Offshore Electricity Infrastructure in Europe - European Wind Energy ...

introduction
1.1 Context and background
Europe has ambitious targets for renewable energy
deployment. By 2020, 20% of gross final energy consumption
should be met by renewable sources [19].
Offshore wind power is expected to deliver a large contribution.
An installed capacity of 40 GW of offshore
wind power is expected in Europe by 2020, in 2030
this can amount to 150 GW, of which about 126 GW
will be located in Northern Europe [20].
The EC 2050 Roadmap [21] fosters this development
further with the long-term target to cost-efficiently reduce
European Greenhouse Gas emissions by 80%
to 95% by 2050. This goal is only achievable with
large-scale deployment of renewable energy generation
with offshore wind energy as a dominant
generation source.
Consequently, the number of wind farms is expected
to increase rapidly within the next decade, particularly
in the North and Baltic Seas. All these wind farms
will have to be connected to onshore power systems.
This raises questions on how to connect the future
wind power capacity and how to integrate it into the
national power systems in an efficient and secure way.
The first offshore wind farms were connected individually
to the onshore power system. However, these wind
farms were limited in capacity and relatively close to
shore. Future wind farms may be up to several thousand
MW’s, at distances of more than 200 km from
shore. In particular for these wind farms bundling the
electric connection at sea and carrying the energy over
a joint connector to the onshore connection points can
be more efficient than individual connections of wind
farms to shore. This so-called hub connection design
can reduce costs, space usage and environmental impact
dramatically. Once these wind farms or hubs are
in place, new connection design opportunities open:
The hubs can be teed-in to interconnectors, or can be
interlinked with other hubs or to other shores, creating
a truly integrated offshore power system.
This thinking is particularly driven by the idea that
such an offshore grid can bring a variety of benefits
to the security of the power system, the European
electricity market and the overall integration of renewable
energy.
• Increased security of supply:
- improve the connection between big load centres
around the North Sea,
- reduce dependency on gas and oil from unstable
regions,
- transmit indigenous offshore renewable electricity
to where it can be used onshore,
- bypass onshore electricity transmission
bottlenecks.
• Further market integration and enhancement of
competition:
- more interconnection between countries and
power systems enhances trade and improves
competition on the European energy market,
- increased possibilities for arbitrage and
limitation of price spikes.
• Efficient integration of renewable energy:
- facilitation of large-scale offshore wind power
plants and other marine technologies,
- valorisation of the spatial smoothing effect of
wind power and other renewable power, thus
reducing variability and the resulting flexibility
needs,
- connection to the large hydropower capacity in
Scandinavia, thus introducing flexibility in the
power system for the compensation of variability
from wind power and other renewable power,
- significant contribution to European 2020
targets.
However, there is a long list of technical and political
challenges that come with an integrated (meshed)
European offshore grid. Furthermore, the investment
needs are high. This raises the question of how to
design an optimal offshore grid that minimises costs
and maximises the benefits.
18 OffshoreGrid – Final Report