New ways to slash the costs of offshore wind based on a two-year programme of research by the Glasgow-based Offshore Renewable Energy Catapult (OREC) are set to be unveiled in a report to be published later this month.

The report, which makes use of research data obtained from OREC's testing facility at Blyth, aims to identify the ways to jump-start the stalled maritime wind sector, by cutting costs by a third, to £100 per megawatt hour (MW/h).

While this would still be more than the £85 per MW/h average cost of land-based equivalents, it would make the investment return for offshore developments broadly similar to onshore given the fact that windier conditions at sea make offshore turbines 50 per cent more efficient.

The offshore sector's high costs have led to a number of promising potential projects around UK being shelved in recent years, including the planned £5.4 billion 300-turbine Argyll Array off the coast of Tiree, abandoned as financially unviable by Scottish Power in 2013 after four years of planning.

Stephen Wyatt, OREC's strategy director, told the Sunday Herald that the forthcoming study will "identify the blocks the industry is facing as it aims to reduce capital costs by almost 50 per cent by 2020."

Wyatt said he was hopeful that improvements in technology, growth in the industry's supply chain, reductions in the cost of finance and the economies of scale associated with large developments would help the sector achieve its government imposed cost reduction target over the next five years.

One of the main measures to be examined in the report will be increasing the size of offshore turbine blades from a current average diameter of 49m to as much as 100m. Such an increase could more than double the output from each turbine from 3MW to 8MW.

Wyatt also believes that sizeable cost reductions can be achieved by designing new types of foundations and substructures for offshore wind turbines. Reducing the amount of steel used in the construction of subsea jackets by reducing the number of cross beams could also deliver cost savings.

Another more radical solution to reducing costs, which has been trialled at a number of test sites in the UK, the US, Portugal, Norway and France, is to get rid of fixed foundations completely by using floating turbines which are either completely free floating or tethered to the seabed using mooring lines and stabilised using ballast. Loosely anchored semi-submersible platforms as well as tension-leg platforms are other low-cost alternatives being examined.

The high cost of pile-driving turbine foundations into the seabed has been blamed for the cancellation of a number of proposed high-profile projects including, last year, the Celtic Array off the north coast of Wales.

The project's backers blamed the cost of laying foundations in challenging ground conditions but the cancellation of the project also coincided with the introduction of a less generous subsidy regime.

If the development of floating subsea structures is successful it would not only slash the costs of building wind farms in deep water locations but also allow the construction of offshore wind farms in areas of the sea where conventional monopole or tripod foundations cannot be installed. It would also allow the building of wind farms in deeper seas where fixed foundations are not practicable.

The report will also examine how changes to electrical infrastructure could reduce transmission costs by up to 30 per cent. Among the possibilities being examined are moving from AC to DC for medium and high voltage transmission, which could lead to less electricity being lost and allow transmission systems to better cope with strong wind gusts.

Early next year will see a final decision being taken by Scottish and Southern Energy on whether to press ahead with plans to build the 140-turbine Beatrice offshore wind farm, some 14 miles off the coast of Caithness. SSE said in November that it would only give the go-ahead to the project if it "provides the return on capital investment required to be compatible with the risks involved".

Last month Benj Sykes, the manager for DONG Energy's UK wind power business, told a conference in Aberdeen on offshore wind organised by industry body Scottish Renewables, that cost reduction was key to growing the industry. "If we get costs down quickly then the scale of deployment will increase and if we do not it will slow," he said.

Linda Holt of the Scotland Against Spin lobby group, which campaigns for the reform of what it calls the Scottish Government's "unsustainable" wind energy policy, said that the group was in favour of any report which identifies savings for the offshore sector as offshore generation in Scotland has not so far shown itself to be economically feasible.

Apart from a small number of test turbines on the east coast only one major offshore wind farm has so far been installed in Scottish waters: the 180 MW Robin Rigg farm in the Solway Firth. By contrast, around 20 offshore wind farms have been built around the English and Welsh coasts in recent years.

"Unfortunately, the huge amount of public money that has been made available to the sector through subsidies has stifled innovation and research," Holt said