Powering Europe - European Wind Energy Association

side. Further connecting the electric power system
to district heating systems, the transport sector (e.g.
via electric vehicles) and energy storage systems are
important components for such high levels of wind
integration.
Countermeasures identified to prevent overloading
of transmission lines through Jutland could be implemented
on several sides of the power system:
• Market side: market coupling (e.g. NordPool-EEX) to
increase the possibilities of sharing reserves, improvement
of intraday trading possibilities and international
exchange of ancillary services.
• Generation side: utilisation of an electricity management
system for wind power plants, which regulates
the generation, geographical dispersion of offshore
wind farms, mobilising of regulating resources and
new types of plants and further improvement of local
scale production units working on market terms.
• transmission side: reallocation of the grid connection
point for offshore wind power plants, increased grid
transmission capacity, e.g. including the use of high
temperature conductors, and reinforcement and expansion
of the domestic grid and interconnections.
• Demand side: further develop price dependent demand,
utilise and strengthen the coupling of the
power system to heating systems: electric boilers
and heat pumps, develop and exploit coupling of the
power system to the transport sector (electric vehicles
as price dependent demand), and introduction
of energy storage: hydrogen, Compressed Air Energy
Storage (CAES), batteries.
The measures mentioned above were investigated by
the Danish TSO and partners in research and development
to enable the “+3,000 MW” 2025 scenario.
6.4 United Kingdom
With the rapid growth of wind power in the UK, the extent
and cost of the provision of these additional operating
reserves will need to be addressed. In the last
few years, some studies have been carried out in the
UK to comprehend the magnitude and cost of these
chApTEr 3 powersystemoperationswithlargeamountsofwindpower
additional system balancing requirements (Dale et al,
2003; MacDonald, 2003; UKERC, 2006).
Strbac et al. 2007 studied the impact of up to 20 GW
of wind generation (most of it is offshore) on the operation
and development of the UK electricity system
taking into account the existing interconnector with
continental Europe. The study assumed a rather high
forecast error; in practice this reserve requirement
could be less with good forecast systems (four hours
ahead). The additional cost considered is only the
cost for using additional reserves (not their capacity).
On average, the UK system operator commits about
600 MW of dynamic frequency control, while about
2,400 MW of various types of reserve is required to
manage the uncertainty over time horizons of around
three-four hours. The reserve requirements are driven
by the assumption that time horizons larger than four
hours will be managed by starting up additional units,
which should be within the dynamic capabilities of gas
fired technologies.
The additional primary and secondary reserve requirements
due to wind generation and their associated
costs were calculated for various levels of wind generation
in the system, in steps of 5 GW up to 20 GW.
The increase in primary reserves was found to be relatively
small for modest increases in wind power connected.
However, at high wind penetrations, secondary
levels equivalent to 25% of wind installed capacity are
needed to cover the extreme variations in wind output.
The expected minimum figures correspond to a highly
diversified wind output. With the large concentrations
of wind power plants now expected in The Wash,
Thames Estuary, North-west England and Scotland,
the need for primary reserve is likely to be closer to
the expected maximum. It was concluded that the
amount of extra reserve can be handled with the current
conventional power plants, so only the cost of increased
operation of the existing reserves has been
estimated in Table 7.
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