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How the feeder barge method is the key to unlocking increased offshore wind capacity in the USA

Spinergie investigates how the feeder barge installation method has the potential to solve some of the issues faced by offshore wind developers in the USA.

There are currently two East Coast wind farm projects under construction and on track for completion in 2024 (South Fork and Vineyard-Wind 1), with a further two expected to begin the construction phase in 2024 (Revolution Wind 1 and Coastal Virginia Offshore Wind). These four projects have a combined capacity of 4.2 GW - just under 15% of the 30 GW 2030 capacity target. In fact, while US offshore wind capacity is expected to see significant growth in the run-up to that 2030 target, seeing a 138% increase in the seven years between 2023 and 2030, the current trajectory indicates that the country will fall short of its goal by around 40%. 

Market conditions in the US are challenging, with several developers seeking to amend their power purchase agreements (PPAs) due to economic difficulties. This is one of the main factors the country will fall short of its 2030 target. Geopolitical events have exacerbated a strained situation caused by inflation, supply chain disruptions, and increased financial costs. The main issue for developers is that fixed-price contracts have neglected inflation escalation and other protections. While, for example, New York’s most recent solicitation enabled inflation adjustments and cost-sharing mechanisms to share risks better, and Massachusetts' latest RFP contains provisions to address adverse conditions, older projects do not benefit from such measures.

As such, given the relatively low penalties for terminating, developers are requesting renegotiation or termination of the PPAs, with projects to be potentially re-bid in future auctions.

Most planned projects are based on the East Coast, and the vast majority are fixed-bottom developments, but with floating wind expected to make a small contribution to overall capacity by the end of this decade.

The US offshore wind sector faces myriad challenges as it works to increase capacity, including a lack of domestic manufacturing and infrastructure to support the supply chain, but the need to navigate the complex issue of the Jones Act is perhaps the main challenge currently faced by developers. 

The Merchant Marine Act of 1920 (the Jones Act) is a US federal law regulating maritime commerce. The law states that vessels transporting merchandise or people between two US points must be US-built and flagged, majority-owned by US entities, and crewed/operated by US citizens and permanent residents. It was confirmed in the Garamendi Amendment of January 2021 that the Jones Act applies to “non-mineral energy resources,” including offshore wind. This is because wind turbines and substations installed on the US OCS are considered US points. Therefore, transporting components from a US port to a wind farm site is considered a trip between two US points and so falls under the restrictions of the Jones Act.

Developers have had to devise a number of solutions to help navigate the Jones Act constraints. We explored these methods in an earlier article (How to Build a Wind Farm in the USA: Three Solutions Available to Developers), but to recap here: 

  • Using US-Flagged WTIVs: the first US wind turbine installation vessel will be delivered in mid-2025, but it is already booked until late 2026. While up to five US-flagged WTIVs are expected to be available to the market by 2030, this is nowhere near enough vessels to meet growing demand. 
  • Canadian Ports: ports such as Halifax and Argentia can be used as marshaling bases to circumvent the Jones Act restriction. While this remains a feasible option for now, with many current and upcoming projects based on the Northeast Coast (around New York, Massachusetts, etc.), it will become prohibitively expensive as activity travels south towards Florida and distances between port and project increase. 
  • Feedering with HLCs: Cargo vessels can be used to bring components directly from Europe to the wind farm site. However, due to the significant transatlantic distances involved, this can become complex to coordinate and expensive. 
  • US-Flagged Feeder Barges: this method can be used to transport components to the WTIVs, which are stationed on the wind farm site. While there are berthing issues to overcome with this solution used in conjunction with jackup heavy lift vessels, it can potentially serve most of the upcoming demand in the region. 

Can the feeder barge method meet US offshore wind demand?

It is clear that each potential method of working around the Jones Act comes with its own limitations, not least the lack of available Jones Act-compliant WTIVs. But for the feeder barge method, which is already the most viable solution, there are a much higher number of available vessels.

Spinergie analysis indicates that 167 Jones Act-compliant barges are suitable for use in offshore wind, with a third of them owned by small players with just one or two barges in their fleet. Most of the fleet is over 20 years old, with a small minority aged 10 years or less. While this situation is fine for now, it does indicate that there may be some phasing out of the older fleet in years to come, and, as will be discussed later in the article, newbuilds with new wind-focused technologies will also be required to enter the fleet.

In the run-up to 2026, around 5,000 MW of wind farm capacity is expected to be commissioned, and these projects are prime candidates for the feeder barge method. The two wind farms already under construction, South Fork and Vineyard Wind 1, are already using variations of the method. South Fork will use three heavy load carriers as feeders directly from Germany, while Vineyard Wind 1 will use the cargo barge feeder method for turbine installation.

New opportunities are abundant. All awards are yet to be made for installation operations at Ocean Wind 1 and Southcoast 1, while there is potential for the feedering method to be awarded for foundation installation at Skipjack 1, Sunrise, and Revolution. These latter three projects will be the first to utilize the Charybdis, the first Jones Act-compliant WTIV, for turbine installation. Beyond 2026, the number of opportunities for feeder barges is only expected to increase.

Learning by example: feeder barge success in offshore wind

While using the feeder barge method is likely the key to meeting offshore wind demand in the USA, it is already successfully used in established markets to facilitate existing installation methods. For example, it has been used in foundation installation for jackets, monopiles, suction bucket jackets, and gravity-based structures.

Using feeder barges in these foundation installation programs has highlighted the key benefits. It increases installation efficiency by allowing the heavy-lift vessel to remain positioned close to the wind farm, reducing transit time. It also helps developers navigate port restrictions or the challenge of transporting unique foundation designs. When heavy-lift vessels cannot access ports, the feeder barge will be used to “feed” the vessel, situated offshore, with what it requires from the port. Likewise, should a unique foundation design, GBS, for example, be used for a project, it is more practical to transport these components via the barge.

Spinergie analysis has demonstrated that the use of feedering can sometimes result in time-saving for heavy-lift vessels. When looking at the average number of vessel days for installation, feedering saw a reduction in the median installation days per piece for both jackets and monopiles (1.5 days compared to 2.4 for monopiles and 1.7 days compared to 2.0 days for jackets).

Case Study: Fecamp Offshore Wind Farm

EDF’s Fecamp offshore wind farm project is currently under construction to be fully commissioned in 2024. The 71-turbine development, which lies off the northern coast of France, will have an overall capacity of 497 MW.

During the installation of GBS Foundations, three feeder barges were used (Saipem Castoro 11, Saipem S44, and Saipem S45) via two Boskalis AHTSs alternating to transport the foundations to the heavy lift foundation installation vessel (Sleipnir). Another Boskalis AHTS provided assistance to the towing vessel for the berthing operation.

In all, three foundations were transported per barge, per trip, with a median of 5.04 days duration for each barge cycle, including loadout and return.

Solving the limitations of the feeder barge method

As we have seen, the feeder barge method has a proven record of success in offshore wind farm construction; however, it has a crucial technical limitation for projects using jackup vessels. Two aspects need to be considered: stability and collision risks. Feeder barges are susceptible to instability during operations because they have little to no station-keeping ability. This makes it impossible for jackup cranes to lift components reliably and safely from a feeder dock. The lack of station-keeping ability also means there is a risk of colliding with a jackup leg while the barge is positioned underneath in preparation for the jackup lifting components. 

Wind installation jackups are the most frequently used vessels for this task; in mid-2023, Spinergie analysis indicated that such units had been used to install 99% of the global coverage of offshore wind turbines and 60% of foundations. As such, innovation is crucial to make the feeder barge method compatible with jackups.

Fortunately, the market is already seeing solutions for both the existing fleet and future purpose-built newbuilds to make them compatible with jackups.

  • Motion-Compensation Technology: aims to create a stable platform within a floating barge by actively counterbalancing its motion. This technology is suitable for existing barges and will be used during the turbine installation phase of Vineyard-1. 
  • Liftable Barges: The BargeRACK concept from Friede & Goldman enables barges to be lifted during installation operations. COSCO Shipping has entered into an agreement to build a WTIV compatible with this technology. It will be designed by Fride & Goldman and received approval in principle from ABS in May 2022. 
  • Specialized Locking Duo: For use with new, purpose-built barges, this technology allows for a locking mechanism between the barge and the jackup to remain stable. The Maersk Sturgeon WTIV will be designed with this technology in mind, as will the Feederdock WTIV concept. It will be used in the turbine installation phases of the Empire 1 and Empire 2 projects and Beacon 1. 

Further challenges in using the feeder barge method relate to marine spread and the critical path. Using additional vessels inevitably results in more complex marine coordination, potentially sharing vessels with other projects. Any delay on one project may significantly impact subsequent projects relying on the same vessels. In a tight market, the margins for delays and issues are slim. It also results in higher dayrates, which could be prohibitive for smaller developers, and additional contract mechanisms are needed to protect against such delays.   

In summary, the feeder barge method has emerged as the most efficient and readily available solution to the progression of wind farm development in the USA. Not only does it help developers navigate Jones Act restrictions and reduce reliance on foreign ports, but it also allows for deploying next-gen turbines using existing WTIVs. In addition, the feeder barge method facilitates the use of alternative foundation technologies like Suction-Bucket Jackets and Gravity-Based Structures, which are challenging to transport via WTIVs. This opens the door to innovative foundation solutions that otherwise would have been impossible.

The feeder barge method is a crucial solution for the US offshore wind industry. It ensures Jones Act compliance, expedites technology adoption, and supports alternative foundation solutions. As such, its use will position the US for significant progress in increasing its offshore wind capacity.

Contact Spinergie today, and our team will be delighted to arrange a demo to show you how our solution is helping industry players stay on top of market developments. 

Photo of Sarah McLean
Sarah McLean
Marketing Content Writer
Published on
October 4, 2023
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