Analysis - Floating turbines planned for US west coast

UNITED STATES: So far US offshore growth has been focused on the east coast. However, US rig specialist Principle Power said it hopes to secure a federal lease for a 30MW demonstration project -- using floating turbines -- off Oregon in the first quarter of 2016.

Seattle-based Principle then expects the 6MW Siemens turbines, on Windfloat foundations, to be operating by year-end 2017. "Once [that has occurred], we're a commercial technology," says Kevin Banister, project manager, bullishly.

Principle's WindFloat Pacific Project — with semi-submersible floating foundations — would be located in a depth of 366 metres, 30 kilometres off Coos Bay, where winds reach 9m/s and upwards. The turbines and foundations would be assembled onshore and towed, a cheaper and safer scenario than ocean construction, according to Principle.

In late September, the US Bureau of Ocean Energy Management (BOEM) declared that Principle's unsolicited lease request, submitted in May, was complete. BOEM also started gauging whether competitors were interested in the same area.

BOEM's public comment deadline was 30 October, but the impact of the federal government's partial closure — unprecedentedly broad — was unclear. Banister said he expected BOEM then to take 30 to 45 days to decide whether to hold a competitive auction.

"We'd be astonished if there is competitive interest," Banister said, because any entrant would need "credible plans". Amy Grace, lead US wind analyst at Bloomberg New Energy Finance (BNEF), also said she'd be surprised if there were competitive interest. Because of the curent US government shutdown, BOEM was unable to respond to questions about the project.

In 2012, Principle won a $4m advanced technology demonstration grant from the Department of Energy (DOE). It will seek a second grant, of up to $47 million, to complete the development. The DOE is expected to decide on the second grant by mid-May. Both grants require cost-sharing.

"If we're not selected, we'd have to evaluate [the project.] It would certainly make it harder," said Banister, also Principle's vice president of business development and government affairs.

The firm's partners include Siemens, MacArtney Underwater Technology, Houston Offshore Engineering, the American Bureau of Shipping, National Renewable Energy Laboratory (NREL) and Det Norske Veritas. NREL is also partnering on Statoil's competing but shelved the floating-foundation Hywind project off Maine on the east coast.

Principle's Coos Bay project is a scaled-up version of a single prototype developed by Principle Power with EDP and Vestas off the Portuguese coast. This uses a Vestas 2MW v80 on a Windfloat platform. Principle said it was the first offshore turbine to be installed with conventional tug vessels. For Coos Bay, the foundation design need not be altered, although the mooring lines would be longer, said Banister. The Portuguese project is in water depths of only 45 metres.

Floating foundations will open up a huge wind resource above the deep waters of the US west coast. The Pacific Northwest — including Oregon — has an offshore potential of 342GW for areas with annual average wind speeds of 7m/s or greater at 90 metres, said NREL. California has 589GW. However NREL cautions that high waves and swell in the Pacific Northwest "may increase fatigue concerns on offshore wind turbine structures".

Walt Musial, NREL's manager of offshore wind, said floating foundations would not be mature commercially for another eight to ten years. A west-coast offshore industry is distant too. "Principle's [progress] is a step in the right direction, but one project is not an industry," he said.

Opposition is not anticipated, in contrast to what Cape Wind has faced off densely populated New England. The Coos Bay project will be "barely visible" from shore, said Banister.

Significant demand for renewable energy exists in the region, especially in nearby California, which has an aggressive renewable portfolio standard of 33% by 2020. Even so, the regulatory environment is "immature", noted NREL's Musial.

So far, Washington state, Oregon and California have agreed to collaborate with BOEM, DOE and other agencies to evaluate the benefits and impacts off offshore renewables. "An additional goal is to develop the planning and regulatory structure," is all that BOEM's website said.