Alternative Energy Sources: Wave Power

The oceans are a huge repository of the sun’s energy. There are at least three ways to recover this energy. This article looks at one – wave power.

Among many indicators of global warming is the fact that the amount of heat stored in the oceans is increasing. So it makes sense to use that heat to provide for mankind’s energy needs. The US Navy is among those developing ways of doing so. The other sources of energy from the sea are tidal power and wave power.

When the worldwide price of crude oil rocketed following the Middle East crisis of the early 1970’s and the subsequent formation of OPEC to control supplies there was an upsurge of interest in alternatives and ways of harnessing the power of the waves received significant volumes of government investment in the UK and elsewhere. Probably the best known of the devices that were developed during this period is the Salter Duck.

Europe’s Marine Energy Development Centred on Scotland

Further government funding was denied to this device in the 1980s when fears about future trends in crude oil prices had subsided. Professor Salter’s facility at the University of Edinburg remains in business however and continues to play a significant role in the testing and development of wave power devices.

Indeed, a significant proportion of the world’s wave power development is centred on Scotland, with the European Marine Energy Centre (EMEC) based at Stromness providing facilities for full scale testing of wave and tidal power devices in some of the most adverse conditions likely to be encountered anywhere in the world.

EMEC plays a leading role in assisting developers by creating standards and ensuring that environmental impacts are properly assessed as part of the design process. Devices currently or soon to be deployed at EMEC’s wave power testing facility include Pelamis 1 and 2, Oyster and Penguin.

Off-shore Energy on Ireland’s West Coast

Meanwhile Ocean Energy Limited (OE) of Cobh in County Cork, Ireland have developed a device which has been tested in Atlantic gales and, since February 2010, have been in partnership with US multinational Dresser-Rand Corporation. In addition their platform is being used in Galway Bay by Europe’s Hydraulics and Maritime Research Centre (HMRC) as a testbed for peripheral devices such as control systems, telemetry and grid interface technology. All of these technologies are essential requirements for the efficient transfer of wave generated electricity into a nation’s power grid.

Elsewhere, Ocean Power Technologies (OPT) have deployed devices at test sites in Hawaii, Atlantic City and Spain as well as at the EMEC test site in Orkney. OPT also intend to deploy an array of their devices at Wave Hub off the Cornish coast. This is a similar facility to the one operated by EMEC. OPT are developing “wave parks” at Reedsport and Coos Bay, Oregon.

Need to Lower Total Cost of Wave Energy

Critics of the current state of wave power development believe that there is a basic mistake being made in concentrating on areas where there are frequent high waves. In addition to the difficulty of designing equipment capable of surviving in such harsh conditions, such locations are often far from major centres of industry and population.

One such critic is Cliff Goudey, whose own wave energy company won an entrepreneurship competition in November 2010. In January 2011 he stated in a comment on the Renewable Energy World website, that developers need to “recognize that Kw/$ is what matters.” Generating a lot of power, most of which is lost in transmission, can be seen as wasteful. Accepting that lower outputs of energy at source makes sense if the cost of the equipment required to do so can be kept down and the transmission losses reduced because of the relative proximity of the generating devices to the point of use.