Addressing the challenges of offshore wind turbine installation and maintenance in high winds

Crane rails: Why they improve offshore lifting capabilities

Crane rails: why they improve offshore lifting capabilities

As demands on offshore wind installation processes increase, crane technology is being pushed to its limits. Not only do offshore cranes need to lift heavier and larger wind turbine components, but they also need to operate in more gruelling weather conditions.

Increasingly, vessel owners and contractors are looking to meet these demands by boosting crane capabilities with technologies such as taglines and various forms of intelligent lifting systems. But there are important implications of these additional demands that impact crane design and performance.

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Intelligent guidance for offshore lifting: The next DP2?

Intelligent guidance systems

A number of years ago, it was normal practice for offshore contractors to win major offshore wind turbine installation projects using non-propelled jack-up barges supported by tugboats and anchors for positioning. This was the established way – it was safe, reliable and efficient.

Then, in around 2011, the introduction of second-generation jack-up vessels brought Dynamic Positioning Systems (DP systems) into play. This became the new ‘state of the art’. In the typical progression of ‘order winners’ becoming ‘qualifiers’, today, vessel owners are not even invited to tender if their installation vessels are not DP2-capable.

If you consider offshore lifting operations of large components such as turbine blades, there is a strong parallel to that of vessel positioning before DP2 became the industry standard. During the lift, manual winches, people with ropes and, in some cases, simple constant-tension systems try to keep the blade under control during the lift. You could compare it to the tugboat-and-anchor method of positioning your jack-up barge. Continue reading

DEME CEO: Driving down offshore wind costs

Driving down offshore wind costs

In this second of two exclusive interviews with High Wind Challenge, DEME Group CEO Alain Bernard explains why the company invests in innovation and how it contributes to reducing offshore wind costs.

Can you explain the DEME Group’s basis for diversification, particularly into offshore renewables?

The essence is our speciality within certain niches and that we aim to be the best in those niches. Our dredging background has given us knowhow within different areas, such as the seabed, sea conditions and other marine environment factors as well as the associated technologies. We have specialised further in related niches, and without losing the focus of our core knowhow, we have expanded our activities. Continue reading

How to overcome technical constraints of the offshore wind lifting process

Technical constraints of lifting

The lifting process on jack-up vessels is a key process in any offshore wind turbine installation or maintenance project. Control systems such as tagline systems are a necessary part of the lifting setup. Their purpose is to help manoeuver loads – such as wind turbine components – to the desired point accurately and safely.

The most obvious source of movement of a hoisted load is due to inertia and wind. Yet the solutions for controlling these motions are subject to other practical constraints that often make it difficult to achieve sufficient control during the lifting process. Continue reading

Reducing weather downtime in offshore wind turbine installation

Reducing weather downtime in offshore wind turbine installation

Recent advancements in technology can bring about a long-awaited positive development in the offshore wind industry: reducing weather risk associated with offshore wind turbine installation.

Difficult weather conditions often lead to significant project delays caused by downtime that extends project time and increases costs.

Of course, weather downtime is an unavoidable part of any installation process and must be figured into project costs alongside all of the different activities required of the jack-up, including mobilisation and demobilisation, loading of the wind turbine elements, transit between the port and the wind farm, positioning and jacking, and installation of the turbine. Continue reading

How can contractors contribute to a sustainable offshore wind industry?

Offshore wind now accounts for about 7% of European renewable energy generation.  Most of this new capacity has been built since 2015. Although the rate of growth has been slower than many expected or hoped, it is still a significant shift in the way Europe generates electricity. The change has been biggest in the UK, where offshore wind now generates about 5% of all its UK electricity demand.

But it hasn’t been cheap. In 2012, new offshore wind farms at final investment decision (FID) had a levelised cost of energy of about €150/MWh. At the time, the ambition was to get to about €110 for projects reaching FID in 2020. Led by the rapid introduction of next generation of offshore wind turbines, recent analysis by BVGA suggests that the 2020 target is well within reach. Continue reading