). A baseline controller design has been established for the 5 MW concept and analysed in simulations with turbulent wind inflow in different operating conditions, including start-up and shut-down sequences. Model simulations indicate that the controller meets the most important control requirements: 1) optimal aerodynamic efficiency through variable speed operation; 2) damping of the large twice-per-revolution aerodynamic torque variations; 3) limitation of rotor speed; 4) efficient operation at high wind speeds through storm control; and 5) safe start-up and shut-down both in low and high winds.
Mooring, floating and torque absorption systems contributed with an optimized floater design for the 5 MW baseline design as an initial design, and a revised design for the conceptual design. Main dimensions for spar-type floating support structure and the mooring system configuration has been conducted.
Integration of technologies and upscaling addresses on integration of the various results for establishing the 5 MW platform. It was decided to freeze the 5 MW design iteration by October 1 2013, and that the results implementation was carried out hereafter, in parallel with the 20 MW outlook. Simultaneous engineering of the baseline design into the 5 MW conceptual design illustrated challenging aspects of the Multidisciplinary Design Analysis and Optimization (MDAO) framework. The team has with the industrial partner NENUPHAR developed a cost model for this concept. A 20 MW outlook is conducted as an exercise to find the limits of pultrusion and to forecast levelized cost for the concept. With two alternative cost models, based on an industrial - and a research based approach, the 5 MW concept is found to achieve a Cost of Energy of around 100€/MWh. For alternative floater materials and depending on the floater size the cost is driven even further down.
Dissemination and Exploitation focused on the dissemination of scientific and technical results on the web, articles and publications, and aimed to stimulate publishable results into workshops and conferences, as well as to deal with IPR issues within the consortium. Contributions, invited speeches and interviews have been conducted in news media (Danish radio and TV, international magazines, papers and journals) during the period. The presentations were held at offshore conferences in Europe and USA in 2011, and conducted at EWEC 2012, EWEC 2013 and 2014. An exhibition concept model was shown at the EWEA conference 2012 and used for different occasions shown to public. The results are disseminated for public awareness, making the technology socially acceptable and widening information for the wind energy industry and power distributors for an emerging technology. In the project duration of three years, three PhD's have been created and two Post Docs have been connected to the project. About ten students from four universities have been involved in looking into the technical aspects of the concept.
Potential Impact:
The project comprises research on an emerging high risk energy technology. The project is to a large extent based on previous knowledge and development in vertical axis technology, but it is combined with recent deep sea-based offshore technologies and with advanced, large scale blade pultrusion technology in order to establish a new field of development. The expected results will reflect this new combination of different technologies, and will primarily give answers to whether the proposed technology has a chance to emerge into a development of large scale wind turbine systems based on the proposed concept. More specifically, the project resulted in a range of demonstration activities (proof-of-principle tests, laboratory testing) and development of toolboxes containing design tools that will support the overall key question of driving down the cost of energy for offshore wind power plants. The project results will first of all be exploited by the project partners that will gain substantial knowledge for development of the concept in future projects. The project consortium will with the background of this project gain the prerequisites necessary for prototyping and later up-scaling to very large systems. Spin-offs in the new field of technology may transform into potential patents. The results are disseminated for public awareness, making the technology socially acceptable and widening information for the wind energy industry and power distributors for an emerging technology.
The website www.deepwind.eu was established 1 Month after project start, and contributions were made due to inputs provided to the news press at DTU Risø, local newspapers (technical and non-technical), Danish National Radio Broadcast(2) and TV programs(1), interviews in various international Technical Magazines, invited speeches on virtual portal and conferences and establishing networking with colleagues and organizations within the wind energy business. Also Deutschlandfunk prepared an interview with the coordinator broadcasted from the 2014 Wind Energy meeting in Barcelona (E).
The web administration was with DTU, and was in its design not suited to provide direct web input by consortium members. A newly constructed web service (April 2014) has these facilities and can allow 3 members to participate. AAU has volunteered as the only member to directly place information on the server(still though administrated at DTU). Updating of the publications, movies and contributions for dissemination are worked on also after project end. An overview of the potential journals we wanted to reach within the project scope shows that 6 contributions out of 15 are satisfied. Other relevant contributions, such as materials science and magnetic technologies magazines are not counted in.
List of Websites:
Name of the scientific representative of the project's co-ordinator , Title and Organisation: Uwe Schmidt Paulsen, Senior scientist, Technical University of Denmark, Risoe DTU
Tel: +45 46774666 or +4521329405
Fax:
E-mail: uwpa@dtu.dk
Project website address: www.deepwind.eu
DeepWind challenges the existing offshore wind turbine concepts on design, installation and O&M aspects for lesser cost of energy with a radical new and simple design. Design and optimisation works have been supported by development of wind turbine design tools for more efficient and cost-effective deep-sea use of the DeepWind concept, consisting of a 2-bladed Darrieus rotor and a long spar buoy extending subsea. An aero-elastic modelling suite has been developed in the project for full numerical simulation of the concept, and this design tool integrates results from investigations done on the concept and calculates the effects of external loads on the main components consisting of few parts: wind turbine rotor, floater, power transmission module, and loads transmitted to the sea bed via the mooring system. The team has also delivered computer code for the blade pultrusion manufacturing process, for the generator and wind turbine bearings design as well as a particular tool for turbine control simulation.
DeepWind developed a proof-of-principle prototype one kilowatt (kW) wind turbine to demonstrate the principle under near-to-realistic operating conditions with a 2-bladed rotor, as well to study floater kinematics under controlled conditions in an ocean laboratory and in a wind tunnel to study the performance of the inclined rotor with 3 blades. An inbuilt monitoring system has provided data on movements of the rotating components and submerged parts in floating conditions. In particular the physics of the Magnus force and interaction with waves have been experimentally investigated and numerically verified on a model scale floater in a towing tank. Researchers have achieved to analyse power transmission, mooring and torque absorption components relative to environmental conditions such as wind, waves and currents. In parallel, the team prepared an outlook for a 20 megawatt (MW) baseline design, based on upscaling the 5MW conceptual design.The project has achieved to contribute with high quality results: new promising high-performance airfoils were developed for the 2 bladed design with potential increase of rotor efficiency, to provide a design of a permanent magnetic generator and a magnetic bearings system for the 5 MW conceptual design with a laboratory facility testing the bearing, to provide the controls of the power at the different wind speeds with rotor speed limitation. Furthermore, the team has achieved to provide a simulation tool for the pultrusion manufacturing process of specimen up to 60mm shell thickness, and in the HAWC2 simulation tool to integrate an engineering formula of the Magnus forces exerted on the rotating floater in waves, and to develop an optimised floater and mooring system integrated with the 5 MW conceptual design. The commercialisation aspects and estimation for costs of parts to produce the 5 MW conceptual design are analysed, and the expected plant-level costs of electricity generation is estimated for a 100 MW plant to be in the same order of cost estimations for a land based wind power plant(based on 2013 values). Furthermore substantial cost reductions can be obtained with reinforced concrete materials for the floater part. It is found that a cost impact is also originating from the anchoring system made of conventional design. DeepWind results have been published in numerous scientific journals and conference proceedings and DeepWind has been presented in the news media and at various conferences. It has stimulated creation of a new theme on deep offshore and floating installations, such as at the conferences of the European Wind Energy Association. DeepWind results show that gusty winds far out at sea to produce electricity are better tolerated than existing horizontal-axis wind turbines, and that the concept falls within an important niche and increased momentum from public awareness, pushing technology one step closer to commercialisation.
Project Context and Objectives:
The hypothesis of this project is that a new wind turbine concept developed specifically for offshore application has potentials for better cost efficiency than existing offshore technology. Based on this hypothesis the objectives are: i)to explore the technologies needed for development of a new and simple floating offshore concept with a vertical axis rotor and a floating and rotating foundation, ii)to develop calculation and design tools for development and evaluation of very large wind turbines based on this concept and iii)evaluation of the overall concept with floating offshore horizontal axis wind turbines.
Upscaling of large rotors beyond 5MW has been expressed to have more cost potentials for vertical axis wind turbines than for horizontal axis wind turbines due to less influence of cyclic gravity loads. However, the technology behind the proposed concept presents extensive challenges needing explicit research, especially: dynamics of the system, pultruded blades with better material properties, sub-sea generator, mooring and torque absorption system, and torque, lift and drag on the rotating and floating shaft foundation. In order to be able in detail to evaluate the technologies behind the concept the project comprise: 1) numerical tools for prediction of energy production, dynamics, loads and fatigue, 2) tools for design production of blades 3) tools for design of generator and controls, 4) design of mooring and torque absorption systems, and 5) knowledge of friction torque and lift and drag on rotating tube. The technologies need verification, and in the project verification is made by: 6) proof-of concept testing of a small, kW sized technology demonstrator, partly under real conditions, partly under controlled laboratory conditions, 7) integration of all technologies in demonstration of the possibility of building a 5MW and an evaluation of the concept.
The new proposed simple floating offshore wind turbine concept consist of a long vertical tube that rotates in the water, a vertical axis rotor at the top, a bottom based generator and a sea-bed fixing system at the bottom. However, though being simple, the technology behind the concept presents extensive challenges needing explicit research, especially: dynamics of the system, pultruded blades with better material properties, sub-sea generator, mooring and torque absorption system, and torque, lift and drag on the rotating and floating shaft foundation.
In order to evaluate the concept against floating offshore horizontal axis wind turbines, exploration of new technologies was needed for development of the individual components, and for evaluation of the overall concept.
These technologies comprised:
1) numerical tools for prediction of energy production, dynamics, loads and fatigue,
2) tools for design and production of blades
3) tools for design of generator, magnetic bearing and controls,
4) design of mooring and torque absorption systems
5) knowledge of friction torque and lift and drag on rotating tube.
As the technologies needs verification, verification is made in the project by:
6) proof-of principles testing of components and a small kW sized technology demonstrator,
7) integration of all technologies in demonstration of the possibility of building a 5MW wind turbine based on the concept, and an evaluation of the perspectives for the concept.
Six work packages include research in key technologies, in which development of tools for optimization and design are substantial elements. One work package comprises demonstration of the concept feasibility with the demonstrator and dedicated experiments. One work package integrates all technologies in demonstration of the possibility of building a 5MW wind turbine based on the concept, and the outlook of a 20MW turbine. One work package associates dissemination and exploitation of the results, and one with management.
Project Results:
The project comprised research and laboratory testing on an emerging high risk energy technology. The project combined different technologies into answering how the proposed concept can emerge into MW size with likely uptake towards industrialized concepts. The project resulted in a range of tests of physical models, and development of two main toolboxes for designs and simulations. The concept has been presented at offshore and at European wind energy conferences, and in various papers for publication. In the first stage of the project, the question arose about Magnus forces might challenge the soundness of the concept, and during the project it was successfully answered with carrying out the exploration of torque, lift and drag experiments on a rotating tube in a water flume with waves. The works confirmed that the results do not call attention for unexpected Magnus forces. The team conducted a posteriori analysis of the effects and derived an engineering model of the Magnus force for integration with code. Proof-of-principle experiments were conducted on a 1kW wind turbine with 5m overall height, and rotor diameter 2m. This demonstrator was designed and purpose built by the consortium. A special designed and built watertight generator was mounted at the end of a flexible shaft on a 2-bladed Aluminium Darrieus rotor. The manufacture of the GRP blades was not finished at that time. It was deployed and tested August-November 2012 in the fjord at DTU Campus Risø(DK) under various near to real operating conditions. The fjord experiment was designed to explore on the overall system stability, and for validation with the modified simulation tool HAWC2 of important floater motions: heave, pitch, yaw and roll. The site has been approved by the National Danish Naval authorities as a temporary facility for testing the concept. Prior to deployment, the rotor and tube were structurally modelled and modal tested on resonance effects. The deployment was successfully carried out with help of a special built installation and maintenance barge; lessons were experienced on how to install and to service the installation. Fjord testing gave understanding in the effects of currents and large waves rolling over parts of the rotating spar buoy, and input on how to work further on a future safety system. Testing of the demonstrator was carried out under controlled conditions at the ocean laboratory testing facilities at MARIN(NL) in March 2013. A substantial set of test cases, matching the fjord conditions was made. The 3-bladed rotor configuration was tested along with the 2-bladed demonstrator for test cases of different combinations of waves, wind, and current. The data were post processed in a comparison with HAWC2 simulations. Upfront to testing the floating wind turbine, the laboratory wind conditions were improved for operating conditions in the ocean basin and scaled for matching the turbine and sea states in consideration. The wind turbine was instrumented for monitoring movements of the rotating structure and the moving submerged parts. Data analysis of the power transmission system, the mooring - and torque absorption system has been started to be analysed for relevant environmental conditions, including wind, current and waves and comparison with results from simulations at same conditions. Finally the demonstrator was modified for testing the 3-bladed glass fibre reinforced polyester (GRP) rotor in the wind tunnel of MILAN(I). I was instrumented for performance testing and for investigation of the tilted rotor.
The project progressed with establishment of an integrated aero-elastic design and simulation tool HAWC2 for floating VAWTs in dealing with simulation of performance, dynamics and loads. The tool is developed in particular to handle the aerodynamic induction models of VAWTs and the fluids motion on the rotating spar buoy in interaction with waves in an appropriate manner, and is well validated with high fidelity CFD tools supported by the consortium. This code is, except for the detailed generator model, ready as the basic calculation tool for simulation of the concept. The tools have been used for design of the Proof-of-Principle 1 kW wind turbine and the 5 MW conceptual design, and for iterations of the design towards optimisation. Simulations of the 20 MW wind turbine, up-scaled from the 5MW has been carried out. Major developments have been included: turbulent flow field, mooring lines dynamics, an engineering model of Magnus effect, an actuator disk refinement to existing momentum models, generator model with controls, different codes comparison with HAWC2, and lightweight blade design with stall regulated rotor and rotor blade optimisation. A detailed 5 MW conceptual design loads report has been published with results for the Hywind site, situated at the Western coast of Southern Norway.
Blade technology and blade design progressed with a full model description and simulation of pultruded profiles during the manufacture process, and has contributed in the design optimization of a 5 MW floating offshore vertical-axis wind turbine rotor. Furthermore the development of a high efficiency airfoil for the 5 MW DeepWind concept has been developed and tested in the TUDelft(NL) wind tunnel. Two sets of 3 GRP blades for the demonstrator have been manufactured by NENUPHAR(F) for testing the demonstrator in the ocean laboratory and for wind tunnel testing of the rotor.
In the works dealing with the concepts of the generator and the intersection with the floater, the 1kW wind turbine electrical design, and generator built and control made the testing possible. Furthermore major contributions have been achieved on design rules and tools:
• A basic design of submersible 5 MW and 20 MW generator platforms
• Assessment and analysis of the coupling between generator and wind turbine rotor, including tools to design magnetic bearings and to perform testing in a test rig
• Computer code implementing design rules and optimisation for PM generators and magnetic bearing systems design
Within turbine operational control we developed a simplified simulation model of the DeepWind concept suitable for investigation of control strategies. The model takes into account a reduced-order mooring system, double disk BEM rotor aerodynamics that captures dynamic stall effect, and a simple representation of the tower tilt motion (yaw, roll and pitch). A baseline controller design has been established for the 5 MW concept and analysed in simulations with turbulent wind inflow in different operating conditions, including start-up and shut-down sequences. Model simulations indicate that the controller meets the most important control requirements: 1) optimal aerodynamic efficiency through variable speed operation; 2) damping of the large twice-per-revolution aerodynamic torque variations; 3) limitation of rotor speed; 4) efficient operation at high wind speeds through storm control; and 5) safe start-up and shut-down both in low and high winds.
Mooring, floating and torque absorption systems contributed with an optimized floater design for the 5 MW baseline design as an initial design, and a revised design for the conceptual design. Main dimensions for spar-type floating support structure and the mooring system configuration has been conducted.
Integration of technologies and upscaling addresses on integration of the various results for establishing the 5 MW platform. It was decided to freeze the 5 MW design iteration by October 1 2013, and that the results implementation was carried out hereafter, in parallel with the 20 MW outlook. Simultaneous engineering of the baseline design into the 5 MW conceptual design illustrated challenging aspects of the Multidisciplinary Design Analysis and Optimization (MDAO) framework. The team has with the industrial partner NENUPHAR developed a cost model for this concept. A 20 MW outlook is conducted as an exercise to find the limits of pultrusion and to forecast levelized cost for the concept. With two alternative cost models, based on an industrial - and a research based approach, the 5 MW concept is found to achieve a Cost of Energy of around 100€/MWh. For alternative floater materials and depending on the floater size the cost is driven even further down.
Dissemination and Exploitation focused on the dissemination of scientific and technical results on the web, articles and publications, and aimed to stimulate publishable results into workshops and conferences, as well as to deal with IPR issues within the consortium. Contributions, invited speeches and interviews have been conducted in news media (Danish radio and TV, international magazines, papers and journals) during the period. The presentations were held at offshore conferences in Europe and USA in 2011, and conducted at EWEC 2012, EWEC 2013 and 2014. An exhibition concept model was shown at the EWEA conference 2012 and used for different occasions shown to public. The results are disseminated for public awareness, making the technology socially acceptable and widening information for the wind energy industry and power distributors for an emerging technology. In the project duration of three years, three PhD's have been created and two Post Docs have been connected to the project. About ten students from four universities have been involved in looking into the technical aspects of the concept.
Potential Impact:
The project comprises research on an emerging high risk energy technology. The project is to a large extent based on previous knowledge and development in vertical axis technology, but it is combined with recent deep sea-based offshore technologies and with advanced, large scale blade pultrusion technology in order to establish a new field of development. The expected results will reflect this new combination of different technologies, and will primarily give answers to whether the proposed technology has a chance to emerge into a development of large scale wind turbine systems based on the proposed concept. More specifically, the project resulted in a range of demonstration activities (proof-of-principle tests, laboratory testing) and development of toolboxes containing design tools that will support the overall key question of driving down the cost of energy for offshore wind power plants. The project results will first of all be exploited by the project partners that will gain substantial knowledge for development of the concept in future projects. The project consortium will with the background of this project gain the prerequisites necessary for prototyping and later up-scaling to very large systems. Spin-offs in the new field of technology may transform into potential patents. The results are disseminated for public awareness, making the technology socially acceptable and widening information for the wind energy industry and power distributors for an emerging technology.
The website www.deepwind.eu was established 1 Month after project start, and contributions were made due to inputs provided to the news press at DTU Risø, local newspapers (technical and non-technical), Danish National Radio Broadcast(2) and TV programs(1), interviews in various international Technical Magazines, invited speeches on virtual portal and conferences and establishing networking with colleagues and organizations within the wind energy business. Also Deutschlandfunk prepared an interview with the coordinator broadcasted from the 2014 Wind Energy meeting in Barcelona (E).
The web administration was with DTU, and was in its design not suited to provide direct web input by consortium members. A newly constructed web service (April 2014) has these facilities and can allow 3 members to participate. AAU has volunteered as the only member to directly place information on the server(still though administrated at DTU). Updating of the publications, movies and contributions for dissemination are worked on also after project end. An overview of the potential journals we wanted to reach within the project scope shows that 6 contributions out of 15 are satisfied. Other relevant contributions, such as materials science and magnetic technologies magazines are not counted in.
List of Websites:
Name of the scientific representative of the project's co-ordinator , Title and Organisation: Uwe Schmidt Paulsen, Senior scientist, Technical University of Denmark, Risoe DTU
Tel: +45 46774666 or +4521329405
Fax:
E-mail: uwpa@dtu.dk
Project website address: www.deepwind.eu