Grid connection of deep sea wind
farms - options and challenges
John Olav Giæver Tande
SINTEF Energy Research
john.o.tande@sintef.no
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Deep sea wind turbines
„ Installation at deep sea far from shore:
„ Unlimited potential and high energy output
„ Minimized negative environmental impact
„ Cost competitive renewable generation
„ Challenges:
„ Bigger, lightweight and strong wind turbines
(10 MW, 160 m wingspan ~ twice a jumbo jet)
„ Foundation / floater (design, installation, O&M)
„ Grid connection (AC, HVDC, multi-terminal)
„ Power system integration of large scale wind
(mainland and offshore oilrigs)
HYWIND
„ Key Norwegian industry stake-holders:
„
„
„
„
ScanWind; large wind turbines
Hydro and Sway; floater concept
Owec Design; jacket structure
Aker Kværner, Nexans, Devold AMT, Umoe
etc; sub-supplies of components
„ Statkraft; Lyse etc; wind farm developers
„ Statnett; transmission system operator
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Deep sea wind turbines
OWEC Tower
Depth (m) +30
SWAY
+100
HYWIND
+100/200
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NFR KMB Deep sea offshore wind turbine technology
2007-2009 / total budget 18 mill NOK
ƒ The project combines wind
technology know-how with
offshore and energy industry
experience to enhance
development of deep sea wind
farms.
ƒ The main objective is to advance
Norwegian development and pinpoint technical solutions aiming
for cost-efficiency of deep sea
wind farms.
ƒ Partners: SINTEF Energy
Research, MARINTEK, IFE, NTNU,
Statkraft, Lyse, Hydro, Umoe,
Statnett, Statoil, Nexans
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NFR KMB Deep sea offshore wind turbine technology
2007-2009 / total budget 18 mill NOK
ƒ Activities:
ƒ Progress of design tools (analytics, numerical methods and
experiments) for the (structural, control, concurrent
engineering) design of offshore wind energy concepts. The
task includes institute research headed by SINTEF Marintek
and one PhD.
ƒ Assessment of wind turbine design solutions adapted for
deep-sea conditions, including investigation of operational and
extreme behaviour. The task includes institute research
headed by IFE and one PhD.
ƒ Provide solutions for cost effective grid connection and system
integration of large deep sea offshore wind farms. The task
includes institute research headed by SINTEF Energy Research
and one PhD.
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Grid connection – a stepwise development
„ Small wind farm connection to oil & gas installation
„ Wind farm operate in parallel with gas turbines
„ Saves fuel and emissions
„ Large wind farm directly connected to mainland grid
„ Possibly also connects oil & gas installation
„ Options: a) HVAC with SVC b) LCC HVDC c) VSC HVDC.
„ An offshore transmission highway is established
„ Connections to wind farms, oil & gas installations, mainland
grid and trans-national
„ Options: a) HVAC, b) Multi-terminal HVDC, c) combination
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Draugen, Heidrun, Njord, Åsgard,
(Kristin, Tyrihans and Lavrans)
220 MW
220 km
Possible connections of oil and
gas installations
Oseberg, Veslefrikk, Tune,
Kappa, Fram, Troll 200 MW
107 km
Ula, Gyda, Valhall and
parts of Ekofisk 140 MW
280 km
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Internal grid – floaters requires dynamic cable
„
„
„
„
AC, 11 - 33 kV
One feeder per turbine
Remote connection/disconnection
Sub-sea T-junctions not standard
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Connection to oil and gas installations
„ AC, 11 kV
„ Operate in parallel
with gas turbines
(e.g. 2x20 MW)
„ Save fuel and
emissions
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Alternative transmission systems
a)
600 MW
wind farm
SVC
HVAC
SVC
Strong grid
b)
Statcom/
Diesel gen
Filter
Filtre
=
~
HVDC
LCC
Strong grid
=
~
600 MW
wind farm
LCC
c)
VSC
=
~
=
~
=
~
VSC
HVDC
=
~
600 MW
wind farm
Strong or
weak grid
http://www.offshorewindenergy.org
Book: Wind power in the power system (2004)
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Limits of transmission capacity,
Submarine HVAC cables (ref Nexans)
1200 MW
Un=400 kV
1000 MW
800 MW
600 MW
Un=230 kV
400 MW
Un=150 kV
200 MW
Un=132 kV
0 MW
0 km
50 km
100 km
150 km
200 km
250 km
300 km
350 km
400 km
400kV:
>1000 MW
up to
100 km
230 kV:
400 MW
to 100 km
200 MW
to 250km.
U +/-10 %; Losses < 10 %
Max current according to IEC60 287.
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25 TWh/y wind generation for
supply to oilrigs, mainland grid
and trans-national connections
Floating offshore wind turbines –
a sustainable energy future
„ Use Norwegian oil and gas industry know-how.
„ Large scale commercial use of floating offshore wind
turbines is viable by year 2020.
„ The market is global.
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