Powering Europe - European Wind Energy Association
Powering Europe - European Wind Energy Association
Powering Europe - European Wind Energy Association
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4.1 <strong>Wind</strong> generation and wind<br />
plants: the essentials<br />
State-of-the-art wind power technology with advanced<br />
control features is designed to enhance grid performance<br />
by providing ancillary services. Using these power<br />
plant characteristics to their full potential with a<br />
minimum of curtailment of wind power is essential for<br />
efficiently integrating high levels of wind power. Advanced<br />
grid-friendly wind plants can provide voltage<br />
control, active power control and fault-ride-through capability.<br />
Emulating system inertia will become possible<br />
too. The economic value of these properties in the<br />
system should be reflected in the pricing in proportion<br />
to their cost.<br />
<strong>Wind</strong> power provides variable generation with predictable<br />
variability that extends over different time scales<br />
(seconds, minutes, hours and seasons) relevant for<br />
system planning and scheduling. The intra-hour variations<br />
are relevant for regulating reserves; the hour<br />
by hour variations are relevant for load following reserves.<br />
Very fast fluctuations on second to minute<br />
scale visible at wind turbine level disappear when aggregated<br />
over wind farms and regions. The remaining<br />
variability is significantly reduced by aggregating wind<br />
power over geographically dispersed sites and large<br />
areas. Electricity networks provide the key to reduction<br />
of variability by enabling aggregation of wind plant output<br />
from dispersed locations. <strong>Wind</strong> plant control can<br />
help control variability on a short time scale.<br />
The latest methods for wind power forecasting help<br />
to predict the variations in the time scale relevant<br />
for system operation with quantifiable accuracy. Aggregating<br />
wind power over large areas and dispersed<br />
sites and using combined predictions helps to bring<br />
down the wind power forecast error to manageable<br />
levels in the time frames relevant for system operation<br />
(four to 24 hours ahead). Well interconnected<br />
electricity networks have many other advantages. In<br />
order to control the possible large incidental forecast<br />
errors, reserve scheduling should be carried out in<br />
time frames that are as short as possible (short gateclosure<br />
times), assisted by real time data on wind<br />
chApTEr 1 INtrODUctION:aeUrOpeaNVISION<br />
power production and site specific wind conditions.<br />
The significant economic benefits of improved accuracy<br />
justify investment in large meteorological observational<br />
networks.<br />
The way grid code requirements in <strong>Europe</strong> have been<br />
developed historically has resulted in gross inefficiencies<br />
for manufacturers and developers. Harmonised<br />
technical requirements will maximise efficiency for<br />
all parties and should be employed wherever possible<br />
and appropriate. However, it must be noted that<br />
it is not practical to completely harmonise technical<br />
requirements straight away. In an extreme case this<br />
could lead to the implementation of the most stringent<br />
requirements from each Member State. This would<br />
not be desirable, economically sound, or efficient.<br />
A specific <strong>Europe</strong>an wind power connection code<br />
should be established within the framework of a binding<br />
network code on grid connection, as foreseen in<br />
the Third Liberalisation Package. The technical basis<br />
for connection requirements should continuously be<br />
developed in work carried out jointly between TSOs<br />
and the wind power industry.<br />
EWEA proposes a two step harmonisation approach<br />
for grid codes: a structural harmonisation followed by<br />
a technical harmonisation. The proposed harmonising<br />
strategies are urgently needed in view of the significant<br />
increase in foreseen wind power penetration and<br />
should be of particular benefit to:<br />
• Manufacturers, who will now be required only to develop<br />
common hardware and software platforms<br />
• Developers, who will benefit from the reduced costs<br />
• System operators, especially those who have yet to<br />
develop their own grid code requirements for wind<br />
powered plants<br />
The technical basis for the requirements should be<br />
further developed in work carried out jointly between<br />
TSOs and the wind power industry. If the proposals<br />
can be introduced at <strong>Europe</strong>an level by means of a<br />
concise network code on grid connection, it will set a<br />
strong precedent for the rest of the world.<br />
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