Introduction

Wind energy has rapidly developed as a clean and renewable energy source in recent years in order to meet the increasing demand for power. European Union has already installed over 50GW of wind power generating capacity and has planned to increase the use of wind energy in order to reduce carbon dioxide emissions by 20% by the year 2020. The wind energy converters need to be thoroughly investigated with respect to their capacity, effectiveness and integrity. Wind energy potential (greater wind speeds) is greater in higher atmospheric levels. For offshore monopile wind turbine, their environmental loads are more complex than in the onshore ones as they higher average wind velocity and wave loadings. Thus, this makes the development of a new tall offshore tower configuration imperative for the construction of offshore structures under complicated loadings. This OFFSHORE TALL TOWER will offer a novel methodology to study offshore tall wind turbine tower in marine environment which can be used for cost saving of offshore wind turbine manufacture and promotion of energy production efficiency.

Offshore wind turbine tower under current, wave and wind loading
Offshore wind turbine tower under current, wave and wind loading

Funding

Tthe European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No 793316

Aim

The aim of the project is to evaluate the potential risk of offshore monopile wind turbine towers under wind, current and wave loading when these structures satisfy both ultimate limit state and stiffness design criteria.

Gaps that are still present in state-of-the-art

For the design of offshore tall wind turbine towers the major problems that arise are safety analysis and structural improvement of the offshore tall tower under the combination of all environmental loadings, and specifically the structural behaviour of offshore tall towers under combination effect of current, wave and wind loading, and the monitoring of the offshore tall wind turbine towers. The main difficulty to the analysis of the structural response of offshore tall wind turbine towers is the combination effect of current, wave and wind loading on the structural response of tall monopiles. To evaluate potential risks of them and extend their operational life, a series of scale-down towers are measured as laboratory test models.

Objectives and overview of the action

For offshore wind towers, the wave and current loadings will be involved in the design of the wind turbine monopile and tower structures to eliminate potential risk. Thus, to study the combination effect of current, wave and wind loadings, a novel methodology using scaled down model based on the theory of similarity is proposed in the present project. More specifically, FE analysis of the towers is initially performed with the aid of the software ABAQUS (2012). In addition to the wave and wind loadings classically obtained from Eurocode 1991-1-4 (EC, 2005), the wind and wave time-histories data could be obtained by National Renewable Energy Laboratory (NREL, 2015) and National Wind Technology Centre (NWTC, 2015).

Relevant publications

  • Hu, Y., Baniotopoulos, C.C. & Yang, J. (2014), Effect of internal stiffening rings on the structural response of steel wind turbine towers, ENGINEERING STRUCTURES 81, 148-161.
  • Hu, Y., Yang, J, Baniotopoulos, C.C., Wang X, Deng X. (2020), Dynamic analysis of offshore steel wind turbine towers subjected to wind, wave and current loading during construction. Renewable energy.
  • Lavassas, I., Zervas, P., Nikolaidis, G. & Baniotopoulos, C.C. (2008), Repair of a Highly Deformed Steel Tank Damaged due to Extensive Soil Settlements, COMPUTER AND EXPERIMENTAL SIMULATIONS IN ENGINEERING AND SCIENCE 2, 54-58.
  • Stathopoulos, T., Baniotopoulos C.C. & Zisis, I.,  (2010), Urban Habitat Constructions under Wind Catastrophic Events, JOURNAL OF GLOBAL ENGINEERING RESEARCH, 13 (2), 197-202.
  • Makarios, T. & Baniotopoulos, C.C. (2014), Wind Energy Structures: Modal Analysis by the Continuous Model Approach, JOURNAL OF VIBRATION AND CONTROL 20 (3), 395-405.
  • Makarios, T., Efthymiou, E. & Baniotopoulos C.C. (2015), On the Torsional-translational Response of Wind Turbine Towers, ARABIAN JOURNAL OF STRUCTURAL ENGINEERING 41 (4), 1241-1249.
  • Stavridou, N., Efthymiou, E. & Baniotopoulos, C.C. (2015), Welded Connections of Wind Turbine Towers under Fatigue Loading: Finite Element Analysis and Comparative Study, AMERICAN JOURNAL OF ENGINEERING AND APPLIED SCIENCES, 8(4), 489-503.
  • Stavridou, N., Efthymiou, E. & Baniotopoulos, C.C. (2015), Verification of the Anchoring System in Foundations of Wind Turbine Towers, AMERICAN JOURNAL OF ENGINEERING AND APPLIED SCIENCES-AJEAS, Science Publications, 8 (4), 717-729.
  • Zygomalas, I., Kaziolas, D., Stavroulakis, G. & Baniotopoulos, C.C. (2016), Quantification of the Influence of Life Cycle Parameters on the Total Environmental Impact of Steel-framed Buildings, INTERNATIONAL JOURNAL OF SUSTAINABLE ENGINEERING 9 (5), 329-337.
  • Tziavos, N., Hemida, H., Metje, N. & Baniotopoulos, C.C. (2016), Grouted Connections on Offshore Wind Turbine Towers: A Review, ICE-ENGINEERING AND COMPUTATIONAL MECHANICS 169 (4), 183-195.
  • Ma, Y., Martinez-Vazquez, P. & Baniotopoulos, C.C.(2017), Wind Turbine Towers Collapse Cases: A Historical Review, INSTITUTION OF CIVIL ENGINEERS-STRUCTURES & BUILDINGS 172 (8), 547-555.
  • Vita, G., Hemida, H., Andrianne T. & Baniotopoulos, C.(2018), Generating atmospheric turbulence using passive grids in an expansion test section of a wind tunnel, JOURNAL OF WIND ENGINEERING & INDUSTRIAL AERODYNAMICS 178, 91-104.
  • Moeini, R., Tricoli, P., Hemida, H. & Baniotopoulos, C.(2017), Increasing the Reliability of Wind Turbines Using Condition Monitoring of Semiconductor Devices: A Review. IET RENEWABLE POWER GENERATION 12 (2), 182-189.
  • Gkantou, M., Martinez-Vazquez, P. & Baniotopoulos, C. (2017), On the Structural Response of a Tall Hybrid Onshore Wind Turbine Tower, PROCEDIA ENGINEERING 199, 3200-3205.
  • Moeini, R., Entezami, M., Ratkovac, M., Tripoli, P., Hemida, H. & Baniotopoulos, C.(2018), Perspectives on Condition Monitoring Techniques in Wind Turbines, WIND ENERGY 43 (5), 538-555.
  • Stavridou, N., Koltsakis, E. & Baniotopoulos, C. (2018), Structural Analysis and Optimal Design of Steel Lattice Wind Turbine Towers, ICE-STRUCTURES & BUILDINGS 172(8), 564-579.
  • Tziavos, N., Hemida, H., Metje, N. & Baniotopoulos, C.(2018), Non-linear Finite Element Analysis of Grouted Connections for Offshore Monopile Wind Turbines, OCEAN ENGINEERING 171, 633-645.
  • Watson, S., Moro, A., Reis, V., Baniotopoulos, C. (2019), Future Emerging Technologies in the Wind Energy Power Sector: A European Perspective, RENEWABLE & SUSTAINABLE ENERGY 113, https://doi.org/10.1016/.rser.2019.109270.
  • Stavridou, N., Koltsakis, E. & Baniotopoulos, C.C.(2019), Tubular, Lattice and Hybrid Towers Steel Turbine Towers for Offshore Wind Energy: A Numerical Study, LECTURE NOTES IN CIVIL ENGINEERING 18, 524-529.
  • Stavridou, N., Koltsakis, E. & Baniotopoulos, C.C. (2019), A Comparative LCA of Tall Onshore Steel Wind Energy Towers, CLEAN ENERGY (accepted/in press) https://doi.org/10.1093/ce/zkz028.
  • Papaelias, M., Tziavos, N., Hemida, H., Metje, N. & Baniotopoulos, C.C.(2019), Structural health monitoring of grouted connections for offshore wind turbines by means of acoustic emission: An experimental study, RENEWABLE ENERGY 147, 130-140.
  • C.Baniotopoulos, C.Borri & E.Marino (eds) (2018), Wind Energy Harvestig: Focusing on the Exploitation of the Mediterranean Sea, Proceedings of the 2nd International WINERCOST and AEOLUS4FUTURE Conference, Catanzaro, p. 344.
  • C.Baniotopoulos, C.Borri, B.Blocken, H.Hemida, M.Veljkovic, T.Morbiato, R.Borg, N.Hamza & E.Efthymiou (eds), (2019) Advances in Wind Engineering Harvesting IV, Slovak University Bratislava.
  • C.Baniotopoulos, C.Borri, B.Blocken, H.Hemida, M.Veljkovic, T.Morbiato, R.Borg, N.Hamza & E.Efthymiou (eds), (2017) Advances in Wind Engineering Harvesting III, University of Naples, (ISBN: 978-88-908575-4-6).
  • C.Baniotopoulos & C. Rebelo (2017), Wind Energy Harvesting, University of Coimbra, pages 374 (ISBN: 978-989-99226-4-8).
  • C. Baniotopoulos, C. Borri, B. Blocken, H. Hemida, M. Veljkovic, T. Morbiato, R. Borg, S. Huber, E. Efthymiou (eds.) (2016), Advances in Wind Energy Harvesting II, TU Chania, 3-8.04.2016 (ISBN: 978-618-81537-1-4).
  • C. Baniotopoulos, C. Borri, B. Blocken, H. Hemida, M. Veljkovic, T. Morbiato, R. Borg, S. Huber, E. Efthymiou (eds.) (2015), Advances in Wind Energy Harvesting, Malta, 26-30.06.2015.
  • C. Baniotopoulos, C. Borri, B. Blocken, H. Hemida, M. Veljkovic, T. Morbiato, R. Borg, S. Huber, E. Efthymiou (eds.) (2015), Trends and Challenges for Wind Energy Harvesting, Coimbra, 30-31.03.2015, CMM, Coimbra (ISBN: 978-989-98435-8-5).
  • C. Baniotopoulos, C. Borri & T. Stathopoulos (eds) (2012), Environmental Wind Engineering and Design of Wind Energy Structures, Springer Wien, New York, pages 358.
  • C. Baniotopoulos & T. Stathopoulos (eds) (2007), Wind Effects on Buildings and Design of Wind-Sensitive Structures, Springer Wien, New York, pages 228.