Wind Energy

OffshOre #2 | The Magazine
a strOng fOOtIng
fOr hIgh tOwers
The optimisation of the foundations has been driving the engineers
since the initial concept sketches for offshore wind farms. The steel
and concrete footings have to provide a secure foothold while being as
cost-effective to manufacture and assemble as possible. This leads to
various solutions for different wind farms: For a long time, the simplest
case was so-called gravity foundations where the extended tower of the
wind turbine was anchored into the seabed via a concrete base. With
ever larger turbines and increasing water depths, engineers discovered
that monopiles, where the extension of the tower is driven directly into
Tripile Cuxhaven Steel Construction Jacket WeserWind
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the ground, are the best solution. For greater water depths and larger
turbines with 5 MW or more – especially in the German North Sea – various
types of multi legs were developed. Depending on the steel price,
assembly technology and philosophy, companies started using different
models. Most recently, engineers have also been using gravity foundations
for wind turbines with 5 MW and more. With their 4500 tons these
concrete footings now weigh more than five express train railcars. For
water depths beyond the 50 meter mark, new systems are being created
which allow for a floating attachment of the wind turbines.