opportunity

Development of floating wind foundations

The competing floating wind concepts rely on the classical offshore foundations as used in the oil & gas. In oil & gas industry, foundations were produced on a case-by-case basis and they were designed to support a large deck structure. This led to complex structures that were never intended to be produced in series. The wind industry has only need to support a single tower and requires a large number of identical units. It is therefore desired to reduce costs by implementing series production and to simplify the design.

There is need for simple and series producible “monopile type” floating foundation.

Semi-submersible

  • Difficult production process Stress concentrations
  • Difficult integration of turbine mast load in 3 or 4 legs
  • Difficult transport (Fullly assembled voluminous unit) from yard to farm

Spar

  • Limited waterline hence stability from large deep draught weight
  • Extreme draught required for very large turbines
  • Requires up-ending process or very deep construction harbour
  • Turbine erection in extreme water depth (likely offshore – at project location)
  • Difficult transport from yard to farm

Tension leg platform

  • Similar as Semi-Submersible
  • Complex mooring system
  • Complex installation process

Analogy

Failure of offshore oil & gas concepts in bottom fixed wind

When the offshore wind kicked off in the early zeros, strangely enough the foundations for bottom fixed offshore wind (Monopiles) did not rely on the well-known offshore technology (Jackets). And even today, jackets form only a small portion of the total amount of wind foundations.
Why is that?

Jacket foundations

  • Offshore jackets were never designed for series production
  • Complex design
  • Difficult production process
  • Fatigue prone details
  • Difficult integration of turbine mast load in 3 or 4 legs: jackets were used for “deck” loads

Monopile foundations have other characteristics

  • Designed for series production
  • Simple design
  • Very high production efficiency
  • Easy installation
  • Piles provides simple integration of turbine

Monopiles are simple and robust, and allow mass production and therefore they are generally preferred over jackets.