Marrying oil production with offshore wind power sounds far-fetched right now. However, I cannot help but begin to wonder about the prospect while decommissioning seems so important in the North Sea. Talisman Energy in the United Kingdom doesn't have any doubts about the idea. The company is investing serious money in using its Beatrice oil field to help harness offshore wind power in an apparently perfect marriage of fossil and renewable energy resources. It's been billed as a demonstrator project only at this stage to investigate the feasibility of offshore wind farms, as Talisman celebrated 10 years of oil operations in the North Sea. But if Beatrice makes waves in the world of renewable energy, then perhaps there is a lesson here for all oilfield operators with power-hungry offshore structures.

With partners, Talisman is spending US $45.43 million building the wind farm near to Beatrice which is located just 15.6 miles (25 km) off Scotland's eastern coast in the North Sea, in Block 11/30 - the closest offshore oil field to the UK mainland and just visible from land.

Initially two wind turbine towers will be installed 1,600 ft (500 m) apart, 1.25 miles (2 km) southeast of Beatrice Alpha, which comprises two bridge-linked steel platforms. The two turbines - each with capacity to generate 4 MW - will be hooked up by subsea cable to Alpha. From a presentation seen by E&P, the turbine towers will be towed to their location vertically, then apparently ballasted down on to the seabed at a depth of 137.7 ft (42 m) - double the water depth of most existing offshore wind turbines - and then the turbines will be installed on top. Each turbine blade is 197 ft (60 m) long and the turbine hubs will be 279 ft (85 m) above sea level while the total structures will measure 475 ft (145 m) from seabed to the top.
Beatrice, which was discovered in 1976 and started production in 1981, is still producing 5,500 b/d of oil.

It was chosen:

• Because it is near to the end of its productive life; and
• Because its location in the Moray Firth is said to be close to ideal conditions for a wind farm.
Also, Beatrice already has a power cable connection to shore. The power produced by the turbines will be used onboard the installation and thereafter once oil production has ceased - Talisman had not said when that is likely to be - power will be sent into the national grid.

If this demonstrator succeeds, Talisman's President and Chief Executive Dr. Jim Buckee said a larger-scale commercial project will be considered. That could extend the platform's life by 20 years.

"The existing infrastructure at Beatrice offers a unique opportunity to test the feasibility of wind farms in water depths of 114 ft and 147 ft (35 m to 45 m), while optimizing the value of our existing facilities," Buckee said.

"We hope to show that it is possible to use offshore oil and gas expertise in the renewable energy business thereby potentially providing new opportunities for investment and employment in the North Sea."

Offshore construction work was due to begin towards the end of 2004 with power production commencing late 2006.

Ultimately, the plan is to install up to 200 offshore turbines capable of generating 1 gW of electricity - sufficient to power Aberdeen, or 20% of Scotland's electricity demand.

Funding is coming from a variety of sources: Both the Scottish Executive and the UK's Department of Trade and Industry are each supplying $5.48 million for the initiative. Another $7.83 million is coming from the European Commission while Talisman, and Scottish and Southern Electricity are providing another $13.32 million each.