Absorbed power density approach for optimal design of heaving point absorber wave energy converter: A case study of Durban sea characteristics

Authors

DOI:

https://doi.org/10.17159/2413-3051/2022/v33i1a10381

Keywords:

Cylindrical buoy; Heave motion; Absorbed power; Power density; Optimal sizing.

Abstract

This work proposes an approach for the optimal sizing of a cylindrical heaving wave energy converter (WEC). The approach is based on maximising the absorbed power density (APD) of the buoy, with the diameter being the decision variable. Furthermore, two types of buoy shapes were compared to get the best option. The two buoy shapes are the cone cylinder buoy (CCB) and the hemisphere cylinder buoy (HCB). The aim was therefore to determine the best shape and as well as the optimal size of the cylindrical point absorber. To validate the approach, the simulation was performed under Durban (South Africa) sea characteristics of 3.6 m wave significant height and 8.5 s peak period, using the openWEC simulator. The buoy diameter range considered was from 0.5 m to 10 m for both shapes. Simulation results revealed that a diameter of 1 m was the optimal solution for both buoy shapes. Furthermore, the APD method revealed that the HCB was more efficient than the CCB. The power density of the HCB was 1070 W/m2, which was almost double the power density of the CCB, while the two shapes present almost the same absorbed power.

Downloads

Download data is not yet available.

References

Alamian, R., Shafaghat, R., Miri, S. J., Yazdanshenas, N. & Shakeri, M. 2014. Evaluation of technologies for harvesting wave energy in Caspian Sea. Renewable Sustainable Energy Review 32: 468-476. DOI: https://doi.org/10.1016/j.rser.2014.01.036

Alves, M., Traylor, H. & Sarmento, A. Hydrodynamic optimization of a wave energy converter using a heave motion buoy. Proceedings of the 7th European wave and Tidal Energy Conference 2007, Porto, Portugal: 11-14.

Babarit, A. 2015. A database of capture width ratio of wave energy converters. Renewable Energy 80: 610-628. DOI: https://doi.org/10.1016/j.renene.2015.02.049

Babarit, A. & Clement, A. H. Shape optimisation of the SEAREV wave energy converter. Proceedings of the 9th World Renewable Energy Congress 2006, Florence, Italy, 19-25 August 2006.

Babarit, A., Hals, J., Muliawan, M. J., Kurniawan, A., Moan, T. & Krokstad, J. 2012. Numerical benchmarking study of a selection of wave energy converters. Renewable Energy 41: 44-63. DOI: https://doi.org/10.1016/j.renene.2011.10.002

Banks, D. & Schäffler, J. 2005. The Potential Contribution of Renewable Energy in South Africa (Sustainable Energy and Climate Change Project (SECCP)). energize. Johannesburg, South Africa.

Beatty, S. J., Hall, M., Buckham, B. J., Wild, P. & Bocking, B. 2015. Experimental and numerical comparisons of self-reacting point absorber wave energy converters in regular waves. Ocean Engineering 104: 370-386. DOI: https://doi.org/10.1016/j.oceaneng.2015.05.027

Budar, K. & Falnes, J. 1975. A resonant point absorber of ocean-wave power. Nature 5517: 478-479. DOI: https://doi.org/10.1038/256478a0

Corbella, S. & Stretch, D. D. 2012. The wave climate on the KwaZulu-Natal coast of South Africa. Journal of South African institution of civil engineering 54: 45-54.

CSIR 2018. WaveNet: Online/Realtime Waves and Weather. Stellenbosch: Council for Scientific and Industrial Research (CSIR).

De Backer, G. 2009. Hydrodynamic Design Optimization of Wave Energy Converters Consisting of Heaving Point Absorbers. Doctorate Research, Universiteit Gent.

De Backer, G., Vantorre, M., Beels, C., De Rouck, J. & Frigaard, P. Performance of closely spaced point absorbers with constrained floater motion. Proceedings of the 8th European Wave and Tidal Energy Conference 2009, Uppsala, Sweden: 806-817.

Engström, J., Eriksson, M., Isberg, J. & Leijon, M. 2009. Wave energy converter with enhanced amplitude response at frequencies coinciding with Swedish west coast sea states by use of a supplementary submerged body. Journal of Applied Physics 106: 64512-64515. DOI: https://doi.org/10.1063/1.3233656

Evans, D. V. 1980. Some analytic results for 2D and 3D wave energy absorbers. Power From Sea Waves. Edinburgh, UK: Count, B. M. (Ed.), Ac. Press.

Falnes, J. 2002. Optimum control of oscillation of wave-energy converters. International Journal of Offshore and Polar Engineering 12: 147–155.

Flocarda, F. & Finnigan, T. D. 2012. Increasing power capture of a wave energy device by inertia adjustment. Applied Ocean Research 34: 126-134. DOI: https://doi.org/10.1016/j.apor.2011.09.003

Fourie, C. J. S. & Johnson, D. 2017. The Wave Power Potential of South Africa. Power-Gen Africa, Johannesburg, South Africa, 18-20 July 2007

Garcia-Rosa, P. B., Bacelli, G. & Ringwood, J. V. 2015. Control-Informed Geometric Optimization of Wave Energy Converters: The Impact of Device Motion and Force Constraints. Energies 8: 13672–13687. DOI: https://doi.org/10.3390/en81212386

Goggins, J. & Finnegan, W. 2014. Shape optimisation of floating wave energy converters for a specified wave energy spectrum. Renewable Energy 71: 208-220. DOI: https://doi.org/10.1016/j.renene.2014.05.022

Hasselmann, K., Barnett, T. P., Bouws, E., Carlson, H., Cartwright, D. E., Enke, K., Ewing, J. A., Gienapp, H., Hasselmann, D. E., Kruseman, P., Meerburg, A., Müller, P., Olbers, D. J., Richter, K., Sell, W. & Walden, H. 1973. Measurements of Win-Wave Growth and Swell Decay During the Joint North sea Wave Project (JONSWAP). Hamburg, Germany: Deutches Hydrographisches Institut.

Joubert, J. R. & Van Niekerk, J. L. 2013. South African Wave Energy Resource Data: A Case Study. University of Stellenbosch, Stellenbosch, South Africa.

Kamarlouei, M., Gaspar, J. F., Calvario, M., Hallak, T. S., Mendes, M. J. G. C., Thiebaut, F. & Soares, C. G. 2020. Experimental analysis of wave energy converters concentrically attached on a floating offshore platform. Renewable Energy 152: 1171-1185. DOI: https://doi.org/10.1016/j.renene.2020.01.078

Khojasteh, D. & Kamali, R. 2016. Evaluation of wave energy absorption by heaving point absorbers at various hot spots in Iran seas. Energy 109: 629-640. DOI: https://doi.org/10.1016/j.energy.2016.05.054

Kramer, M. M. & Frigaard, P. B. Efficient Wave Energy Amplification with Wave Reflectors. Proceedings of the Twelfth (2002) International Offshore and Polar Engineering Conference, Kitakyushu, Japan, 26-31 May 2002: 707-712.

Kurniawan, A. & Moan, T. Multi-objective optimization of a wave energy absorber geometry. 27th International Workshop on Water Waves and Floating Bodies 2012, Copenhagen, 22-25 April, 2012.

Kurniawan, A. & Moan, T. 2013. Optimal geometries for wave absorbers oscillating about a fixed axis. IEEE Journal of Ocean Engineering 38: 117-130. DOI: https://doi.org/10.1109/JOE.2012.2208666

Leijon, M., Bernhoff, H., Berg, M. & Ågren, O. 2003. Economical considerations of renewable electric energy production - especially development of wave energy. Renew Energy 28: 1201-1209. DOI: https://doi.org/10.1016/S0960-1481(02)00157-X

Mahnamfar, F. & Altunkaynak, A. 2017. Comparison of numerical and experimental analyses for optimizing the geometry of OWC systems. Ocean. Eng 130: 10-24. DOI: https://doi.org/10.1016/j.oceaneng.2016.11.054

Maria-Arenas, A., Garrido, A. J., Rusu, E. & Garrido, I. 2019. Control Strategies Applied to Wave Energy Converters: State of the Art. Energies 12: 1-19. DOI: https://doi.org/10.3390/en12163115

McCabe, A. P. 2013. Constrained optimization of the shape of a wave energy collector by genetic algorithm. Renewable Energy 51: 274-284. DOI: https://doi.org/10.1016/j.renene.2012.09.054

Mutombo, N. M.-A. & Numbi, B. P. 2019. Assessment of renewable energy potential in Kwazulu-Natal province, South Africa. Energy Reports 5: 874-881. DOI: https://doi.org/10.1016/j.egyr.2019.07.003

National Renewable Energy Laboratory and National Technology & Engineering Solutions of Sandia, L. N. 2017. WEC-Sim Release Notes v3.0 [Online]. WEC-Sim. Available: https://wec-sim.github.io/WEC-Sim/dev/man/release_notes.html.

Penalba, M. & Ringwood, J. V. 2016. A Review of Wave-to-Wire Models for Wave Energy Converters. Energies 9: 1-45. DOI: https://doi.org/10.3390/en9070506

Pierson, W. J. & Moskowitz, L. A. 1964. A Proposed Spectral Form for Fully Developed Wind Seas Based on Similarity Theory of S.A. Kitaigorodski. Journal of Geophysical Research 69: 5181-5190. DOI: https://doi.org/10.1029/JZ069i024p05181

Rahmati, M. T. & Aggidis, G. A. 2016. Numerical and experimental analysis of the power output of a point absorber wave energy converter in irregular waves. Ocean Engineering 111: 483-492. DOI: https://doi.org/10.1016/j.oceaneng.2015.11.011

Ramayia, J. 2012. Overview of renewable energy resources in South Africa.

Rautenbach, C., Barnes, M. A., Wang, D. W. & Dykes, J. 2020. Southern African Wave Model Sensitivities and Accuracies. Journal of Marine Science and Engineering 8: 1-23. DOI: https://doi.org/10.3390/jmse8100773

Shadman, M., Estefen, S. F., Rodriguez, C. A. & Nogueira, I. C. M. 2018. A geometrical optimization method applied to a heaving point absorber wave energy converter. Renewable Energy 115: 533-546. DOI: https://doi.org/10.1016/j.renene.2017.08.055

Sjokvist, L., Krishna, R., Rahm, M., Castellucci, V., Hagnestål, A. & Leijon, M. 2014. On the optimization of point absorber buoys. Journal of Marine Science Engineering 2: 477-492. DOI: https://doi.org/10.3390/jmse2020477

Soleimani, K., Ketabdari, M. J. & Khorasani, F. 2015. Feasibility study on tidal and wave energy conversion in Iranian seas. Sustainable Energy Technologies and Assessments 11: 77-86. DOI: https://doi.org/10.1016/j.seta.2015.03.006

Son, D., Belissen, V. & Yeung, R. W. 2016. Performance validation and optimization of a dual coaxial-cylinder ocean-wave energy extractor. Renewable Energy 92: 192-201. DOI: https://doi.org/10.1016/j.renene.2016.01.032

Van Paepegem, W., Blommaert, C., De Baere, I., Degrieck, J., De Backer, G., De Rouck, J., Degroote, J., Vierendeels, J., Matthys, S. & Taerwe, L. 2011. Slamming wave impact of a composite buoy for wave energy applications: design and large-scale testing. Polymer Composites 32: 700-713. DOI: https://doi.org/10.1002/pc.21089

Van Riet, T. 2017. Feasibility of ocean energy and offshore wind hybrid solutions. Master of Science, Delft University of Technology, Netherlands.

Vantorre, M., Banasiak, R. & Verhoeven, R. 2004. Modelling of hydraulic performance and wave energy extraction by a point absorber in heave. Applied Ocean Research 26: 61-72. DOI: https://doi.org/10.1016/j.apor.2004.08.002

Verbrugghe, T. 2016. openWEC Manual. 2.0 ed. github: Universiteit Gent.

Zabihian, F. & Fung, A. S. 2011. Review of marine renewable energies: case study of Iran. Renewable and Sustainable Energy Review 15: 2461-2474. DOI: https://doi.org/10.1016/j.rser.2011.02.006

Photo by Kammeran Gonzalez-Keola from Pexels

Downloads

Published

2022-03-17

How to Cite

Mutombo, N. M.-A., & Numbi, B. P. . (2022). Absorbed power density approach for optimal design of heaving point absorber wave energy converter: A case study of Durban sea characteristics. Journal of Energy in Southern Africa, 33(1), 52–67. https://doi.org/10.17159/2413-3051/2022/v33i1a10381