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

Towards an Offshore Grid – Further considerations
Standardisation
The adoption of common standards across the
European sphere or even globally, should result in
more ‘standard’ designs. The standardisation should
in particular focus on functionalities as e.g. for:
• fault behaviours
• system protection schemes
• control and protection
Standardisation can reduce costs and also facilitates
interconnectivity offshore. In particular it allows offshore
wind farm and grid connection developers to buy
equipment from different suppliers instead of ordering
from a small group of manufacturers that offer turnkey
solutions, for instance for HVDC VSC connections.
At the same time it is important to keep the standardisation
to the necessary minimum in order not to
hamper innovation. Therefore OffshoreGrid recommends
focusing on standardisation of functionalities
of equipment rather than defining concrete technical
specification. This allows manufacturers to develop
different technical solutions while still facilitating the
interoperability of equipment.
Standardisation has been assessed by the OffshoreGrid
consortium as a small barrier.
Onshore bottlenecks
A strong onshore grid is needed for the safe transmission
of offshore power from the coast towards the
onshore load centres. For Germany this was worked
out during in-depth assessments within the dena Grid
Study I and dena Grid Study II [31], proving the need
for huge transmission capacity from the north to the
south 43 . But the need for onshore transmission is also
crucial in other European countries. In many European
countries the necessary onshore grid reinforcements
are often delayed due to low public acceptance.
Without the timely development of a sufficiently strong
onshore grid, offshore grid development is put at risk.
Therefore, onshore bottlenecks are regarded by the
OffshoreGrid consortium as a large barrier for an offshore
grid.
5.1.2 Regulatory framework
and policy
An offshore grid involves different countries and transnational
markets and a variety of support schemes
and regulatory frameworks. The large diversity across
Europe is summarised in Figure 5.2. Further details
are listed in Table 14.1 in Annex E 44 . The difference
in national regulatory systems and support schemes
and in particular their incompatibility can in some cases
be a barrier for the construction of an offshore grid
as outlined below.
Support scheme
Most countries use feed-in tariffs, but certificate or
bonus systems as well as combined systems are also
implemented. The difference of support schemes is
not per se a hindrance for the construction of an offshore
grid and in most cases specific national support
schemes are adapted to the specific national needs.
For the development of an offshore grid it is crucial to
ensure their compatibility. The OffshoreGrid consortium
understands the compatibility of support schemes
as the possibility to allow offshore wind farms to be
connected to two or more countries either directly or
via an offshore grid without endangering the financial
support for the offshore wind farm. The support
should furthermore be guaranteed independently of
the electrical power flows and whether the offshore
wind power is sold across national borders.
The geographic scope of national offshore support
schemes diverges considerably across Europe. In
most countries support schemes are limited to the
territory or the electricity system of the country. This
43 The German decision on the nuclear phase-out might even enforce the need for north-south transmission, as most of the nuclear
power plants are located in the south.
44 A detailed overview over national support schemes, connection regulation and trade limitations is given in Deliverable 6.1 [29].
84 OffshoreGrid – Final Report