The ocean provides a number of resources for people around the globe.  Food is perhaps the most traditional of these resources, but also materials, such as sand for construction work, and possibly even metals vital for much of the technology we use today.  We find a host of medicinal properties, and inspiration for new technologies.  We are also turning to the ocean for renewable, clean forms of energy, a vision which arguably took one step closer in February this year when the world’s first wave-energy farm connected to the electricity grid was switched on in Western Australia.  The project has been a long-term vision for Carnegie Wave Energy, an Australian company based in Perth. 

Costing approximately A$100 million, the company develop CETO - a series of fully submerged buoys that move up and down with the ocean swell.  This predictable movement creates hydraulic pressure that drives onshore hydro-electric turbines, supplying 5% to HMAS Stirling, Australia’s largest naval base located on Garden Island.  These 11 meter steel buoys have a secondary use too – creating sufficient pressure to desalinate seawater by a usually energy intensive process called ‘reverse osmosis’, thus delivering a third of the freshwater used by the base.  

The idea of using waves to generate power is not a new concept, with the first patent being filed in 1799 by Pierre-Simon Girard, a mathematician and engineer specialising in fluid mechanics.  He died without seeing his turbine come into fruition.  Later attempts at building a working model included the Wright Wave Motor, built in 1897 in Southern California – and now buried in sand at the foot of the Manhattan Beach pier.  With difficulties arising from high costs, failing turbines, a lack of research funding, and concerns over impacts to the environment, interest in wave energy dwindled until the 1970s with the oil crisis forcing energy companies to seek alternative forms of powering the human planet.  Many of these difficulties remain today.  The Portuguese-based Aguçadoura Wave Farm project, for example, halted, with its owners ending up in voluntary administration, and the hydraulic rams that make up the machines suffering a (fixable) technical fault.  The ram makers – Pelmis Wave Power – went into administration in 2014.  Despite the numerous challenges, Carnegie Wave Energy are not the only ones who believe wave power is a viable option for meeting our energy demands.  Research published in 2012 by Kester Gunn and Clym Stock-Williams (E.ON New Build & Technology) estimate the theoretical global wave power resource to be 2.11±0.05 TW...

The full article was published in – and can be read in – The Marine Professional, a publication of the Institute of Marine Engineering, Science & Technology (IMarEST).

Image: Pelamis P2 wave energy device.  Pelamis P2 device, pictured at European Marine Energy Centre, Orkney, in July 2011. Pelamis inventor Dr Richard Yemm was presented with the Saltire Prize Medal by First Minister Alex Salmond on March 27, 2012 - in recognition of his contribution to the development of the marine renewable energy industry. Credit: Pelamis Wave Power (CC BY-NC 2.0)