Offshore energy: a fair wind for offshore renewables

There is no denying that the past couple of years have been challenging for the offshore wind sector. Inflation and high interest rates have led to cost overruns for the turbine manufacturers, projects cancelled, few or no bidders for new leases and delays to new grid connections. Additional factors have included a refocus on traditional, predictable energy sources due in part to political changes. Severe weather, environmental concerns and the lengthy processes to obtain regulatory approvals have also added to delays. Supply chains have been under pressure with competition for components as new entrants come into the sector. Yet despite a slowdown in starting new projects, the global industry achieved a 9% increase in output over the period.

The long view

“The offshore wind industry takes a long view and the fact is that demand for energy is only going to grow,” says Frederik Andersen, Head of Renewables at leading maritime consultancy Clarksons, a longstanding partner of Damen with a history going back many decades. “To put it in perspective, offshore renewables currently account for just 0.4% of total global energy production. Analysts are forecasting that by 2035 offshore wind will account for 2-3% of global energy supply, a seven-fold increase in output. By 2050, it is expected to account for 7% of overall global energy output. So, while the sector has its headwinds at present, the medium to long term outlook is highly positive. In the meantime, investors are wary of committing funds while the political and regulatory environments are uncertain.”

From the perspective of energy management, there remains the unpredictability of wind turbines. Until solutions are found for large scale energy storage, the power generated by variable renewable power sources will not be able to fully displace hydrocarbons, hydro and/or nuclear, but in the meantime there is still consistently more demand than supply for clean energy.

Looking ahead

There is much to be optimistic about. The new technologies now being developed have the potential to transform offshore wind. Wind turbines capable of generating more than 20MW with rotor diameters of more than 250 metres are now feasible and should be available from 2030. The final piece of the jigsaw is designing the many different vessel types that will play key roles in transporting, installing and operating these giant offshore power plants.

As the industry matures, it is expected that the first multi-purpose wind turbines will be deployed. These will be able to act as offshore refuelling stations, storing some of the electricity that they produce in batteries or directly recharging electric vessels that are operating in the vicinity. It is also envisaged that they will be used to produce green hydrogen. This is highly energy intensive, but the cost of energy at the point of production would be a boost for hydrogen-powered vessels, and could encourage the adoption of hydrogen and its derivative ammonia as mainstream maritime fuels. The price of liquid hydrogen would fall significantly using cheap energy and zero cost of transport, and allay safety concerns with production taking place far from land.

Strong demand for specialist vessels

“At the end of 2024, there were 14,000 turbines in operation spread across 333 wind farms, with around twenty nations involved, concentrated in the Far East, Europe and the USA,” continues Frederik Andersen. “All these power plants require regular maintenance which is generating demand for the specialist vessels that host and deploy the technicians and their specialist equipment.” Order books are strong with shipbuilders who have developed portfolios of vessel types to meet these specific needs.

Wijtze van der Leij

The look from the inside

At Damen we have continued to see strong demand for our crew transfer vessels (CTVs) and our Service Operations Vessels (SOVs),” says Wijtze van der Leij, Sales Manager Offshore Wind at Damen.

“We offer a wide range of models that continually evolve in response to customer feedback. Our Fast Crew Supplier (FCS) 2610 and 2710 CTVs have sold all over the world, and our latest version, the FCS 3210, which is available in both hybrid methanol and fully-electric versions, is already taking orders and is in build. The intense demand has led to waiting lists but we expect it to ease off in 2025, enabling shorter delivery times.”

Demand is further underpinned by the fact that many of the heavy lift and other vessels from the oil & gas sector that have won contracts in offshore renewables are reaching their end-of-lives and will need to be replaced in the years ahead. Damen’s SOV range, designed to optimise the maintenance of wind turbines, also continues to evolve. Its latest version allows for a range of power systems to be integrated into the vessels. As the technology develops, fully-electric, hybrid, methanol and hydrogen power plants could all be options for those operating in a green environment. “Currently Damen has nine SOVs in build or on order,” adds Wijtze, “and with the oil and gas sector taking an interest in applying the SOV concept to their own activities, more are likely to be in the pipeline.”

While floating offshore wind is still some years away, Damen is already consulting with the industry and based on the feedback is developing the Floating Offshore Wind Support Vessel (FLOW-SV) concept.

This new class will optimise the entire process of installing floating wind turbines, with the FLOW-SV designed to transport and install safely, quickly and reliably, the larger, heavier chains and fastenings that the turbines will require. As mentioned above the moorings are still under development, but the FLOW-SV concepts have already received a positive reception.

As with many new technologies, offshore wind depends on governments, financiers, a collaborative manufacturing base and the landside infrastructure coming together to deliver the solutions that will ensure its success. It is 31 years since the first eleven wind turbines were installed at Vindeby, Denmark, and the industry has achieved so much since then. The next decade will be pivotal, but there is every reason to look forward with optimism.