MARINE engineering specialists are being invited to enter a £2.4 million Scottish Enterprise (SE) competition to find a means of protecting power cables from the wild coastal waters in which tidal energy will be harnessed.

The agency has launched the contest in an apparent recognition that existing cable technologies will not be fit for the strongest Scottish tidal waters.

It comes as several ventures are gearing up to build pre-commercial arrays of tidal turbines for the first time over the next couple of years, with a view to building commercial tidal farms from 2017 on.

MeyGen, owned by Singapore-based turbine manufacturer Atlantis Resources, aims to build a six-turbine 9MW array off Caithness. ScottishPower and Norwegian manufacturer Hammerfest Strom are preparing to build a 10-turbine 10MW array between Islay and Jura.

SE envisages its cabling competition will take place over two stages, with around six companies vying to produce proposals over six months for developing "low-cost safe and effective methods of locating, securing and protecting cables" in tidal waters.

The three best entries will have nine months to build demonstrations at a site to be announced. The agency aims to have at least one viable technology in place by the middle of next year.

The tender document said: "There are a number of significant technical challenges that will need to be tackled to enable the effective deployment and operation of arrays and SE, through this initiative, aims to address one particular key requirement as identified by industry.

"The cabling of tidal arrays presents a challenge as the seabed at tidal energy sites is often severely scoured and burying cables is not an option. Not only is this a key requirement for the deployment and operation of the initial demonstration tidal arrays around Scotland but also the reduction of marine energy project costs over the longer term, hence enabling the commercialisation of the industry."

SE was unable to comment in time for publication.