POWER April 2016 - 14

the removal and lowering of rotor blades
and turbine housings by Swedish firm
Svensk Sjöentreprenad (Figure 2). The
firm also dismantled the towers and leveled
the concrete foundations with the
seabed. " There were no major issues with
the work itself but the operation was
delayed by a month due to bad weather,
which was a major risk throughout the
dismantling process, " Vattenfall said.
The utility will now " restore the site in
such a way that any trace of the former
wind farm will be negligible. " It will
also work to remove underwater cables
this summer. A time-lapse video of the
dismantling project can be viewed on
YouTube: https://www.youtube.com/
watch?v=NZPzOmBj1pc.
Later this year, Danish utility DONG
Energy will also move to decommission a
4.95-MW wind power facility off the island
of Lolland-at the site of the world's first
offshore wind farm. DONG Energy put up
the 11 turbines (each 450 kW) at Vindeby
wind farm in 1991, about 2.5 kilometers
off the Danish coast.
According to the European Wind Energy
Association (EWEA), the growth of the
offshore wind power sector was irregular
until 2001, with just a handful of small,
near-shore projects (a total capacity of 86
MW) coming online in Dutch and Danish
waters. The world's first " utility-scale "
offshore wind farm-the Middelgrunden
project in Danish waters-came online
in 2001 featuring 20 turbines for a total
capacity of 40 MW. That same year, Vattenfall
and DONG Energy grid-connected
seven GE 1.5-MW turbines offshore Utgrunden
in Sweden. EWEA notes that
the world's offshore wind capacity was
concentrated in Europe until 2010, when
China inaugurated the Donghai Bridge
Wind Farm.
But even though just a handful of offshore
wind farms have been operating for
half their 20- to 25-year design lives, offshore
wind farm owners should be wary of
and prepare for what could be exorbitant
decommissioning costs, said consulting
group DNV GL in a March 2015 white paper.
" The techniques and logistics for the decommissioning
of offshore wind farms are
very site-specific, leading to a wide range
of projected costs, " it said. Costs can vary
on project characteristics, as well as the
scope of decommissioning-whether piles
and cables will be removed or left in-situ,
for example-and site conditions. Then,
as with construction of offshore wind
farms, they will also be very dependent on
the vessels selected and optimization of
marine logistics.
" When all aspects of the decommissioning
phase are considered, costs may approach
[€1 million] per turbine unit and
in particular cases the costs are estimated
to be much higher, " warned DNV GL. It is
important to capture all the contributions
in a cost model and to recognize those
that have the strongest influence, said the
firm. " Furthermore, by considering decommissioning
costs early in the life of a project,
it is possible to introduce measures to
reduce these costs. "
Commission Backs Plan
to Store World's Nuclear
Waste in Australian
Outback
A nuclear power plant in Australia-a
country that harbors the world's largest
resources of uranium but uses no nuclear
power-wouldn't be economical, but
building a nuclear storage and disposal
facility in the outback to store the world's
INNOVATING.
For more than a century, Fluor has executed some of the most
challenging projects in the power industry. Building on our legacy,
today we deliver integrated solutions and innovation for the next
generation of power.
www.fluor.com
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