Environmental Engineering Reference
In-Depth Information
the particular l ocation. Elsewhere i n Europe, t he experience with offshore wind
fa rms to date ha s been limited to much shallowe r wa ters a nd sites much close r to
the coast. Design, construction, transportation and erection are four areas where
optimisation i s c rucial if the economic viability of offsh ore sites i n su c h deep
wa t e r s i s t o b e g u a r a n t e e d. Fa c t o r y - fa b r i c a t i o n o f i n d ivid u a l s t r u c t u r a l c o mp o n e n t s
and t he deve lopment of prefa bricated solutions for t he entire structure result in
economic benefi ts and the chance to op timi se t he construction cost s of t owers and
foundations.
The choice of foundation type, t he length of time required for construction and, due to
the weather, t he limited w indow f or the t ransp ortation a nd on-site erection procedur es
are further critical fa ctors that i nflue nce the c ost s. Fundamental here for both
nearshore and offshore w ind turbi nes are the water depths, t he subso i l c on ditions
and t he ability t o deploy heavy plant, for examp le pontoons, jack-up barges, heavy-lift
crane vesse ls, drilling and drivi ng equipme nt, and so on. Another vital aspect for si t es
nea r the c oast is acce ssi bility for the t ransport of c onst ruction materials and the plant
re qu ired, s ee [79].
Current design and construction approaches are described in the following. Earlier
projects have already been described in detail in [8].
5.4.1
Compact substructures with ice cones
5.4.1.1 Middelgrunden offshore wind farm
Round substructures topped with ice cones were conceived for this location in shallow
waters near Copenhagen.
Comparison of prices for various compact substructures (Figure 5.10):
Steel caisson:
380 000
Concrete structure:
D
315 000
D
Monopile:
420 000
D
Fig. 5.10 Substructure options. (source: www.middelgrunden.dk )
 
Search WWH ::




Custom Search