A review on potential applications of carbon nanotubes in marine current turbines Kai-Wern Ng, Wei-Haur Lam n , Saravanan Pichiah Department of Civil Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia article info Article history: Received 12 September 2012 Received in revised form 26 July 2013 Accepted 11 August 2013 Available online 28 August 2013 Keywords: Marine current turbine Carbon nanotube Turbine blade Bio-fouling release Structural health monitoring abstract Marine current turbine is one of the promising marine renewable energy technologies that could provide clean and sustainable energy. This field has undergone rapid growth in both industry and academia during the last decade. However, there was no study being done in incorporating nanotechnology into marine current turbines. Carbon nanotubes, as one of the most studied nanomaterials, are a potential candidate to be incorporated into marine current turbines. This paper aims to review some of the researches done on carbon nanotubes to date, and proposed some potential applications in marine current turbines based on the review. The potential applications proposed are based on the need of marine current turbines. Apart from that, it also aims to act as a starting point to connect the two research areas (marine renewable energy and nanotechnology) together. The proposed applications include: structural reinforcement, fouling release coating, structural health monitoring, high perfor- mance wires/cables and lubrication. & 2013 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................ 331 2. Characteristics of carbon nanotubes ..................................................................................... 332 2.1. Mechanical properties .......................................................................................... 332 2.2. Chemical properties............................................................................................ 332 2.3. Electrical properties ............................................................................................ 332 2.4. Implementation considerations................................................................................... 333 3. Potential applications of carbon nanotubes ............................................................................... 333 3.1. Reinforcement of turbine blades .................................................................................. 333 3.2. Coating ...................................................................................................... 334 3.3. Structural health monitoring..................................................................................... 335 3.4. Other potential applications ..................................................................................... 336 4. Discussions......................................................................................................... 336 5. Conclusion ......................................................................................................... 336 Acknowledgements ...................................................................................................... 337 References ............................................................................................................. 337 1. Introduction Marine renewable energy as one of the renewable energy sources has gained attention from European countries and US since 1970s [1]. However, limited researches and studies were conducted in this field until the last decade [2]. Generally, types of marine renewable energy can be categorised into tidal, wave, current, ocean temperature gradient, salinity gradient and offshore wind. [1,2]. Offshore wind is a product of the interaction between the heat from the ocean surface and the atmosphere above it. This is the reason for categorising offshore wind as part of the marine renewable energy. These energy sources, especially tidal, wave and current, are said to possess greater potential in generating electricity compared with other renewable energies, as they are relatively consistent and predictable [3–6]. The rapid growth of marine renewable energy in the last decade, both in industry and academia, can be seen from the Annual Reports published by Ocean Energy Systems Implementing Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews 1364-0321/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.rser.2013.08.018 n Corresponding author. Tel.: þ603 7967 7675; fax: þ603 7967 5318. E-mail address: wlam@um.edu.my (W.-H. Lam). Renewable and Sustainable Energy Reviews 28 (2013) 331–339