Dominion begins offshore area tests

US-flagged lift vessel Inez Eymard is taking core samples off Virginia’s Atlantic coast at locations where Dominion would install two 6MW turbines in a demonstration wind project and lay electric cable for a connection onshore.

A Dominion spokesperson tells Recharge that the utility holding company expects the vessel to be collecting samples and other data for the next several weeks from 300 (91.4 meters) to 3,300 feet from shore for the underground cable, and 27 miles (43.4km) out where the turbines would be located.

The vessel will drill four borings at the turbine site 330 feet below the ocean floor. Dominion will use the samples to determine soil characteristics – such as composition and strength – to finalize the design of the wind turbine foundations.

Near shore, the vessel has finished two borings and has nine more to complete – each drilled 80 feet below the ocean floor.

Dominion will utilize those samples to finalize the installation plan of the underground distribution line. The line will connect onshore to Dominion’s electric grid at the US National Guard base at Camp Pendleton.

The demonstration project will be located in federal waters adjacent to a 472.6sq km area that Dominion is leasing for commercial wind energy development from the US Interior Department.

Dominion has received two US Energy Department grants totaling $51m for the demonstration project. If DOE approves the project, the company will install the two turbines and test design features intended to lower the cost of construction, reduce maintenance and withstand hurricane-force winds.  

Dominion intends to use lessons learned from the demonstration turbines to guide the development of up to 2GW of commercial wind energy.

"This proposed [demonstration] project provides a very interesting opportunity to develop renewable offshore wind energy for Virginia," says Paul Ruppert, senior vice-president of Dominion’s business development and generation construction unit.

Dominion is part of a public-private consortium that would carry out the demonstration project that includes turbine supplier Alstom, the Us National Renewable Energy Laboratory and several Virginia agencies and groups.