Larger turbines bring capacity pressures for project logistics

Larger wind turbine components require specialised logistics equipment, which can lead to constraints when it comes to transport activities, installation operations and the space available in ports, acccording to Francisco Rodrigues, global segment lead – offshore wind for Mammoet.

“…the oil market has gone through a bumpy period and the oil and gas project sector has not been as hot recently as previously anticipated.” - Christian Hoffmann, SAL Heavy Lift.

“Mammoet is consequently investing in research and development (R&D) to be ready for extra-large monopiles, new types of jackets, turbines of more than 15 MW capacity, and new floating steel/concrete substructures,” he commented.

Another issue arising from the increasing size of turbine components is the future availability of the right type of high-end heavy lift shipping capacity to transport them.

Christian Hoffmann, head of marketing and corporate communications for SAL Heavy Lift, agreed.12-18 months ago an expected increase in new offshore oil and gas projects had prompted warnings that there might not be sufficient such capacity available to fully meet the requirements of both that sector and the offshore wind industry.

“Since then, the oil market has gone through a bumpy period and the oil and gas project sector has not been as hot recently as previously anticipated.

“However, the global heavy lift shipping industry has not added any specialised top- end of the market tonnage for years, so the likelihood of pressure on capacity at some point in the future is still there,” he said.

Vessel shortage

Rodrigues voiced similar concerns, suggesting that the number of available transport and installation vessels is “currently minimal relating to the size of offshore wind turbine components coming up”.

“That is due to the rapid increase in turbine size over the past decade. Nevertheless, we remain confident the industry will deliver more newbuild carriers and/or upgrade existing vessels to cover global demand,” he stated.

“Where we had seen a bottleneck coming up was that flat deck carriers, which are predominantly used to transport modules for the oil and gas industry, were also being used for monopile transport. However, maybe for now the Covid-19 pandemic has solved this issue [by slowing the pace of new oil and gas projects].”

Adapting market

Thore Schreiber, head of business development and sales for Rhenus Offshore Logistics, also expressed a mix of optimism and caution about the future availability of suitable heavy lift shipping capacity to support offshore wind projects.

“It is extremely important to understand and define what the true needs are in terms of port developments in some countries, as this will have a big impact in terms of supply chain investment.” - Francisco Rodrigues, Mammoet.

“It is a very natural supply and demand sector and as long as new projects with even heavier components are planned, the vessel market will adapt accordingly,” he suggested. “However, a bottleneck can occur where unplanned changes to the schedule are required.”

Brian Sørensen, head of business development port service and wind logistics, Esbjerg, for Blue Water Shipping, speculated that the increasing size and weight of offshore turbine components might create a requirement to review the type of vessel and port operations deployed to handle them.

“Maybe the industry will have to find a different way to load and unload those components, an alternative to lifting. Perhaps there will be a move away from the sort of lo-lo operations currently used to ro-ro or another solution,” he said.

Running in tandem with the increasing size of offshore wind turbines is the continuing geographical expansion of that industry, sometimes into countries with only limited basic infrastructure, resulting in specific logistics challenges.

Mammoet, for instance, is involved with several developments in countries that are relatively new to offshore wind, including some “where our work has required us to think creatively at times”. Rodrigues said one example was Taiwan where Mammoet assisted local companies in how to prepare a port to receive and handle offshore wind components, as well as performing the actual heavy lifting for the project.

“It is extremely important to understand and define what the true needs are in terms of port developments in some countries, as this will have a big impact in terms of supply chain investment,” he explained. Other new logistics challenges set to come more to the fore over the next few years will arise from the anticipated growth in floating offshore wind turbine installations – specifically, how to handle the land to sea movement of the large floating foundation structures (floaters) they are attached to.

Onland assembly

Lucile Héritier, director of ports for the Brittany region in north-west France, explained that the floaters for the planned next generation of floating wind turbines would be too large to be constructed in most drydocks and would therefore have to be assembled on land. 

However, that development will present new operational challenges when it comes to getting the units into the ocean. Possible solutions, she suggested, included using a very heavy crane, launching via a quay onto a very large barge or constructing a slipway. However, each option has its drawbacks.

Sarens bullish about floating wind energy technology

Sarens recently joined the World Forum Offshore Wind (WFO), which is dedicated to fostering offshore wind growth worldwide. It believes that floating technology is critical to unleash the full potential of the marine energy industry; as much as 7 GW of floating capacity could be installed off Europe, the USA and Japan.

Sarens said that floating wind energy requires fewer foundation materials, has a shortened installation and decommissioning cycle, and can generate power at water depths exceeding 50-60 m – the current limit for fixed-base offshore installations. “With analysts forecasting a 50 percent annual growth rate for floating offshore wind over the next

five years, the market represents a massive opportunity for marine tech businesses and innovators right across the supply chain,” said the company.

Wind turbines can be assembled and pre- commissioned onshore before being towed to site. For this, heavy-duty trailers are needed to move the structures onshore and position them on oceangoing vessels. Sarens owns modular barges capable of supporting up to 25 tonnes per sq m that can carry these structures offshore.

The turbine is stabilised at sea by applying a semi- submersible concept, single-point anchorage (SPAR) buoys, or other technologies. This means that the assembly takes place in a much safer and more controlled environment when compared with traditional bottom-fixed structures, Sarens added.

Kleopatra Kyrimi, global director of communication and marketing at Sarens, identified the UK as a key growth market for this technology. The 30 MW Hywind project in Scotland, developed by Equinor and commissioned in October 2017, is the only large-scale floating wind farm in operation at present: “With an unbeatable geographical location, surrounded by the coast, the UK has a great opportunity for reindustrialisation into ecological sectors and with enormous potential in floating wind and offshore wind power,” she said.

This article has been taken from the August/September 2020 edition of HLPFI.