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

The great offshore wind paradox

The offshore wind industry faces a well-known paradox. It needs wind to generate electricity, but too much wind makes it difficult to create the necessary infrastructure. Quite simply, lifting major components in high winds is one of the biggest issues facing offshore wind turbine installation. Over the years, thousands of days of installation time have been lost, leading to cost increases in the billions of Euros and huge project delays.

Various remedies have been attempted, but the nut still has not been cracked. In fact, I am rather surprised at the half-hearted efforts to address the paradox. Why? Because the impact of weather downtime has far-reaching ramifications in and beyond the industry.

Readers of this site can access an exclusive report from BVG Associates that illustrates the point.

According to BVG Associates, the biggest single cause of weather downtime during offshore turbine installation is the sensitivity of component lifts to high wind speed. Even small increases in the wind limits for lifting operations can reduce wind farm capital expenditure (CAPEX) and the levelised cost of energy (LCOE) significantly.

The crucial aspect is increasing the maximum wind speed for turbine lifts and especially for blades. BVG analyses the potential impact of this increase on the levelised cost of energy (LCOE), putting it down to five key elements:

  • Installation costs by reducing time on site
  • Interest costs by cutting the time to first generation
  • Cost of capital by lowering project risk
  • Construction insurance
  • Yield losses from quicker operations and maintenance (O&M)

The report illustrates that a reduction in some or all of these factors will have a significant impact on LCOE.

Specifically, based on a number of realistic assumptions, the report concludes that increasing the maximum wind speed for lifts from 11 to 16 m/s can reduce LCOE by as much as 1.8 percent, with large saving achieved through lower installation costs.

The importance of reducing LCOE on the industry cannot be underestimated, particularly if it is to be competitive with other energy sources in the long term and if we are to continue to raise the bar on safety – which we must.

One of the main issues to be tackled is where the innovation needs to take place, and whose responsibility it is to drive innovation. Is it in the turbines, vessels or in installation methods?

We have seen development in the recent purpose-built jackup vessels, which has given them better capabilities in larger waves and stronger currents.

But in terms of offshore lifting equipment and operations, the procedures and technologies have remained largely the same for several years, with only relatively small step-changes in technology.

Fortunately, there are a growing number of players in the industry who are willing to contribute to the development. For example, the vessel operator GeoSea uses the Boom Lock system by High Wind on the crane of its jack-up vessel Neptune, and it is also preparing the new vessel Apollo for the system. This system provides greater control of the movement of turbine components in higher wind speeds.

Bart De Poorter, General Manager of GeoSea explains why he has wanted to challenge the status quo:

“There is a large potential for the industry to reduce costs by increasing workability offshore. As the turbines and blades grow in size, the weather limits and controllability during lifting operations will decrease, unless we introduce smart solutions.”

The report by BVG Associates focuses on one particular technology innovation that makes component lifting possible in higher winds. But of course, increasing wind speed is not the only factor, and other innovations are also outlined, such as increasing wind turbine capacity, introducing DC power take-off, improving jacket manufacturing, and introducing suction bucket technology.

It is the total combination of these technologies that will have maximum effect in the long term. But in the short term, developers and contractors have a choice to make: do they stick to current practices to solve here-and-now challenges, or do they take the bull by the horns and look to innovate to ensure the future of offshore wind energy?

Like this post? Subscribe now and get notified about new content!

2 Responses to The great offshore wind paradox