Reduce, reuse, recycle

While offshore wind has taken off rather successfully in Europe – the US offshore wind industry has some way to go. Karen Boman reports on how existing offshore oil and gas technologies can be applied on offshore wind projects in the states.

Installation at the Block Island Wind Farm offshore Rhode Island. Photo from Deepwater Wind.

By the end of last year, nearly 4000 offshore wind turbines had been installed in the North Sea. The industry has matured enough that the first offshore wind farm – DONG’s Vindeby, commissioned and installed in 1991 southeast of Denmark – is now being decommissioned.

The US has now also joined the ranks of offshore wind farm players, thanks to the start of operations at the first US offshore wind farm, the Block Island project off Rhode Island in December last year (OE: July and November 2016).

Momentum is building in this space, said Alanna Duerr, offshore wind energy lead for wind energy technologies office in the US Department of Energy (DOE), during a luncheon at this year’s Offshore Technology Conference (OTC) in Houston.

Duerr says that there are 13GW of projects in various planning stages currently ongoing. In December 2016, Statoil paid US$43 million for a 79,350-acre wind lease 14-30mi offshore New York in water depths ranging 65-131ft. Of the lease, Statoil says the area could potentially accommodate more than 1GW of offshore wind. Statoil is seeking a phased development with 400-600MW to start.

“The US is a key emerging market for offshore wind – both bottom-fixed and floating – with significant potential along both the east and west coasts,” said Irene Rummelhoff, Statoil’s executive vice president for New Energy Solutions, in Statoil’s December 2016 announcement.

Other European wind players such as DONG Energy and Copenhagen Infrastructure Partners also are starting to invest heavily in the US. DONG took over an offshore New Jersey wind lease previously held by RES America Developments in early 2016, its second lease off the US. The first lease area, Bay State Wind, was acquired in 2015. Copenhagen Infrastructure Partners acquired a 166,886-acre offshore lease south of Massachusetts, called Vineyard Wind, in 2016.

Offshore wind power will be needed not only to meet electricity demand, but is viewed as a potential economic boon for parts of the US economy, such as the nation’s marine transportation sector.

Current cost challenges and lack of supply chain for the US offshore wind sector could also be met by using existing oil and gas technologies, Duerr says. These include spars, semisubmersibles and tension leg platforms (TLPs), which could expand offshore wind capacity out beyond fixed foundation water depth capability, Duerr says (Read: The future floats).

Challenges ahead

Image from Statoil.

Repurposing these technologies for offshore wind presents challenges, however. Spars need to be assembled in a protected area, which works well in Norway’s deep fjords, but could limit the use of spars for offshore wind in other parts of the world. Spars also must be floated out, and turbines must be installed from a stable platform, not a floating vessel, Duerr says.

Semis for offshore wind can’t be one-off designs, but should be designed to be replicated by the tens of hundreds to create an offshore wind farm. Semis can be assembled onshore and floated out, making them an attractive option for deployment offshore the US west coast, which has deeper waters compared to the US east coast. TLPs designed for offshore wind use the same basic technology as oil and gas, but are leaner and require smaller foundations, Duerr says.

By integrating more expertise from oil and gas, Duerr says that DOE can tackle the technology challenges for offshore wind. DOE also plans to work with the Bureau of Ocean Energy Management to address regulatory challenges that pose barriers to offshore wind growth.

To meet US electricity needs, DOE is seeking to develop US offshore wind power capacity and industry. Nearly 80% of national US power demand lies in coastal regions. In these regions, approximately 2000 GW of offshore wind energy exists that could be accessed and exploited with technology available right now, Duerr says.

“There are lots of good wind resources in the Midwest, but no great infrastructure to support bringing that energy in the Midwest and Texas to the US coasts,” Duerr explains. To produce electricity near densely populated regions, the US needs to tap into its offshore wind power potential.

DOE not only looks to offshore wind to meet US electricity demand in its coastal regions, but reduce greenhouse gas emissions. Further developing the US offshore wind industry could also strengthen local manufacturing centers and economies in regions such as the US Northeast.

“If offshore wind develops as we think it can, in 20 years, there could be 43,000 permanent jobs in the US offshore wind industry,” Duerr says.

But, first, market barriers that block development of US offshore wind must be removed. These include cost and technical risks; establishing regulatory certainty and understanding and mitigation of environmental risks; and understanding of the benefits and cost of offshore wind, according to DOE’s 2016 National Offshore Wind Strategy.

In addition to Block Island, several additional projects could be operating by 2020, including two DOE Advanced Technology Demonstration Projects in Ohio and Maine – the Lake Erie Energy Development’s (LEEDCo) Icebreaker project, and the University of Maine’s New England Aqua Ventus I (OE: July 2016). The University of Maine project, expected to be deployed by year-end 2019, will address the technical challenges of a deepwater offshore project in a highly energetic wind regions. The LEEDCo project will address technical challenges of deploying fixed bottom infrastructure in an area with weak soil and ice accumulation. The project will be deployed about 7-10mi offshore Cleveland, Ohio, Duerr says.

To develop US offshore wind, vessel installation capacity will need to grow as well. Enough jackup/lift vessels exist in Europe to install increasingly larger turbines and structures, but more are needed in the US. With larger turbines, monopiles also will have to grow. The North Sea offshore wind industry can handle that, but the US currently doesn’t have that type of manufacturing capability. Monopile installations are the most prevalent in Europe; but soil conditions along the US east coast make it unlikely that many monopile structures will be used.

One pervasive challenge – and a question asked at every wind conference – is how to develop a supply chain for the US offshore wind industry to help bring down costs. The situation facing the US offshore wind sector is the chicken and egg scenario. Companies aren’t willing to expand their manufacturing capabilities because there is no supply chain. But without this investment, an effective supply chain can’t be formed.

“The federal government won’t invest in infrastructure development,” Duerr says. “That’s not our role.” States can play a role by creating tax incentives and structures to develop the offshore wind supply chains in their states. These incentives could be tied to an RFP (request for proposal) for a power purchase agreement, or require a local content piece that would drive investment in manufacturing.