© The Institution of Engineering and Technology
The use of hydraulic power transmission to transport offshore wind energy from deep offshore sites to shore may present a more feasible option for integrating wind farms with land-based hydro-energy storage systems. Yet the incurred losses resulting from fluid friction are significantly larger than those encountered in electrical power cables. This study investigates the possibility of compensating for such losses by exploiting cold deep-seawater (DSW) from below thermoclines. A numerical study simulating a single large-scale offshore wind turbine-driven pump supplying DSW to shore across a pipeline in the Central Mediterranean is presented. Seawater leaving the grid-connected hydroelectric power plant is allowed to flow through a centralised district air-conditioning unit operating on a vapour compression cycle. Any shortfall in DSW supply due to lack of wind is compensated for by sea surface water to maintain a constant flow rate. The analysis is repeated for seawater pipelines having different sizes. It is shown that the deep seawater supply from the offshore wind turbine, though being intermittent, reduces the energy consumption of the air-conditioning system considerably. The resulting savings are found to compensate for a significant proportion of the losses encountered in the hydraulic transmission pipeline.
References
-
-
1)
-
10. Sant, T., Buhagiar, D., Farrugia, R.N.: ‘Offshore floating wind turbine-driven deep sea water pumping for combined electrical power and district cooling’, J. Phys. Conf. Ser., 524, p. 012074. .
-
2)
-
13. Jonkman, J., Butterfield, S., Musial, W., et al: ‘Definition of a 5 MW reference wind turbine for offshore system development’ (National Renewable Energy Laboratory, 2009), .
-
3)
-
15. , Tønsberg, Norway, 1997–2010.
-
4)
-
6. Laguna, A.J.: ‘Modeling and analysis of an offshore wind turbine with fluid power transmission for centralized electricity generation’, J. Comput. Nonlinear Dynam, 2015, 10, (4), p. 041002, .
-
5)
-
17. Lakshmanan, P., Liang, J., Jenkins, N.: ‘Assessment of collection systems for HVDC connected offshore wind farms’, Electr. Power Syst. Res.2015, 129, pp. 75–82, .
-
6)
-
18. Negra, N.B., Todorovic, J., Ackermann, T.: ‘Loss evaluation of HVAC and HVDC Transmission solutions for large offshore wind farms’, Electr. Power Syst. Res., 2006, 76, (11), pp. 916–927, .
-
7)
-
5. Izadian, A., Hamzehlouia, S., Deldar, M., et al: ‘A Hydraulic wind power transfer system: operation and modelling’, IEEE Trans. Sustain. Energy, 2014, 5, (2), pp. 457-465, .
-
8)
-
1. Diepeveen, N.: ‘On the application of fluid power transmission in offshore wind turbines’. , Delft University of Technology, Delft, 2013.
-
9)
-
2. Laguna, A.J., Diepeveen, N.F.B., van Wingerden, J.W.: ‘Analysis of dynamics of fluid power drive-trains for variable speed wind turbines: parameter study’, IET Renew. Power Gener., 2013, 8, (4), pp. 398-410, .
-
10)
-
4. Skaare, B., Hörnstenand, B., Nielsen, F.G.: ‘Modelling, simulation and control of a wind turbine with a hydraulic transmission system’, Wind Energy, 2013, 16, pp. 1259–1276, .
-
11)
-
8. Sant, T., Farrugia, R.N.: ‘Modelling the energy yield enhancement from a wind turbine at a deep offshore low wind site through combined power and thermocline energy production’, J. Sol. Energy Eng., 2014, 137, (1), p. 011002.
-
12)
-
13)
-
3. Jiang, Z., Yang, L., Gao, Z., et al: ‘Numerical simulation of a wind turbine with a hydraulic transmission system’, Energy Procedia, 2014, 53, pp. 44–55.
-
14)
-
7. Buhagiar, D., Sant, T., Bugeja, M.K.: ‘Control of an open-loop hydraulic offshore wind turbine using a variable-area orifice’. ASME 2015 34th Int. Conf. on Ocean, Offshore and Arctic Engineering, St. John's, Canada, 2015, .
-
15)
-
12. Haaland, S.E.: ‘Simple and explicit formulas for the friction factor in turbulent flow’, J. Fluids Eng., 1983, 105, (1), pp. 89–90.
-
16)
-
11. Dasgupta, K., Mandal, S.K.: ‘Analysis of the steady-state performance of a multiplunger hydraulic pump’, Proc. Inst. Mech. Eng. J Power Energy, 2002, 206, pp. 471–479.
-
17)
-
14. Farrugia, R.N., Sant, T.: ‘Mediterranean inshore wind resources: combining MCPs and CFD for marine resource quantification’, Wind Eng., 2013, 37, (3), pp. 243–256.
-
18)
-
9. Buhagiar, D., Sant, T.: ‘Steady-state analysis of a conceptual offshore wind turbine driven electricity and thermocline energy extraction plant’, Renew. Energy, 2014, 68, pp. 853–867, .
http://iet.metastore.ingenta.com/content/journals/10.1049/iet-rpg.2016.0040
Related content
content/journals/10.1049/iet-rpg.2016.0040
pub_keyword,iet_inspecKeyword,pub_concept
6
6