Annex 1—Transport System Details
Subsea Power Cable Subsystem
The Subsea Power Cable Subsystem provides the electrical power transport from
the transmission station to shore. For this case the total length of this cable is
estimated at 30 NM (55 km).
The technical specifications and cost figures used in this case were and can be
extracted from the internet (e.g. http://www.nationalgrid.com/NR/rdonlyres/62196427C4E4-483E-A43E-85ED4E9C0F65/39230/ODISAppendicesFinal_0110.pdf).
Estimated cost for a 300 kV cable 1031 MW (price level of 2013):
CAPEX (20 years depreciation): 111.120.000 Euros
OPEX (annual): 560.000 Euros
Offshore Wind and Fish Farming Support Ships
The Offshore Wind and Fish Farming Support Ships are important to attain the 10%
savings on O&M costs. The design requirements of these ships include:
• capable to transport and accommodate 40 persons, working in 3 shifts for one
week
• wind farm spares transport and repair capability
• mussel harvest and transport capability.
In addition this ship must be also be capable to navigate and work in harsh
weather conditions. The following equipment is considered to make this possible:
• a dynamic position system (DP-2)
• a motion compensated crane
• a wide working deck.
The size, shape, weight contribution and propulsion should be tuned on such a
way that this ship will be a comfortable platform to live on for one week and to
work on 24/7 h with a significant wave height up to 3 m (North Sea conditions).
For an illustration of a new preliminary design of a Wind & Mussel Farming
Support ship which could meet these specifications, see Stavenuiter (2009).
The optimization of size, shape and displacement makes these ships stable
platforms to operate in a working window up to 95% over the year. Besides this, the
dynamic position system (DP2) and motion compensated crane make it possible to
access wind turbines, with personnel, by man riding with a crew basket, but also
with spare parts and tooling, up to 3000 kg.
As support ship for Mussel Farming it is assumed that these ships will be
equipped with a cargo hold for 600 tons of mussels. For inspecting and harvesting
the mussels, the dynamic position system and motion compensated crane are also
4 Operation and Maintenance Costs of Offshore Wind Farms …
111
Subsea Power Cable Subsystem
The Subsea Power Cable Subsystem provides the electrical power transport from
the transmission station to shore. For this case the total length of this cable is
estimated at 30 NM (55 km).
The technical specifications and cost figures used in this case were and can be
extracted from the internet (e.g. http://www.nationalgrid.com/NR/rdonlyres/62196427C4E4-483E-A43E-85ED4E9C0F65/39230/ODISAppendicesFinal_0110.pdf).
Estimated cost for a 300 kV cable 1031 MW (price level of 2013):
CAPEX (20 years depreciation): 111.120.000 Euros
OPEX (annual): 560.000 Euros
Offshore Wind and Fish Farming Support Ships
The Offshore Wind and Fish Farming Support Ships are important to attain the 10%
savings on O&M costs. The design requirements of these ships include:
• capable to transport and accommodate 40 persons, working in 3 shifts for one
week
• wind farm spares transport and repair capability
• mussel harvest and transport capability.
In addition this ship must be also be capable to navigate and work in harsh
weather conditions. The following equipment is considered to make this possible:
• a dynamic position system (DP-2)
• a motion compensated crane
• a wide working deck.
The size, shape, weight contribution and propulsion should be tuned on such a
way that this ship will be a comfortable platform to live on for one week and to
work on 24/7 h with a significant wave height up to 3 m (North Sea conditions).
For an illustration of a new preliminary design of a Wind & Mussel Farming
Support ship which could meet these specifications, see Stavenuiter (2009).
The optimization of size, shape and displacement makes these ships stable
platforms to operate in a working window up to 95% over the year. Besides this, the
dynamic position system (DP2) and motion compensated crane make it possible to
access wind turbines, with personnel, by man riding with a crew basket, but also
with spare parts and tooling, up to 3000 kg.
As support ship for Mussel Farming it is assumed that these ships will be
equipped with a cargo hold for 600 tons of mussels. For inspecting and harvesting
the mussels, the dynamic position system and motion compensated crane are also
4 Operation and Maintenance Costs of Offshore Wind Farms …
111