Ronnie Quinn, senior development manager at The Crown Estate, which manages British waters, confirmed he was in the early stages of planning a fourth round of offshore wind development that is likely to exceed the 25GW of concessions that have been handed out for round three.
The Crown Estate has completed a consultation with around 50 stakeholders and public bodies. It aims to license a developer to build a demonstrator wind farm that would operate in depths beyond the current 50-metre limit of round-three projects out to about 100 metres.
In a bid to catch up with floating turbine demonstrations in countries such as Norway, and others planned in Japan and the US, and to maintain the UK's pole position in the offshore wind sector, the authority is looking to grant a licence that will see the demonstrator built during the second half of this decade. Full-scale wind farms would then follow into the 2020s.
While the current projects being developed in Scotland are mostly on the east coast (the palest shaded areas of the map pictured), moving to deeper waters raises the prospect of development off the Western Isles.
In contrast, most waters off the English coast are either shallower or heavily restricted by shipping routes. The only area off England that looks to have substantial potential is around Cornwall.
Deeper waters have been avoided to date because they are more challenging in engineering terms and because the favoured technology there is floating turbines, which are far less developed than the turbines being used for shallower waters, which stand on the seabed.
"It has the potential to be bigger than round three," said Quinn. "It certainly does make the west coast in particular much more interesting.
"If we can get test-and-development turbines in the water by the second half of this decade, then you are talking about needing a couple of years to gather data. The mid-2020s for commercialisation would seem doable."
The Crown Estate is looking to come back with proposals in the coming months. Depending on the number of interested parties, it will then either start a tender process or grant an agreement for lease to a selected party. It is then likely to have to spend several years going through environmental assessments and planning applications.
The Crown Estate's decision to move forward will be of interest to Statoil, the Norwegian company that has been running a demonstrator off its own native shores for a couple of years and has previously expressed an interest in setting up a larger demonstrator in Scottish waters by 2015 – a timetable that now looks to have slipped. It is also looking at Maine in the US, where it got permission earlier this year to build four test floating turbines. It has not yet confirmed whether it will move forward with the project.
The Japanese authorities are in the process of constructing a similar demonstrator by 2015 off the shores of Fukushima, the site of last year's nuclear disaster caused by the tsunami. It wants to have 80 floating turbines in those waters by 2020 – the boldest statement of intent by any government in this area so far.
There are currently 2GW of offshore wind power in UK waters – only 180MW in Scotland. But the first round-three planning application in the UK was submitted for a 1.5GW project in the Moray Firth by Spanish-Portuguese team Repsol and EDPR several months ago.
Quinn said: "There's a huge opportunity for Scotland not just with the resource but to capitalise on the engineering knowledge from the universities, and the oil and gas industry."
For deepwater wind turbines, floating structures are expected to replace deep foundations, known as monopiles, or the conventional concrete bases commonly used as foundations for shallow water and land-based turbines. The technical challenge is that the floating structure must provide enough buoyancy to support the weight of the turbine and restrain pitch, roll and heave within acceptable limits.
According to experts, the economics of deepwater wind turbines will be determined primarily by the additional costs of the floating structure and of the costs of connecting to onshore power grids.