This environmental impact assessment for Kriegers flak ... - Vattenfall

As examples, the technique behind the RePower 5
MW turbine is presented in Attachment 2.2 and similar
information on the Enercon 4.5 MW turbine is presented
in Attachment 2.3.
At the time of procurement, the turbine that offers
best economic and environmental conditions will be
chosen.
Offshore-based wind turbines differ from onshorebased
turbines in several ways. The main difference
is that offshore-based turbines are subjected to much
harder conditions due to stronger winds, greater dif-
Þ culty in performing service and harsher climate (salt
water, waves and ice).
5.4.2 The foundations
The foundations anchor the wind turbines to the seabed.
For offshore turbines, there are several different
types of foundations. The choice of foundation depends
on the water depth, the seabed condition, the weight of
the turbines and the cost. As the seabed condition and
the depth vary on the site, different types of foundations
will have to be used. Examples are monopiles,
tripods and gravitation foundations.
MODIFICATIONS FOR OFFSHORE USE
• A service crane will be installed in the nacelle to
reduce the cost for barge-mounted cranes.
• A container is mounted on the working deck, some
10 metres above sea level, containing all electronic
equipment including the transformer (690V/20kV).
It will be hermetically sealed to shield the equipment
from the salty air. (Electronic equipment and transformers
are mounted in the nacelle in most modern
wind turbines).
• Ladders and a mounting system to allow for safe
landing and boarding will be attached to the towers.
• A room for overnight stays in case of emergency,
also for use by the service team, will be built inside
the tower.
• Meticulous encapsulation of electronic equipment in
the voltage centre will be made.
DESCRIPTION OF THE WIND FARM 27
Monopile Gravitationsfundament Tripodfundament
• Anti corrosion treatment is very important for
prolonging the turbine life. During evaporation, the
seawater forms a dangerous salt water mist in the
higher air layers. All exterior surfaces will, in accordance
with ISO 12944-2 (1998), be treated with class
C5-M anti corrosion protection. Exterior surfaces
that may come in direct contact with water will be
treated with class 1m 2/high. Interior surfaces that
are subjected to outdoor air will be protected with
class C4 and surfaces that don’t with class C3 corrosion
protection.
• Redundant support systems will be installed.
• Collecting containers for oil spill will be installed